Biopsych

• Neuroplasticity


  Ability to adapt and change because of experience
• Cortical remapping


  Reorganise in response to injury or experience
• Neural unmasking


  Dormant or inactive neural pathways activated
• Long-term potentiation


  Strengthening neural connections
• Synaptic pruning


  Unused synaptic connections deleted
• Functional recovery


  Ability to rewire undamaged area after trauma
• Axonal sprouting


  New connections to reconnect undamaged neurons that lost function
• Denervation supersensitivity


  Nerve cells more sensitive to neurotransmitters to compensate from loss of input from other neurons
• Neurogenesis


  New neurons generate in the brain
• Equipotentiality theory


  Intact areas of brain have equal potential to take over functions of damaged area
• Increase in gray matter

  • Regions of the brain responsible for information processing
• Increase in neuroplasticity


  • Music / 2nd language
• Greater activation of gamma waves


  • In Buddhist monks - meditation
• Gamma waves


  • Cognitive processes - memory, attention, perception
• Increase in gray matter in posterior hippocampus


  • In London taxi drivers
• Infants have 2x neural connections than adults


  • Cortical remapping
• Capacity of neuroadaptation


  • Greater in children
• Changes in brains of medical students


  • Before and after exam - more gray matter, hippocampal changes
• Increase in number of new neurons


  • In rats in enriched environment - neurogenesis
• Functional recovery


  • Rats injected with stem cells near site of injury
• Unethical - lesion induction - surgery, chemicals, genetic mutations
• Denervation supersensitivity


  • In patients with Parkinson's caused by dopamine depletion
• Occipital cortex activated during non-visual tasks


  • In blind individuals
• Biorhythms


  Recurring cycles in physiological processes
• Circadian


  24 hour cycle - sleep-wake cycle
• Infradian


  >24 hour cycle - female menstruation cycle
• Ultradian


  <24 hour cycle - sleep cycle, basic rest activity cycle
• Endogenous pacemakers


  Internal biological clocks - suprachiasmatic nucleus in hypothalamus (melatonin, cortisol, temperature) (can be affected by environment)
• Exogenous zeitgebers


  External cues (light, social cues)
• Absence of external cues increased circadian to 24.5hrs


  • In Siffre study (1 month earlier)
• Hamsters circadian rhythms of 20 hr


  • SCN transferred to normal hamster - changed
• People in WW2 bunker circadian rhythms 24-25 hours

  • In Aschoff & Wever study
• Woman with 3 months in cave had shortened menstrual cycle

  • 28-25 days - in Reinberg study
• Female menstrual cycles synchronised


  • With other females through odor exposure - in Russel et al study
• Seasonal affective disorder (SAD) common in northern countries


  • Less light in winter
• Light therapy effective


  • In 80% people with SAD - in Sanassi study
• Cycles adjusted to new times

  • When clocks manipulated to be faster - in Folkard et al study
• Preference for going to bed early and rising early vice versa


  • Larks and owls - in Duffy et al study
• BRAC


  90 minutes
• Localisation of Function


  Specific mental processes and behaviours associated with different regions of the brain