Biopsychology: Evaluation Flashcards
Localisation of Function AO3
+ aphasia studies: evidence for functions of Broca’s and Wernicke’s areas comes from discovery that damage to these areas results in different types of aphasia, Broca’s aphasia is impaired ability to produce language, Wernicke’s aphasia is impaired ability to understand language
+ case studies: Phineas Gage accident iron rod went through frontal lobe, change in his personality seen
- Lashley’s idea of equipotentiality: studied how rats learnt maze, removing 10-50% of different areas in cortex, no area more important than another to ability to learn maze, process appeared to require every part, not just one, human brains more complex, language
- early research relies on case studies: Broca case study on man who could only say ‘tan’, after death Broca found damage to what now called Broca’s area, concluded this area controls speech production, not generalisable, unique situation
Lateralisation AO3
+ increases neural processing capacity: leaves other hemisphere to do separate function, little empirical evidence of any advantage, Rogers et al found in chickens lateralisation associated with enhanced ability to perform two tasks simultaneously, finding food and vigilance for predators
- relationship between lateralisation and immune system: mathematically gifted have superior right-hemisphere skills and more likely to be left handed and have problems with immune system, Tonnessen et al (1993) found small but significant relationship between handedness and immune systme disorders, suggests same genetic processes that lead to lateralisation may also affect development of immune system
- doesn’t stay the same throughout life: lateralised patterns in young switch to bilateral in older, Szaflarski et al (2006) found language lateralisation more to left with age but decreases after 25
Split Brain Research AO3
- unrepresentative sample: epileptic prior to surgery, can’t be generalised to neurotypical, 11 people
- language may not be restricted to left hemisphere: damage to left worse than right, case studies refute this, J.W. developed capacity to speak out of right hemisphere, can speak about stimuli presented to both visual fields
+ high degree of control: stimuli shown for very short duration, operationalises IV, isolates image in each hemisphere, patient doesn’t have time to look from side to side
Plasticity AO3
+ human studies: Maguire et al (200) found no change to hippocampus in who failed to qualify or in group, all trainees significantly better at memory tasks with London landmarks than the control group, high ecological validity true memory test, low population validity, sample of right handed males aged 30-60.
+ animal studies: Kempermann et al (1998) found evidence of increased number of new neurons in brains of rats in complex environments compared to in lab cages, increase in neurons in hippocampus, associated with formation of new memories and ability to navigate
- reduces with age: greater natural tendency for reorganisation in childhood, constantly adapting to new experiences and learning, Bezzola et al. (2012) found 40 hours of golf training produced changes in neural representation of movement in ps aged 40-60, observed reduced motor cortex activity in novice golfers compared to control, more efficient neural representations after training
- can sometimes have maladaptive behavioural consequences: prolonged drug use shown to result in poorer cognitive functioningand increased risk of dementia later in life (Medina et al. 2007), 60-80% of amputees develop phantom limb syndrome, unpleasant, painful, due to cortical reorganisation in somatosensory cortex (Ramachandran and Hirstein, 1998).
Functional Recovery AO3
+ link between educational attainment and functional recovery: Schneider et al (2014) shown highly educated people make better recovery from brain injury than, 769 patients who experienced moderate to severe traumatic brain injury, found 39.2% with 16+ years of education achieved DFR after year, 9.7% with <12 years of education achieved DFR, could be due to cognitive reserve, correlational, intervening variable such as wealth and access to healthcare.
+ real world application to therapy: should be encouraged to practice ability that is impaired, with Broca’s aphasia should have speech therapy, promotes recruitment of homologous areas, stroke in left hemisphere should have physiotherapy for right half of body
- age differences: commonly accepted view functional recovery reduces with age (Huttenlocher, 2002), only option following traumatic brain injury beyond childhood is to develop compensatory behavioural strategies (seeking social support, developing strategies to deal with cognitive deficits), studies have suggested abilities commonly thought to be fixed in childhood can still be modified in adults with intense retraining
Fight or Flight AO3
+ real world applications: use of benzodiazepines and beta-blockers as drug treatments, stress inoculation therapy and biofeedback in management of stress-related conditions
- positive behaviours: Von Danwans et al (2012) challenge view that men only respond with fight or flight and women tend and befriend, found acute stress leads to greater cooperation in both men and women, explains human connection in times of crisis
- doesn’t tell whole story: Gray (1988) argues first phase is to avoid cofnrontation, most animals display freeze response where animal is hyper-vigilant, adaptive advantages for humans as it focuses attention and looks for new info to make best response
fMRI AO3
+ high levels of replicability (can be done over again on anyone, non-invasive, same visual stimuli, images can be compared to see whether has particular function)
+ shows localisation of function (eg if reading something Broca’s area becomes active and shows as red)
- isn’t direct relationship (measures changes in blood flow, isn’t direct measure of neural activity)
- doesn’t look at brain as whole (overlooks networked nature of brain activity, focuses only on localised activity, communication aamong different regions it most critical to mental function)
Post-Mortem Examinations AO3
+ more detailed (examine anatomical and neurochemical aspects in more depth, examine deeper regions eg hippocampus and hypothalamus)
+ further understanding of mental illnesses (Harrison (2000) claims they have played part in understanding of sz, discovered structural abnormalities and evidence of changes in neurotransmitter systems associated with disorder)
- other factors may be at play (die in variety of circumstances and varying stages of disease, can influence post mortem brain, length of time between death and exam, drug treatments and age are confounding influences)
- retrospective approach (unable to follow up on anything that arises concerning relationship between abnormalities and cognitive functioning)
ERP AO3
+ continuous measure of processing (possible to determine how processing affected by specific experimental manipulation, eg during presentation of different stimuli)
+ measure processing in absence of response (make it possible to monitor covertly processing of particular stimulus without requiring person to respond)
- small and difficult to pick out (requires large number of trials to gain meaningful data, limitations on types of questions reading can answer)
- only sufficiently strong voltage changes recorded (important electrical activities occuring deep in brain not recorded, generation of ERPs restricted to neocortex)
EEG AO3
+ high temporal resolution (accurately record when activity to nearest millisecond, useful for detecting response to stimuli, used to detect and diagnose epilepsy and brain tumors and see if patient is brain dead)
- low spatial resolution (activity can be picked up by neighbouring electrodes, not useful for pinpointing exact sources, can’t distinguish between activities originating in different but closely adjacent locations)
- electrodes on outside of skull (detect activity in superficial regions not deeper regions, can be implanted in non-humans, not ethically permissable for humans)
Circadian Rhythms AO3
+ link between biological factors (Baehr et al (2001) questionnaire about sleeping preferences, found large individual differences, reflected in real differences in circadian rhythms in body temp, morning types had minimum temp earlier, correlation could be extraneous variable of exercise)
+ case study (Michael Siffre cut himself off from world, slept when tired, turned lights on when awake, recorded hours slept and body temp, sleep wake cycle extended to 25-32 hours, body temp maintained 25 hours)
- methodology of early research (ps isolated from variables eg clocks, radio, daylight, not isolated from artificial light, Czeisler et al (1999) altered ps rhythms down to 22 and up to 28 with artificial light
- temperature may control body clock (light may be trigger, SCN transforms info about light into neural messages that set body temp, small changes in temp can send powerful signal to body clocks)
Infradian Rhythms AO3
+ affected by endogenous and exogenous cues (Russell et al (1980) collected sweat from one group of women and placed on lip of other group, kept separate, menstrual cycles became synched, high internal validity due to control of extraneous variables as kept separate)
+ menstrual cycles influences mate choices (Penton-Voak et al (1999) suggests mate choice varies across cycle, preference for slightly feminised faces when picking for long term, ovulatory phase preference for masculinised face)
Ultradian Rhythms AO3
+ lab experiment (Dement and Kleitman studied ps wearing electrodes in lab, woken at different stages asked to recall dream, eye movements measured, cycles length differed between individuals but consistent, 79.6% awakenings from non-REM sleep no dream recall, high internal validity, weren’t told stage or eye movements, reduces demand characteristics)
+ Tucker et al (2007) (studied ps over 11 days and nights in controlled environment, measured sleep duration, time to fall asleep, length of each stage, large individual differences and differences consistent)
Endogenous Pacemakers AO3
+ Stefan and Zucker (1972): measured when rats ran on wheel and drank water, 12 hours of light and dark, group with no SCN had no circadian rhythm and no difference in activity, control group had more activity in night, group with no retinas maintained activity at night, high internal validity due to operationalisation, SCN only part harmed, used computer to measure activity
+ Michael Siffre: cut himself off from world, slept when tired, turned lights on when awake, recorded hours slept and body temp, sleep wake cycle extended to 25-32 hours, body temp maintained 25 hours
Exogenous Zeitgebers AO3
+ Vetter et al (2011) (changed light temp from 4000K to 8000K, continuously measured sleep wake and activity rest behaviour using sleep logs and actimitry watches, control group woke up with sunrise on days off, experimental group woke up in time for work on days off, high internal validity and ecological validity, use of actimitry watches and in workplace for 8 hours, high mundane realism as in usual workplace)
