Mod. 6 - Video 1 - Overview of Sensory System

Question 1

Specific types of sensory information are carried along specific afferent pathways and processed by specific brain regions.

A. True
B. False

Answer 1

A. True

Explanation:

This statement is true: all sensation begins with the detection of stimuli by a receptor, and specific types of sensory information are carried along specific afferent pathways and processed by specific brain regions

Question 2

Converting mechanical energy into a neural signal is an example of which of the following?

A. absolute threshold
B. sensory transduction
C. signal detection theory

Answer 2

B. sensory transduction

Explanation:

The conversion of a sensory stimulus (form of energy) into a neural signal is called sensory transduction. The absolute threshold is the minimum stimulus intensity that must be present in order for a stimulus to be detected at least 50% of the time. Signal detection theory states that detection of a sensory signal depends on the stimulus intenstiy and the physical and psychological state of the person.

Question 3

The type of stimulus that a sensory receptor is adapted to respond to is considered the adequate stimulus for that receptor.

A. True
B. False

Answer 3

A. True

Explanation:

This statement is true: in each sensory system there is an adequate stimulus for which the sensory receptor is particularly sensitive ( meaning it has a low threshold for activation and high sensitivity to changes in stimulus intensity). Thus, the receptor is adapted to respond to that particular stimulus.

Question 4

The minimum amount by which stimulus intensity must be changed in order to produce a noticeable variation in sensory experience is called the absolute threshold for that stimulus.

A. True
B. False

Answer 4

B. False

Explanation:

This statement is false: the minimum amount by which a stimulus intensity must change in order to produce a noticeable variation in sensory experience is known as the “just noticeable difference” and it is a constant proportion of the original stimulus intensity. Again, the absolute threshold is the minimal stimulus intensity needed in order for the stimulus to be detected 50% of the time (e.g., the lightest touch that can be felt).

Question 5

Receptive field properties of neurons and the topographical organization in the central nervous system allows the sensory system to encode which of the following?

A. stimulus modality
B. stimulus location
C. stimulus duration

Answer 5

B. stimulus location

Explanation:

The topographic arrangements in the CNS, such that excitation of receptors in a specific location results in activity within a specific area of the CNS (receptive field properties of neurons) is how the sensory system encodes spatial location of stimuli. Stimulus modality is encoded by the receptor being responsive to one type of stimuli (adequate stimulus for the receptor) and by the processing of that signal in dedicated afferent pathways/brain regions; stimulus duration is encoded by the different adaptive capacities of receptors (some will be slowly adapting and others rapidly adapting.

Question 6

An increasing number of action potentials being fired by a single sensory receptor as stimulus intensity increases is an example of population coding.

A. True
B. False

Answer 6

B. False

Explanation:

This statement is false: an increase in the rate of production of action potentials as stimulus intensity increases is an example of FREQUENCY CODING. Activation of a greater number of receptors as stimulus intensity increases is an example of POPULATION CODING.

Question 7

Which of the following receptors detects stimuli from muscles, tendons, and joints?

A. exteroceptors
B. proprioceptors
C. special sensory receptors

Answer 7

B. proprioceptors

Explanation:

Proprioceptors detect stimuli from muscles, tendons, and joints and allow us to sense limb position and changes in limb position (movement); exteroceptors detect stimuli from the external world that comes in contact with our body surfaces allowing us to detect touch, pressure, vibration, pain and temperature sensations; special sensory receptors are located in the head and detect various types of stimuli allowing us to have our 5 special senses.