Ways of Studying the Brain

Flashcards covering different methods of studying the brain including post-mortems, fMRI, EEG, and ERPs based on the provided A Level Psychology text.

What are post-mortem examinations used for in the study of the brain?

They are used to establish the underlying neurobiology of a particular behaviour by examining brains for structural differences after death.

What did Broca's post-mortem work with his patient, Tan, reveal?

It revealed a lesion in an area of the brain now known as 'Broca's area', which is important for speech production.

What brain structure was linked to Henry Molaison’s (HM) inability to store new memories during his post-mortem examination?

The hippocampus.

According to Cotter et al. (2001), what did post-mortem studies find in the frontal cortex of patients with depression?

Evidence of reduced numbers of glial cells.

What is one specific advantage of post-mortem examinations over non-invasive scanning like fMRI?

They allow for a more detailed examination of anatomical and neurochemical aspects and enable researchers to examine deeper regions such as the hypothalamus.

According to Harrison (2000), how have post-mortem studies contributed to the understanding of schizophrenia?

They helped discover structural abnormalities and changes in neurotransmitter systems associated with the disorder.

Why is the time between death and the examination (post-mortem delay) considered a limitation?

It is a possible confounding influence that makes it harder for researchers to draw accurate conclusions about the cause of death or behaviour.

What does a Functional magnetic resonance imaging (fMRI) scan measure to indicate neural activity?

It measures changes in blood flow and blood oxygenation in particular areas of the brain.

Why is fMRI considered a non-invasive technique?

It does not involve the insertion of instruments into the body or expose the brain to potentially harmful radiation.

What is a major limitation of fMRI regarding its measure of mental activity?

It is not a direct measure of neural activity and therefore is not a truly quantitative measure of mental activity.

What do critics of fMRI say about its focus on localized brain activity?

They argue it overlooks the networked nature of the brain, as communication among different regions is critical to mental function.

How does an electroencephalogram (EEG) detect activity in the brain?

Electrodes placed on the scalp detect small electrical charges resulting from the activity of brain cells.

Which EEG wave pattern is recorded when a person is awake but relaxed?

Alpha waves.

In which state would an EEG show low amplitude and fast frequency beta waves?

When the person is physiologically aroused or in REM sleep.

What do delta and theta waves typically indicate on an EEG?

They occur during sleep; as a person moves from light to deep sleep, alpha waves are replaced first by theta and then by delta waves.

Why is EEG useful in the clinical diagnosis of epilepsy?

Epileptic seizures are caused by disturbed brain activity which shows up as sudden spikes on an EEG reading.

What is the primary limitation of EEG regarding the depth of brain activity it can record?

It can only detect activity in superficial regions of the brain and cannot reveal what is happening in deeper regions.

What are Event-related potentials (ERPs)?

Small voltage changes in the brain triggered by specific events or stimuli, identified by averaging multiple EEG readings.

How do researchers isolate ERPs from background neural 'noise'?

They use many presentations of the stimulus and average the responses together to cancel out extraneous activity.

What is the difference between 'sensory' and 'cognitive' ERPs?

Sensory ERPs occur within the first $100\,ms$ and reflect initial response to physical characteristics; cognitive ERPs occur after $100\,ms$ and reflect information processing.

What is one strength of ERPs compared to standard EEG?

ERPs provide a continuous measure of processing in response to a specific stimulus, making it a more precise way of investigating the brain.

How can ERPs monitor processing 'covertly'?

They can measure the processing of stimuli even in the absence of a behavioural response from the patient.

What is a limitation related to the data collection process of ERPs?

Because records are so small, a large number of trials are required to gain meaningful data.

To which part of the brain are ERP recordings restricted?

The neocortex.

What does a slowing of electrical activity on an EEG typically indicate?

Brain disease or brain injury.