3.5 Methods to Measure Neural Activity

Question 1

single-cell recording

Answer 1

By measuring the action potentials produced by individual neurons in living animals, researchers could begin to uncover how the brain responds to sensory information, produces movement and changes with learning. The primary goal of a single-cell recording experiments is to determine which experimental manipulations produce a consistent change in the response rate of an isolated cell.

Question 2

receptive field

Answer 2

All visually sensitive cells respond to stimuli in only a limited region of space.

Question 3

retinotopic maps

Answer 3

Neighboring cells have at least partially overlapping receptive fields. As such, cells form a topographic representation - in vision, we refer to topographic representations as retinotopic maps.

Question 4

multiunit recording

Answer 4

A neurophysiological method in which an array of electrodes is inserted in the brain such that the activity of many cells can be recorded simultaneously.

Question 5

electrocorticography (ECoG)

Answer 5

where a grid or strip of electrodes is placed directly on the surface of the brain, either outside the dura or beneath it, and the activity of the populations of neurons is recorded for a sustained amount of time.

Question 6

electrocorticogram

Answer 6

In a second procedure, they remove the electrodes and perform the corrective surgery. Researchers can stimulate the brain with the electrodes, using them to localize and map cortical and subcortical neurological functions such as motor or language function. The time-varying record of the signals from the electrodes is an electrocorticogram.

Question 7

event-related potential (ERP)

Answer 7

is a tiny signal embedded in the ongoing EEG triggered by the stimulus or movement. ERP’s also provide an important tool for clinicians. The visual evoked potential can be useful in diagnosing multiple sclerosis, a disorder that leads to demyelination.

Question 8

magnetoencephalography (MEG)

Answer 8

a technique that measures the magnetic fields produced by the brain’s electrical activity. As with EEG, the MEG traces over a series of trials to obtain event-related signals, called event-related fields.