Biopsychology

• what is neuroplasticity?

  - the brain's ability to change and adapt, modifying its own structure and function as a result of experience
• when does plasticity occur in the brain?

  - at the beginning of life

  
  

  - in the case of brain injury

  
  

  - through adulthood
• what is meant by positive neuroplasticity?

  - the fact we can train our minds and transform our neural pathways

  eg: proper nutrition + sleep, mental stimulation, physical exercise
• what is meant by negative neuroplasticity?

  - changes in neuronal connections in the brain that can be harmful to our internal experience + functioning

  eg: sedentary lifestyle, inadequate nutrition + sleep
• what is meant by developmental plasticity?

  - as the brain develops, simpler associations formed previously are replaced by more intricately connected neuronal structure
• what is meant by synaptic pruning?

  - when axons are removed from synaptic connections that are not functionally appropriate

  > strengthens important connections and eliminates weaker unnecessary neuronal structures
• procedure, Maguire et al?

  - researchers compared MRI scans of 16 male London taxi drivers vs 50 male non-taxi drivers
• findings, Maguire et al?

  - hippocampi of taxi drivers was larger, than the controls and size correlated with how long they had been a taxi driver

  - demonstrated plasticity of the hippocampus in response to environmental demands
• procedure, Kuhn et al?

  - compared a control group with a video game training group that was trained for 2 months, 30 mins per day, on Super Mario
• findings, Kuhn et al?

  - significant increase in grey matter in various brain areas, including cortex, hippocampus and cerebellum

  - increase NOT evident in the control group
• conclusions, Kuhn et al?

  - video game training resulted in new synaptic connections in brain areas involved in spatial navigation, working memory and motor performance
• what is meant by functional recovery?

  - the recovery of abilities and mental processes that have been compromised as a result of brain injury or disease
• what is meant by axon sprouting?

  - when adjacent axons sprout extra connections to a neuron after an axon has been damaged, replacing these connections that have been destroyed
• what is meant by neuronal unmasking?

  - when there is an increased rate of input, normally due to brain damage, in order to activate synapses that would be dormant under 'normal conditions' (input too low for them to activate)
• what is meant by denervation supersensitivity?

  - axons that do a similar job become aroused to a higher level to compensate for ones that are lost

  - can have the consequence of over sensitivity
• research by Marquez de la Plata?

  - age differences in functional recovery

  - deterioration of the brain in old age affects the extent and speed of recover, older brains = less plastic
• research by Ratcliff et al?

  - gender differences in functional recovery
• research by Schneider et al?


  - educational attainment and functional recovery

  - study of 769 patients
• outline fMRI

  - works by detecting oxygen concentration in the blood and blood flow as a result of neural activity, increased oxygen = increased activity

  - completed by a magnetic field and radio signals

  - provides a moving picture of brain activities
• outline EEG

  - involve continuous recording of electrical activity in the brain

  - electrodes placed on scalp to detect small electrical charges resulting from activity in brain

  - graphed over a period of time
• outline ERP

  - measure electrical activity in response to a specific stimulus

  - an EEG signal is time-locked to a stimulus

  - many presentations of the stimulus and their responses are then averaged together
• outline post-morgen.

  - used to establish underlying neurobiology of a particular behaviour

  - involve a detailed examination of the anatomical and neurochemical aspects of the brain after death

  - used to see where damage occurred and how this could have affected behaviour prior to death
• what is meant by biological rhythms?

  - cyclical changes in the wat the biological system behave
• what is meant by circadian rhythms?

  - last about 24 hrs, set/reset by environmental factors

  > sleep/wake cycle

  > temperature cycle

  > hormone production
• what is meant by infradian rhythms?

  - last longer than 24 hrs, can be weekly, monthly or annually

  > female menstrual cycle
• what is meant by ultradian rhythms?

  - occur over a period of less than 24 hrs

  > sleep cycle

  > feeding cycle
• what is meant by endogenous pacemakers?

  - internal 'body clocks' that regulate biological rhythms
• what is meant by exogenous zeitgebers?

  - environmental cues that help to regulate the biological clock in an organism

  > light
• what is the name of the master circadian pacemaker?

  - SCN = suprachiasmatic nucleus

  - located in the hypothalamus
• what is meant by a 'free-running' internal circadian clock?


  - the sleep/wake cycle will maintain a cycle of about 24-25 hrs even in absence of external cues
• identify 2 factors that could have significant impact on sleep/wake cycle

  - jet travel and shift work

  - cause the biological clock to become completely out of sync with the outside world
• how long did Michel Siffre spend in a cave?

  - 179 days
• what were the conditions of the cave?

  - no daylight or cues as to the day or time (exogenous zeitgebers)

  - artificial lights turned on when Siffre was awake

  - ate and slept when he desired to
• what happened to Siffre's circadian rhythm?

  - settled into sleep/wake cycle of 25-30 hrs

  - lost track of the days, believed it to be a month less
• what are the conclusions from Siffre?

  - circadian rhythms persist despite isolation from exogenous zeitgebers, suggests existence of exogenous clock

  - SCN continued to regulate sleep/wake cycle

  - external cues are important in keeping circadian rhythms in sync with the outside world
• what are criticisms of Siffre?

  - individual differences/lacks population validity

  - extraneous variables, eg: being cold

  - not isolated from artificial light, waking = light switched on which could 'reset' his body clock
• what is meant by chronotherapeutics?

  - treatment of an illness by administering a treatment at a time of day believed to be in sync with the body's natural rhythms
• what is a research study that supports the existence of monthly cycles (infradian rhythms)?

  - McClintock + Stern (1998)
• what did McClintock + Stern collect?

  - daily samples of sweat from armpits of 9 women

  - rubbed onto upper lips of another group of 20 women
• what % of women from Mc+S study respond to the odourless compound (sweat)?

  - 68%