Flashcards in Biopsychology part 2: Deck (35):
What is an EEG? (remember you need to only write this once then you can write 'EEG')
EEG = Electroencephalogram.
What is an ERP? (you can write ERG instead after you have written it once)
What are Post-mortem examinations?
A post mortem examinations a technique involves the analysis of a person's brain following death.
In psychological research, individuals whose brains are subject to post-mortem are likely to be those with a rare disorder and have experienced unusual deficits in mental processes or behaviour.
Areas within the brain are examined after death in order to see if damage could have caused the behaviour.
Why do they compare brains in Post-mortem examinations to neurotypical brains?
So that they can compare whether the areas are the same or similar in order to look at whether the cause of any disorders was the brain itself, e.g. Any differences in region sizes, for example,psychopaths, the researchers observed deformations in another part of the brain called the amygdala
What is an EEG?
An EEG is a measure of electrical activity in the brain via electrodes that are placed on the scalp using a skull cap.
The scan records brainwave patterns that are generated from the action of millions of neurons, providing an overall account of brain activity.
EEG is often is used by clinicians as a diagnostic too as unusual arrhythmic patterns of activity may indicate neurological abnormalities.
What is an ERP?
Although EEG has many scientific and clinical applications, in its raw form it is a crude and overly general measure of brain activity.
Researchers have developed a way of teasing out and isolating responses.
Using a statistical averaging technique, all extraneous activity from the original EEG is filtered out leaving only those responses that relate to, for example, the presentation of a specific stimulus or performance of a task. What remains is event related potential: types of brainwaves that are triggered by particular events.
What is FMRI?
A method to measure brain activity while a person is performing a task that uses MRI technology (detecting radio waves from changing magnetic fields). This enables researchers to detect which regions of the brain are rich in oxygen and thus are active.
What's the role of the master circadian pacemaker and what's its name?
To synchronise the circadian rhythms and body clocks.
It is called the Superchiasmatic nucleus
Explain the term 'hotoentrainment':
Light provides the primary input to the system setting the body clock to the correct time.
Describe two other circadian rhythms:
- ore body temperature: Decreases at 2-4 AM to 36 degrees c, also decreases at 2-4 pm. Core body temperature increases at 6pm.
- Hormone production; Releases and follows a circadian rhythm. For example the production and release of melatonin from the pineal gland occurs due to the absence of light, when light is present and detected melatonin production is decreased.
Outline Siffre's cave study and discuss the findings:
He spent several extended periods underground to study the effects on his own biological rhythms.
He deprived himself of all natural light, he had dim lamp which allowed him to get around the cave.
He surfaced in Sept 1962 after two months in the cave. He believed it was August.
In both cases upon which he went into caves his 'free-running' biological rhythm settled down to one that was just beyond the average 24 hours though he did still sleep and wake on a regular schedule.
describe the sleep/wake cycle:
The fact we feel drowsy when it's night-time and alert during the day time demonstrates the effects of light on our biological cycles.
However, the biological clock, if left to its own devices, will continue to run, therefore it is a free-running cycle.
Evaluation for the circadian rhythms: Practical application to shift work: Part 1
Researchers have a better understanding of rhythms which has allowed them to better understand the adverse effects of disrupting rhythms. This is common for shift workers and nurses . At around 6 am workers experience a drop in concentration which could lead to accidents or mistakes that could be dangerous. (bovin et al 1996).
Evaluation for the circadian rhythms: Practical application to shift work: Part 2
Relationship also found between Shift work and poor health: Shift workers 3x more likely to develop heart disease (Knutsson 2003) which may in part be due to stress of adjusting a rhythm to a new pattern and the lack of poor quality sleep during the day.
Evaluation for the circadian rhythms: Practical application to drug treatments: p[art 1
Circadian rhythms co-ordinate a number of the body's basic functions such as heart rate, digestion and hormone levels.
This in turn has an effect on pharmacokinetics, that is, the action of the drugs on the body and how well they are absorbed and distributed.
Evaluation for the circadian rhythms: Practical application to drug treatments: part 2
Research into circadian rhythms has revealed that there are certain peak times during the day or night when drugs are likely to be most effective.
This led to the development of guidelines to do with the timing of drug dosing for a whole range of medications including anticancer, cardiovascular. (Baraldo 2008)
What does the homeostatic drive do?
Causes an increase in the need to sleep, throughout the day.
What does the sleep-wake cycle get affected by?
It is affected by daylight.
When does the sleep drive become the strongest?
Strongest between 2-4am and 1-3pm
Where is melatonin produced and why is it produced?
Produced by the pineal gland in the brain, in response to darkness.
How long do free-running circadian rhythms last?
It is a 24-25 hour cycle but can vary from individual to individual.
How long does a circadian rhythm last?
24 hours or so.
How long does ultradian cycles last?
Less than 24 hours.
How long does an infradian rhythm last?
Longer than 24 hours.
Name an example of a circadian rhythm:
Name an ultradian rhythm?
Name an example of infradian rhythm:
Weekyl, monthly and annual rhythms.
What is an endogenous rhythm?
An internal body clock in the brain.
What does an endogenous pacemaker do?
Mechanisms within the body that govern the internal biological rhythms.
What is the suprachiasmatic nucleus and where is it?
A cluster of nerve cells in the hypothalamus.
What does the SCN do?
generates the body's circadian rhythm. Acts as a 'master clock' with links to the other brain regions to control sleep, arousal and has control of other biological clocks.
What influences the SCN in setting our body clock?
External lights level changes. Receptors iin the SCN are sensitive to light level changes during the day and use this information to synchronise the activity to the body's organs and glands. Light resets the internal biological clokc.
What is the link between the SCN and melatonin?
Pineal gland produces melatonin.
What does melatonin do?
Melatonin induces sleep, when light levels are higher the production of melatonin is stopped and in lower light levels melatonin production increases and therefore causes drowsiness.