Biopsych AO3 points

Fight or Flight 3 neg

•Beta bias - Taylor et al. (2000) – for females it’s more tend & befriend. Fleeing too readily would put her offspring at risk and so she nurtures her young & befriends other women when stressed.

•Fight or flight is adaptive if you need an energetic response…. Unlike most modern day stressors. Stress responses are commonly activated & end up giving us high blood pressure, heart disease & a suppressed immune system.

•Not limited to two responses - Gray (1988) – First phase is actually to FREEZE (a stop, look and listen response). Advantageous for making us hyper-vigilant & looking for new info to make the best response.

Localisation – Evaluation 2 neg (studies) 2 positive (2 case studies)

Individual differences in language areas

• Herasty (1997) (Beta Bias) found that women have proportionally larger Broca's and Wernicke's areas than men, which can perhaps explain greater ease of language use.

• Lashley removed areas of the cortex in rats that were learning the route through a maze. No area was proven more important than another. 

• Phineas Gage Case study, frontal lobe responsible for regulating mood

• Tan, brocas area case study found damage to brocas area after only saying tan

Evidence for Lateralisation Sperry Study explained + Findings

Sperry Study, studied patients commissurotomy and compared to controls. Comparing performance on visual and tactile tasks (using tachistoscope) to test functions of L/R hemisphere

• Drawings better on LVF (controlled by RH)

• If shown a picture, they name what it is when in RVF only. But select matching images to what’s shown in LVF

• When describing by touch, they could describe it in LVF but wild guesses in RVF.

Sperry Study Lateralisation – Evaluation 3neg 1 pos

• Lacks ecological validity (people can just shift their view)

• Low population validity, only 11 people studies with epilepsy and some had more disconnection of both hemispheres (issues generalising)

• Quasi Experiment in controlled conditions, standardised and controlled.

• Ignores effect of plasticity JW developed ability to speak about info on any hemisphere.

FMRI - Evaluation 2pos 2 neg

• Non-invasive

• High quality images shown

• Only measures bloodflow

• Poor temporal resolution - 5sec time lag

EEG - 2 pos 2 neg

• Useful in diagnosing epilepsy and understanding sleep

• High temporal res

• Very generalised info, not specific areas

• Cant identify deeper brain activity

Post mortem - evaluation 2 pos 2 neg

Vital before neuroimaging was possible

More detailed, can see deeper parts

Difficulty establishing cause and effect, cofounding variables like age and drug use

Only retrospective data collected, too late to test cognitive function

ERP 2 pos 2 neg

measures activity relating to specific task, more specific that EEG

high temporal resolution

Requires large repetitions of activity, time consuming

Can’t measure deeper brain regions

Plasticity - Evidence

Maguire - more grey matter in hippocampus for black cab drivers in comparison to control

Kuhn - compared the brains of people asked to play 30 mins a day on super Mario to a control group.  They found an increase in grey matter in brain areas like the cortex, hippocampus and cerebellum.

Hubel – sewed eye shut on kittens and found the area of the brain receiving input from this eye was still active (processing into from open eye)

Functional Recovery 2 Evidence, 1 neg

EB had left hemisphere removed at age 2 1/2. After substantial rehab language gradually recovered until at age 17 he was retested as excellent.

Human echolocation -humans sense environment from sound echoes. fMRI have shown the auditory information is processed by brain regions usually processing visual information.

Affected by environmental factors College level educated more likely to recover from traumatic brain injury (TBI). Researcher looked at US TBI database, 40% of college educated recovered, less than 10% of early school leavers.

Evaluation of Maguire study 2 neg

Cant randomly allocate due to being quasi experiment so cant controlled extraneous variables like previous hippocampus size

Cant establish cause and effect, they may have had large hippocampus previously

Circadian Rhythms 3 pos(2 support study) 1 neg

(+) Case Study Support – Siffre – shows circadian rhythms not dependent on light or social cues

(+) Morgan – Hamsters whose SCN was removed lost their nocturnal sleeping pattern. When fetal SCN was implanted, they regained their circadian rhythm. If they implanted diurnal animals SCN into the hamsters they became diurnal.

(+) Practical Applications – knowledge of adverse consequences if there is disruption i.e. due to shift work- economic implications in how best to manage worker productivity

(-) Individual (innate) differences in peoples sleep wake cycle. Vary from 13- 65 hours, morning people prefer to rise & go to bed early v. evening people

Ultradian Rhythms 1 neg 1 pos and example

(-) Individual differences in sleep patterns. Tucker et al.- stages 3&4 particularly different lengths suggesting range of contributing factors. Suggests sleep might be biologically driven, as conducted in lab study with variables controlled.

(+) Brain Scan Support – Researchers monitored sleep of 9 p’s and found evidence for the stages of sleep, including REM correlating with dreaming.

BRAC (Kleitmann) , basic,rest activity cycle

90min ultradian rhythm of alertness, explaining why athletes and musicians train in 90 min intervals

 

Infradian Rhythms 1 neg 2 pos w/example

(+) Supporting research – McClintock showed a females menstrual cycle can be changed by the pheromones of other females. Pheromones from armpits of 9 women frozen and rubbed on upper lips of p’s.

• however many cofounding variables like age and diet

(+) Practical application for jetlag: Lightbox stimulates very strong light in morning & evening. Resets melatonin levels relieving symptoms.

EXAMPLE: Seasonal Affective Disorder

This is a depressive disorder (low mood, lack of energy) with a seasonal pattern.  The symptoms seem to be triggered in the winter months and is thought to be due to the decrease in light.

Endogenous pacemakers & exogenous zeitgebers 4 limitations for theory

• Cannot be studies in isolation as it’s an interactionist explanation

• Environmental differences, these don’t have the same affect in every environment e.g. people in arctic have similar sleep patterns despite living in mostly darkness suggesting control being primary by endogenous pacemakers

• Ethics of animal studies used to back explanation, animals in Decoursey studies left vulnerable in wild after being left.

• Reductionist, factors such as age ignored highlighted by Duffy study and changes in circadian rhythm as we age