BIOPSYCHOLOGY
The divisions of the nervous system; central and peripheral (somatic and automatic)
The function of the endocrine system; glands and hormones
The fight or flight response
The structure and function of sensory, relay and motor neurons
The process of synaptic transmission
Localisation of function in the brain
Hemispheric lateralization and split-brain research
Plasticity and functional recovery of the brain
Ways of studying the brain
Circadian rhythms
Ultradian and Infradian rhythms
Endogenous pacemakers and exogenous zeitgebers
Endogenous pacemakers and Exogenous zeitgebers
A01 - Exogenous cues (light and social) reset the biological clock. Light has an indirect influence on controlling
hormone secretion and blood circulation. Campbell and Murphy - light detected by skin receptor sites on the
knee. Deviation in cycle up to 3 hours. Thus, don't rely on its influence on the brain. Social cue - baby cycles are
random, 6 weeks - circadian rhythms begin and by 16 weeks their rhythms are imposed by parent schedules. Jet
lag - training circadian rhythms needed.
A01 - Endogenous pacemakers - SCN in the hypothalamus located above the optic chiasm. The pineal gland
releases melatonin affected by light. Decoursey et al destroyed the SCN connection in the 30 chipmunks, 10
returned to their habitat and observed for 80 days. Ralph et al bred mutant hamsters with a 20 hour sleep wake
cycle, SCN cells from foetal tissue of mutant hamsters transplanted into normal hamsters, cycle defaulted to 20
hours. Melatonin is causal for SAD (low mood, irritability and guilt).
A03 - animals have similar mechanisms to humans e.g SCN and pineal gland (chipmunks and hamsters). One
can generalise as both species have similar brain structures. However, DeCoursey’s research showed
chipmunks not returning to their natural habitat and couldn't function, dying as a result. This questions the ethical
issues of harm in animals and whether or not it is worth the knowledge.
A03 - Siffre was a French cave explorer who spent 6 months in a cave in Texas with no light or clock. The
biological clock was free running with an erratic sleep/wake cycle at first but then settled to a pattern averaging at
24 hours. Endogenous pacemakers can’t be studied in isolation. Artificial light may have reset his biological
clock. Eps and Ezs interact. If separated, this lowers the validity.
A03 - People living within the Arctic Circle have similar sleep patterns annually, despite 6 months in darkness. EZ
is not the same in all environments. This experience doesn't fit with research/theory. Sleep wake cycle is
controlled by Eps overriding environmental changes in light.
A03 - Miles et al recount a study of a young blind man from birth with an abnormal circadian rhythm of 24.9hours.
Despite exposure to social cues e.g regular mealtimes, it couldn't be adjusted. This challenged EZs despite light
being important. Social cues are limited in resetting biological rhythm.
Ultradian and Infradian rhythms
A01 Infradian rhythms (more than day, less than year) e.g SAD and menstrual cycle
SAD - low mood, no enjoyment, winter blues, daylight shorter, pineal gland secretes melatonin until dawn with
light increase - winter affects serotonin
Menstrual cycle - 28 days, 1st day lining of womb is shed, driven by fluctuating hormone levels regulating
ovulation
Pituitary gland releases FSH and LH triggering ovaries to release oestrogen and progesterone (helps lining of
womb prepare for pregnancy)
A01 Infradian rhythms (synchronising menstrual cycle) influenced by exogenous factors e.g other women’s
cycles
Stern and McClintock - pheromones cause synchronisation. 29 women w/ irregular periods, samples gathered
from 9 at different stages of periods (cotton pad in armpit for 8 hrs). Pads treated with alcohol and frozen upper
lip. Pads applied to other 20 - 68% changes cycle as closer to odour donor
, A01 ultradian rhythms (less than 24 hours) - human sleep cycle (90 minutes). 5 stages of sleep: first 3 are NREM
and final is REM. Stage 1 and 2 - light sleep, alpha waves, easily woken, relaxed makes brain waves slower and
regular. Stages 3 and 4 - slow wave sleep hard to wave, body’s repair work is undertaken, growth hormones.
Rem sleep - brain and eyes active but body is paralysed
A03 Slow wave sleep reduces with age as growth hormone is produced. Cauter et al researched sleep
deficiency and issues in age e.g reduced alertness. Increase SWS through medication to help relaxation and
medication. RWA understanding age related changes in sleep.
A03 Tucker et al investigated differences in sleep patterns. Ppts studied over 11 days and nights in a controlled
lab. Assessed sleep duration, time slept and amount of time in each stage. Individual differences from 8 nights.
Stages 3 and 4 are partially significant. Ultradian rhythms vary between people.differences are biologically
determined. Difficult to describe normal sleep.
A03 Many factors affect the change in the menstrual cycle e.g stress, diet, exercise as confounding variables. As
well as that, Stern and Mcclintock used a small sample and self report. There is an evolutionary basis though as
it is an advantage for women to menstruate and get pregnant together as they have access to breast milk for
survival.
A03 Phototherapy uses very strong lights (6000-10000 lux) in the evening/early morning to change serotonin
levels. SAD sufferers reported daily use of such boxes relieves feelings of lethargy, depression and other related
symptoms. Sanassi - phototherapy reduces effects for 80% of people but can cause eyestrain and headaches -
CBT may be better.
Circadian Rhythms
A01 Biological rhythms are regularly repeated
24 hour circadian rhythm - reset by light
Core body temperature
Sleep wake cycle - governed by daylight (exogenous zeitgeber) and internal (endogenous pacemaker) as a clock
called SCN above optic chiasm. Exogenous zeitgebers reset the SCN
A01 Siffre - effects of own biological rhythms
No light or sound but food and drink
In cave in southern Alpes, resurfacing after two months in September believing it was mid August
Decade later, went to texas cave for 6 months with free running rhythm settled at 25 hours, slept and woke at
regular schedule
A01 Aschoff and Wever - groups of ppts spending 4 weeks in a WW2 bunker with no light. All 25 hour rhythm,
except one at 29 hours. Shows circadian should be longer than 24 hours. Folkard - studied 12 people for 3
weeks, slept at 11:45 and rose at 7:45
Sped clock to 22 hour day
Only one adjusted, free running rhythm is not overridden by exogenous zeitgebers
Effects of desynchronisation - night shift workers experience circadian trough (dip in concentration) at around
6am - mistakes more likely to occur (Boivin et al). Consequences when sleep is disrupted. Health problems likely
e.g heart disease. RWA economic implications for worker productivity, avoiding accidents for compensation
costs.
Solomon - Shift work and deprived sleep may contribute to higher divorce rates.
- Correlational research cannot establish direct cause-and-effect relationships.
- Other factors within shift workers' lives (e.g. pre-existing marital issues, stress from shift work) may also
influence divorce rates.
Circadian rhythms coordinate the body’s basic processes e.g heart rate, digestion and hormone levels.
Chronotherapeutic - medical treatment being administered to correspond with persons biological rhythm (Bonten
et al) e.g aspirin prevents heart attacks, tend to happen in morning so tinting matters - useful in increasing
effectiveness of drug treatment.
Individual differences - Duffy et al - some go to bed early and some late. Siffre - his own sleep/wake cycle slowed
down since youth. Limitation - generalisation is hard to make. Small sample.
The divisions of the nervous system; central and peripheral (somatic and automatic)
The function of the endocrine system; glands and hormones
The fight or flight response
The structure and function of sensory, relay and motor neurons
The process of synaptic transmission
Localisation of function in the brain
Hemispheric lateralization and split-brain research
Plasticity and functional recovery of the brain
Ways of studying the brain
Circadian rhythms
Ultradian and Infradian rhythms
Endogenous pacemakers and exogenous zeitgebers
Endogenous pacemakers and Exogenous zeitgebers
A01 - Exogenous cues (light and social) reset the biological clock. Light has an indirect influence on controlling
hormone secretion and blood circulation. Campbell and Murphy - light detected by skin receptor sites on the
knee. Deviation in cycle up to 3 hours. Thus, don't rely on its influence on the brain. Social cue - baby cycles are
random, 6 weeks - circadian rhythms begin and by 16 weeks their rhythms are imposed by parent schedules. Jet
lag - training circadian rhythms needed.
A01 - Endogenous pacemakers - SCN in the hypothalamus located above the optic chiasm. The pineal gland
releases melatonin affected by light. Decoursey et al destroyed the SCN connection in the 30 chipmunks, 10
returned to their habitat and observed for 80 days. Ralph et al bred mutant hamsters with a 20 hour sleep wake
cycle, SCN cells from foetal tissue of mutant hamsters transplanted into normal hamsters, cycle defaulted to 20
hours. Melatonin is causal for SAD (low mood, irritability and guilt).
A03 - animals have similar mechanisms to humans e.g SCN and pineal gland (chipmunks and hamsters). One
can generalise as both species have similar brain structures. However, DeCoursey’s research showed
chipmunks not returning to their natural habitat and couldn't function, dying as a result. This questions the ethical
issues of harm in animals and whether or not it is worth the knowledge.
A03 - Siffre was a French cave explorer who spent 6 months in a cave in Texas with no light or clock. The
biological clock was free running with an erratic sleep/wake cycle at first but then settled to a pattern averaging at
24 hours. Endogenous pacemakers can’t be studied in isolation. Artificial light may have reset his biological
clock. Eps and Ezs interact. If separated, this lowers the validity.
A03 - People living within the Arctic Circle have similar sleep patterns annually, despite 6 months in darkness. EZ
is not the same in all environments. This experience doesn't fit with research/theory. Sleep wake cycle is
controlled by Eps overriding environmental changes in light.
A03 - Miles et al recount a study of a young blind man from birth with an abnormal circadian rhythm of 24.9hours.
Despite exposure to social cues e.g regular mealtimes, it couldn't be adjusted. This challenged EZs despite light
being important. Social cues are limited in resetting biological rhythm.
Ultradian and Infradian rhythms
A01 Infradian rhythms (more than day, less than year) e.g SAD and menstrual cycle
SAD - low mood, no enjoyment, winter blues, daylight shorter, pineal gland secretes melatonin until dawn with
light increase - winter affects serotonin
Menstrual cycle - 28 days, 1st day lining of womb is shed, driven by fluctuating hormone levels regulating
ovulation
Pituitary gland releases FSH and LH triggering ovaries to release oestrogen and progesterone (helps lining of
womb prepare for pregnancy)
A01 Infradian rhythms (synchronising menstrual cycle) influenced by exogenous factors e.g other women’s
cycles
Stern and McClintock - pheromones cause synchronisation. 29 women w/ irregular periods, samples gathered
from 9 at different stages of periods (cotton pad in armpit for 8 hrs). Pads treated with alcohol and frozen upper
lip. Pads applied to other 20 - 68% changes cycle as closer to odour donor
, A01 ultradian rhythms (less than 24 hours) - human sleep cycle (90 minutes). 5 stages of sleep: first 3 are NREM
and final is REM. Stage 1 and 2 - light sleep, alpha waves, easily woken, relaxed makes brain waves slower and
regular. Stages 3 and 4 - slow wave sleep hard to wave, body’s repair work is undertaken, growth hormones.
Rem sleep - brain and eyes active but body is paralysed
A03 Slow wave sleep reduces with age as growth hormone is produced. Cauter et al researched sleep
deficiency and issues in age e.g reduced alertness. Increase SWS through medication to help relaxation and
medication. RWA understanding age related changes in sleep.
A03 Tucker et al investigated differences in sleep patterns. Ppts studied over 11 days and nights in a controlled
lab. Assessed sleep duration, time slept and amount of time in each stage. Individual differences from 8 nights.
Stages 3 and 4 are partially significant. Ultradian rhythms vary between people.differences are biologically
determined. Difficult to describe normal sleep.
A03 Many factors affect the change in the menstrual cycle e.g stress, diet, exercise as confounding variables. As
well as that, Stern and Mcclintock used a small sample and self report. There is an evolutionary basis though as
it is an advantage for women to menstruate and get pregnant together as they have access to breast milk for
survival.
A03 Phototherapy uses very strong lights (6000-10000 lux) in the evening/early morning to change serotonin
levels. SAD sufferers reported daily use of such boxes relieves feelings of lethargy, depression and other related
symptoms. Sanassi - phototherapy reduces effects for 80% of people but can cause eyestrain and headaches -
CBT may be better.
Circadian Rhythms
A01 Biological rhythms are regularly repeated
24 hour circadian rhythm - reset by light
Core body temperature
Sleep wake cycle - governed by daylight (exogenous zeitgeber) and internal (endogenous pacemaker) as a clock
called SCN above optic chiasm. Exogenous zeitgebers reset the SCN
A01 Siffre - effects of own biological rhythms
No light or sound but food and drink
In cave in southern Alpes, resurfacing after two months in September believing it was mid August
Decade later, went to texas cave for 6 months with free running rhythm settled at 25 hours, slept and woke at
regular schedule
A01 Aschoff and Wever - groups of ppts spending 4 weeks in a WW2 bunker with no light. All 25 hour rhythm,
except one at 29 hours. Shows circadian should be longer than 24 hours. Folkard - studied 12 people for 3
weeks, slept at 11:45 and rose at 7:45
Sped clock to 22 hour day
Only one adjusted, free running rhythm is not overridden by exogenous zeitgebers
Effects of desynchronisation - night shift workers experience circadian trough (dip in concentration) at around
6am - mistakes more likely to occur (Boivin et al). Consequences when sleep is disrupted. Health problems likely
e.g heart disease. RWA economic implications for worker productivity, avoiding accidents for compensation
costs.
Solomon - Shift work and deprived sleep may contribute to higher divorce rates.
- Correlational research cannot establish direct cause-and-effect relationships.
- Other factors within shift workers' lives (e.g. pre-existing marital issues, stress from shift work) may also
influence divorce rates.
Circadian rhythms coordinate the body’s basic processes e.g heart rate, digestion and hormone levels.
Chronotherapeutic - medical treatment being administered to correspond with persons biological rhythm (Bonten
et al) e.g aspirin prevents heart attacks, tend to happen in morning so tinting matters - useful in increasing
effectiveness of drug treatment.
Individual differences - Duffy et al - some go to bed early and some late. Siffre - his own sleep/wake cycle slowed
down since youth. Limitation - generalisation is hard to make. Small sample.
