Week 1: Introduction

Question 1

Absolute Threshold

Answer 1

AKA Detection Threshold

The intensity required for detecting a stimulus (lower is better).

Question 2

Adaptation

Answer 2

Prolonged stimulation results in a decrease in the rate of firing.
Results: increased detection threshold for similar stimuli; reduction of perceived intensity for similar suprathrshold stimuli; perceived properties of other similar stimuli can appear biased (e.g. motion aftereffects).

Question 3

Axon

Answer 3

The long slender projection of a neuron that conducts electrical impulses away from the cell body.

Question 4

Action Potential

Answer 4

Brief burst of electrical activity that travels along a neuron’s axon. It’s passed on to other neurons when it triggers chemical signal messages in the synapse.

Question 5

Bias

Answer 5

…

Question 6

Plasticity

Answer 6

Neural mechanisms are modifiable, i.e. neural paths can adapt or be changed.
Examples: during development or when recovering from a brain injury.

Question 7

Compressive Non-linearity

Answer 7

Increases in sensory magnitude are not experienced in a linear manner. I.e. if the intensity of the stimulus is doubled, the sensation of the new level is less than double. This allows us to detect very small changes in stimulus intensity.

Question 8

Cortical Magnification

Answer 8

Stimuli that are deemed more important/more useful are processed by a larger amount of cortex.

Question 9

Detectability

Answer 9

The more intense a stimulus is, the more likely you will detect it.

Question 10

Detection Threshold

Answer 10

AKA Absolute Threshold.

The intensity required for detecting a stimulus (lower is better).

Question 11

Discrimination Threshold

Answer 11

The difference in intensity between two stimuli required for successful discrimination.
AKA “Just Noticeable Difference” (JND)

Question 12

Feedback

Answer 12

When the brain influences its processing with its own electrical field.

Question 13

Functional Magnetic Resonance Imagery (fMRI)

Answer 13

Neuroimaging technique which indirectly maps neural activity by measuring blood-oxygen levels. The more oxygen used in certain area, the more neural activity must be occurring.

Question 14

Grey Matter

Answer 14

The darker tissue of the brain, mostly found in the outer layer and consisting mostly of the cell bodies.

Question 15

Hierarchical Processing

Answer 15

Neural impulses travel “up” the cortex, from the least to most complex regions.

Question 16

Transcranial Magnetic Stimulation (TMS)

Answer 16

A method of creating transient lesions to study brain function. A magnetic field is generated over certain areas of the brain which interferes with the electrical signals.

Question 17

Lateral Connections

Answer 17

Information travels sideways to different parts of the brain as well as from the bottom-up and top-down.

Question 18

Tuning

Answer 18

Certain cells fire more vigorously when the stimulus matches the characteristics they prefer (e.g. a vertical line; a note of a certain pitch).

Question 19

Sensory Magnitude

Answer 19

Measuring perceived stimulus intensity.

Question 20

Thalamus

Answer 20

The “Relay Station” of the brain: part of the brain through which almost all sensory information (not olfaction) goes through on its way to higher cortical levels.

Question 21

White Matter

Answer 21

The lighter tissue in the brain, consisting mostly of axons (which are covered with a light-coloured tissue called myelin).

Question 22

Microstimulation

Answer 22

Method of investigating neural activity by stimulating individual neurons (usually in cats or primates) using microelectrodes.

Question 23

Optical Imaging

Answer 23

Method of investigating surface neural activity wherein part of the skull is cut out (exposing the cortical surface) and an extremely sensitive camera is used to monitor blood levels in that area whilst the subject performs certain activities.

Question 24

Neural Impulse

Answer 24

AKA Action Potential.
Brief burst of electrical activity that travels along a neuron’s axon and is passed on to other neurons when it triggers chemical signal messages in the synapse.

Question 25

Staining Techniques

Answer 25

Injecting substances into neurons which colours certain cells or certain regions of the brain.

Question 26

White Matter

Answer 26

The lighter tissue in the brain, consisting mostly of axons (which are covered with a fatty insulating tissue called myelin).

Question 27

Visually Evoked Potentials (VEPs)

Answer 27

Patterns of neural activity in response to visual stimulus, which are measured at the back of the brain (the occipital cortex) using electroencephalography (EEG).

Question 28

Yes-No Paradigm

Answer 28

A paradigm in which participants are presented with a series of stimuli (e.g. images) and asked to decide whether or not each image fits into a certain category.

Question 29

Two Alternative Forced Choice (2AFC)

Answer 29

A method for psychophysics: paradigm for measuring the subjective experience of a subject through the pattern of their choices and response times.
Subjects are presented with two alternative scenarios (e.g. which interval of time does the flash occur) and asked to choose the correct one.

Question 30

Probe Stimulus

Answer 30

???

Question 31

Psychometric Function

Answer 31

An inferential (mathematical) model used in detection/discrimination tasks: the curve on the graph marks the probability that a stimulus/differential of a certain intensity will be detected by an individual.

Question 32

Receptor

Answer 32

A neural cell which detects a stimulus, transducing the external energy into electrical energy (action potentials).

Question 33

Suprathreshold

Answer 33

Describes a stimulus that is intense enough (large enough in magnitude) to produce an action potential in the neuron which detects it.