Ways To Study The Brain Flashcards
Define Haemodynamic Response
The change in the blood flow activity
Define Non-Invasive
Designating processes or tests which do not necessitate perforation or laceration of the skin or insertion of a tool or gadget into the body for diagnosis or remediation
Define Spatial Resolution
A Measure of the accuracy or detail of a graphic display, expressed as dots per inch
Define Temporal Resolution
Refers to the precision of a measurement with respect to time.
Define Brain Scanning Techniques
Brain imaging techniques allow researchers to view activity or problems within the human brain without invasive neurosurgery. There are a number of accepted, safe imaging techniques in use today in research facilities and hospitals throughout the world.
Explain fMRI
A method used to measure brain activity while a person is performing a task that uses MRI technology. This enables researchers to detect which regions of the brain are rich in oxygen and thus are active.
Evaluate fMRI : Non-invasive
A strength of using fMRI is that it is non-invasive nor does it expose the brain to potentially harmful radiation as is the case with some other scanning techniques used in the study the brain
Evaluate fMRI : Objective measurement
Another Strength is that it offers a more objective and reliable measure of psychological process than is possible with verbal reports it is useful as a way of investigating psychological phenomena that people would not be capable of providing that people would not be capable of providing in verbal reports.
Evaluate fMRI : Direct Measure
Because they measure changes in blood flow in the brain, then it is not a direct measure of neural activity in particular brain areas. This means it is not a truly quantitative measure of mental activity in these brain areas.
Evaluate fMRI : Overlooked
Critics argue that fMRI overlooks the networked nature of brain activity as it focuses only on localised activity in the brain. They claim that it is communication among the different regions that is most critical to mental functions.
Real Life examples to use fMRI
Someone who has suffered a stroke
Someone suffering Alzheimers
In extreme cases of confusion, dizziness, vision issues all factors that show no physical change but a change in behaviour is apparent.
Explain EEG
A measurement of the electrical activity of the brain by recording from electrodes placed on the scalp. Electrodes measure the activity of the cells immediately under the electrode, therefore using more electrodes allows for a wider, more in depth picture. The resulting traces represent an electrical signal from
Dement and Kleitman Aim
The aim of the study was to investigate the relationship between eye movements and dreaming
Dement and Kleitman Procedure
Nine participants were studied under controlled laboratory conditions just before their usual bedtime. An EEG was used to amplify and record the signals of electrodes which were attached to the participants face and scalp.
Dement and Kleitman Findings
All the participants showed periods of REM every night during sleep. The REM EEG was characterised by a low voltage, relatively fast pattern. In between REM periods the EEG patterns were either high-voltage, slow activity or spindles with a low-voltage background, both characteristic of deeper sleep. REM never occurred at the beginning of the sleep cycle
REM periods which were not terminated by an awakening varied between 3 minutes and 50 minutes, and they tended to increase in length as the night progressed.
EEGs can be used to detect various types of brain disorders including
Sleeping Disorders
Dementia
Strokes
Epilepsy
Evaluate EEG: High Temporal Resolution
One advantage of the EEG technique is that it provides a recording of the brains activity in real time rather than a still image of the passive brain. This means that the researcher can accurately measure a particular task or activity with the brain activity associated with it
Evaluate EEG: Clinical Diagnosis
EEG is useful in clinical diagnosis by recording the abnormal neural activity associated with epilepsy. Epileptic seizures are caused by distributing brain activity which means that the normal EEG reading suddenly changes. This helps diagnose whether someone experiencing seizures has epilepsy
Evaluate EEG: Superficial Regions
Because EEG can only detect the activity in superficial region of the brain, it cannot reveal what is going on in the deeper regions such as the hypothalamus or hippocampus. Electrodes can be implanted in non-humans to achieve this, but it is not ethically permissible to do this with humans because this would be too invasive.
Evaluate EEG: Pinpointing source
Electrical activity can be picked up by several neighboring electrodes, therefore the EEG signals is not useful for pinpointing the exact source of an activity. As a result, it does not allow researchers to distinguish between activities originating in different but closely adjacent locations in the brain
