Please enable JavaScript.

Coggle requires JavaScript to display documents.

Biopsychology - Coggle Diagram

- - - - Monozygotic
      - Dizygotic
- - - - Suprachiasmatic nucleus (SCN)
        
        DeCoursey et al (2000) :chipmunk:
        
        Destroyed SCN connections in 30 chipmunks then returned to their natural habitat and observed for 80 days
        
        Sleep/wake cycle disappeared
        
        Many died through predation
        
        Ralph et al. (1990), Morgan (1995) :hamster:
        
        Mutant golden hamsters bred with tau mutation - 20 hour sleep/wake cycle
        
        When brain tissue was transplanted into normal hamsters their sleep/wake cycle defaulted to 20 hours.
      - Pineal gland + melatonin
        
        Behind hypothalamus
        
        SCN supresses melatonin in response to blue light
    - - Light
        
        Retina
        
        Rods
        
        Cones
        
        Melanopsin (protein)
      - Social cues
        
        Aschoff et al (1971) - Individuals can compensate from absence of zeitgebers like light by responding to social cues instead
        
        Klein & Wegmann (1974) - circadian rhythms adjust quicker if travellers went outside more at destination (and were exposed to social cues)
        
        Skene & Arendt (2007) - Circadian rhythm of blind people same as those of sighted - argument for social cues, but most likely due to light exposure (and aspects eye-SCN system that don't depend on visual perception)
    - - Peripheral oscillators, complexity and nuance
        
        Independent, but influenced by SCN
        
        Pancreas
        
        Skin
        
        Lungs
        
        Liver
        
        Damiola et al (2000) - changing feeding patterns in mice altered liver circadian rhythm by 12 hours, but left SCN rhythm unaffected
      - Interactionist system
        
        Endogenous pacemakers cannot be studied in true isolation
        
        Even Siffre's cave study had exogenous zeitgebers (artificial lamp) :bulb:
      - Campbell & Murphy (1998) :flashlight:
        
        15 participants, woken at various time and light pad shone on backs of their knees
        
        Sleep/wake cycle altered by up to 3 hours
        
        Light doesn't rely on just the eyes, but is a powerful zeitgeber
      - Touitou et al. (2017)
        
        Artifical light exposure disrupts circadian rhythm
        
        Blue light from LEDS :large_blue_circle: :bulb: supresses melatonin
        
        long term contributions to cardiovascular & mood disorders and depression
      - Vetter et al. (2011)
        
        5 week study period
        
        Blue light vs warm light
        
        Warm light synchronised circadian rhythms with natural light of dawn as it advanced 42 mins over course of study
        
        Blue light group did not adjust and synchronised to office hours
      - Burgess et al. (2003) :airplane: jet lag
        
        3 conditions of light prior to an East - West flight, aimed at shifting their sleep wake cycle by 1 hour/day over 3 days
        
        Continuous bright light ( = 2.1 hours shift)
        
        Intermittent bright light ( = 1.5 hours shift)
        
        Dim light ( = 0.6 hours shift)
        
        Continuous group felt sleepier 2 hours earlier and woke 2 hours earlier, pre-entraining their patterns to the local time
  - - - Hormonal
      - Sleep-wake
      - Temperature
        
        36 degrees at 4:30am
        
        38 degrees at 6pm
        
        Small drop between 2-4pm
        
        Sleep occurs when temp. drops, and rises in final hours of sleep to promote awareness
    - - 179 days (6 months) in cave with no natural light or clocks :red_cross: :timer_clock::sunny::red_cross:
      - Maintained 25 hour sleep-wake cycle despite absence of social cues, but needs entrainment for 24 hours
      - Critique: Artifical lights were used and Czeisler et al (1999) claims that without this confounding variable the rhythm is precisely 24 hours
      - Cave stays
        
        1962 - 61 days :mountain:
        
        1972 - 179 days :flag-us:
        
        1999 - 76 days :flag-fr: Exploring effects of age (up to 48 hours)
    - - Benefits of research
        
        Productivity
        
        Effectiveness of drug treatments Bonten et al. (2015) :pill:
        
        Chronotherapeutics
        
        Aspirin most effective at night for prevention of heart attacks
        
        Safety + Heath
        
        Bolvin et al (1996)
        
        Circadian 'trough'
        
        Accidents more likely approx. 6am
        
        Knutsson (2003) - Shift workers 3 x more likely to develop heart disease compared with normal workers
        
        Counterpoint - Solomon (1993) :red_cross:
        
        Correlation-causation of shift work research
        
        E.g. high divorce rates in shift work a result of missing family event, not biological factor
      - Impact of disrupted sleep wake cycle and impacts on jet lag/shift work
        
        Increased anxiety
        
        Decreased vigiliance
      - Individual differences :red_cross:
        
        Make research difficult to generalise
        
        Morning Larks vs Night Owls (Duffy et al. 2001)
      - Wolfson & Carskadon (1998) suggestion to shift school day 2 hours :school:
        
        :arrow_up: academic and behavioural performance
        
        Teenage chronotype
        
        Impractical
      - Folkard et al (1985) Strong free running circadian rhythm :check:
        
        12 pps in a cave for 3 weeks
        
        Clock set for 11:45pm and 7:45am rise
        
        Clocks were unknowingly adjusted to a 22hr day
        
        Only 1 pp managed to adjust to new rhythm
      - Buhr et al. (2010) :thermometer:
        
        Temperature controlled body clock, rather than light?
        
        Found fluctuations in temp. set timing of cells in body causing them to become active or inactive
      - Hughes (1977)
        
        Cortisol patterns changed in 4 pps in Antarctic winter (no light for 3 months)
        
        Usually peak in morning, lowest at night :arrow_right: Peak at noon
        
        Arctic research found no such change :red_cross:
  - - - Tucker et al. (2007)
        
        Although non-biological factors determine sleep patterns too e.g. sleep hygiene
        
        11 consecutive days in tightly controlled sleep environment
        
        Large individual differences which suggest in part biologically determined sleep cycles
    - - 90 min sleep cycle continues during the day via
        
        Alertness
        
        Fatigue
      - Examples of morning and afternoon chunking - Morning 9.00-10.30 & 10.30-12.00
      - Ericsson et al. (2006) :violin:
        
        Elite performers utilise 90 min bouts of intense practice
        
        Frequent naps to recover from practice
        
        Patterns observed in other musicians, writers and athletes :pen: :musical_note: :sports_medal:
  - - - Menstrual cycle
        
        Stern & McLintock (1998) - Synchronistation through pheremones
        
        29 women with irregular periods
        
        cotton pads left under arm for 8 hours as various stages of menstural cycle of 9 donors
        
        Pads treated with alcohol and frozen
        
        On day one pads from start of menstrual cycle rubbed on upper lip of other 20 women
        
        68% experienced changes that brought cycle closer to odour donor
        
        Evolutionary advantage to synchronisation of fertility? :check:
        
        Penton-Voak et al (1999) mate choice variation during menstruation
        
        Preference for masculine face during ovulation
        
        Preference for feminine face for long-term relationship
        
        Trevathan et al. (1993) failed to replicate findings :red_cross:
        
        Multiple confounding factors influence menstrual cycle :red_cross: (methodological)
        
        diet
        
        stress
        
        exercise
      - Seasonal affective disorder
        
        DSM-5 classified mental disorder
        
        Low mood and lack of interest
        
        Related to lack of light and melatonin production :arrow_up:
        
        Also influences serotonin production
      - Blood pressure & heart rate
        
        Halberg et al. (2002) reported 7 day rhythms of BP and HR in humans
        
        Evidence is poor to match the 7-day a week cycle despite changes in activity levels and some hormonal profiles
      - Lunar cycles :first_quarter_moon:
        
        Arliss et al. (2005) - demonstrated it was a subjective association that more babies were born during full moon (midwife's tale)
        
        Vance (1995) persistent belief that lunar cycles alter behaviour - but no consistent evidence that this is a causal relationship (Foster & Roenneberg, 2008)
- - - - Maguire et al. (2000)
        
        Taxi drivers with 'The Knowledge' vs control
        
        :arrow_up: grey matter posterior hippocampus
      - Mechelli et al (2004)
        
        Bilingual vs monolingual controls
        
        :arrow_up: parietal cortex
    - - New synaptic connections
      - Unmasking of secondary neural pathways
      - Doidge (2007)
        
        Reformation of blood vessels
        
        Recruitment of homologous areas on other side of brain
        
        Axonal sprouting
  - - - Right - visuo-spatial processing (synthesiser)
      - Left - language centres (analyser)
      - Centre - Corpus callosum
    - - Sperry and Gazzaniga (1967)
      - Evaluation
        
        Gazzaniga (1998) :red_cross:
        
        Although damage to LH worse for language than damage to RH, early discoveries now disconfirmed by later research
        
        Turk et al. (2002)
        
        Case study of J.W.
        
        Developed ability to speak about info presented to left or right hemisphere
        
        Andrewes (2001) :red_cross:
        
        Small sample sizes
        
        Other confounding physical disorders e.g. epilepsy creates a generalisation issue
        
        Incomplete comissurotomy
        
        Sperry - Left brain and Right brain are 'distinct' :check:
        
        Luck et al. (1989)
        
        Split brain patients better than controls on certain tasks
        
        Split brain identifying 'odd one out'
        
        Kingstone et al. (1995)
        
        LH's cognitive skills 'watered down' by inferior RH skills
    - - Rogers et al. (2004) :check:
        
        Limited support of increased neural capacity
        
        Domestic :chicken:
        
        Enhances efficiency by allowing 2 things to be done at once
        
        Weak support? - Validity?
      - Immune system function
        
        Tonnessen et al. (1993) :check:
        
        Small sig. relationship between handedness and immune system disorders
        
        Morfit & Weekes (2001) :check:
        
        Left handers = :arrow_up: immune system disorders
        
        Similar/same genetic processes involved in lateralisation & immune function
      - Lateralisation changes with age
        
        Szaflarski et al. (2006) :check:
        
        :arrow_up: lateralisation of language through childhood/adolescence
        
        :arrow_down: lateralisation after 25 for each decade
        
        Other hemisphere compensates for age-related functional decline?
      - Nielsen et al. (2013) :red_cross:
        
        Brain scans of over 1000 between 7-29 yo
        
        Certain people used certain hemispheres for certain tasks
        
        No 'dominant' side
        
        :red_cross: LH as analyser and RH as synthesiser is an oversimplification
  - - - Occipital lobe
        
        Visual area/cortex
        
        Contralateral visual fields
      - Temporal lobe
        
        Wernicke's area
        
        Petersen et al. 1988
        
        Brain scans
        
        Reading task - Broca's aphasia
        
        Listening task - Wernicke's area
        
        Language comprehension
        
        Left hemisphere
        
        Wernicke's aphasia
        
        Fluent but incomprehensible speech
      - Parietal lobe
      - Frontal lobe
        
        Motor area/cortex
        
        Dougherty et al. (2002) :check:
        
        Cingulotomy for 44 with OCD check in after 32 weeks
        
        14% partial response
        
        33% successful response
        
        :Check: Review by Buckner and Petersen (1996) Different areas of prefrontal cortex for
        
        Semantic memories
        
        Episodic memories
        
        Broca's area
        
        Speech production
        
        Left hemisphere
        
        Broca's aphasia
        
        difficulty producing fluent speech
        
        speech is slow
        
        speech has missing words and/or poor grammar
        
        :red_cross: Fedorenko et al (2012)
        
        Area for language tasks
        
        2 distinct areas within Broca's area
        
        Area for demanding cognitive tasks (maths)
        
        Bavelier et al. (1997) :red_cross:
        
        variability in patterns of activation when reading
        
        Activity observed in right temporal lobe, left frontal, temporal and occipital lobes
    - - :check:Clinical case study research demonstrates damage to specific areas of the brain and subsequent loss of function
        
        Wernicke
        
        Wearing
      - :red_cross: Case studies are not replicable, mri scans of these has been seen in multiple regions - what is truly responsible
      - :red_cross: Some functions are highly localised (motor/somatosensory). Some are not localised (consciousness). Localism vs holism is therefore function dependent. There is also no truly independent area of the brain.
      - :check: Modern brain scanning techniques support older research on language centers
      - :red_cross: Lashley (1950) Equipotentiality
      - :red_cross: Dick & Tremblay (2016)
        
        Only 2% of modern researchers believe language is completely controlled by Broca and Wernicke's areas
        
        Advances in technology e.g. fMRI suggest language is distributed more holistically across cortex
        
        Including right hemisphere
        
        Subcortical regions e.g. thalamus
- - - - Cerebral cortex
      - Two-hemispheres
  - - - Parasympathetic
        
        Rest
        
        Digest
      - Sympathetic
        
        Fight
        
        Flight
    - - Transmits information from receptors in sense organs :arrow_right: CNS
      - Receives information from CNS directing muscle action
- - - - Synaptic pruning - (Gopnik et al., 1999) at 2-3 yo, 15,000 synaptic connections per neuron are pruned down
      - https://www.youtube.com/watch?v=0S0jKbh6R1I
    - - Maguire et al. (2000) :taxi:
        
        Positive correlation of time in job and degree of structural change
        
        Larger hippocampus of those with the 'knowledge' than matched control group
      - Draganski et al. (2006) :male-doctor:
        
        Brain imaging 3 months before and after final exams of medical students
        
        Learning induced changes in parietal cortex and posterior hippocampus
      - Boyke et al. (2008) :juggling:
        
        60 year olds taught to juggle
        
        Increases in grey matter in the visual cortex, which reversed when practising stopped
      - Davidson et al. (2004) :peace_symbol:
        
        8 practitioners of meditation vs 10 student volunteers with no previous meditation experience
        
        During meditation electrodes picked up significantly more gamma wave activity in experienced practitioners. This was the case before they even started meditating
        
        Meditation changes not only short term but permanent changes in brain activity
      - Kempermann et al. (1998) :mouse2: :house:
        
        Increased neurons in hippocampus of rats living in complex environments vs laboratory cages
        
        Hippocampus associated with new memory formation and navigating from one location to another
      - Kuhn et al. (2014) :computer:
        
        Super mario players 30 min/day for 2 months vs control
        
        Significant increase in grey matter in cortex, hippocampus and cerebellum
        
        Increased synaptic connections in brain areas involved in spatial navigation, strategic planning, working memory and motor performance
    - - 'Negative' plasticity
        
        Medina et al. (2007) :red_cross:
        
        Prolonged drug use leads to poorer cognitive function later in life & increased risk of dementia
        
        Potential negative behavioural consequences
        
        Ramachandran & Hirstein (1998) :red_cross:
        
        Phantom limb syndrome in 60-80% of amputees
        
        Due to cortical reorganisation of somatosensory cortex
      - Age and plasticity
        
        Plasticity reduces with age (Huttenlocher, 2002), but might be lifelong
        
        Bezzola et al. (2012) :golf:
        
        40-60 years old completed 40 hours of golf training
        
        fMRI showed increased activity in motor cortex of novice golfers compared to controls
        
        Elbert et al., (2001) - capacity for neural reorganisation far greater in children than adults (who need far more practise to create change)
      - Tramontin & Brenowitz (2000) - Seasonal changes :fallen_leaf:
        
        SCN shrinks during spring and expands in autumn
        
        Seasonal plasticity research is extensive in songbirds :bird:, might not be the same in humans
    - - Secondary neural pathways are unmasked/activated (Doidge, 2007) to maintain function
        
        Axonal sprouting - growth of new nerve endings which connect with other undamaged nerve cells to create new neuronal pathways
        
        Denervation supersensitivity - similar axons become aroused to a higher level to compensate for damaged/lost neurons. Negative consequence of oversensitivity = pain
        
        Recruitment of homologous areas in opposite hemisphere - e.g. equivalent of Broca's in r.hemisphere. Function can return over time.
        
        Neuronal unmasking (Wall (1977) dormant synpases are unblocked by a higher rate of input
        
        Stem cells - implanted stem cells directly replace injured cells or secrete growth factors that 'rescue' damaged cells
      - Evaluation
        
        Real world application :check:
        
        Understanding processes (e.g. axonal sprouting) improves neuro-rehabilitation
        
        Constraint-induced movement therapy
        
        Cognitive reserve (Schneider et al., 2014) :check:
        
        Time in education improves 'cognitive reserve' and chances of functional recovery
        
        40% of those who achieved a disability free recovery (DFR) after traumatic brain injury had more than 16 years in education
        
        Those with less than 12 years in education only 10% achieved a DFR
        
        Banerjee et al (2014) :red_cross:
        
        Treating people with total anterior circulation stroke (TACS) with stem cells - all participants recovered vs 4%
        
        Only 5 participants and no control group
        
        Animal studies support - Tajiri et al (2013) :mouse:
        
        Rats with brain injury received transplanted stem cells vs control
        
        Development of new neuronal cells not evident in control
        
        Stem cell infusion led to migration of stem cells to injury site and growth of neuron-like cells