C8 Terms

Question 1

absolute threshold

Answer 1

The minimum stimulus intensity detectable 50% of the time, marking the boundary between detectable and undetectable stimuli.

It reflects sensory sensitivity and varies across individuals and conditions.

Question 2

adequate stimulation

Answer 2

The specific type of stimulus energy to which a sensory receptor is most responsive.

It explains why different nerves produce specific sensations regardless of how they are stimulated.

Question 3

Bell-Magendie Law

Answer 3

The principle that dorsal spinal roots carry sensory input and ventral roots carry motor output.

It established functional specialization in the nervous system.

Question 4

Broca’s area

Answer 4

A region in the left frontal lobe responsible for speech production.

Damage leads to expressive aphasia, where comprehension is intact but speech is impaired.

Question 5

clinical method

Answer 5

A research approach involving detailed study of individual cases, often with brain damage.

It helps link brain structures to functions.

Question 6

differential threshold

Answer 6

The smallest detectable difference between two stimuli.

Also called the just noticeable difference (jnd).

Question 7

doctrine of specific nerve energies

Answer 7

The idea that each sensory nerve produces a specific sensation regardless of stimulation type.

Perception depends on neural pathways, not external stimuli directly.

Question 8

formal discipline

Answer 8

The belief that mental faculties can be strengthened through exercise.

Influenced education by emphasizing training general abilities like memory and reasoning.

Question 9

just noticeable difference (jnd)

Answer 9

The smallest difference between two stimuli that can be detected.

It is a constant proportion of stimulus intensity (Weber’s law).

Question 10

kinesthesis

Answer 10

The sense of body movement and position from muscles and joints.

It allows coordination and awareness of limb placement.

Question 11

method of adjustment

Answer 11

A psychophysical method where participants adjust a stimulus until it meets a criterion.

It is quick but less precise.

Question 12

method of constant stimuli

Answer 12

A method presenting stimuli in random order to determine detection thresholds.

It is accurate but time-consuming.

Question 13

method of limits

Answer 13

A method using increasing or decreasing stimuli to find thresholds.

It balances efficiency and accuracy.

Question 14

negative sensations

Answer 14

Aftereffects where perception reverses after prolonged stimulation.

Example: seeing complementary colors after staring at a stimulus.

Question 15

panpsychism

Answer 15

The belief that all matter has some form of consciousness.

Associated with Fechner’s philosophical views.

Question 16

perception (Helmholtz)

Answer 16

The process of interpreting sensory input using unconscious inference.

The brain makes automatic assumptions to construct reality.

Question 17

personal equations

Answer 17

Systematic differences in observers’ reaction times.

They highlighted variability in human measurement.

Question 18

phrenology

Answer 18

The belief that mental traits are localized in brain areas and reflected in skull shape.

Though flawed, it promoted localization of function.

Question 19

physiognomy

Answer 19

The belief that personality traits can be inferred from facial features.

It lacks scientific support.

Question 20

principle of conservation of energy

Answer 20

Energy cannot be created or destroyed, only transformed.

Applied to physiology to reject vitalism.

Question 21

psychophysics

Answer 21

The study of relationships between physical stimuli and psychological experience.

It introduced quantitative methods to psychology.

Question 22

reaction time

Answer 22

The time between stimulus presentation and response.

Used to study mental processing speed.

Question 23

resonance place theory of auditory perception

Answer 23

The idea that different sound frequencies stimulate different places on the basilar membrane.

It explains pitch perception.

Question 24

sensation

Answer 24

The detection of physical stimuli by sensory receptors.

It is the raw input for perception.

Question 25

two-point threshold

Answer 25

The minimum distance at which two touches are perceived as separate. It varies across body regions.

Question 26

unconscious inference

Answer 26

Helmholtz’s idea that perception involves automatic, unconscious judgments. These inferences shape how we interpret sensory input.

Question 27

vitalism

Answer 27

The belief that living organisms are governed by a special life force. Rejected by mechanistic physiology.

Question 28

Weber’s law

Answer 28

The principle that the jnd is a constant proportion of the original stimulus. It shows perception is relative, not absolute.

Question 29

Young-Helmholtz theory of colour vision

Answer 29

The theory that color vision is based on three receptor types: red, green, and blue. Different combinations produce all perceived colors.