Biopsychology: Lateralization, Depression, Sleep, Emotion, Memory, Aphasia, Drug Effects, Brain Imaging, Amyloidosis

This document covers various topics in biopsychology including lateralization, depression, sleep, emotion, memory, aphasia, drug effects, brain imaging, and amyloidosis. It provides an overview of each topic and discusses relevant research findings and theories. The document also explores the role of different brain regions and structures in regulating memory and language. Additionally, it discusses the effects of drugs on the brain's reward system and the use of brain imaging techniques in diagnosing and studying neurological conditions. Finally, it examines the relationship between amyloidosis and Alzheimer's disease and the concept of cognitive reserve in preventing age-related cognitive decline.

Running head: BIOPSYCHOLOGY
BIOPSYCHOLOGY
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1BIOPSYCHOLOGY
Question 1
The function of ‘lateralization’ in the brain is the phenomenon of specialization of the
certain cognitive, behavioral and emotional functions across specific hemispheres in the cerebral
cortex. Lateralization across the brain occurs due to structural features of the cortex, comprising
of two hemispheres of the brain to be connected by the corpus callosum and differentiated along
with medial longitudinal fissure (Dalton, Hornberger & Piguet, 2016). It has been primarily
observed that components of language such as vocabulary, comprehension of words and
grammar are lateralized across the left hemisphere in right hand dominant individuals. For
sensory functions of vision, touch and hearing, the neural activities of the optic, dermal and
auditory nerves for each eye, skin surface and ears are lateralized to the hemisphere opposite to
their location (Rogers & Vallortigara, 2017).
Despite such independent functioning, unison across the hemispheres can be observed
especially in case of damages or injuries incurred in hemispheres. For example, damage to the
right hemisphere, responsible for fine motor skills, visual functioning associated with the left
hemisphere will still allow the individual to present a drawing where individual parts coalesce to
form a whole. Similarly, damage to the left hemisphere associated with language does not hinder
the cognitive ability of individuals to derive meaning from words or speech (Trimmel et al.,
2017).
Abnormalities in the above functioning has been observed in case of ‘split brain’ - a type
of disconnection syndrome comprising of damage to the corpus callosum. To mitigate the
damage, a transactional surgery is performed known as corpus callostomy, resulting in
hemispherical separation with each hemisphere presenting with separate cognitive functioning

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(Fabri et al., 2017). Such differences have been postulated in the research by D’Alberto et al.,
(2017), where patients with a split brain syndrome, improved inhibitory control was observed in
the right hemisphere whereas the left hemisphere presented with improved performance in terms
of Stop Signal Reaction Time. Further research by Kingstone (2016), emphasize split brain
syndrome can result in a condition of interhemispheric competition where the right hemisphere
may dominate the left hemisphere and also present superior object-based attention. Such research
can hence prompt the cognitive neuroscientist to conduct further research on the physiological
and neural based structural differences which contribute to dominance by the right hemisphere in
split brain syndrome and hence, enhance understanding of patients inflicted with this condition.
Question 2
The chosen psychiatric disorder is depression which is characterized by alterations in
mod, prolonged feelings of melancholy and sadness and loss of enthusiasm to engage in
activities of choice. According to the National Institute of Mental Health, depression can
manifest in terms of both physiological and behavioral aspects. Physiological signs and
symptoms include: disturbances in normal sleep schedule, sleeplessness, loss of appetite and
excessive weight loss, gastrointestinal disorders, cramps and aches throughout the body,
restlessness or perception of fatigue and slowed speech or movements. Behavioral symptoms
include: constant preoccupation with feelings of hopelessness and sadness, states of guilt,
irritability and helplessness, lack of interest in pleasurable activities and constant thoughts on
depression and self-harm (National Institute of Mental Health, 2019).
The causative factors of depression can be addressed in terms of various theories. The
humanistic and a recovery oriented approach highlight that depression is correlated with social

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incidents such as traumatic life events (Watson & Pos, 2017). The medical model postulates that
depression may emerge due to physiological abnormalities such as reductions in production of
neurotransmitters like dopamine and serotonin (Patten, 2015). Alternatively, the biopscyhosocial
models also postulate a genetic predisposition to depression where individuals with a familial
history of depression may be likely to be inflicted with its symptoms (Ormstad & Eilertsen,
2015). Prevalent behavioral treatments include Cognitive Behavioral Therapy (CBT) while
pharmacological treatments include anxiolytics, antidepressants and selective serotonin reuptake
inhibitors (SSRI). An exploration on the structural changes in the brain and its effects on
behavior during depression, along with an evaluation of biochemical changes across neural
circuits during depression can pave the way for further research among biopsychologists and
neuroscientists (Forand et al., 2019).
Question 3
Sleep is a state of rest and recuperation in the body, characterized by alterations in
consciousness and inhibition of sensory and muscular processes. A normal sleep cycle is
composed of four stages of stage 1, 2, 3 and rapid eye movement (REM) stages. Every stage
comprises of approximately 15 minutes with the complete sleep cycle comprising of an average
of 90 to 110 minutes (Liu et al., 2017). The first stage is considered as the mildest stage of non-
rapid eye movement of sleep characterized by physiological changes such as slowed brain
activity, relaxation of muscles tone and possible spasms and jerks in the muscle. The second
stage is characterized by physiological changes such as discontinuation of slowed eye
movements, slowed heart rates, reduced body temperatures and activities of K complexes and
sleep spindles to prevent sudden awakening (Morgan, 2017). The third stage of sleep is

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considered the deepest stage with physiological changes such as delta waves and possibility of
parasomnias. The fourth stage is characterized by rapid eye movements and it is here where
dreaming sets in. Additional physiological changes include side-to-side, quick eye movements,
actively working brain waves and increased tendency to encounter arousal or awakening.
Disruption of sleep results in feeling of over sleepiness, fatigued, tiredness, feelings of distress
and mood shifts and increased somatic pain (Zhao et al., 2017). Sigmund Freud postulated the
most common theory of viewing dreams as projections of wish fulfillment and repressed longing
where unfulfilled desires are expressed. Additionally, Carl Jung theorized that dreams are a
direct expression of our experiences across our unconscious or conscious mind. The Activation-
Synthesis Hypothesis theory of dreams postulates that dreams are projections of the neural
changes occurring during REM sleep stages. The threat simulation theory of dreaming suggest
that dreams are projection of our intrinsic defense processes when being met with incidences of
threat and danger (Zink & Pietrowsky, 2015).
Question 4
The evolutionary theory of emotion by Charles Darwin emphasize that emotions are a
means of adaption aimed at survival. For example, emotions of love emerge to ensure
reproduction and species survival. In criticism however, such a theory makes it difficult to
hypothetically interpret emotions since different individuals may project the same emotion with
however, diverse underlying motives. The James Lang theory of emotion postulate that emotions
emerge in congruence with physiological processes. For example, sweating, shivering or
trembling due to a challenging situation instills emotions of fear (Ong, Zaki & Goodman, 2015).
This theory has been criticized by the Canon-Bard Theory, with views that emotions need not

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always be related with physiological mechanisms. For example, engagement in intense activity
can result in sweating, without any emotions of fear. According to the Schachter-Singer Theory,
emotions emerge as a result of cognitive evaluation of physiological responses. Such a theory
however, defies the normal fight or flight mechanisms which leaves little room for individuals to
cognitively interpret a situation of threat and instead act merely in accordance to neurological
processes of the sympathetic nervous system. According to the Facial Feedback theory of
emotion, emotions are directly expressed through facial gestures. In criticism however, such
expressions may not be observed in mental health issues such as depression, where individuals
may otherwise choose to suppress their emotions (Barrett, 2015).
In my personal opinion, the evolutionary theory of emotion by Charles Darwin is perhaps
the best explanation for emotional expression across individuals. Indeed, we all engage in the
projection of various emotions as an attempt to fulfill or express needs, desires, preferences
resulting in achievement of personal objectives and hence, overall survivability (Al-Shawaf &
Lewis, 2017).
Question 5
A number of neuro-chemical systems are associated in initiating the sleep cycle. These
include: histamine (reduces activity at non-REM sleep stages), serotonin (enhances sleep onset
latency), dopamine (promotion of wakefulness as well as dreaming) and acetylcholine
(stimulation of cerebral cortex and forebrain resulting in wakefulness and alertness). Brain
regions such as the hypothalamus play a key role in sleep promotion, since it houses the
ventrolateral preoptic nucleus (VLPN). Neurons in the VLPN induce sleep through inhibition of

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activities of the brainstem – the cerebral region responsible for maintaining wakefulness
(Overeem & Reading, 2018).
The Circadian rhythm comprise of intrinsic process in the body which regulate the cycle
of sleep and wakefulness in individuals, across intervals of 24 hours. The neurobiological
mechanism which regulates an individual’s circadian rhythm is the suprachiasmatic nucleus
(SCN) – also known as the ‘master clock’ and comprise of a neuronal bundle of approximately
20, 000 neurons, located in the hypothalamus. Endocrinal mechanisms which regulate the
circadian rhythm, include body temperatures, heart rates, cortisol in the plasma responsible for
alertness and melatonin produced by the pineal gland, responsible for instilling sleep in response
to light (Potter et al., 2016).
Question 6
The brain regions and structures responsible for regulating memory include: prefrontal
cortex for short and long term memory, temporal lobe for memory associated with facial
identification and of the long term type and the medial temporal lobe responsible for episodic
and declarative memory. Memory is also regulated by the amygdala and the hippocampus,
through functions such as emotional processing of memory and transitioning short term to long
term memory (Sprague, McBee & Sellers, 2016).
According to the research by Epstein et al., (2017), the hypothesis of ‘cognitive mapping’
emphasize that for the purpose of incorporating memory in future activities, the brain constructs
a visual representation of the surrounding environment. The hippocampus plays a key role in the
development of these cognitive maps through formulation of grid borders, head directions and
spaces. The research also evidences that spatial codes, similar to maps are developed by the

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entorhinal cortex and the hippocampus, establishment of relationships between real life spatial
surroundings and cognitive maps are regulated by the retrosplenial cortices and
parahippocampus and the routes for navigating through these cognitive maps are regulated
entorhinal and hippocampul cortices. Such scientific evidence has emerged in response to over
forty years of research using electrophysiological processes.
Question 7
The condition of Aphasia implies hindrances in the expression and understanding of
language – a common aspect in both Broca’s and Wernicke’s aphasia. Broca’s aphasia is
characterized by impairment of the Broca’s area (left interior frontal hemisphere) resulting in
halting and non-fluency of speech and impairment in communicating with long sentences. In
contrast, Wernicke’s aphasia is characterized by damage to the left hemisphere resulting in
absolute loss of linguistic understanding followed by meaninglessness and jargon in speech.
Such abnormalities are highlight the role of the left hemisphere in not just understanding of
grammar and vocabulary, but also in the comprehension and understanding of linguistic
components (Vuković, Vuković & Miller, 2016).
Question 8
Upon comparison, the similarity between the effect of cocaine and heroin on the reward
system of the brain, is characterized by their activation of neurotransmission of dopamine
resulting in stimulation of the reward center in the nucleus accumbens and feelings of reward and
pleasure (Haro et al., 2018). In contrast, differences can be observed in case of heroin which
exerts in actions via reaction with opioid receptors resulting in production of endorphins,

8BIOPSYCHOLOGY
reduced perception of pain and regulation of physiological processes (Compton, Jones &
Baldwin, 2016). While each drug exerts its own unique effect, almost each of these contribute to
the production of dopamine which further highlight the importance of learning and condition in
drug tolerance. This occurs due to the increased production of dopamine via drug intake which
stimulates sensations of reward and hence, compels the individual to repeat the intake for reward.
Repeated learning, positive reinforcement and conditioning of drug intake resulting in increased
need for reward, increased intake of drugs to fulfill aggravated perceptions of reward and hence,
drug tolerance (Bespalov et al., 2016).
Question 9
A CAT scan, with the aid of specialized X ray, improves brain understanding by
producing pictures of skull, brain, cerebral blood vessels and sinuses. Detection of fluid
accumulation, inflammation, hemorrhages and congenital abnormalities in the brain are
examples of its usage. An MRI scans assists in producing high quality images of structures
underlying the cortex and brain stem using radio waves and magnetic fields with detection of
bleeding, cysts, tumors, infections, structural abnormalities as key examples (Bhatkar et al.,
2017). A PET scan assists in scanning of the processes undergoing in the brain and is used in the
detection of cancer and dementia and their progression. An fMRI scan specifically addresses
scanning of the circulatory processes undergoing in the brain with detection of preparedness of
brain prior to surgery and cognitive functioning of an injured brain as key examples of its usage
(Schrepf et al., 2016).

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Question 10
Amyloids are abnormal clumps of protein which are formed from the bone marrow and
deposit across tissues and organs resulting in amyloidosis. Amyloidosis can be a key contributor
in the pathogenesis of Alzheimer’s disease. This occurs due to excessive deposition of beta-
amyloid clumps of protein in the brain, resulting in destruction of synapses, accumulation of
plague and death of nerve cells in the brain (Selkoe & Hardy, 2016). Cognitive reserve can be
built up through engagement in higher fields of education, engagement in occupations requiring
complex task performance and participation in lifestyle behaviors like nutritious diet intake,
exercise, social interaction and intellectual activities like reading. Beneficial effects of building
cognitive reserve include decreased age associated neurological risks such as dementia and
Alzheimer’s and improved memory and cognitive skills in later life (Opdebeeck, Martyr &
Clare, 2016).

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References
Al-Shawaf, L., & Lewis, D. M. (2017). Evolutionary psychology and the
emotions. Encyclopedia of personality and individual differences, 1-10.
Barrett, L. F. (2015). Ten common misconceptions about psychological construction theories of
emotion. The psychological construction of emotion, 45-79.
Bespalov, A., Müller, R., Relo, A. L., & Hudzik, T. (2016). Drug tolerance: a known unknown in
translational neuroscience. Trends in pharmacological sciences, 37(5), 364-378.
Bhatkar, S., Goyal, M., Takkar, A., Lal, V., Mukherjee, K., & Singh, P. (2017). MRI versus CT
scan of brain in evaluation of suspected cavernous sinus syndromes-Prospective study of
48 patients in a tertiary centre in India. Journal of the Neurological Sciences, 381, 962.
Compton, W. M., Jones, C. M., & Baldwin, G. T. (2016). Relationship between nonmedical
prescription-opioid use and heroin use. New England Journal of Medicine, 374(2), 154-
163.
D’Alberto, N., Funnell, M., Potter, A., & Garavan, H. (2017). A split-brain case study on the
hemispheric lateralization of inhibitory control. Neuropsychologia, 99, 24-29.
Dalton, M. A., Hornberger, M., & Piguet, O. (2016). Material specific lateralization of medial
temporal lobe function: An f MRI investigation. Human brain mapping, 37(3), 933-941.
Epstein, R. A., Patai, E. Z., Julian, J. B., & Spiers, H. J. (2017). The cognitive map in humans:
spatial navigation and beyond. Nature neuroscience, 20(11), 1504.

11BIOPSYCHOLOGY
Fabri, M., Foschi, N., Pierpaoli, C., & Polonara, G. (2017). Split-Brain Human Subjects.
In Lateralized Brain Functions(pp. 29-78). Humana Press, New York, NY.
Forand, N. R., Feinberg, J. E., Barnett, J. G., & Strunk, D. R. (2019). Guided internet CBT
versus “gold standard” depression treatments: An individual patient analysis. Journal of
clinical psychology, 75(4), 581-593.
Haro, G., Renau-Lagranja, J., Costumero, V., Baquero, A., Meneu, E., Salamone, J., & Correa,
M. (2018). Demotivating outcome of asymmetrical Nucleus Accumbens disconnection
for cocaine related disorder: a translational point of view. Adicciones, 30(4), 306.
Kingstone, A. (2016). Covert orienting in the split brain: Right hemisphere specialization for
object-based attention. Laterality: Asymmetries of Body, Brain and Cognition, 21(4-6),
732-744.
Liu, S., Teng, J., Qi, X., Wei, S., & Liu, C. (2017). Comparison between heart rate variability
and pulse rate variability during different sleep stages for sleep apnea
patients. Technology and Health Care, 25(3), 435-445.
Morgan, K. (2017). Sleep and ageing. Routledge.
National Institute of Mental Health. (2019). NIMH » Depression. Retrieved from
https://www.nimh.nih.gov/health/topics/depression/index.shtml.
Ong, D. C., Zaki, J., & Goodman, N. D. (2015). Affective cognition: Exploring lay theories of
emotion. Cognition, 143, 141-162.

12BIOPSYCHOLOGY
Opdebeeck, C., Martyr, A., & Clare, L. (2016). Cognitive reserve and cognitive function in
healthy older people: a meta-analysis. Aging, Neuropsychology, and Cognition, 23(1),
40-60.
Ormstad, H., & Eilertsen, G. (2015). A biopsychosocial model of fatigue and depression
following stroke. Medical hypotheses, 85(6), 835-841.
Overeem, S., & Reading, P. (Eds.). (2018). Sleep disorders in neurology: a practical approach.
John Wiley & Sons.
Patten, S. B. (2015). Medical models and metaphors for depression. Epidemiology and
psychiatric sciences, 24(4), 303-308.
Potter, G. D., Skene, D. J., Arendt, J., Cade, J. E., Grant, P. J., & Hardie, L. J. (2016). Circadian
rhythm and sleep disruption: causes, metabolic consequences, and
countermeasures. Endocrine reviews, 37(6), 584-608.
Rogers, L. J., & Vallortigara, G. (2017). Lateralized brain functions. Springer New York.
Schrepf, A., Harper, D. E., Harte, S. E., Wang, H., Ichesco, E., Hampson, J. P., ... & Harris, R. E.
(2016). Endogenous opioidergic dysregulation of pain in fibromyalgia: a PET and fMRI
study. Pain, 157(10), 2217.
Selkoe, D. J., & Hardy, J. (2016). The amyloid hypothesis of Alzheimer's disease at 25
years. EMBO molecular medicine, 8(6), 595-608.
Sprague, S. A., McBee, M. T., & Sellers, E. W. (2016). The effects of working memory on
brain–computer interface performance. Clinical Neurophysiology, 127(2), 1331-1341.

13BIOPSYCHOLOGY
Trimmel, K., Sachsenweger, J., Lindinger, G., Auff, E., Zimprich, F., & Pataraia, E. (2017).
Lateralization of language function in epilepsy patients: A high-density scalp-derived
event-related potentials (ERP) study. Clinical Neurophysiology, 128(3), 472-479.
Vuković, M., Vuković, I., & Miller, N. (2016). Acquired dyslexia in Serbian speakers with
Broca’s and Wernicke’s aphasia. Journal of communication disorders, 61, 106-118.
Watson, J., & Pos, A. E. (2017). Humanistic and experiential perspectives. The Oxford handbook
of mood disorders, 459.
Zhao, M., Yue, S., Katabi, D., Jaakkola, T. S., & Bianchi, M. T. (2017, August). Learning sleep
stages from radio signals: A conditional adversarial architecture. In Proceedings of the
34th International Conference on Machine Learning-Volume 70 (pp. 4100-4109). JMLR.
org.
Zink, N., & Pietrowsky, R. (2015). Theories of dreaming and lucid dreaming: An integrative
review towards sleep, dreaming and consciousness. International Journal of Dream
Research.