The brain is an essential part of the human body and has got structures and components that control body functions. The hypothalamus combines with other endocrine glands such as the pituitary glands and gonads in controlling the reproductive system (Dyer, 1989). The three glands work incorporation and there is no way one can work without the others. The three form a single system that affects all the reproductive cycles in the human body. The reproductive system of a human being is controlled by hormones that are normally generated by the three endocrine glands (Dyer, 1989). The hormones produced by these glands keep on fluctuating every time in order to have the desired effect on the reproductive system (Johnson, 2012). The hypothalamus is the origin of the entire process because it triggers other endocrine glands that control the reproductive system to start playing their roles (Johnson, 2012). This paper will highlight how the brain structures govern the timing and cycles of reproduction in humans.
The hypothalamus is responsible for secreting the Gonadotropin-Releasing Hormone which is commonly referred to as GnRH. The hormone initiates all the reproductive cycles in the human body (Johnson, 2012). The GnRH then travels through the hypophyseal portal system all the way to the pituitary gland. The adenohypophysis cells in the pituitary gland are then stimulated by the Gonadotropin-Releasing Hormone to secrete both the Follicle Stimulating Hormone and the Luteinizing Hormone (Johnson, 2012). The secretory cells in the pituitary gland have receptors that accommodate the Gonadotropin-Releasing Hormone from the hypothalamus as it stimulates the pituitary glands to secrete the two reproductive hormones (Dyer, 1989). The Follicle Stimulating Hormone and the Luteinizing Hormone are then released to the bloodstream immediately after being produced to play a critical role in controlling the activities of gonads (Johnson, 2012).
The menstrual cycle is normally regulated by the two hormones from the pituitary glands (Dyer, 1989). The Luteinizing Hormone and the Follicle Stimulating Hormone stimulate the ovaries which are the female gonads to produce two female reproductive hormones which include estrogen and inhibin. The two hormones produced by the ovaries are responsible for regulating the entire menstrual cycle (Johnson, 2012). The Luteinizing Hormone in men stimulates the testicles which are the male gonads to produce a male reproductive hormone known as testosterone. The interstitial cells located within the testis are the ones responsible for secreting testosterone. On the other hand, the Follicle Stimulating Hormone facilitates the production of sperms in men through a process called spermatogenesis (Johnson, 2012). The amount of estrogen in men is very negligible and does not have any effect on the male reproductive system.
The ovarian and uterine cycles are controlled by the hypothalamus effect (Johnson, 2012). The activities of the hypothalamus are normally put in check by the ovary depending on whether conception takes place or not. During ovulation time, a regulatory hormone is known as progesterone is normally released by the ovary to inhibit the reproductive activities of the hypothalamus in case of a conception (Dyer, 1989). If conception does not take place after ovulation, the hypothalamus begins another reproductive cycle. In men, spermatogenesis is normally regulated by testosterone which communicates with the hypothalamus (Johnson, 2012). The inhibin hormone that is normally produced by both male and female gonads is meant to control the production of the Gonadotropin-Releasing Hormone in the hypothalamus (Johnson, 2012). The brain plays a critical role in the entire human reproduction system by controlling all the reproduction cycles.
References
Dyer, R. (1989). Brain opioid systems in reproduction. London: Oxford University Press.
Johnson, M. (2012). Essential reproduction. New York, NY: John Wiley & Sons.
Language expression and reception are executed by specialized parts of the brain that include Wernicke’s area, Broca’s area, and certain regions of the cerebral cortex (Egolf, 2012, p.36). The parietal lobes and the temporal lobes are the two parts of the cerebral cortex involved in language expression (Friston et al, 2004, p.42). The cerebral cortex consists of the right hemisphere and the left hemisphere. It covers the largest portion of the brain. It is the most developed part because it is responsible for numerous brain functions such as perception, production, and comprehension of language.
Discussion
Broca’s area is a part of the brain that is responsible for language production. It controls language expression by regulating all motor functions involved in the process of speech production (Glees, 2005, p.34). Individuals whose Broca’s area gets damaged encounter difficulties in producing speech and forming words even though they may comprehend language. Other functions of Broca’s area include speech production, language processing, and facial neuron control (Glees, 2005, p.35). Broca’s area is situated on the frontal lobe and it is connected to the Wernicke’s area by a mass of neurons. It has the ability to control all muscle movements that direct speech production. It is made up of two parts that enable it to express language, the Pars opercularis and the Par triangularis. The Pars triangularis is responsible for encoding sensory information that is related to language whereas the Pars opercularis is responsible for language production (Friston et al, 2004, p.45).
Wernicke’s area is primarily involved in language development and controls language reception. It is located on the left side of the brain. Its main function is to aid in comprehension and expression of speech (Peng, 2005, p.74). Any damage to this part of the brain results in severe impairment of language usage and development. Carl Wernicke discovered this area after he realized that another part of the brain was involved in language reception and expression in addition to the Broca’s area. The Broca’s area is connected to the Wernicke’s area by a mass of neurons referred to as the arcuate fasciculus (Peng, 2005, p.76).
The temporal lobes are important parts of the cerebral cortex that are involved in language reception and expression. They are among four groups of lobes that comprise major parts of the cerebral cortex. Their functions include organization of sensory information, production of language and speech, and perception of sound impulses (Egolf, 2012, p.38). The parietal lobes also aid in reception and expression of language. They receive and process sensory information from other parts of the body. Other functions of parietal lobes include speech production, visual perception, and cognition (Egolf, 2012, p.39). However, only certain parts of the parietal lobes take part in language expression. These parts possess structures that enable them to express language. The other parts serve for the purposes that are not related to language perception and expression.
Conclusion
Language reception and expression are executed by parts of the brain that include the Broca’s area and the Wernicke’s area. In addition, certain parts of the cerebral cortex that include parietal lobes and temporal lobes are also involved. To facilitate language reception and expression, the Broca’s area and the Wernicke’s area are connected by neurons. It contains a mass of interconnected neurons. Damage to these parts causes severe language complications that include slurred speech and poor comprehension of language.
References
Egolf, D. (2012). Human Communication and the Brain. New York: Lexington Books.
Friston, K., Frith, C., Dolan, C., and Penny, W. (2004). Human Brain Function. New York: Academic Press.
Glees, P. (2005). The Human Brain. New York: Cambridge University Press.
Peng, F. (2005). Language in the Brain: Critical Assessments. New York: Continuum International Publishing Group.
According to different learning theories, human beings perceive and process information in different ways (Winstanley, 2005). Experts have also proved that the human brain is responsible for the different manner of thinking and consequently, the learning process (Deutsch and Springer, 1997). This research paper will evaluate and discuss how the left and the right brain affect the learning process in human beings.
Winstanley (2005) says that, the structure and functions of the mind suggest that the two sides of the brain perform different functions. According to research, the left and the right sides of the brain “control different modes of thinking” (Deutsch and Springer, 1997). According to Right-Brain Vs Left-Brain theory, individuals prefer one mode over the other. However, some individuals can use the whole brain and adapt different modes at the same time.
The concept of left-brain versus right brain is based on what is generally referred as the lateralization of the brain; it determines how individuals process information (Philips, 2011). This concept argues that one side of the brain control specific functions and people are either left-brained or right-brained. According to this theory, the right side of the brain functions well in expressive and creative tasks (Philips, 2011).
As such, the right side of brain performs well in areas of music, expressing emotions, reading emotions, indentifying colors, images, and expressing feelings (Turgeon, 1993). On the other hand, the left side of brain is considered to perform well at those tasks that involve reasoning, understanding language, creativity, critical thinking, and expressing numbers (Turgeon, 1993).
In fact, the left-brain is more competent in dealing with calculations, assessing issues that require logic, understanding and expressing language, and thinking critically (Philips, 2011). All Left- brained people are said to display this characteristics and they perform well in mathematics.
Usually, the two sides of the brain can reason. However, reasoning can only happen in different ways. As already observed, the left-brain is considered logical while the right brain is considered more holistic (Philips, 2011). Left-brained people process information faster and successfully.
Left-brained individuals prefer to learn step-by step; they prefer to learn by getting the details leading to logical understanding of the concept (Philips, 2011).On the other hand, right-brained people are “simultaneous processors” and they prefer to learn concepts beginning with understanding the general concept and then breaking points into parts in order to understand specific ideas (Philips, 2011).
Notably, learning is a process. The manner in which an instructor teaches the class affects the learning process. According to research, left-brained teachers prefer to teach using lecture and discussion (Turgeon, 1993). Mostly, such teachers are strict on deadline and usually adhere to learning schedule.
In addition to this, left-brained teachers like to give the students take-away assignment because they want students to learn independently. Similarly, left-brained students prefer working on their own and independently (Turgeon, 1993).
Mostly, left-brained students also prefer to carryout research because this learning technique is appealing to them. This means that, when left-brained teachers train left-brained students, learning process becomes more effective and enjoyable. Such students tend to perform better in this situation.
The right brained teachers prefer to use gestures and hands when teaching (Deutsch and Springer, 1997). Such teachers incorporate arts, creativity, and do music lesson in most cases. Turgeon (1993) observes that right-brained teachers also prefer “busy, active, and noisy classroom environment.” Generally, right-brained teachers prefer to teach students in groups, and have a preference of instructing students to work in groups.
Just like right-brained teachers, the right-brained students also prefer working in groups. As such, these students also like to do projects, designs, and music. The right-brained students always prefer doing projects rather than writing essays and doing research (Winstanley, 2005). This also affects the learning process.
Generally, left or right-brained students prefer a specific learning approach although they can be able to learn using different modes. However, even though student can learn using other techniques, they learn effectively using their areas of strength (Turgeon, 1993). In fact, students become contented when they are taught using modes of learning that are appealing to them. Therefore, the difference in learning modes affects the learning process among different students.
The opinion is that teachers should take this perspective as a challenge. Teachers should be observant in order to indentify the learning modes preferred by different students. Once an instructor indentifies the modes of learning preferred by different students, the learning process will become more effective.
In conclusion, the right brain and the left brain affects learning process because of the different modes of learning. While different sides of the brain have different preferences, both the left and the right sides of the brain are involved in the learning process although in a different way.
Because individuals process information in different ways, it is important that people should indentify how best they process information in the brain. Once an individual indentifies this concept, learning will become very effective (Deutsch and Springer, 1997). In addition to this, people can be able to improve the strategies used in learning.
Reference List
Deutsch, G., & Springer, S. (1997). Left brain, right brain: perspectives on cognitive neuroscience. Dallas: Freeman.
Philips, C. (2011). Left Brain Right Brain. New York: Connections Book Publishing, Limited.
Turgeon, M. (1993). Right-brain left-brain reflexology: a self-help approach to balancing life energies with color, sound, and pressure point techniques. New York: Bear & Co.
Winstanley, D. (2005). Personal effectiveness: a guide to action. London: CIPD Publishing.
It is interesting that one is required by law to have a license to operate an automobile but not to operate the brain yet the latter is a more sophisticated device that, nevertheless, works according to relatively simple principles. The brain is a triune structure that consists of three different parts, each having its own unique intelligence, sense of time and space, memory, and motor.
The three parts are reptilian complex, the limbic system, and the neocortex. This paper explores these three parts, their components. However, special attention will be paid to the two hemispheres: left and right brain components -, which are found in the neocortex part of the brain.
The first part of the brain to be considered in this paper is the reptilian complex. This part consists of the cerebellum, and the brainstem. The brainstem is composed of the medulla oblongata, the pons, and the mesencephalon (Turgeon, 1993). The last part of the reptilian complex is the diencephalon.
This comprises of the pineal and pituitary glands, thalamus, hypothalamus, and optic nerves. As its name suggests, the reptile complex is part of the brain that humans share with reptiles. It is the most primitive part of the brain. The reptilian complex is home to a number of functions. To begin with, it regulates all vital roles such as heartbeat, blood pressure and circulation, breathing, digestion, fluctuations in body temperature, the waking, sleeping, or dreaming cycle, and the endocrine system (Davidson & Hugdahl, 1996).
The reptilian complex also controls automatic and instinctive reactions such as hunger, thirst, survival, sexual activity, fertility, and lactation. In addition, it is involved in selective concentration whereby sensory messages going to the higher levels of the brain are filtered.
The reptilian complex also coordinates muscular activity such as balance, sense of position, muscle tone, as well as fine motor control. This part of the brain is also entrusted with motivation and drive, sensory switching, and certain social behaviors such as imitation, mating habits, feeding habits, and repetitive behaviors.
The reptilian complex is constantly informed about the physical state of an individual, and when necessary, it transmits this information to the other parts of the brain. As such, this part is considered representative of the body in the brain. However, the reptilian brain is very limited in its ability to learn and respond to varying conditions because it is confined to genetically programmed behavior patterns (Turgeon, 1993).
The second part of the brain is limbic system, which is found on top of the reptilian complex. The limbic system is found in all mammals and weighs about three quarters of a pound. It is directly connected to the cerebral cortex and to the hypothalamus, and indirectly to all sensory input.
It comprises of the septum and septal region, the amygdale, the mammillary bodies, and the hippocampal gyrus and fimbria (Turgeon, 1993). The limbic system has two vital roles. To begin with, it acts as selector. It chooses from the environment whatever is suitable to cater for the needs of an individual.
Secondly, being the physical core of human memory, it records all information based on the strength of emotion or sensation felt at the time of the experience. The limbic system remembers unpleasant experiences, successes, and failures as a guide for present-moment action. This part of the brain is involved in every stage of information processing including the selection, evaluation in the light of past experience, motivating action, and remembering the results as successes or failures for future reference (Turgeon, 1993).
Although the limbic system gives humans the ability to learn from experience, it largely depends on the interpretation of events made by the neocortex in order to analyze and comprehend its environment.
The last part of the brain, the neocortex, is divided into two interconnected hemispheres with complementary functions. These are the left and right hemispheres. The two hemispheres are distinct in nature and functions. The rest of this paper examines the comparison between the two hemispheres. The left hemisphere is analytical. It breaks things down into distinct parts in order to understand the whole. In order to do so, it reviews each element and retains those it feels are vital (Hellige, 1993).
As such, it can act on each of them and change them as needed. This tendency of the left brain to focus on details that have an emotional impact leads to a loss of objectivity, and to some extent, isolates it from reality. This emphasis on details results to the left brain developing precise plans, which are difficult to apply as they suggest a rigid course of action that cannot adapt to life’s dynamic conditions.
The analytical approach of the left brain presupposes a static view of life and provides the basis for the accumulation of knowledge. The left brain is the action brain. It does not seek to know the reasons driving it towards a certain goal (Iaccino, 1993). It is concerned on how to get there. As such, it proceeds by trial and error, checking out the feasibility of its theories in actual practice and experimenting until it obtains the desired results.
On the other, the right hemisphere is systematic. It grasps the whole system at once and makes sense of the parts within this overall context. This is the fundamental difference between the left and right brain. The right brain has an overview of things. It relates events to each other and studies the effects of their interaction. It is capable of acting on a group of variables concurrently in order to achieve its objective.
For instance, if the objective is long-term, it will not give up. Given that the right brain perceives an issue as a whole, it develops the broad outlines of a plan after having set very precise objectives. This plan is flexible and can be adapted to all types of situations. Nevertheless, it checks the action model against reality before applying the plan. As such, it relies on experience before heading into the unknown.
This systematic approach adopted by the right brain offers a more dynamic view of life and supports thinking. In spite of these fundamental differences, the two perceptions give rise to all the achievements of the human mind (Springer & Deutsch, 1997). This is because humans need to make full use of both sides of the brain. Nevertheless, every human being has a predisposition to one side or the other and may lack an understanding of the potentials inherent in the non-dominant side.
Under normal circumstances, the left and right hemispheres exchange information when each has hemisphere has access to the information that passed initially to the opposite hemisphere. All this occurs through the corpus callosum.
If this is the case, what happens when the corpus callosum is split? Any damage whatsoever to the corpus callosum leads to impaired exchange of information. This is evident from those who have had surgery to interrupt severe epilepsy. In these individuals, epileptic seizures are limited to only one side of the body (Servellen, 1997).
In conclusion, although the two hemispheres of the brain are different in their functions, they work together complimentarily. As discussed above, the left brain is the center for abstract thought whereby it isolates the elements of a whole and analyzes them in series.
On the abstract level, it is logical and has accurate reasoning and sound judgment. In stark contrast with this, the right brain is the center for concrete thought. It supports its thinking with actual experience and uses a collection of images taken from that experience. The practice of resourcing from the past experiences makes the right brain tend in the direction of introversion and reflection.
References
Davidson, R. J., & Hugdahl, K. (1996). Brain Asymmetry. London: MIT Press.
Hellige, J. (1993). Hemispheric asymmetry: what is right and what is left. London: Harvard University Press.
Iaccino, J. F. (1993). Left brain–right brain differences: inquiries, evidence and new approaches. Pennsylvania: Lawrence Erlbaum Associates.
Servellen, G. M. (1997). Communication skills for the health care professional: concepts and techniques. London: Jones & Bartlett Learning.
Springer, S. P., & Deutsch, G. (1997). Left brain, right brain: perspectives on cognitive neuroscience. London: Freeman.
Turgeon, M. (1993). Right-brain left-brain reflexology: a self-help approach to balancing life energies with color, sound, and pressure point techniques. New York: Traditions Bear & Co.
Evidence suggests that brain memories are not whole; rather, pieces of information stored in different areas of the brain are combined to create memories (Matlin, 2012). This explains why recalled information is not entirely accurate. Encoding, storage and recall of skills and facts (semantic memory) or experiences (episodic memory) involve different parts of the brain. This implies that there is a close relationship between memory processes and brain functioning.
Working and Long-term Memories
Over the years, there has been an intense debate on whether working and long-term memories are related. While there are many similarities between the long-term memory (LTM) and working memory (WM), distinct differences also exist between the two. One difference is that the functioning of LTM does not require the activation of WM.
A study by Morgan et al. (2008) revealed that many qualities of LTM such as procedural memory and motor skills do not depend on the working memory. However, episodic memories, which rely on past experiences, may at some point involve the activation of the working memory (Morgan et al., 2008).
Long-term memory has two distinguishing properties; (1) it has no capacity limits and (2) it lacks temporal decay associated with short-term memory (Morgan et al., 2008). In contrast, WM encompasses tasks of short-term memory that demand more attention, but are not directly associated with cognitive aptitudes. It is a combination of different memories working together, including some components of the long-term memory, to organize information in the working memory into fewer units in order to reduce the working memory load.
Both WM and LTM are affected by the level of semantic processing or encoding in the brain. LTM is known to be affected by the qualitative depth of initial memory encoding (Matlin, 2012).
For example, it has been established that encoding during semantic processing results in improved long-term memory of episodic items compared to recall of visual or phonological items (Morgan et al. 2008). Similarly, since the performance of WM depends on the level of processing at the encoding stage, semantic processing can lead to improved WM.
Memory Formation in the Brain
Stadthagen-Gonzalez and Davis (2010) propose that memory is formed through dendrite-axonal networks, which become more intense with an increase in the number of events stored in the LTM. Stadthagen-Gonzalez and Davis (2010) also postulate that memory storage involves different cortical areas of the brain, where the sensory experiences are processed.
The neural (brain) cells involved in memory formation undergo physical changes through new interconnections as cognitive and perceptual processes in the brain increase. The synapses (a vast system that connects neurons) are involved in the formation of interconnected memories or neural networks.
It is the neural networks that facilitate the formation of new memories. Karpicke and Roediger (2009) postulate that, through a closely related activity (relayed through similar synapses), a new memory is formed causing changes to the neural circuit to accommodate the new item.
Also, new neurons can be joined to the circuit, if they are correlated with previously formed neural networks (Matlin, 2012). Long-term potential (LTP) is associated with reverberation (depolarization) in the post- and pre-synaptic neurons during learning. It is induced through prolonged stimulation of synapses during learning. New memories are maintained through repetitive excitation of LTP, which increases the release of neurotransmitters that can persist for several days or even months.
Adaptive Recall and Forgetfulness
Evidence suggests that the amygdala and the hippocampus regions of the brain interact during the formation of verbal and visual memory (Matlin, 2012). However, the amygdala identifies and stores emotionally important information while the hippocampus creates new neural networks for cognitive material.
It is through the amygdala-hippocampus interaction that emotionally important memories are recalled. The same applies for less emotionally significant events, which are less arousing. Thus, personal and emotional experiences are easily recalled than neutral events. It also explains why reinforcements improve memory while damage to hippocampus and amygdala results to impaired memory functioning.
From an evolutionary standpoint, the neural relationship between the hippocampus and the amygdala is an adaptive response to life experiences. Karpicke and Roediger (2009) suggest that stressful conditions affect the processing and storage of new memories. Also, the retrieval strategies of the hippocampus may be repressed under stressful conditions.
Consequently, it becomes adaptive to remember relevant and emotional memories for survival purposes. Also, through amygdala-hippocampus interaction, it becomes adaptive to forget or repress some traumatic or unpleasant memories in order to maintain normal cognitive functioning.
Accuracy of the Memories
Studies have shown that human recollections are often not accurate. This raises questions regarding the extent of accuracy of the memory. Unsworth and Engle (2011) demonstrate that the hippocampus-amygdala interaction is essential in memory encoding and retrieval, with the amygdala regulating information encoding, storage and recall from the hippocampus.
Thus, for some time, the recall accuracy of emotionally arousing events is high compared to neutral ones. Evidence also suggests that physiological changes in the level of arousal affect the way memories are replayed. For instance, Unsworth and Engle (2011) show that, at the encoding stage, the level of activation of amygdala influence memory retention while its damage impairs memory arousal. This highlights the fact that emotional arousal enhances memory accuracy, at least in the short-term.
Memory Aids for Memory Impaired Individuals
Memory impairment or loss may have a number of causes, including neurological diseases, aging, trauma, stroke, or brain injury. Individuals suffering from poor memory, amnesia and PSTD can benefit from memory aids that enhance their memory. Prospective memory (PM) aids can help such people to recall essential actions in their daily lives (Matlin, 2012). They are normally external aids that facilitates semantic memory or systems that allow caregivers to monitor the cognitive functioning of patients with memory problems.
Karpicke and Roediger (2009) group memory support systems into three; assurance systems that monitor a person’s cognitive health at home or care setting; compensation systems, which involve functionalities that accommodate the user’s memory impairments; and assessment systems, which are technologies that continuously monitor the cognitive status of users under rehabilitative care.
Developers of these systems rely on the knowledge regarding the functioning of the brain and memory encoding processes to make memory aids. Also, understanding the type of memory affected can help in the treatment of the individual through psychoanalysis.
The Effect of Age and Environment
Age and environment influence several cognitive and physical abilities in humans. While some types of memories (semantic/conceptual memory) increase with advanced age, others such as episodic memory (specific events) decrease with age (Matlin, 2012). Elderly people often experience difficulties in performing high cognition-demanding tasks because aging impairs memory processes such as working memory, encoding and sensory functioning.
This leads to a decline in memory, reasoning and problem-solving ability. However, automatic processes that do not involve much cognitive resources remain unimpaired during old age. Karpicke and Roediger (2009) suggest that old age does not significantly affect memory processes as attention-demanding tasks may, with time, become automatic.
Environmental conditions also influence the development and maintenance of memory. The environment affects memory through neural mechanisms. Environmental enrichment through memory-based tasks and physical activities increase hippocampus volume by promoting cell (neuron) proliferation (Matlin, 2012). Also, problems associated with social environment such as stress affect memory and brain functioning in humans.
References
Karpicke, J., & Roediger, H. (2009). The Critical Importance of Retrieval for Learning. Science, 15(3), 966-968.
Matlin, M. (2012). Cognition. New York: Wiley
Morgan, C., Hazlett, G., Baranoski, M., Doran, A., Southwick, S., & Loftus, E. (2008).
Accuracy of Eyewitness Identification is significantly associated with performance on a standardized test of face recognition. International Journal of Law and Psychiatry, 30, 213–223.
Stadthagen-Gonzalez, H., & Davis, J. (2010). The Bristol norms for age of acquisition, imageability and familiarity. Behavior Research Methods, 38(3), 598–605.
Unsworth, N., & Engle, R. (2011). Simple and complex memory spans and their relation to fluid abilities: Evidence from list-length effects. Journal of Memory and Language, 54(3), 68–80.
The brain is by far the most sophisticated yet complex organ possessed by man. Its ability to receive, decipher, and store massive amounts of information is to say the least amazing. Over the years scientists and other medical practitioners have dedicated their time and resources into trying to understand how it works, what makes it work and how it relates and function with other organs in the human physiology. As such, they have developed theories that indeed help divide it according to various parts and their functionality.
As a result, in depth research has ensued as pertaining to how the brain processes our thoughts, assist in locomotion and most importantly how it helps us learn and actually retain that knowledge; memory. In this paper, we shall focus on the creation of memory as one of the core functions of the brain. Using documented proof, the discussion shall set to ascertain the fact that the human memory does indeed comprise of multiple cognitive systems as regarding to the different types of memory.
Every field of research must always have a main focus through which questions and answers for that particular study are structured and provided. This having being said, memory research evolves around the belief that there are different types of memory systems that are interconnected and interact with each other to provide a particular outcome (Nyberg and Tulving, 1997).
Additionally, these systems are sub divided into those that handle long- term memories and those that are in charge of short- term memories. The fact that there are separate memory systems seems to be agreed upon by many scholars.
However, theories have been developed that dispute this statement and back the idea that some of these multiple cognitive memory systems function on independent levels depending on the current action or event. In terms of the long term memories, four systems have been irrefutably established over the years whose main aims are to provide insight on how the long term memory works and the situations that institute to its usage.
These systems include the episodic memory system, the semantic, procedural and finally, the Perceptual Representation System (PRS). Over the years, a criterion known as the converging dissociations have been implemented to shed some light on how these different memory systems are totally separate especially in the handling of tasks that use or are affected by any of these systems.
Maine de Biran wrote in 1804 that the brain does indeed consist of multiple memory systems. Among those that he focused on were the mechanical memory which deals with the skeletal coordination, sensitive memory which is in charge of the emotions and other feelings and representative memory which deals with our perception to the facts and events of the external world and influences the decision making structures that govern the same.
In relation to this, Squire acclaims that the different memory systems are developed and function according to the activities and tasks that the brain perceives and our bodies perform. He further describes these memory systems as distinguished by the various tasks that we often carry out (2004). For example reading, walking talking and so forth. To prove this, medical practitioners and memory research experts set an experiment based on the mirror drawing theory to further explain the existence of multiple memory systems.
The experiment was performed to patients who exhibited amnesic tendencies therefore making them perfect candidates. The finding later showed that the eye-hand coordination was not affected by the fact that the patients were amnesic. The patients were able to learn how to draw without any prior recollection of doing this in the past. This example showcased the use of the periodic memory system which focuses on recalling short term memories in relation to repetition of a given task.
The various memory systems are often distinguished through the different ways that they process received information to the brain and the standards through which they operate. As a result of this, new and clearer theories pertaining to memory systems have been established under which the earlier mentioned systems fall under. The theory assumes that memory is defined under two categories which are the declarative memories and the non declarative memories.
Declarative memories are what are referred to in layman’s language as memories. The guiding principle under this type of memory is its ability to identify and simulate the unique attributes that occur at a given place or time. However the term goes deeper than what we remember and term as a memory.
The system focuses on why we remember things or even store information while we discard or forget other memories. This memory generally refers to mans capacity to recollect facts and events on a conscious level. In addition to this, declarative memory allows man to compare and contrast what they remember and it helps in establishing a relationship between these memories and the events that lead to their creation.
On the same note, declarative memory is representational in nature. This means that it is responsible for the way we remember things in our surrounding and consequently how we base their validity through our own experiences. However, this is the memory system that is affected or impaired by amnesia and old age in some cases. It therefore contributes to our performance in various conditions depending on how we perceive the situations.
The semantic and episodic memories consequently fall under the declarative memory system. The semantic memory is described as the memory that is responsible for processing information and facts received about external world.
On the other hand, the episodic memory caters for and supports our ability to perform an action in context to how we did it during its original occurrence. This includes our motor functionalities and coordination. For the episodic memory to be fully effective, it has to depend on other brain systems and the support of the semantic memory, for example the use of the frontal lobe of the brain.
The best example used to show the relationship between these two memory systems would be the case study of K.C. After being in a motorcycle accident, he incurred multiple and severe brain damage and up to date suffers from acute amnesic tendencies. However after a series of tests, it was declared that his brain functionalities were on most cases normal.
He could remember most of the important things in his past and was able to learn new things slowly but surely. However he could not remember his personal involvement in these tests or even in other events that had happened to him. In addition to this, he lacked the ability to project his thoughts into the future or even think about the past no matter the designated duration (Tulving, 2002).
Evidence derived from this case point to the fact that his episodic memory was somewhat impaired after the accident while his semantic memory system was amazingly left intact. That is probably why he could only remember the things and actions that he had over learned or rehearsed in his day to day activities but could not remember things that happened to him less often in his life.
The non-declarative memory system is in total contrast to the declarative systems. In this category, the memories are dispositional and are manifested through the performance of actions rather than recollections of the same. The factors that influence this type of memory systems include perceptual learning, emotional and skeletal responses (classical conditioning) and non associative learning.
As such, the procedural memory system falls under this category. The memories in this category are revealed when the systems within which an event originally occurred are reactivated. This system of memory is unique through its ability to systematically extract common attributes from a series of differentiated occurrences (Squire, 2004). This can best be illustrated by the inclusion of applied knowledge throughout the learning process.
It should be noted that the memory systems used by the brain to some extent operate in parallel to aid behaviors exhibited by human beings. For example, in a case scenario where a child is knocked down by a bicycle this may lead to a permanent declarative memory of the event and at the same time the child may develop a non-declarative memory subjected to the fear of bicycles.
This example shows how the different cognitive memory systems work together in simulating this event. Another illustration that best describes the presence of multiple memory systems would be during child birth whereby the mothers exert fears of what would be and even the process itself.
In addition to this statement, there are situations where one memory system may act as a substitute for another. What we learn, store or retrieve from the brain differs from one person to the other depending on the memory system applied. This is why performance and reception through the learning process differs from one person to another.
In a recent study where the participants were given three-word sentences to memorize and later asked to recall them; the learning occurred rapidly and majority of the participants were able to remember the sentences even in absence of some words. Those that could not recall showed less use of the short term memory which is used to remember things or events within a short period of time.
Consequently, more research has been performed in a bid to improve the usage of both the long and the short term memory for both normal and amnesic patients. On the same note, theories have been created through which the human race can be taught or guided to effectively utilize the various multiple cognitive memory systems while exercising a balanced functionality of the same.
The semantic episodic, periodic and perceptual representation system (PRS) has been put under scrutiny. Three articles have been analyzed so as to further assist in proving that there are multiple cognitive memory systems at work in the human physiology.
As a result, the various systems that have been developed have been discussed at length and illustrations and examples that may provide deeper insight on the memory systems have also been provided. It is clear that the choice as to what we remember or forget depends on the memory system that we implement accompanied by the events or facts that we are involved in.
Further research needs to be conducted in order to give more information about how the memory works. In addition to this, clearer methods need to be established through which those that suffer from various brain and memory disorders get assisted to cope and manage their conditions. Also training techniques should be developed to further assist in the full utilization of all the multiple cognitive memory systems.
References
Nyberg, L & Tulving, E. (1997). Searching for Memory Systems. Psychology press, pp.121-125
Squire, L, R. (2004). Memory systems of the brain: A brief history and current perspective. Elsevier Inc, pp 171-177.
Tulving, E. (2002). EPISODIC MEMORY: From Mind to Brain. Annual Review of Psychology Volume 53, 2002, pp. 1-25
The brain receives and responds to all stimuli of the body. Any alteration to the brain causes unusual stimuli receptions and responses. Because of that, the eating, personality, and sexual identity disorders are caused by the brain disturbances leading to abnormal communications between the brain and the respective body receptors. This paper will examine the details of the above mentioned disorders.
Sexual and Gender Identity Disorder (SGID)
Sexual and Gender Identity Disorders (SGID) are disorders exhibited by individuals when they persistently and strongly desire to be the opposite sexes. SGID can be classified into two categories. 1. Children SGIDs. 2. Adult and adolescent SGIDs.
The Boys may claim that their reproductive organs are irritating. At times, they may not signify their male organs. In several occasions, they reject male toys. Such boys prefer female individuals to male colleagues (Sue, 2006).
Girls with such disorders prefer urinating while standing just as men do. They desire to possess male reproductive organs, and they dislike future growth and development of their breasts. Such girls prefer male clothing to female clothing.
In adults and adolescents, the victims desire to be handled as their opposite sexes, and they have classical emotions and responses to their cross-genders. On top of that, the victims are usually concerned with changing their sex organs (Sue, 2006).
The behavioral components can be attributed to individuals’ exposure to unusual sexual behaviors such watching pornography (Stone, 2011). Such behaviors can cause sexual abnormalities. For cognitive components, a person can be triggered sexually to an abnormal level, which would produce maladaptive processes to contain the detected abnormality.
Therefore, the unsuitable behaviors affect the maladaptive thoughts, which are needed to contain such behaviors. The concerned biological components include smoking, sicknesses, unbalanced diet, and old age (Stone, 2011).
In this case, vulnerabilities in the endocrine system are the core causes of the SGIOs. In addition to that, unusual sexual behaviors are used as protective measures by the victims. This behavior is attributed to the poor parental care (Stone, 2011).
Eating disorders
Eating disorders are mental sicknesses that cause severe alterations in an individual’s daily meal. It may begin as eating exceptionally small or seriously large quantities of food. This condition may begin slowly and develop into severe levels. It can cause serious injuries in growth, fertility, mental and social health, and death. Eating disorders impact the body shape and size (Mandal, 2013).
The cognitive components are concerned with overeating or starving (Stone, 2011). This is due to the perception that overeating may cause excessive weight. Some individuals with over-sized bodies may opt for starvation because they fear of gaining weight. Emotional components are incorporated in individuals whose responses and hopes are very high as initiated and supported by some people (Stone, 2011).
Such individuals set high targets and experience the impacts of failure (Stone, 2011). The behavioral components include extreme starving, training, vomiting, and use of laxatives. The neural connection, genetic materials, and hormonal imbalance form the biological elements of this disorder. Brain disturbance may lead to endocrine and hormonal imbalance, which would stimulate overeating or starvation (Stone, 2011).
Personality disorders
Personality disorders are concerned with the convincing ways individuals think and act (Cherry, 2013). It can also mean the model of behavior that makes people different. Personality traits are made up of characteristic behaviors and thoughts. When this reasoning and characteristic behaviors become rigid and extreme, they form personality disorders.
Personality disorders are caused by the environmental and genetic impacts (Cherry, 2013). The personality components include disrupted brain make-up, minimized volume of white and grey matter, exposure of the prenatal matter, and unusual neurotransmitter (Stone, 2011).
The emotional components result from childhood abuse, which makes a person to depend on maladaptive protection methods. Therefore, child disapproval and mockery are the primary causes of this disorder. The cognitive elements indicate that childhood encounters create particular forms of thoughts, which result in this disorder.
The behavioral elements show that personality disorders command unproductive beliefs to individuals. These beliefs are unachievable because the victim sets high targets than he, or she can manage. This abnormality is created in childhood by the thought methods and /or maladaptive behaviors. This disorder continues regardless whether or not the victim is maladaptive Stone, 2011).
The Classification of all these disorders is based on the DSM-IV codes for easy identification.
Joe’s Story-Eating disorder
Biological components
Joe’s eating disorder originated from hormonal imbalance, genetic inheritance, and unusual neural connectivity. Since he suffered from anorexia, he must have had a low level of serotonin and unusual brain make-up. Joe might have experienced brain disturbances at birth, which triggered variations in endocrine and metabolic reactions to call for starvation (World –press, 2013).
Emotional components
The sickness hindered Joe from attaining his playing target. This triggered an anxiety and distress, which consequently triggered for an abnormal eating habit. Also, he was taking cover in eating after being abused by his friends in school (World –press, 2013).
Behavioral components
Joe did extreme exercises to avoid weight gain.
Cognitive component
Joe thought that overeating would make him more masculine and good-looking.
Conclusion
Because of the diagnostic complexities, it is difficult to establish abnormalities. Despite that, biological and psychodynamic aspects are making it easy to define abnormalities by providing reliable evidences. The cause of sexual, personality, and eating disorders include child abuse, physical abnormalities, and genetic inheritance. These abnormalities cause a great deal of human inadequacies.
References
Cherry, K. (2013). Overview of personality disorder. Web.
Cognition refers to the process through which information is processed, stored, and recovered for use (Glees, 2005). This process involves several mental processes that play different roles in order to enhance functions such as memory, comprehension, learning, problem solving, thinking, and decision making. The brain plays a pivotal role in cognition.
It is a faculty that helps to process sensory information, apply knowledge, and make important decisions (Glees, 2005). Cognition comprises mental functions and processes, as well as intelligent entities. The brain uses its various parts to process information.
For example, certain parts are concerned with memory while other parts deal with learning. The case of Phineas Gage is widely used to demonstrate the role of the brain in cognition. His brain injury is used in the field of psychology to understand and explain the functioning of the human brain with regard to cognition.
Role of the brain in cognition
The brain plays a pivotal role in supporting cognitive functions. Examples of cognitive functions include learning, memory, and perception (Glees, 2005). The brain has several parts that play different roles in the execution of cognitive functions. Parts of the brain involved in cognition include prefrontal cortex, frontal and parietal lobes, temporal lobes, and occipital lobe (Roizman, 2010).
The prefrontal cortex is the latest part of the brain to be discovered in the field of psychology. It executes high-priority cognitive functions that include planning, assessment of the outcomes of actions, and expression of personality traits (Roizman, 2010). In addition, this area expresses the aptness of various behaviors in different social contexts.
The frontal lobes deal with two main cognitive functions that include language comprehension and memory (Roizman, 2010). The left and right frontal lobes perform different functions. The left lobe deals with language comprehension while the right lobe processes information. Damage to these lobes is characterized by poor decisions and inability to make good plans.
Parietal lobes aid in the processing of sensory information. For example, it converts and consolidates sensory input into memories that are stored in the brain. Temporal lobes serve the role of processing auditory sensory information mainly for speech recognition (Glees, 2005).
In addition, they aid in memory and recognition of physical objects. For example, the brain’s role of identifying sounds and odors is executed by the temporal lobes. Finally, the occipital lobe plays the role of processing visual information (Roizman, 2010). Damage to the occipital lobe causes a condition that is characterized by reduced functionality of sight, and inability to recognize apparent deficits.
The case of Phineas Gage
Phineas Gage was a railroad construction worker who is an important figure in psychology. Gage survived an accident in which his brain’s frontal lobe was damaged by an iron bar that passed through his head (Flesichman, 2004). The injury had far-reaching effects on his behavior and personality for the 12 years that he lived after the accident.
This incident is widely used in the field of psychology to explain how certain brain areas support cognitive functions. After the injury, Gage showed certain changes in behavior that characterized changes in behavior due to damage to certain brain areas. The frontal lobe plays roles such as problem solving, planning, and decision-making. The prefrontal cortex expresses personality.
After the accident, studies of Gage’s behavior revealed several changes. For example, he could make plans and fail to execute them to completion (Flesichman, 2004). His friends also reported that his personality had changed significantly. Before the accident, Gage was a shrewd, persistent, and energetic businessperson. However, after the accident, these traits were replaced by destructive qualities that affected his life negatively.
He neither made good plans nor completed his projects due to lack of persistence. His personality traits after the accident included irreverence, impatience, and irresponsibility. Other behaviors that resulted from the injury included irresponsible sexual behavior, domestic violence against his wife and children, lying, gambling, bullying, and lack of foresight (Flesichman, 2004).
These behaviors mainly resulted from poor judgment and planning. One of the most common signs of frontal lobe damage is change in behavior. An individual who suffers damage to their frontal lobes does not behave as they used to before the damage.
People who are close to the individual can observe these changes in behavior. After the accident, Gage showed a decrease in the efficiency of functions that included planning, judgment, inhibition, and decision making (Flesichman, 2004).
Conclusion
The brain serves several roles, one of which is supporting cognitive functions. Parts of the brain that support cognition include prefrontal cortex, frontal and parietal lobes, temporal lobes, and occipital lobe. Each of these parts performs a different role. Examples of cognitive functions performed by these parts include judgment, memory, and decision-making, problem solving, and planning.
The brain injury of Phineas Gage is used by psychologists to demonstrate the role of the brain with regard to cognition. After the accident, Gage’s personality changed tremendously after damage to his brain’s frontal lobe. Behavioral changes included irresponsible sexual behavior, domestic violence against his wife and children, lying, gambling, bullying, and lack of foresight.
References
Flesichman, J. (2004). Phineas Gage: A Gruesome but True Story about Brain Science. New York: Houghton Mifflin Harcourt.
Glees, P. (2005). The Human Brain. London: Cambridge University Press.
Roizman, T. (2010). The Brain Functions Involved in Cognitive Functions. Web.
The investigations conducted by Benson and the team of sophisticated scientists (2006) are based on the fact that intercessory prayer may influence the process of recovery in a variety of ways.
However, Benson et al. evaluate the conditions when people with CABG suffer from depressions and inabilities to control their illnesses even under being properly treated and supported by prayers and offer the idea that prayers should not be regarded as one of the main factors of human recovery.
The experiment aims at dividing people into several groups where some people are aware of receiving intercessory prayer and some people are not aware of this fact. The results were not as impressive as expected: the chosen intercessory prayer “had no effect on complication-free recovery from CAGB” (Benson et al., 2006, p. 942).
Such conclusions were made by the researchers, still, they wanted to support the idea of religion in treatment and admit that such results could be predetermined by the limitations set on the study: some constraints were placed without any kind of feedback.
This is why the result of the study should not challenge the chosen belief and make people doubt about the God’s existence. The main point was to discuss how prayers may influence treatment, and this article show the rationality of the required medical interference.
The works by Newberg et al. (2010, 2005, 2006. & 2007) aim at discussing the religious perspective in medical treatment and possibilities to improve human health and brain activation. The works have been introduced in different years and show how evident the progress of the experiments could be.
Neuroscience research is based on theological and epistemological questions (Newberg & Lee, 2005), and people should understand that spiritual pursuits may define the quality of brain and body work as such state like glossolalia (Newberg et al., 2006) and meditation (Newberg et al., 2007) which are closely connected to the field of spirituality may improve human health considerably.
Though the last investigations conducted in 2010 show that long-term meditators in comparison to non- meditators may have absolutely different activity patterns which are observed in brain, and meditation should be considered as an activity on a spiritual level that defines the way of how human brain works (Newberg et al., 2010)
The next article contains the results of the investigations conducted by Schjoedt et al. (2009) in order to prove that special formalized and improvised forms of prayers may cause different BOLD response. 20 young participants were observed; the cases of depression and stress should be analyzed to explain how praying may control human emotions and actions.
The main point of this research is that all participants believe in God, still, it turns out to be hard to prove that praying may cause different results. The results of their funding are all about praying to God as “an intersubjective experience comparable to normal interpersonal interaction” (Schjoedt et al. 2009).
Neuroscience as well as some other spiritual theological fields discovers a new ability to affect human mind and create the conditions under which humans are under the impact of their religion full of arguments and true evidences.
At the end of their investigations, Schjoedt et al. (2009) admit the fact that experimental neuroscience of such spheres like religion has to be studied further in order to find out the required realistic account of the discovered phenomenon of personal prayer.
The final portion of the articles helps to understand how cognitive and emotional processes may undergo certain challenges due to properly developed religious experience. As a result of principle component analysis and PET data evaluation, the researchers (Azari, Missimer, & Seitz, 2005) prove that religious experience not only can but also have to unite cognitive neural networks controlled by human brain.
In spite of the fact that religion does not actually consider limbic neural substrate, emotions can do such things and cooperate with certain cognitive factors to improve the quality of brain work (Azari & Birnbacher, 2004).
In comparison to the first research (Azari et al., 2001) where religious experience is regarded as preconceptual event, current ideas and perspectives seem to be more confident and properly argued under the conditions people have to live nowadays.
In general, the five types of research discussed in this paper show that religious aspect play an important role in human life and the work of human brain. There are many people who truly believe that God has certain powers and may influence people’s styles of life as well as human health.
Though not all scientists admit the influence of religion on brain, the articles considered help to realize that if a person is in need of prayer in order to improve personal condition and find the required piece, it is necessary to provide such person with a chance to pray and ask God to forgive and help. Religion is considered to be a complex phenomenon; this is why it is wrong to neglect its importance in human lives.
References
Azari, N.P. et al. (2001). Short communication: Neural correlates of religious experience. European Journal of Neuroscience, 13, 1649-1652.
Azari, N.P. & Birnbacher, D. (2004). The role of cognition and feeling in religious experience. Zygon, 39(4), 901-918.
Azari, N.P., Missimer, J., & Seitz, R.J. (2005). Religious experience and emotion: Evidence for distinctive cognitive neural patterns. The International Journal for the Psychology of Religion, 15(4), 263-281.
Benson, H., Dusek, J.A., Sherwood, J.B., et al. (2006). Study of the therapeutic effects of intercessory prayer (STEP) in cardiac bypass patients: A multicenter randomized trial of uncertainty and certainty of receiving intercessory prayer. American Heart Journal, 151(4), 936-942.
Newberg, A.B. & Lee, B.Y. (2005). The neuroscientific study of religious and spiritual phenomena: Or why God doesn’t use biostatistics. Zygon, 40(2), 469-489.
Newberg, A.B. et al. (2007). Regional brain activation during meditation shows time and practice effects: An exploratory FMRI study. Evidence-Based Complementary and Alternative Medicine, 7(1), 121-127.
Newberg, A.B. et al. (2006). The measurement of regional cerebral blood flow during glossolalia: A preliminary SPECT study. Psychiatry Research: Neuroimaging, 148(1), 67-71.
Newberg, A.B. et al. (2010). Cerebral blood flow differences between long-term meditators and non-meditators. Consciousness and Cognition, 19(4), 899-905.
Schjoedt, U. et al. (2009). Highly religious participants recruit areas of social cognition in personal prayer. Social Cognitive & Affective Neuroscience, 4(2), 199-207.
The ability of the brain to change following an individual’s experience is referred to as neuroplasticity (Alamacos, Segura, & Borrel, 1998). This characteristic of the brain was discovered more recently and discredits the earlier belief that the brain could never change after a person has gone through the critical period of infancy. The brain is chiefly made up of nerve cells and glial cells which are usually linked.
Learning can be achieved through the alteration of the strength of these connections. In the last century, the common belief was that the lower brain and the neocortical areas could not be altered in structure after structure after childhood (Winship & murphy, 2009).
This belief has been challenged by the new revelations that indicate that all parts of the brain are plastic and can be altered even in older individuals. This paper seeks to identify the ability of the brain to re-task a different area to perform a function that has been affected by brain damage (Lazar, Kerr, & Wasserman, 2005).
Earlier studies
Previous studies done by Wiesel and Hubel showed that ocular dominance columns that are located in the lowest neocortical visual area were largely not changeable after one has passed the critical period in development (Black, Cianci, & Markokowitz, 2001).
These critical periods were also examined in respect to language development; the findings suggested that all the sensory pathways were permanent subsequent to the critical period (Kaeser, et al., 2010). However, the earlier brain studies had also shown that changes in the environment could result in change in behavior and cognition.
This change was linked to the alteration in neuronal connections and neurogenesis in specific parts of the brain such as the hippocampus (Boudrias, Mcpherson, Frost, & Cheney, 2010).
Decades of enduring research on the functions and structure of the brain indicate that alterations take place in the lowest neocortical processing areas and that the alterations could result in marked changes in the pattern of neuronal activation in response to experience (Kaeser, et al., 2010).
The resulting neuroplasticity theory asserts that experience can result in the modification of the brain’s physical structure and the functional organization (Alamacos, Segura, & Borrel, 1998).
Neurobiology and cortical maps
The idea of synaptic pruning forms one of the important aspects of neuroplasticity. Synaptic pruning explains that specific links in the brain are subjected to constant removal or recreation depending on how they are being used (Draganski, 2006).
The concept of synaptic pruning is best captured in the aphorism “which states that neurons that fire together, wire together/neurons that fire apart, wire apart” (Boudrias, Mcpherson, Frost, & Cheney, 2010, p. 8). This indicates that two neighboring neurons that concurrently produce an impulse can form one cortical map.
Cortical maps are used to explain cortical organization of, in most cases, the sensory system (Giovanna, Paolo, Luca, & Thomas, 2008). For instance, sensory impulses from the two arms are projected to different cortical sites in the brain.
Thus the cortical organization defined by the response to sensory inputs represents the human body in form of a map. Researchers Merzenich, Doug Rasmusson and Jon Kaas conducted studies on the cortical maps by removing sensory inputs (Cutler & Hoffman, 2005).
Their findings which have been supported by various other studies show that the removal of an input in the cortical map results in the rewiring of the impulse through adjacent inputs.
Treatment of brain damage as an application of neuroplasticity
Through neuroplasticity studies it has been found out that a brain activity that results into a certain function can be relocated to a different part of the brain. This may take place in the course of normal experience or may occur in the course recovery following brain damage (Draganski, 2006).
Neuroplasticity forms the basis on which the scientific explanation for the treatment of acquired brain injury is founded. The restoration of the lost functions through therapeutic programs in form of rehabilitation is achieved due to the plastic nature of the brain (Frost, Bury, Friel, Plautz, & Nudo, 2002).
Cortical tissue damage, as might occur following stroke, is usually known to affect the initiation and execution of muscular contraction in the extremities opposite the side of the injury (Winship & murphy, 2009). In addition the precise manipulative power and the ability to skillfully utilize the upper extremity are usually weakened.
Depending on the extent of the injury, some functions usually return in weeks or months, although full recovery is uncommon in human beings. There is increasing evidence which indicates that the return of function observed following “cortical injury is largely attributed to the adaptive plasticity in the remaining cortical and sub-cortical motor apparatus” (Black, Cianci, & Markokowitz, 2001).
For instance, the studies pneurophysiologic and neuroanatomic on animals and the neuroimaging and other non invasive stimulation research studies conducted on humans provide evidence to show that adaptive changes take place in the undamaged tissues that surround a cortical infarct (Lazar, Kerr, & Wasserman, 2005).
Contrary to the previous beliefs, the adult brain is not “hard wired” with fixed immutable neuronal circuits (Draganski, 2006). There are several instances through which the cortex and sub cortex can be rewired as a consequence of training or following an injury to the brain. This is supported by evidence that new brain cells can develop even in the adult mammal even at old age.
The research findings so far have shown that this mainly occurs in the hippocampus and the olfactory bulb, however, there is increasing evidence that indicates that other regions of the brain may undergo neurogenesis (Frost, Bury, Friel, Plautz, & Nudo, 2002). In most parts of the brain, dead neurons are not recreated but the specific functions are seen to be restored.
However, evidence on the active, “experience-dependent re-organization of the synaptic networks of the brain involving multiple inter-related structures including the cerebral cortex is lacking” (Kaeser, et al., 2010, p. 13). The specific pathway through which the process takes place at the molecular level is subject to intense research.
Some theories have been advanced to explain how experience results in the synaptic organization of the brain, one of the theories include the general theory of the mind and epistemology referred to as Neural Darwinism which was developed by Gerald Edelman (Lazar, Kerr, & Wasserman, 2005).
Neuroplasticity also occupies a central point in the memory and learning theories that are characterized by changes in the structure and function of the synapses through experience (Lazar, Kerr, & Wasserman, 2005).
Sensory substitution and neuroplasticity is best remembered through the works of Paul Bach-y-Rita (Lazar, Kerr, & Wasserman, 2005). He came up with a brain port while working with a patient whose vestibular system had been injured. The “brain port machine would replace the patient’s vestibular apparatus by sending signals to her brain via the tongue” (Winship & murphy, 2009, p. 15).
The patient used the machine for a certain period of time and regained the normal function. Her experience is best explained through plasticity because her vestibular system was disorganized following prolonged gentamicin medication and thus was sending uncoordinated signals to the brain.
Using the machine developed by Paul bay her vestibular system was able determine new neural pathways that were instrumental in reinstating the lost function.
Paul Bach-y-Rita used the following analogy to explain the plasticity concept; “if one is driving from one place to another and the main bridge that connects the two places goes out, he will be paralyzed before deciding to take the old farmland roads that are definitely shorter” (Winship & murphy, 2009). By using these roads more, one will start getting wherever he wanted to go faster.
Thus the new established neural pathways become stronger with more use. The unmasking process of the new neural pathways is generally understood to one of the main principal ways through which the plastic brain reorganizes itself (Boudrias, Mcpherson, Frost, & Cheney, 2010).
Another group referred to as the Randy Nudo learned that if an infarction leads to the cutting of blood supply to a certain part of the motor cortex of a monkey, the part of the body that is stimulated by the affected brain portion will respond when adjacent areas are stimulated (Kaeser, et al., 2010).
In one of their studies, the intracortical microstimulation (ICMS) mapping techniques were applied on nine normal monkeys (Draganski, 2006). Some of the monkeys were subjected to ischemic infarction protocols. The monkeys that underwent ischemic infarction retained more finger flexion during food retrieval and after several months this deficit returned to the levels they were before the operation (Kaeser, et al., 2010).
In regard to the mapping conducted to represent the distal forelimb, it was shown that cortical representations of movements had undergone reorganization in the entire surrounding cortex that had not been damaged. Better understanding on how the normal and damaged cortical tissues interact has formed the basis for current therapeutical approach in the treatment of stroke patients (Frost, Bury, Friel, Plautz, & Nudo, 2002).
The Nudo group is currently taking part in studying the treatment approaches that may result in better management of stroke. Such approaches include “physiotherapy, pharmacotherapy and electrical stimulation therapy” (Cutler & Hoffman, 2005, p. 4).
A professor at the Vanderbilt University known as Jon Kaas has been able to reveal “how somatosensory area 3b and the ventroposterior (VP) nucleus of the thalamus are affected by long standing unilateral dorsal column lesions at cervical levels in macaque monkeys” (Kaeser, et al., 2010, p. 10).
This shows that the brains of an adult mammal can reorganize following brain damage or injury but the reorganization will be injury dependent. His more recent studies have been focused on somatosensory structure.
Normally when injury is inflicted on the somatosensory cortex, one experiences a dysfunction in the perception of some part of the body. Jon Kaas is currently trying to understand how these systems (somatosensory, cognitive, motor systems) are plastic as a result of injury (Frost, Bury, Friel, Plautz, & Nudo, 2002).
More recently, neuroplasticity was applied in the treatment of traumatic brain injuries. The treatment was done by a team of doctors and researchers at Emory University, particularly Dr. Donald Stein and Dr. David Wright (Cutler & Hoffman, 2005). This particular treatment was first of its kind to be applied in that it is affordable and does not show any side effects.
Dr. Stein had had earlier observed that female mice recovered better from brain injuries as compared to their male counterparts. In addition he realized that the female mice had a better recovery record in some stages of the estrus cycle. After intense research studies, the team attributed this phenomenon to the levels of progesterone (Cutler & Hoffman, 2005).
The higher the progesterone levels the better the recovery witnessed in the mice. Thus they developed a therapeutic approach that included enhanced levels of progesterone administration to patients with brain injuries.
It was shown that if progesterone administration was done following brain injury that result in “stroke there were fewer instances of edema, inflammation, and neuronal cell death, and enhanced spatial reference memory and sensory motor recovery” (Kaeser, et al., 2010, p. 7). Administration of progesterone on a group of severely brain injured patients showed a reduction in mortality rates by up to 60%.
Conclusion
This paper sought to use existing literature in academic sources to explain how a lost function due to brain injury or damage can be re-tasked to another part of the brain. The area concerned with this study is referred to as neuroplasticity which can be simply defined as the ability of the brain to change following an individual’s experience (Boudrias, Mcpherson, Frost, & Cheney, 2010).
Neuroplasticity has led to a major shift in the way the understanding of the human brain. Major studies have been carried out by researchers and doctors to understand how the brain is able to re-task different area following damage to one area. Though there is no conclusive evidence to show how this occurs at the molecular level, there has been a marked improvement in the understanding and therapeutical application.
References
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