Cognitive Neuroscience Lecture 1 - Intro And Imaging Methods

Front 1

Dual-aspect theory (Of the mind-body problem)

Back 1

The notion that the mind and brain are two levels of explanation of the same thing.

Front 2

Phrenology

Back 2

A now disbanded theory based on the assumption that the shape of the head corresponded to personality traits.

Front 3

Functional Specialisation

Back 3

The still relevant assumption that there is some degree of specialisation of neurones in certain areas of the brain.

Front 4

Wilder penfield's famous electrical stimulation experiment.

Back 4

Observed that physical stimulation of the brain created mental and subjective phenomena for the individual. gives credence to idea of physical basis of mental experiences.

Front 5

Single-cell recording

Back 5

An invasive technique that directly measures the number of action potentials per second across an electrode planted directly into the brain.

Front 6

ERP (event related potential)

Back 6

An averaged voltage fluctuation representing a spike in brain activity. Can be shown to represent a particular mental event such as the recogniton of any face (n170) or a famous or familiar face (p300)

Front 7

EEG (electroencephalography)

Back 7

A non-invasive electrophysiological technique in which a cap of 10-20 electrodes are placed on the scalp. The activity in various areas of the brain are gained as a function of the difference in electrical activity recorded between different electrodes.

Front 8

The 4 classsic types of brainwaves.

Back 8

Delta, theta, alpha and beta

Front 9

MEG (magnetoencephalography)

Back 9

A very expensive and advanced neuroimaging technique that makes use of Superconducting Quantum Interference devices or SQUIDS.
A functional model of the brain can be produced by detecting the fluctuations of magnetic fields produced by the electrical activity in the brain.

Front 10

MRI (structural)

Back 10

A neuroimaging technique that uses strong magnets and radiology to create a STATIC image of the brain.

Front 11

CT scan (computed tomography)

Back 11

A relatively primative neuroimaging method that creates a 3D image of the brain through differential absorbtion of x-rays.

Front 12

PET scan (positron emission tomography)

Back 12

A neuroimaging method that works by detecting the radioactive decay of a tracer injected into the blood stream. When the material in an active brain area (carried there by the increased need for blood flow) undergoes radioactive decay, a positron is released and picked up by detectors. Areas of higher radioactivity are associated with greater brain activity.

Front 13

fMRI (Functional)

Back 13

one of the most widely used techniques in modern functional neuroimaging. Uses strong magnets and radiology to create a 3D living image of the brain. Poor temporal resolution.

Front 14

BOLD response.
(Blood oxygen level dependent contrast)

Back 14

The basis of MRI (both structural and functional). blood oxygenation is a sign of neural activity. the contrast in blood oxygenation is a contrast from which brain activity is inferred.

Front 15

Voxels

Back 15

the smallest distinguishable part in a 3D brain image. short for volume pixels.

Front 16

The reason why blood flow or oxygenation should always be measured RELATIVE to other areas.

Back 16

The whole brain must have some degree of oxygenation and blood flow at all times or it would die. (What does this mean for measuring brain activity?)

Front 17

cogntive subtractions

Back 17

the process of subtracting control/baseline activity in a neuroimaging study from experimental conditions to work out areas of higher relative activity.

Front 18

pure insertion

Back 18

an assumption of neuroscience that an increase in neural activity is directly related to the introduction of a new cognitive task to a participant and not that the resulting higher activity is indicative of an overall change in brain function. basically it is assumed that you can add a requirement to an individual and what you measure as a result of that new task is built UPON the previous activity. not that the whole nature of the process involved have changed.

Front 19

Reasons why you may see lesion data that suggests a brain area is involved in a task but neuroimaging shows no increased activation while performing that task.

Back 19

may be intrinsically difficult to measure activity in that brain area.
Impaired performance after lesion may be due to damage of tracts running through affected area.

Front 20

Why imaging data might show an area is crucial in a task but lesion data of the same area shows no defecit in this task

Back 20

Because the imaging may be picking up inhibition of an area as opposed to activation.
region that looks active in imaging may not be crucial to the task rather it reflects a general cognitive process.

Front 21

TMS (Transcranial magnetic stimulation)

Back 21

A method of interfering with electrical activity in the cortex by way of holding electric coils over the area creating a magnetic field. can work out function of an area by seeing what defecits follow the interferrence of this area.

Front 22

tDCS (transcranial direct current stimulation)

Back 22

A method of facilitating electical activity in the brain by creating a weak current flow across the skull. An anode is placed at one side of the brain and a cathode on the other. Has been shown to improve stroke and altzheimers patients.