ways of studying the brain Flashcards
what is the purpose of scanning techniques in psych?
the main purpose is to investigate localisation - to determine which parts of the brain do what
what are the 4 methods for studying the brain?
functional magnetic resonance imaging (fMRI),
electroencephalogram (EEGs),
event-related potentials (ERPs),
post-mortem examinations.
how does a functional magnetic resonance imaging (fMRI) scan work?
fMRI works by detecting changes in both blood oxygenation and flow that occurs as a result of neural (brain) activity in specific areas of the brain.
what happens when a brain area is more active?
when an area of the brain is more active, it consumes more oxygen.
To meet the increased demand of oxygen, blood flow is directed to the active area (haemodynamic response).
what do fMRIs produce?
fMRIs produce 3D images showing which parts of the brain are involved in a particular mental process.
this has important implications for our understanding of localisation of function.
what are the strengths of fMRI?
- It doesn’t rely on the use of radiation
- It is virtually risk-free, non-invasive and straight forward to use.
- It produces images with very high spatial resolution, providing a clear image of the brains activicty
what are the weaknesses of fMRI?
- Expensive
- Poor temporal resolution as there is around a 5-seconnd time lag behind image the image on the screen and the initial firing of
neuronal activity. Means fMRI may not truly represent moment-to-moment brain activity.
what is a functional magnetic resonance imaging scan?
a method used to measure brai8n activity while a person is performing a task. fMRI detects 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 is an electroencephalogram (EEG)?
A record of tiny electrical impulses produced by the brain’s activity. By measuring characteristic wave patterns, the EEG can help diagnose certain conditions of the brain.
what do electroencephalogram’s measure?
measure electrical activity within brain via electrodes that are fixed to an individuals scalp using a skull cap.
the scan recording of the EEG represents what?
scan recording represents the brainwave patterns that are generated from action of thousands of neurons, providing an overall account of brain activity.
EEGs is used by who and for what?
EEGs is used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity may indicate neurological abnormalities such as epilepsy, tumours or disorders of sleep.
strengths of EEGs
- useful in studying stages of sleep and in diagnosis of conditions such as epilepsy.
- extremely high temporal resolution so can accurately detect brain activity at a resolution of a single millisecond.
weaknesses of EEGs
- generalised nature of info received - EEG isn’t useful for pinpointing the exact source of neuronal activity.
Therefore, it doesn’t allow researchers to distinguish between activities originating in different but adjacent locations.
what are event-related potentials (ERPSs)?
the electrophysical response of the brain to a specific sensory, cognitive, or motor event can be isolated through statistical analysis of EEG data.
