Biopsychology Flashcards
Motor cortex
Back of frontal lobe in both hems
Controls volun behav
Left hem controls movement in right side v.v.
Damage = loss of fine control
Somatosensory cortex
Processes info e.g., heat, pressure and touch
In both hems separate from motor by sulcus
Each part = allocated area - some = m than one
Visual cortex
If seen in left visual field processed in right hem v.v.
In occipital lobe
Damage in left hem = blindness in right eye v.v.
Auditory cortex
Temporal lobes
Process auditory info
Perception of sounds in environment signal from a.c. to other areas to process high level info
Broca’s Area
Lang processing
Left hem
Found area for speech production
Damage = aphasia = slow laborious speech - lacks fluency
Wernike’s Area
Language comprehension
Did research into patients who could speak ok but lacked ability to understand & comprehend speech
Language = fluent but meaningless
Case Studies
Clive Wearing had procedural and semantic no episodic
Brain Scan Evidence
Peterson et al (1988)
Used brain scans to show Wernike’s area = active in reading task - did functions
Tulving et al (1994)
Revealed semantic and episodic = dif areas of pre frontal cortex
Neurological Study
Dougherty et al (2002)
Reported on 44 ppl w/ OCD had eingulotomy at post surgery follow up = 32 weeks 1/3 met criteria for positive response & 14% for partial response
Holistic Theory
Lashley
Removed areas of cortex (10-50%) in rats learning a maze & found isn’t 1 section that = m NB - need whole cortex
Plasticity
When brain = damaged & a func = compromised/lost rest of the brain reorgs self to recover func - suggests not stuck in order
CNS
Made of brain: cerebral cortex what allow high level functioning = 2 hems
Spinal cord: extension of the brain - reflex actions
PNS
Transmits messages to and from the CNS
Subdivided into ANS & SNS
ANS
Governs vital function e.g., breathing, stress, heart rate and digestion
Sub divided into sympathetic and parasympathetic
Sympathetic = fight / flight - increased heart rate = for action
Parasympathetic = returns to resting state = rest and digest - blood goes back to digestion
SNS
Controls muscle movement
Receives info from sensory receptors
Endocrine System
Controls vital function
Slower than NS = m effective = widespread
Done via glands - uses hormones as chemical messengers
Pineal Gland
Releases melatonin
Responsible for NB bio rhythms e.g., sleep wake cycle
Thyroid Gland
Releases thyroxine - metabolism
Testes
Testosterone
Male sex characteristics
Muscle growth
Ovaries
Oestrogen
Reproduction and menstruation
Pituitary Gland
Controls and stimulates hormone release in other glands
Controlled and stimulated by the hypothalamus
Adrenal Gland (medulla)
Adrenaline and noradrenaline
Fight / flight response
Adrenal Gland (cortex)
Cortisol
Stimulates glucose release = energy and immune system
Glands and Hormones
Behaviour as a result of hormones
Glands secrete into blood - helps growth etc can increase / decrease cell processes
Fight / flight
Stress response system = acute / chronic stressors
Co-ord by hypothalamus - detects threat
= arousal of the ANS - SNS - stress hormone - F/F - sympha adrenal medullary system (SAM) ANS - PNS - normal
SNS & SAM = sympathomedullary pathway
Physiological changes = arousal for f/f acute response = automatic
PNS & SNS = antagonistic
Behaviour not limited to 2 responses (f/f AO3)
Gray (1988) doesn’t take into account freezing = hyper vigilant until decide correct response
Doesn’t fully explain complied cognitive and biological factors
Doesn’t fully explain females (f/f AO3)
Taylor et al (2002) adopt a tend & befriend tactic = m likely to protect offspring and make alliances
F/f = limited bc doesn’t explain
M recent research = beta bias assumes women respond same as men
Fight / Flight negative impact on health
Modern life don’t need to run so high blood pressure and flow can damage heart and lead to heath disease
= maladaptive now
Motor Neuron
Short dendrites and long axon
Connect CNS to effectors in CNS
Control muscle movement
When stimulated release neurotransmitters to receptors on muscles - trigger response = movement
Relay Neuron
Short dendrites and short axon
Connect motor and sensory / other relay
In brain and spinal cord
Allow sensory and motor neurones to communicate
Fast reflex bypass brain
Sensory Neuron
Long dendrites and short axon
In receptors e.g., eyes, ears, skin
Carry nerve impulses to spinal cord and brain and translate to sensations e.g., vision
Don’t all reach brain some stop at spinal cord
Quick reflex action
Firing of a neuron
Resting neuron = negatively charged when activated by stimulus in cell =positively charged for split second
Action potential = passing through when positively charged allows electrical impulse to move through
Synaptic Transmission
Process = 1 neuron communicates with another and sends information down axon as an electrical impulse = action potential - when at end need to - to neuron / tissue
Process of Synaptic Transmission
Vesicles release neurotransmitters to synaptic cleft
Neurotransmitter binds to receptor and activate
Excess = taken up by presynaptic neuron
Enzymes released to breakdown remaining
Vesicles replenished with new and reused neurotransmitter
Neurotransmitters
Chemical messengers found in brain, spinal cord and some glands
Transmit sign, across synaptic cleft - communicates between neurons
Only certain ones fit receptors = specialised function
Excitation
Increased likelihood of something happening
E.g., adrenaline causes excitation - increases neurons positive charge makes firing m likely
Inhibitation
Decreased likelihood of something happening
E.g., serotonin inhibits neighbouring neurons = - charge = less likely
Summation
Effect of neurotransmitters at synapse depends on number of factors:
1. How much = released
2. Action on postsynaptic neuron e.g., E/I - brings closer/further from AP threshold
Inputs at same time add together if E trigger AP and transmission of nerve impulse = summation
Temporal: 2 / m APs arrive in rapid succession along single presynaptic neuron and add together
Plasticity
Brains apparent ability (in infancy) to change & adapt physically & func
In infancy brain grows - peaks 15,000 synaptic connections at 2-3 (Gopnick 1999) = 2x adult brain
Originally thought that brain moves out of critical period & changes stop
Now think learning and experience changes the brain
Synaptic Pruning
As we age unused connections = deleted and used = strengthen
Maguire et al (2000)
Aim: investigate func of hippocampus in spatial memory
Ptps: 16 male London TD’s comp to MRI scans of 50 male non TDs
Hippocampus = bigger in TDs & volume = correlated w/ time as TDs
Function Recovery
After physical injury / trauma e.g., stroke unaffected areas comp for damage = ex of plasticity
Healthy areas take over damaged roles
= quick at start and then slows
Axonal Sprouting
Growth of new nerve endings to connect w/ undamaged nerve cells
Form new neural pathway can unmask neural pathways
Reformation of Blood Vessels
Blood vessels = refed to ensure brain funcs in affected areas
Recruitment of Homologous Areas
Sim area on opposite side = used
E.g., Broca’s Area = damaged so Wernike’s Area carries out func
Can shift back
Case Study - P
Gabby Giffords = shot & put in waking coma
In months made progress w/ physical rehab - could walk under supervision, control 1 arm & leg, could read, understand & speak short phrases
5% of ppl recover
Individual differences
Recovery
Age
How quick = in therapy
Level of education
Seriousness
Pre-existing conditions
Whether = localised
Practical Applications
Understanding the plasticity process = contrib to neuro rehab after illness/ injury
Spontaneous recovery slows after a few weeks is physical therapy is needed to increase func movement
Electrical therapy to counter deficits in motor / cognitive func
Negative Plasticity
Brains ability to rewire can have cons
Medina et al (2007) decreased cognitive func = increased dementia risk
60-80% of amputees get phantom limb syndrome - experience sensations due to cortical reorg in somasen cortex - Ramachrandran & Hirsten
Animal Research
Early evidence of plasticity & func recovery = study by Hubel & Wise (1963) - sewed 1 eye of a kitten shut & found the visual cortex of the shut eye = active & processed info from open eye
Age & Plasticity
Func plas decrease w/ age
Ladina Bezzola et al (2012) found 40hrs of golf training = changes to the neural movement in ptps age 40-60 using fMRI observed desired motor cortex activity in novice players comp to control = m efficient after training
Cognitive Reserve
Evidence suggests that a persons education attainment may influence how well brain func adapts after injury
Schneider et al (2014) discovered M time brain injury patients spent in education increased chance of dis ability free recovery = 40% in M than 16 yrs of education and 10% if less than 12 years
Hemispheric Lateralisation
Idea that the 2 1/2s of the brain = func dif & each hem has func specialisations
Split Brain Studies
Sperry & Gazzaniga (1967) = 1st to investigate hem lat
SB patients have procedure that cuts their corpus callosum to treat severe epilepsy
Procedure
Describe: pic presented to L/R visual field & describe
Tactile: object placed in L/R hand describe / pick sim object
Drawing: pic in L/R visual field had to draw
Describe
Could describe if in R VF - L hem = lang prod
In L VF couldn’t R hem often said = nothing there
Touch Recognition
R: could verbally describe & identify with sim object
L: couldn’t describe but could guess similar object
Composite Word
If 2 words presented 1 to each VF simultaneously could select object with their left and say the word
Drawing
R: attempted = not as clear
L: better at visual motor tasks = clearer R hem = superior for motor tasks
Matching Faces
R hem = superior in facial recognition when asked to match faces processed in R hem = consistently selected
L: ignored 1/2
L hem = superior in verbal description & right in matching
Support for Hemispheric Lateralisation
Rogers et al (2004) found domestic chickens brain lat allowed them to do 2 tasks simultaneously e.g., find food & watch for predators
1 hem doing 1 and 1 the other
Positives of the Method
Used standardised procedure - ppl stare at fixed spot and shown image for 10th of a millisecond so eye can’t move image to other visual field - only one hemisphere receives so = good validity
Problems w/ Generalisation
Ideographic - SB = rare & ptps = hard to find so = small number & not easily generalisable to population
Theoretical Basis
Prompted theoretical debate about level of communication between hems in normal func & nature of consciousness
Pucetti (1988) argued we are all in 2 minds
Differences in Function Could be Overstated
Mod neuro scientists argue distinction is less clear between hems & = constant com when performing everyday tasks
Any behaviours associated with 1 can be done by the other
FMRI
Functional Magnetic Resonance Imaging
Detects changes in blood oxygen & flown as a result of neural activity
Active brain areas consume more oxygen
Produces 3D activation maps showing larger amounts of oxygen in brain areas
FMRI Evaluation
Unlike PET scans doesn’t use radiation = virtually risk free & non invasive & straight forward
High spatial resolution - mm
= expensive, have to stay still, poor temp res = 5 second lag, only measure blood flow not neurons so not what kind of activity
EEG
Electroencephalogram
Measure electricity in the brain via electrodes on the scalp, scan recording reps brainwave patterns generated from neuron action = overall account of brain activity
Used for diagnosis of conditions e.g., epilepsy chara by unusual arrhythmic patterns
EEG Evaluation
NB for epilepsy diagnosis, helped understand sleep stages, = v high temporal resolution 1 millisecond
Gen info not pinpointed to source & doesn’t distinguish between sim areas
ERP
Event Related Potentials
Isolate specific neural response associated with sensory/cognitive/motor events
Statistical averaging tech used to filter out extraneous activity so only response to stimulus = left
Triggered by specific events
Research shown ERPs linked to cognitive processes e.g., perception & attention
ERP Evaluation
Partly addresses EEG issues = m specificity in measurement of neural processes, good temp res led to widespread use of measurement of cognitive func & can identify many different types to describe precise roles
Lack of subordination in method between different studies dif to confirm findings, dif to get pure data
Post Mortem
Analysis of brain after death in psych likely bc have rare disorder & unusual deficits - damage = examined to establish cause & = comp to norm
Post Mortem Evaluation
Vital for understanding key processes - Broca & Wernike, improves medical knowledge & gens hypothesis
Causation = issue observed damage might not = cause & = ethical issues - consent before might not = informed e.g., HM no mental ability to for consent
Bio Rhythms
= any cyclical change in level of bodily chemicals / func
Circadian Rhythms
Occur over approx 24 hours
Sleep Wake Cycle
EPs: suprachiasmatic nucleus = bundle of nerve fibres above the optic chiasm, stims pineal gland to release melatonin - EZ & EP interact & melatonin wakes up
Siffre’s Cave
2 months in a cave, no tech, clock, calendar / sun
Slept & ate when body told him to
After 1st 62 days resurfaced 17th Sept thought = 20th Aug
Settled into 24hr & 30 min cycle
2nd time = 24hrs
Lacks pop val & eco val & control - had artificial light
Aschoff & Wever’s Bunker (1976)
Ptps in WW2 bunker for 4 weeks - no natural light
25-27 hr SWC 1 = 29hr - EP controls
Folkard’s Cave (1985)
12 ptps iso from natural light for 3 weeks manip clocks day = 22 hrs
No one could adjust comfy shows strength of CR = free running ?s EZ
Methodological Problems
Duffy (2001)
found some ppl = larks & others owls
Changes w/ age
Practical Application CRs
Knowledge of CR troughs (Boivan 1996) & desynchronisation helped inform workplaces how to avoid accidents caused by these e.g., Chernobyl
Research has helped decrease stress of shift work - can cause heart disease (Knutson 2003) - fixed / phase delay not advance
Czeisler (1999)
Found individual sleep wake cycles can vary 13-65 hrs also showed you can use dim light to adjust from 22-28 hrs meaning Siffre’s lamp could = confounding
Infradian Rhythms
Take longer than 24hrs to complete
SAD
Depression w/ seasonal pattern = circannual rhythm = yearly
Attributed to long periods of darkness in winter - melatonin = secreted longer so decrease serotonin
Menstrual Cycle
1st day womb lining sheds & ends before next period
Increased oestrogen levels during menstruation = ovulation
Progesterone thickens for menstruation
Entrainment
Menstrual synchrony = McClintock - 29 women w/ irregular periods
Gathered armpit sweat from 9 & rubbed on upper lip of 20
68% experienced change in cycle = more in line w/ donor
McClintock Meth Problems
Confounding variables could change bc of other factors e.g., stress, diet, exercise, chance
= small sample & reliant on self report
Trevathan (1993) failed to replicate in small samples
Evolutionary Basis (menstruation)
= good to fall pregnant same time = col care e.g., breast feeding = m likely to survive
Valid = ? By Shank (2004) as ovulating at same time have to comp for best male & resources - not synch would = adaptive
Ultradian Rhythms
Happen more than once in 24 hrs
Stages of sleep
4-5% = light sleep - muscle activity slows = occasional twitch
45-55% = breathing & heart rate slow and body temp decreases
4-6% = deep sleep = slow delta waves
12-15% = v deep sleep = rhythmic breathing, lim muscle movement, delta waves, dream
20-25% = REM sleep rapid eye movement, brainwaves speed up, dream, muscles relax, heart rate increases & breathing = rapid & shallow
Dement & Kleitman (1957)
Monitored brainwave activity of 9 ptps using EEG
REM activity correlated w/ dreaming
Replication found sim findings REM =NB
Basic Rest Activity Cycle
Suggested = 90 minute rhythm best violinists 3 seshs = 90 min / less w/ breaks
Randy Gardner
Some sleep stages = m NB
Awake for 264hrs = blurred vision & disorganised speech
Slept 15 hrs = 25% lost sleep = recovered 70% of stage 4 sleep 50% of REM & v little of the others - allows flexibility
Endogenous Pacemakers
Internal body clocks that regulate bio rhythms
SCN
Information from eye stims melatonin released
Have own regular rhythms
M NB EP
Pineal Gland
Small structure in the brain
Secretes melatonin
Regulates bio rhythms & controlled by SCN
Melatonin
SCN passes info on day length & light to PG during night releases melatonin
Induces sleep = inhibited in awake periods
Could cause SAD
Chipmunks
DeCoursey (2000) destroyed the SCN in some chipmunks
Found = more active at night & m likely to be eaten
Mutant Hamsters
Ralph - if mutant hamsters are bred w/ CR of 20hrs & their SCN is put in a normal hamster then have 20hr CR
Binkley (1977)
Chickens = v responsive to light - out hat over their eyes did not what up at dawn
Not just SCN
Body temp rhythm persists when both SCNs are removed - suggests = another
Maybe = ventromedial hypothalamus
Aldcroft (1996) spent weeks in a cave after 25 days her temp adapted 24hr rhythm but sleep = 30hr
Problem w/ Animal Studies
Gen prob
Ethical issue - chipmunks put at more risk when returned home
Does the discovery justify
Exogenous zeitgebers
External cues that may affect / entrain our bio rhythms
E.g., light on sleep wake cycle
Light
Can reset SCN plays role in s/w cycle
Also has role in controlling hormone secretion & blood circulation
Campbell & Murphy (1998)
Demoed that light may be detected by skin receptor in other areas not just eyes
15 ptps woken up at various times via light shone on the backs of their knees
Produced variation in sleep wake cycle of up to 3hrs which suggests light = powerful EZ
Social Cues
Mealtimes, radios, clocks
Human infants born w/ random s/w cycle
At about 6 weeks Cars begin
By 16 weeks = m entrained schedules imposed by mealtimes
Research w/ Blind ppl
NBance of light as a EZ - have different sleep patterns 1 man blind from birth Had CR of 24.9 hrs had to take stimulants and sedatives to set rhythm - Miles et al (1977)
Czeisler (1995) discovered some respond to exposure to very bright light w/ decreased melatonin levels - suggests = 2 pathways eyes & SCN
Campbell & Murphy Method Issues
Haven’t been replicated
May have been some light to eyes = CV
Doesn’t show effect of other EPs
Influence may be overstated
Miles et al (1997) blind man = exposed to social cues & didn’t change
Ppl in arctic regions have normal pattern even tho in summer = no dark
Interactionist
Only in extreme circums are EPs free running
Total iso studies eg Siffre = rare & lack val
In real life EP & EZ interact wouldn’t make sense to separate in research
