Biopsychology Flashcards
Phineas Gage
1848 - working on a rail line
Piece of iron through skull
Change in personality - loss of inhibition and anger
Motor Area
Located in the frontal lobe
Responsible for voluntary movement
Hitzig + Fritsch - motor
Different muscles are coordinated by different areas of the motor cortex
Electrically stimulating motor areas of dogs - muscular contractions in different areas of the body depending on where the probe was inserted
Somatosensory area
Located in the parietal lobe
Recieves incoming sensory information from the skin to produce sensations related to pain
Robertson - somatosensory
Somatosensory area of the brain is highly adaptable, with braille readers having larger areas in the somatosensory area for their fingertips compared to sighted participants
Visual area
Located in the occipital lobe
Recieves and processes visual information
Information from the right hand side is processed in the left hemispere and info from the left is processed in the right hemisphere
Auditory area
Located in the temporal lobe
Analysing and processing acoustic information
Info from the right goes to the left hemisphere and vice versa
Brocas aphasia
impaired ability to produce language
Wernickes aphasia
inability to extract meaning from spoken or written words
Peterson - brain scans
demonstrated Wernickes area was activeduring a listening task and Brocas area during a reading task
Dougherty - OCD
lesioning the cingulate gyrus improved symptoms of OCD
Neuroplasticty
The brains ability to change over time through learning and experience
Synaptic pruning
rarely used connections are deleted and frequently used connections are strengthened
When do synaptic connections peak?
Age 2-3 with around 15,000 per neuron
Maguire - taxi drivers findings
significantly more grey matter in posterior hippocampus than in matched control group
Posterior hippocampus associations
Spatial and navigation skills in humans and animals
Draganski - brain scan of med students
Imaged the brains of medical students 3 months before and after final exams
Learning-induced changes were seen in the posterior hippocampus and the pariettal cortex, presumably as a result of learning
Process of Functional Recovery
- Axonal sprouting - growth of new nerve endings which connect up
- Denervation supersensitivity
- Recruitment of homologous areas on opposite sides of the brain
Negative Plasticity
Brains adaptation to prolonged drug use leads to poorer cognitive function in later life
60-80% of amputees have been known to develop phantom limb syndrome - thought to be due to cortical reorganisation in the somatosensory cortex
Bezzola - Age and Plasticity
40 hours of golf training produced changes in the neural representations of movement in ppts age 40-60
fMRI showed increased activity in motor cortex in novice golfers, suggesting more efficient neural representations after golfing
Seasonal Brain Changes
Suprachiasmatic nucleus regulates sleep/wake cycle
Shrinks in spring, expands in autumn
Most research done on animals
Application of functional recovery
Neurorehabilitation
Understanding axonal growth encourages new therapies
Constraint-induced movement therapy used on stroke patients
Cognitive Reserve - Schenider
Those who spent more time in education had a greater chance of a disability free recovery
Banerjee - Total Anterior Circulation Strokes
5 participants all treated with stem cells - all made a full recovery compared to typical 5%
Hemispheric Lateralisation
The idea that the 2 halves of the brain are functionally differeny and that certain mental processes and behaviours are mainly controlled by on hemisphere
Where is Broca’s area?
left frontal lobe
Where is Wernickes area?
left temporal lobe
What is the function of the right hemisphere in relation to language?
Produce rudimentary words and phrases but contributes emotional context to what is being said
The Synthesiser
What is the function of the left hemisphere in relation to language?
The analyser
How is vision Contralateral and ipsilateral?
Each eye recieves information from both the left and right visual field, allowing visual areas to compare the slightly different perspective from each eye and aids depth perception
What is usually severed in a split-brain operation to reduce epilepsy?
Corpus callosum
What did Sperry do?
devised a system to study how 2 separated hemispheres deal with speech and vision
Sperry - Method
11 ppts - split-brain op
Describe what you see - LVF, RVF
Tactile tests - Objects placed in hand
Drawing task - reproduce picture shown to LVF and RVF
Fink - Hemispheric lateralisation
PET scans identify which areas active during visual processing task
ppts with a connected brain asked to attend to global elements of an image, regions of the RH were much more active
Finer details - LH dominated
Nielson - one brain (opposing evidence for LH analyser and RH synthesiser)
Analysed brain scans from over 1000 people aged 7-29
People use certain areas for different tasks but there is no evidence of a dominant side
Suggests the notion of left or right brained people is wrong
Lesley Rogers - Lateralised Chickens
Lateralised chickens could find food whilst watching for predators, but normal chickens couldn’t
Lateralisation vs plasticity
Lateralisation allows 2 tasks to be performed simultaneously with greater efficiency
Neural Plasticity could be seen as adaptive, following illness or trauma
Split-brain Support - Gazzaniga
Split brain ppts perform better than connected controls on certin tasks, such as spotting the ‘odd one out’
In the normal brain, LH cognitive strategies are ‘watered down’ by the inferior RH
Supports Sperrys findings that the left and right brain are distinct
Sperry - Generalisation Issues
Causal Relationships are hard to establish
Sperrys split-brain epileptic ppts compared to neurotypical group
Unique features could be due to epilepsy rather than the split brain
Sperry - Ethics
Op not performed for purpose of research
Procedures explained, full consent
Trauma of the operation may mean ppts did not fully understand implication
Subject to repeated testing over a lengthy period - causing stress
Sperry - describe what you see findings
RVF - could describe what they see, demonstrating the superiority of the left hemisphere
LVF - could not describe what was shown ‘nothing present
Sperry - tactile tests findings
Right hand - describe verbally what they felt, could identify object, could identify similar object
Left hand - could not describe verbally what they felt but could identify a similar object
Sperry - drawing task findings
RVF - right hand would draw the picture, but was never as clear as the left hand
LVF - Left hand would consistently draw clearer and better pictures
FMRI
Measure brain activity whilst a person is performing a task
Detects radiowaves from changing magnetic fields
Enables researchers to detect which regions of the brain are rich in oxygen and are active
Electroencephalogram - EEG
A record of tiny electrical impulses produced by the brain’s activity
By measuring characteristic wave patterns, the EEG can help diagnose certain conditions of the brain
Event-related Potentials (ERPs)
The electrophysiological response of the brain to a specific sensory, cognitve, or motor event can be isolated through statistical analysis of EEG data
Post-Mortem Examinations
The brain is analysed after death to determine whether certain observed behaviours during the persons lifetime can be linked to structural abnormalities in the brain
FMRI - strengths
Does not rely on the use of radiation
Risk free, non-invasive and straightforward to use
Very high spatial resolution. depicting detail by the mm
FMRI - weaknesses
Expensive
Poor temporal resolution
5s time lag
May not truly represent movemet-moment brai activity
EEG - Strengths
Studing stages of sleep
Diagnosis of neurological disorders
High temporal resolution
Detect brain activity at a resolution of a single millisecond
Event-related potentials - Strengths
Addresses limitations of EEG
Increased specificity to measurement of neural processes
Excellent temporal resolution
Use of ERPs
Measure cognitive functions and deficits such as allocation of attentional resources and the maintenance of working memory
ERP - Limitations
Lack of standardisation in ERP methodology between studies
In order to estalish pure data, background noise and extraneous material must be completely eliminated
Post-Mortem Examination - Strengths
Providing a foundation for early understanding of key processes in the brain
Broca and Wernicke - used post mortem decades before neuroimaging was even a possibility
HM - examined post mortem to identify areas of damage, which could then be associated with his memory deficits
Post-Mortem Examination - Weaknesses
Issue establishing causation
Observed damage may not be linked to deficits undr review but due to unrelated trauma or decay
Ethical Issues - HM lost his memory and could not provide informed consent
Endogenous Pacemakers
The body’s internal biological clock, which regulates biological rhythms
Exogenous Zeitgebers
External cues, helping to regulate internal biological clocks
What regulate biological rhythms?
Endogenous Pacemakers and Exogenous zeitgebers
Suprachiasmatic nucleus
Main endogenous pacemaker
Lies in the hypothalamus
Linkked to areas of the brain linked to sleep and arousal
Where is the suprachiasmatic nucleus located?
Hypothalamus
Hormone which induces sleep
Melatonin
Melanopsin
A protein in the eye, sensitive to light, carries signals to the SCN to set the 24hr cycle
What can act as exogenous Zeitgebers in the absence of light?
Social cues, such as mealtimes
Where does the word ‘Circadian’ come from?
Latin
‘Circa’ - about
‘dian’ - day
Primary input to the sleep-wake cycle
Light
What else, other than light, plays an important role in the sleep-wake cycle?
Homeostasis
Why does homeostasis tell the body that there is a need for sleep?
Energy consumption
When does the homeostatic drive from sleep peak?
Late evening
When is body temp at its lowest and highest?
Lowest - early morning
Highest - early evening
When does sleep occur, relating to temperature?
Sleep occurs when the core body temperature drops
Body temperature starts to rise towards the end of a sleep cycle, promoting feelings of alertness
Siffre - cave study
Spent several extended periods of time underground
2 months in Alpa, 6 months in Texas
NO natural light
Cycle reset to 25 hours with a regular sleep/wake cycle
When he returned, he believed the date to be a month earlier than what it was
Individual differences in sleep/wake cycles - Duffy
‘morning’ vs ‘evening’ people
There may be innate individual differences in circadian rhythms, which suggests that researchers should focus on these differences during investigations
Buhr - temperature vs light and sleep
Fluctuations in temperature set the timing of cells in the body and caused tissues and organs to become active or inactive
Claimed that information about light levels is transformed into neural messages which set the body’s temperature
What happens when circadian rhythms are disrupted?
Desynchronisation
When do night workers experience a period of reduced concentration?
6am
What effect has shift work been found tyo have on health compared to those who work more typical patterns?
Shift workers are 3x more likely to experience heart disease
What did Soloman suggest that high divorce rates in shift workers may be due to?
Strain of deprived sleep and other influences such as missing out on important family events
Chronotherapeutics
How medical treatment can be administered in a way which corresponds to a persons biological rhythms
How does aspirin reduce the risk of a heart attack?
Lowers blood platelet activity
When is aspirin most effective as treatment for a heart attack?
Why?
Last thing at night as heart attacks are most likely to occur first thing in the morning
Infradian Rhythms
Last longer than 24hrs and can be weekly, monthly or annually
How long does ovulation last
16-32hrs
When does ovulation occur?
Roughly halfway through the menstrual cycle, when Oesrogen levels are at their highest
What happens after ovulation?
Progesterone levels increase in preparation for the possible implantation of an embryo
Seasonal Effective Disorder
People become depressed in winter as a lack of light results in a longer period of melatonin secretion, which has been linked to depressive symptoms
What happened to the menstrual cycle of a women who spent 3 months in a cave?
went from 28 days - 25.7 days
Why do menstrual cycles become synchronized?
Odor exposure
Menstrual Cycle Synchronisation Exp - sweat sample
Sweat samples from one group of women rubbed onto the upper lip of another group of women, despite the fact that the women were seperated, their cycles became synchronised
What do evolutionary psychologists suggest about synchronisation of menstrual cycles?
They provide an evolutionary advantage for groups of women, as the synchronisation of pregnancies means that childcare can be shared among multiple mothers who have children at the same time
What is the effect of the menstrual cycle on behaviour?
Women expressed a preference for feminised face at the least fertile stage and a preference for masculine faces at the most fertile stage
Where is seasonal affective disorder more common?
% of New Hampshire vs Southern Florida
Northern countries where the winter nights are longer
New Hampshire - 10%
Southern Florida - 2%
Ultradian Rhythms
Last fewer than 24hrs and can be found in the pattern of human sleep
Sleep stage 1&2
light sleep
Brainwave patterns become slower and more rhythmic, starting with alpha waves and progressing to theta waves
Sleep stages 3&4
Deep sleep
Slow wave sleep stages - difficult to wake
Associated with delta waves
Sleep stage 5
REM - dreaming
The body is paralysed and brain activity resembles that of an awake person
How often does the sleep cycle repeat?
Every 90 minutes
How many full sleep cycles can a person experience in a night?
Up to 5
What did Tucker find about individual differences in sleep cycles?
Evaluation?
Significant differences in duration of each stage, particularly 3&4
may be innate individual differences in ultradian rhythms
Lab setting so not due to situational variables
Lacks ecological validity
Randy Gardner - sleep deprivation experiment
stayed awake for 264hrs
Numerous problems such as blurred vision and disorganized speech
Slept for 15hrs after
and over several nights, recovered oly 25% ot total lost sleep. 70% stage 4, 50% REM
BRAC
Basic Rest Activity Cycle
What is the BRAC?
The idea that the sleep-wake cycle as a 24 hour circadian rhythm continues throughout the day with the difference being that we progressively move from a state if alertness to a state of physiological fatigue
What is an issue with evidence supporting BRAC?
It is anecdotal and lacks scientific rigour
Prodigious Violinists - BRAC study
Practice for 3 sessions a day, lasting no more than 90 minutes, with a break in order to recharge
This indicates that an ultradian rhythm exists, however these people are atypical so may not apply not everyone
Dement + Kleitman - Study showing REM sleep is associated with dreaming
EEG
Controlled for effects of caffeine and alcohol
REM sleep highly correlated with dreaming - the more vivid the more active
Waking people during REM meant they could clearly recall their dream
Which area of the brain did Phineas Gage damage?
Frontal lobe
Longitudinal Fissure
Deep groove which separates the brain into 2 hemispheres
Role of corpus callosum
Connects the 2 hemispheres of the brain, allowing them to communicate
Associations of the cerebral cortex
Higher level processes such as consciousness, thought, emotions, language and reasoning
Role of the thalamus
Sensory relay for the brain, routing all of our senses, except for smell, into other areas of the brain
Role of the limbic system
Processing emotion and memory
3 main structures in the limbic system
Hippocampus
Amygdala
Hypothalamus
Role of hippocampus
Learning and memory
Role of amygdala
Our experience of emotion and in tying emotional meaning to our memories
Role of hypothalamus
Regulates some homeostatic processes
Provides an interface between the nervous and endocrine system
Regulates sexual motivation and behaviour
Where is the hindbrain located
The back of the head, and looks like an extension of the spinal cord
What does the hindbrain contain?
Medulla
Pons
Cerebellum
Role of Medulla
Controls automatic processes of the autonomic nervous system, such as breathing, blood pressure and heart rate
Role of Pons
Connects the brain and spinal cord and is involved in regulating brain activity during sleep
Brainstem
Medulla, Pons and midbrain together
Role of the cerebellum
Recieves messages from muscles, tendons, joints and structures in our ear to control balance, coordination, movement and motor skills
What type of memories does the cerebellum process?
Procedural memories
Brain structure associated with procedural memory
Cerebellum
Location of Basil Ganglia
Base of forebrain
Structure close to and interconnected with the basil ganglia
Thalamus and cerebral cortex
Striatum
Affects motivation and reward anticipation
Term meaning ‘black substance’
‘Substantia niagra’
Substantia niagra
Meaning ‘black substance’
Appears darker than surrounding brain tissue, plays a role in reward seeking and addiction
Role of putamen
Learning motor skills
Role of caudate nucleus
Associative learning and in learning to inhibit certain actions
Structure thought to be involved in controlling ones own actions
Basil ganglia, thalamus and cerebral cortxe
Which structures does the forebrain contain?
Cerebral cortex
Pituitary Gland
Thalamus
Structure consisting on the medulla, pons and midbrain
Brainstem
What are hormones secreted into?
Bloodstream
Effects of hormones compared to NTs
Slower to take effect but are longer lasting
What controls hormone regulation?
Interactions between the hypothalamus and the pituitary gland
Where is the pituitary gland located?
Descends from the hypothalamus at the base of the brain and acts in close association with it
Master gland
Pituitary gland
Why is the pituitary gland referred to as the master gland?
It’s messenger hormones control all the other glands in the endocrine system
Where is the thyroid gland located?
Neck
What hormones does the pituitary gland release
Growth hormones, endorphins and other hormones which regulate fluid levels in the body
2 disorders resulting from the thyroid gland producing too much thyroxine
Hyperthyroidism
Graves disease
Location of the adrenal glands
On top of the kidneys
Role of adrenal glands
Secrete hormones involved in the stress response, such as adrenaline and noradrenaline
Role of pancreas
Secretes hormone that regulates blood sugar levels: insulin and Glucagon
Role of Gonads
Secrete sexual hormones which are important in reproduction
Mediate both sexual motivation and behaviour
Male gonads
Testes
Female gonads
Ovaries
Pineal Gland
Small pea shaped gland in the brain, involved in the production and regulation of melatonin
Parathyroid gland
Lies behind the thyroid gland and produces and regulates parathyroid hormone, which regulates the body’s minerals calcium and phosphate
Thymus Gland
Located in the centre of the chest
Produce progenitor cells, which mature into T-cells, important in the immune response
What does the hypothalamus release in response to stress?
Corticotrophin-releasing factor
Role of corticotrophin-releasin factor
Causes the pituitary gland to release adrenocorticotropic hormone (ACTH)
Role of ACTH
Activates the adrenal glands to secrete a number of hormones into the bloodstream, including cortisol
Role of cortisol in fight or flight
Stress hormone
Provides a boost of energy when we first encounter a stressor, preparing us to run away or fight
Negative effect of cortisol
Weakens the immune system
