Ways of studying the brain

Question 1

What are the four ways of studying the brain in biopsycholgy

Answer 1

Post-Mortem examiniations, Functional Magnetic Resonance Imaging (fMRI), Electroencephalogram (EEG) and Event-related Potentials (ERPs)

Question 2

When are post-mortem examinations used

Answer 2

When psychologists want to establish the underlying neurobiology of a particular behviour, such as behaviour which suggests possible brain damage

Question 3

Who is an early example of post-mortem examinations

Answer 3

Broca on Tan

Question 4

What do researchers look for in post-mortem examinations

Answer 4

Abnormalities not found in control patients which might explain the behaviour

Question 5

How have post-mortem’s impacted research on memory

Answer 5

Made it possible to identify some of the structures involved in memory, such as a post-mortem of HM confirming that his inability to store new memories was linked to lesions in the hippocampus

Question 6

How have post-mortems impacted psychiatric disorders

Answer 6

Made it possible to establish a link between disorders like schizophrenia and depression, and underlying brain abnormalities. For example, studies revelealed a reduced number of glial cells in the frontal cortex of patients with depression

Question 7

What are some strengths of post-mortems

Answer 7

-Allow for a more detailed examination of anatomical and neurochemical aspects of the brain that would be impossible with only non-invasive techniques. For example examining deeper areas of the brain like the hypothalamus and hippocampus
-Harrison claims that post mortems are central in our understanding of schizpohrenia. He suggests that as a direct result of post mortems researchers discovered structural anomalies of the brain and found evidence of changes to neurotransmitter systems, both linked to Sz

Question 8

What are some weaknesses of post-mortems

Answer 8

-Many factors can influence the post-mortem brain. Time between death and post-mortem (post-mortem delay), drug treatments and age of death are all possible confounding influences
-It is retrospective as the person’s brain is (hopefully) already dead. As a result, the researcher is unable to follow up anything that arises from the post-mortem concerning a possible relationship between brain abnormalities and cognitive functioning

Question 9

Who suggested that post-mortems directly helped our understanding of Sz

Answer 9

Harrison

Question 10

What is fMRI

Answer 10

Functional Magnetic Resonance Imaging. It measures changes in blood flow to particular areas of the brain when a person performs a task, indicating increased neural activity in those areas

Question 11

What has fMRI allowed researchers to develop

Answer 11

Produce maps showing what parts of the brain are involved in particular mental activity

Question 12

What are some strengths of fMRI

Answer 12

-fMRI is noninvasive, nor does it expose the brain to potentially harmful radiation
-fMRI offers a more objective and reliable measure of psychological processes than is possible with verbal reports
-It can scan deep into the brain, allowing for researchers to see activity activity not visible from superficial researchm methods like EEG

Question 13

What are some weaknesses of fMRI

Answer 13

-It measures changes in blood flow, but this is not a direct measure of neural activity in particular brain areas. This means it’s not really a quantitative measure of mental activity in these brain areas
-Some argue that it overlooks the networked nature of brain activity, focusing on only localised activity in the brain. It is possible that there is communication among the regions of the brain that is most critical to mental function

Question 14

What is EEG

Answer 14

Electroencephalogram, which measures electrical activity in the brain with electrodes placed on the scalp detecting the small electrical charges resulting from the activity of brain cells. When these are graphed over time the result is called an EEG

Question 15

What can EEG be used to do

Answer 15

Identify the various types of brian disorder like epilepsy, or to diagnose other disorders that influence brain activity, like Alzheimers. For example, EEG readings of epilepsy patients show spikes of electrical activity, whereas those with brain disease or brain injury show signs of overall slowing electrical activity

Question 16

What are the waves detected by EEG (Eg Alpha)

Answer 16

Alpha, beta, delta and theta waves. When a person is awake and relaxed, alpha waves are recorded. When psychologically aroused low amplitude and fast frequency beta waves are recorded. These are also found during REM sleep. Delta and theta waves occur during deep sleep, with alpha waves decreasing from light to deep sleep and being replaced by lower frequency theta and then delta waves.

Question 17

What are some strengths of EEG

Answer 17

-Records the brains activity in real time rather than a still image. This means a researcher can accurately measure a particular task or the activity associated with it
-It is useful in clinical diagnosis, for example recording the abnormal activity associated with epilepsy. This helps diagnosing whether someone experiencing seizures has epilepsy.

Question 18

What are some weaknesses of EEG

Answer 18

-It can only detect the activity in the superficial regions of the brain, it cannot reveal what is happening in the deeper regions like the hypothalamus or hippocampus. Electrodes can be implanted in non-humans to achieve this but it is not ethical in humans
-Activity can be detected by several neighboring electrodes, therefore EEG is not useful for pinpoiniting the exact location of activity. Does not allow for distinguishing between activities originating in different but closely adjacent brain sectors

Question 19

What are ERPs

Answer 19

Event-related potentials are very small voltage changes in the brain triggered by specific events or stimuli. They are difficult to pick out from other electrical brain activity at a given time. To pick out a praticular response a target stimuls requires many presentations of the stimulus with responses averaged together.

Question 20

What are the two ERP categories

Answer 20

-Waves occuring within the first 100 milliseconds after presentation are termed ‘sensory’ ERPs as they reflect an initail response to the physical characteristics of the stimulus.
-ERP’s generated after the first 100 milliseconds reflects the manner in which the subject evaluates the stimuls and are termed ‘cognitive’ ERPs as they demonstrate information processing

Question 21

What are some strengths of ERPs

Answer 21

-As they provide a continous measure of processing in response to a particular stimulus, it makes it possible to determine how processing is affected by specific experimental manipulation, for example during presentation of visual stimuli
-They can measure the processing of stimuli even in the absence of a behavioural response. ERP recordings make it possible to monitor ‘covertly’ the processing of a particular stimulus without requiring the person to respond to them

Question 22

What are some weaknesses of ERPs

Answer 22

-As they are small and difficult to pick apart from other brain activity, it requires a large number of trials to gain meaningful data. This limits the types of questions ERPs can realistically answer
-Only sufficiently strong voltage changes across the scalp are recordable. Imporant electrical activities occuring in the deep brain are not recorded , meaning that the generation of ERPs is restricted to the neocortex