Methods in biological and cognitive psychology

Question 1

Goal of cognitive neuroscience?

Answer 1

To explain cognitive processes and behaviour in terms of the structure and function of the brain and the rest of the nervous system. Critical contribution to emphasise the importance of measuring behavioural responses during cognitive and perceptual tasks. Been able to directly relate biology of brain functions to mental functions studied by cognitive scientists.

Question 2

Neuroscience based approaches *2

Answer 2

1) Studying changes in cognitive behaviour when the brain has been perpetuated in some way 2) Measuring brain activity while cognitive tasks are being performed.

Question 3

Disturbances of brain function due to clinical brain lesions

Answer 3

Resulting from stroke, trauma or disease have been enormously useful for investigating the role of the brain in specific cognitive processes.

Question 4

Independent Variable

Answer 4

Presumed to cause changes in another variable. Often the variable manipulated by the researcher.

Question 5

Dependent Variable

Answer 5

The presumed effect or outcome of the study. Variable that is measured by the researcher and influenced by the IV.

Question 6

Intracranial electrical stimulation

Answer 6

One of the earliest methods used to directly examine cognitive brain function. Although highly invasive, sometimes used in humans to enable neurosurgeons to map the functions of brain regions on or near the site of a tumour, suspected epileptic focus or other lesion that needs to be dealt with surgically. Because no pain receptors in brain tissue, can be preformed when an individual is awake.

Question 7

Problems with lesion studies

Answer 7

• Patients are rare
• Damage is not often circumscribed
• Plasticity (brain’s ability to change throughout life)

Question 8

Diaschisis

Answer 8

Can lead to wrongly attributing the lost functionality to the lesioned area rather than to the downstream area.

Question 9

(PET) Positron Emission Tomography

Answer 9

-Patient/participant is infused with a radioisotope
-The radioactive decay can be used to measure cerebral blood flow - this tells us what part of the brain is busy
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Question 10

X- Ray techniques

Answer 10

Non-invasive but do not image soft tissue in the brain and do not provide 3-D images.

Question 11

Computerised Tomography (CT)

Answer 11

• First technological breakthrough
• Uses movable x-ray tube that is rotated around the patients head
• Gathers intensity of information gleaned from multiple angles
• Today largely replaced by MRI

Question 12

Magnetic Resonance Imaging (MRI)

Answer 12

• When person is inside MRI protons in hydrogen atoms of the brain become aligned with the very strong main magnetic field of the scanner
• Resonance: Protons in a strong magnetic field will efficiently absorb energy when the energy is delivered at a particular resonant frequency of protons
• Imaging: In order to create an image from MR signal, electromagnetic coils in the scanner can cause the local magnetic field to differ in strength along specific directions

Question 13

Electroencephalography (EEG)

Answer 13

• Real time millisecond resolution of brain activity
• Poor spatial resolution due to spatial smearing
• EEG results from the combined activity of a large number of similarly oriented pyramidal neurons
• Requires synchronous activity across groups of cells
• EEG reflects summed post synaptic activity of large cell ensembles

Question 14

Magnetoencephalography (MEG)

Answer 14

• Real time millisecond resolution of brain activity
• Better spatial resolution than EEG
• Unlike EEG, MEG signal is not distorted by intervening tissue between generator and sensor

Question 15

Transcranial Magnetic Stimulation (TMS)

Answer 15

Focal magnetic pulses are used to disrupt brain function in localised brain areas