Biopsychology Flashcards
Where is the motor area located to?
Frontal lobe
Where is the somatosensory area located to?
Parietal lobe
Where is the visual area located to?
Occipital lobe
Where is Wernicke’s area located?
Temporal lobe
Where is Broca’s area located?
Frontal lobe
Function of the motor cortex/ area?
Responsible for the generation of voluntary motor movements
What are examples of circadian rhythms?
Sleep-wake cycle and body temperature
What synchronises the body clocks found in all cells of the body?
The master circadian pacemaker
What is the master circadian pacemaker and where is it located?
The suprachiasmatic nucleus (SCN) in the hypothalamus
What is photoentrainment?
Light setting the body clock to the correct time
What detects the environmental light levels? And where do they send messages to about the changes in light levels?
Light-sensitive cells within the eye act as brightness detectors sending messages to the SCN via the optic nerve
What happens in the morning in the sleep-wake cycle?
Eyes detect light and so messages are sent via the optic nerve to the SCN
SCN sends messages to raise body temperature and blood pressure, and delay the release of hormones like melatonin from the pineal gland.
Sharpest rise in blood pressure and reduction in secretion of melatonin causes us to feel awake.
Highest levels of cortisol (in the morning), also makes us feel awake.
What happens in the evening in the sleep-wake cycle?
Sun disappears, signals sent to SCN about change in light levels
SCN sends messages to make body temperature cool and sleep inducing hormones like melatonin are released
This signals it is time to sleep
What are the two greatest dips for the circadian rhythm?
Between 2am and 4am, and between 1pm and 3m (post-lunch dip).
Means the greatest sleep drive usually occurs in these two dips.
Post-lunch dip may be due to a small drop in body temperature between 2pm and 4pm.
How can dips in the circadian rhythms be intense for some people?
People with sufficient sleep, experience less intense sleepiness in the dips
Sleep deprived people experience more intense sleepiness dips
What else are sleep and wakefulness determined by?
Homeostasis
Why is the circadian rhythm intolerant to any major alterations?
Because this causes the biological clock (and the internal systems that are dependent on this) to be completely out of balance
What did Siffre do?
Lived in a dark cave for 7 months
He measured his performance, heart rate, blood pressure and brain waves
What did Siffre find?
His ‘natural’ sleep-cycle was 25 hours
What is one the research method problems with Siffre’s study? (Confounding variable)
Artificial light was used so that Siffre could measure all of his recordings which would potentially act as a confounding variable and influence his sleep-wake cycle.
Research by Czeilser found dim artificial light could adjust circadian rhythms between 22-28 hours
What is one the research method problems with Siffre’s study? (Aim)
He knew the aim of the study and so may have acted differently as a result (demand characteristics) e.g. trying to stay awake or trying to age a ‘normal’ pattern of waking and sleeping in which may not be a valid result.
What is one the research method problems with Siffre’s study? (Case study)
He was an individual, may be individual differences
He found when he went back into the cave at 60 years old his sleep-wake cycle was more like 48 hours
Does not take gender and age into account
What does Siffres study tell us?
Our ‘natural’ sleep-wake cycle is slightly longer than 24 hours. Light therefore seems to be the exogenous zeitgeber that entrains (affects) the cycle to make it 24 hours.
What has shift work been found to do to circadian rhythms?
Causes them to desynchronise which has adverse cognitive and physiological effects
Concentration lapse at 6am
3x more as likely to suffer heart disease due to stress of adjusting sleep-wake cycles
What is an ultradian rhythm?
Biological rhythm that lasts less than 24 hours (more than one cycle in 24 hours)
What is an infradian rhythm?
Biological rhythm with a duration of over 24 hours.
What is the sleep cycle (sleep stages) an example of?
Ultradian rhythm
How long are the stages of sleep?
90-100 minutes
The sleep cycle: What happens in stage 1?
Light sleep
Muscle activity slows
Occasional muscle twitching
Person is easily woken
The sleep cycle: What happens in stage 2?
Breathing pattern and heart rate slows
Slight decrease in body temperature
The sleep cycle: What happens in stage 3?
Deep sleep begins
Brain begins to generate slow delta waves, which have a greater amplitude than earlier waves
The sleep cycle: What happens in stage 4?
Very deep sleep
Difficult to wake someone at this point
Rhythmic breathing occurs
Limited muscle activity
Brain produces delta waves
The sleep cycle: What happens in stage 5 (REM)?
Rapid eye movement
Brain waves speed up and dreaming occurs
Muscles relax
Heart rate increases
Breathing rapid and shallow
Body is paralysed, yet brain activity speeds up to resemble the awake brain
What percentage of the sleep cycle is stage 1?
4-5%
What percentage of the sleep cycle is stage 2?
45-55%
What percentage of the sleep cycle is stage 3?
4-6%
What percentage of the sleep cycle is stage 4?
12-15%
What percentage of the sleep cycle is stage 5 (REM)?
20-25%
Sleep Cycle: How are brainwave activity monitored?
EEG
What is the menstrual cycle an example of?
Infradian rhythm
Menstrual cycle: What is the cycle governed by?
Monthly changes in hormone levels which regulate ovulation.
Menstrual cycle: What period of time does the cycle refer to?
Time between the first day of the woman’s period, when the womb lining is shed, and the day before her next period.
Menstrual cycle: How long is the cycle?
Approximately 28 days to complete
Menstrual cycle: What is ovulation, when does it occur and how long does it last?
When rising levels of the hormone oestrogen cause the ovary to develop and egg and release it.
This occurs half when through the menstrual cycle when oestrogen levels are highest.
Usually lasts 16-32 hours
Menstrual cycle: What happens after ovulation?
The levels of the hormone progesterone increase which helps the womb grow thicker, readying the body for pregnancy
Menstrual cycle: What happens if pregnancy does not occur?
The egg is absorbed into the body and the womb lining comes away and leaves the body (the menstrual flow).
Menstrual cycle: Who did Stern and McClintock (1998) study?
Studied 29 women with irregular periods
Menstrual cycle: What did Stern and McClintock (1998) do?
Took samples of pheromones from 9 women, at different stages of their cycle.
On day 1, pads from the start of the menstrual cycle we’re applied to all 20 women, on day two they were given a pad from the second day of the cycle etc.
Menstrual cycle: How did Stern and McClintock (1998) gather pheromones and how were they given to the other women?
Via a cotton pad placed in their armpit (worn for at least 8 hours to ensure the pheromones were picked up.
The pads were then treated with alcohol and frozen, and then were rubbed on the upper lip of the other women.
Menstrual cycle: What did Stern and McClintock (1998) find?
68% of the women experienced changes to their menstrual cycle which brought them closer to the cycle of their ‘odour donor’.
Menstrual cycle: What does Stern and McClintock (1998) suggest?
Supports the endogenous infradian rhythm of the menstrual cycle.
However, suggest that it may be influenced by exogenous factors, such as the cycles of other women.
What is an endogenous pacemaker?
Internal body clocks that regulate many of our biological rhythms, such as the influence of the SCN on the sleep-wake cycle
What is an exogenous zeitgeber?
External factors that affect or entrain our biological rhythms such as the influence of light on the sleep-wake cycle
What is plasticity?
The brains tendency to change and adapt (functionally and structurally) as a result of experience (positive or negative), new learning or training.
What age does plasticity occur?
Throughout the life span; existing neural connections can change or new neural connections can be formed as a result of learning and experience
Does functional plasticity reduce and why?
Tends to reduce with age. The brain has a greater propensity for reorganisation in childhood as it is constantly adapting to new experiences and learning.
Brain plasticity: What happens during infancy?
The brain experiences a rapid growth in the number of synaptic connections it has, peaking at approximately 15,000 at 2-3 years.
What is synaptic pruning?
The process that as we age, rarely used connections are deleted and frequently used connections are strengthened.
What did Macguire et al. (2000) study?
Studied the brains of London taxi drivers. As part of their training, they have to complete a complex test called ‘the Knowledge’, which assesses their recall of the city streets and possible routes.
What did Mcguire et al. (2000) find?
That there was significantly more volume of grey matter in the posterior hippocampus compared to matched controls.
This is the part of the brain that is associated with the development of spatial and navigational skills in humans and other animals.
The longer they had been in the job, the more pronounced the structural difference (a positive correlation).
What did Mcguire et al. (2000) study suggest for theory of plasticity?
This suggests that the brain changes and adapt functionally and structurally (increases grey matter) as a result of learning and experience, supporting the theory of plasticity.
What did Mechelli et al. (2004) study?
Compared bilingual brains to matched monolingual controls.
What did Mechelli et al. (2004) find?
Found a larger parietal cortex in the brains of people who were bilingual. The experience of learning a new language led to changes in the brain’s structure (increased volume of the parietal cortex) and function (learning the new language).
What did Mechelli et al. (2004) suggest for theory of plasticity?
Suggest the brain changes and adapts functionally (learning new language) and structurally (increased volume of parietal cortex), supporting the theory of plasticity.
What is functional recovery?
The brain’s ability to redistribute or transfer functions usually performed by a damaged area(s) to other, undamaged area(s). I.e. the brain changes functionally (and sometimes structurally) as a result of the experience of trauma- making it a type of plasticity.
How quickly do neuroscientists suggest functional recovery occurs?
Process can occur very quickly after trauma (spontaneous recovery) and then slows down after several weeks or months. At this point the individual may require rehabilitation to aid their recovery.