2: Biological Foundations of Sensory Perception

Question 1

Action potential

Answer 1

A regenerative process of NA+ channel openings once the threshold potential is reached, resulting in a large depolarizing event immediately followed by repolarization due to K+ efflux.

Question 2

Adaptation

Answer 2

A brief period of reduced neural response that occurs after prolonged stimulation.

Question 3

Anion/cation

Answer 3

Anions are negatively-charged particles, and cations are positively-charged particles.

Question 4

Aphasia

Answer 4

An impaired ability to speak (Broca’s) or to understand language (Wernicke’s)

Question 5

Astrocyte

Answer 5

A type of glial cell that provides structural support to neurons, regulates the ionic balance in the fluid, and helps form a tight seal around blood vessels.

Question 6

Central nervous system

Answer 6

The term given to the brain and spine.

Question 7

Cerebral cortex

Answer 7

A thin band of cells that covers the surface of the brain.

Question 8

Cerebrum

Answer 8

The largest part of the brain consisting of two cerebral hemispheres.

Question 9

Cranial nerves

Answer 9

Sensory and motor nerves that emerge form the brain stem and proceed to various parts of the neck.

Question 10

Cytoarchitectonics

Answer 10

The architecture of the cerebral cortex in terms of its cellular composition and distribution among different layers. Different regions of the cortex display distinctive cytoarchitectonic features.

Question 11

Depolarization

Answer 11

A positive shift in the membrane potential that is usually caused by the influx of NA+ ions into the cell.

Question 12

Diffusion

Answer 12

A fundamental law of physics that states that molecules of a high concentration in one compartment will migrate to a neighbouring one if the concentration there is lower.

Question 13

Electroencephalogram

Answer 13

The record obtained by placing electrodes on the scalp and measuring the localized electrical activity in the underlying cortex.

Question 14

Event-related potentials

Answer 14

Electrical activity produced by sensory stimulation and picked up in an EEG

Question 15

fMRI

Answer 15

Functional magnetic resonance imaging; a non-invasiveimaging technique that relies on capturing radio waves from spinning atoms.

Question 16

Functional anatomy

Answer 16

The study of how anatomical features, such as cortical columns, contribute to the function of the nervous system leading to perception.

Question 17

Gamma rays

Answer 17

High energy photons that are released by radioactive substances or after collisions between atomic particles.

Question 18

Gyrus

Answer 18

An elevated convulsion on the surface of the brain, usually separated by sulci on either side.

Question 19

Hemoglobin

Answer 19

The oxygen-carrying protein that is found inside red blood cells.

Question 20

Histology

Answer 20

Study of the fine structure and organization of a tissue or organ at the microscopic level.

Question 21

Hyperpolarisation

Answer 21

A negative shift in membrane potential that sometimes occurs at the end of an action potential due to an excessive efflux of K+ ions.

Question 22

In vivo, in vitro

Answer 22

In vivo takes place within the body while in vitro takes place outside of the body.

Question 23

Interneurons

Answer 23

Neurons that process information within the CNS. Local neurons process information within specific brain sites, whereas projection interneurons transmit information, often over large distances, to other brain sites in the same or opposite hemisphere.

Question 24

Lateralization

Answer 24

The idea that certain behavioural functions are dominated by one hemisphere.

Question 25

Lesion studies

Answer 25

Surgical removal of a brain region in an animal followed by careful examination of any behaviour changes. Humans are also subjects following surgery or brain damage.

Question 26

Membrane potential

Answer 26

A voltage difference across the cell membrane that arises due to the separation of charges. The inside of a cell is negative compared to the outside.

Question 27

Modality

Answer 27

One of the primary sensory forms, such as vision, touch, etc.

Question 28

Multipolar and bipolar neurons

Answer 28

Neurons in which multiple dendrites emerge from the cell body. Bipolar neurons only have a single dendritic process. They only have 1 axon each.

Question 29

Myelin

Answer 29

The insulating material formed by glial cells. These cells form the myelin sheath by wrapping their cell membranes around an axon several times.

Question 30

Neuron doctrine

Answer 30

The principle that the nervous system is composed of a network of interconnected cellular elements, neurons.

Question 31

Neurotransmitters

Answer 31

Specialized chemicals that are involved in the transmission of neural signals across the synapse.

Question 32

Nucleus

Answer 32

A collection of brain cells within the CNS

Question 33

Oligodendrocyte

Answer 33

A type of glial cell found in the CNS that is responsible for producing the myelin sheath around axons.

Question 34

Parallelism

Answer 34

The presence of multiple pathways within a given sensory system that transmit and process different features of a complex stimulus in a more or less independent manner.

Question 35

Peripheral nervous system

Answer 35

A term given to the spinal nerves and other associated neural structures that are outside the CNS.

Question 36

Phenomenology

Answer 36

A mere descriptive account of phenomena without attempting to account for the underlying cause.

Question 37

Phrenology

Answer 37

The first complete theory of cerebral localization proposed by Gall in the 18th century.

Question 38

Presynaptic

Answer 38

The neuron that carries action potentials towards a synapse is this neuron.

Question 39

Postsynaptic

Answer 39

The recipient of presnyaptic signals.

Question 40

Receptive field

Answer 40

The area on a sensory surface that will influence the activity of a neuron, regardless of where it is located in the hierarchy of the nervous system.

Question 41

Receptor potential

Answer 41

The result of transduction process that creates a change in the membrane potential of receptor neurons.

Question 42

Schwann cell

Answer 42

A type of glial cell found only in the PNS that produces the myelin sheath in peripheral nerve fibers.

Question 43

Sodium-potassium pump

Answer 43

A membrane-bound protein that ejects NA+ ions from the cell and brings K+ ions back in.

Question 44

Somatosensory

Answer 44

This system deals with all aspects of touch perception.

Question 45

Spatial resolution

Answer 45

The ability to distinguish different physical stimuli that are separated in space when they’re close together.

Question 46

Sulcus

Answer 46

A narrow fissure that separates adjacent convolutions of the brain.

Question 47

Synapse

Answer 47

A physical gap at the junction between two neurons.

Question 48

Synaptic potential

Answer 48

A change in the membrane potential of the postsynaptic neuron that results from neurotransmitters binding to specialized receptors.

Question 49

Temporal resolution

Answer 49

The ability to distinguish physical stimuli that are applied at different moments in time rapidly.

Question 50

Transduction

Answer 50

The transformation of energy contained in a physical stimulus into a biological signal by a sensory receptor neuron.