2.2 - Biopsycholgy (set D - Studying The Brain) Flashcards

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1
Q

Define spatial resolution?

A

How accurate we can be about identifying the exact location of a brain structure or activity

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2
Q

Define temporal resolution?

A

Level of accuracy in identifying the exact location of a brain activity when it took place

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3
Q

Give 4 ways of studying the brain?

A
  • FMRI - functional magnetic resonance imaging
  • EEGs - electroencephalogram
  • ERPs - event related potential
  • post mortem dissection

often approaches are combined and results compared to allow for more accurate research and utilisation of pro’s of all methods

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4
Q

Explain the method of FMRI for studying the brain?

A
  • uses magnets to detect blood flow and changes (of oxygenated blood) in the brain
  • have the patient complete tasks and detects where higher blood flow is = area is more active compared to lower activation areas with low blood supply
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5
Q

Give 2 advantages of using FRMI to study the brain?

A
  • creates a very detailed image and precisely identity’s active brain regions - good spatial resolution within 1mm (advantage)
  • Safer and less invasive compared to options like PET scans which use radiation (advantage)
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6
Q

Give 3 disadvantages of using FRMI to study the brain?

A
  • Delay between when neurones fire and when blood reaches neurones - image taken every few seconds, not live - poor temporal resolution
  • Expensive to build and operate - implications to the economy
  • participant must remain still for a clear image - reduces use in any experiment that requires movement (may not be a good option for children, ADHD or claustrophobia which can make it hard to stay still)
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7
Q

Explain the method of EEGs for studying the brain?

A
  • collection of between 22 and 34 electrodes attached to a cap and fitted to the scalp with conducive gel
  • each electrode picks up activity of an area which is displayed as a series of lines showing distinct patterns called brain waves (amplitude show brain wave intensity frequency and speed of activation)
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8
Q

Give 3 advantages of using EEGs to study the brain?

A
  • historically important in understanding brain activity in areas such as sleep and medical diagnosis
  • significantly cheaper than other techniques and is portable - allowing use when looking at movement
  • very high temporal validity - measures brain activation practically live within a resolution of mili seconds
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9
Q

Give 2 disadvantages of using EEGs to study the brain?

A
  • Poor spatial resolution - each electrode is picking up a large area of the brain - so not precise
  • only from cortex not deep within the brain
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10
Q

Explain the method of ERPs for studying the brain?

A
  • uses same equipment as the EEG (electrodes attached to scalp)
  • looks at responses to a particular stimulus and the brain activity is recorded each time - creating a smooth curve of activation by combing data in a process called statistical averaging (removes background electrical noise unrelated to the stimulus)
  • waveforms peal and dips show exactly when cognate processes in the brain happen after the stimulus is presented, gather average of activity
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11
Q

Give 2 advantages of using ERPs to study the brain?

A
  • can isolate and study individual cognitive processes taking place in the brain - EEGs record general patterns of brain activity
  • good temporal validity but poor spatial resolution (advantage + disadvantage)
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12
Q

Explain the method of post mortem direction for studying the brain?

A

brains are precisely cut after treatment (treatment done to give a firmer texture) - unusual brains (such as those associated with trauma or mental illness) are compared with a typical (healthy) brain

example is case study of TAN - who it was discovered had damage to his brocas which explained the lack of language production

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13
Q

Give 2 advantages of using post mortem dissection to study the brain?

A
  • only option before advancements in technology for scanning ext - improved knowledge and understanding of the Brian

can study the brain at a high spatial resolution (study brain at a microscopic level down to neuronal level - looking at cells)

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14
Q

Give a disadvantage of using post mortem dissection to study the brain?

A
  • not conducted on a living brain - unusual behaviour in life and damage found in dissection is correlational (possible link - can not say one thing has caused the other)
  • but can lead to hypothesis and generation of theories which can then be investigated with other experimental research using scanning technique
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15
Q

Define biological rhythms?

A

A change in the body processes or behaviour in response to cyclical changes within the environment or internal processes within the body - help us to function

3 biological rhythms

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16
Q

Outline and explain the biological rhythm - circadian rhythm?

A
  • lasts about 24 hours (happens once ever 24 hours)
  • example is the sleep-wake cycle
  • optimises our physiology and behaviour to best meet the varying demands of the day/night cycle
17
Q

Explain how biological rhythms are fine tuned and maintained?

A

Maintained through a combination of exogenous zeitgebers (external time giver) and endogenous pacemakers (our body clock)

  • exogenous zeitgebers include external factors like light and darkness and social cues - for children it can be a nightly routine like dinner and bath
18
Q

Explain the role of light (exogenous zeitgeber) in the circadian rhythm?

A
  • light provides primary input to system
  • light is first detected by the eye (sends message to the SCN in relation to brightness)
  • SCN uses information to coordinate activity of the entire circadian system by signaling pineal gland which releases melatonin causing sleepiness
  • when it starts getting lighter SCN signals to pineal gland to stop producing melatonin - causes you to wake up

Homeostasis also involved

19
Q

Explain what the SCN is?

A

Involved in circadian rhythm

  • bundle of nerves in the hypothalamus which influences sleep and wake
  • gets info from optic nerve about light/dark
20
Q

Outline a human study which supports research into the circadian rhythm - mention siffre’s cave study?

A

Siffre spent 61 days and nights underground in a cave with no exogenous zeitgebers - only influence was endogenous pacemakers

  • natural rhythm extended to over 24 hours - naturally its probably 25 hours (suggests society has constructed 24 hours)
  • thought less time had passed than it did
21
Q

Outline a problem with siffre’s experiment into the circadian rhythm?

A

case study - involving only 1 person, who was an experienced cave explorer - may not be generalisable to everyone

22
Q

Outline research into the SCN - mention DeCourseys research with chipmunks?

A

Destroyed the SCN connection in the brain of 30 chipmunks - then returned them to their natural habitat and observed them for 80 days - the sleep/wake cycle of the chipmunks disappeared (by the end of the study a considerable number had been killed by predators due to them being awake when they should have been sleeping)

  • suggests its evolutionary - in order for us to survive
  • not generalisable to humans - due to different factors eg social cues
23
Q

Outline the role of the pineal gland in the circadian rhythm?

A
  • where melatonin is made - allows SCN to control the manufacture and secretion of the hormone
  • melatonin is essential to the sleep/wake cycle of
  • light rescues melatonin activity - darkness increase
24
Q

Define ultradian rhythms?

A
  • take less than 24 hours (occur more than once over 24 hours)
  • eg the sleep stages
25
Q

Define infradian rhythm?

A
  • take longer than 24 hours (Can be weekly, monthly or annually)
  • eg the menstrual cycle
26
Q

Outline and explain the menstrual cycle as an infradian rhythm - what hormones are involved and what do they do?

A
  • involves monthly changes in hormones which control the cycle (oestrogen and progesterone)
  • first day - involves the shedding of the womb lining
  • during the cycle - raisin levels of oestrogen cause the ovary to develop an egg and release it (ovulation)
  • after ovulation, progesterone helps the womb lining thicken to prepare the womb for pregnancy (if not pregnant - egg is absorbed into body and womb lining comes away - menstrual flow)
27
Q

Outline research support for the infradian rhythm - look at the research into pheromones and menstrual cycles?

A

Gathered a group of woman with irregular periods - took samples of pheromones of some of the women with a cotton pad placed on the armpit (pads worn for a few hours - then treated by freezing and with alcohol) rubbed on the lips of the women (due to large presence of receptors there)

  • noticed that 68% of women experienced changes to their cycle which brought them closer to the donor women
  • suggests external zeitgeber involved not just an internal process governed by endogenous pacemakers
28
Q

Outline research support for the infradian rhythm - look at the research into pheromones and menstrual cycles?

A

Gathered a group of woman with irregular periods - took samples of pheromones of some of the women with a cotton pad placed on the armpit (pads worn for a few hours - then treated by freezing and with alcohol) rubbed on the lips of the women (due to large presence of receptors there)

  • noticed that 68% of women experienced changes to their cycle which brought them closer to the donor women
  • suggests external zeitgeber involved not just an internal process governed by endogenous pacemakers
29
Q

Explain seasonal affective disorder (SAD) as an infradian rhythm?

A
  • melatonin secreted by the pineal gland at night - longer nights lead to increased melatonin secretion
  • linked to depressive symptoms
30
Q

Explain treatment for Seasonal affective disorder (SAD)?

A

Artificial light through phototherapy - can be used to treat SAD and result in full remission of depression

  • light extremely bright

does not work for people with depression - suggests SAD is a combination of melatonin and its effect in serotonin

31
Q

Outline the stages of sleep - as an example of ultradium rhythms?

A
  • stage 1 - light sleep (easily woken - may be sensations of falling or hallucinations)
  • stage 2 - deeper sleep (body and heart relaxed, harder to wake up - temperature lowered)
  • stage 3 - deepest sleep (body and heart fully relaxed - very hard to wake)
  • REM - brain returns to active state, body is paralysed, rapid eye movement (associated with dreaming)

after REM sleep there cycle is repeated - in REM longer than others

32
Q

Explain sleep stages as an example of ultradium rhythm?

A
  • EEG will show the frequency of waves (brain activity) - with deeper sleep there will be less frequency waves (theta and delta)
  • 4 distinct states - first 3 are NREm with the final being REM (rapid eye movement) with each cycle taking 90 minutes
33
Q

Outline 2 pieces of research support into sleep stages for ultradium rhythm?

A
  • EEG recordings involving 33 participants - showed the brain waves followed a cyclical pattern, with bodily relaxation occurring during slow wave sleep and rapid eye movement during periods of high activation
  • 9 participants woken at different stages in sleep cycle reported dreaming more frequency when woken in the REM stage
  • found marathon runners showed longer sleep in Stage 3 (stage where physical body recovery takes place)
34
Q

Explain research into the REM sleep cycle?

A

EEG in 10 patients recovering from drug overdose showed an increased REM sleep in Stage - suggesting REM is for mental recovery

35
Q

Evaluate sleep cycles as an ultradium rhythm?

A
  • overall pattern of sleep - but some individual differences with newborn babies spending 80% of sleep in REM where as adults its about 20-25% suggesting sleep is invoked in development and cognitive consolidation (negative)
  • led to developments of technology which can help track and aid in providing better sleep - avoiding waking up in stage 4 stops people feeling groggy and disoriented (positive)
36
Q

Give 3 types of biological rhythms?

A
  • Circadian rhythm
  • Ultradium rhythm
  • Infradian rhythm