Chapter 1—Introduction to Perception

Question 0

Action

Answer 0

Motor activities such as moving the head or eyes and locomoting through the environment. Action is one of the major outcomes of the perceptual process.

Question 1

Absolute threshold

Answer 1

The minimum stimulus energy necessary for an observer to detect a stimulus.

Question 2

Bottom-up processing

Answer 2

Processing that is based on the information on the receptors. Also called data-based processing.

Question 3

Classical psychophysical model

Answer 3

The methods of limits, adjustment, and constant stimuli described by Fechner, that are used for measuring thresholds.

Question 4

Cognitive influences on perception

Answer 4

How the knowledge, memories, and expectations that a person brings to a situation influences his or her perception.

Question 5

Difference threshold

Answer 5

The minimal detectable difference between two stimuli

Question 6

Environmental stimulus

Answer 6

The stimulus “out there,” in the external environment.

Question 7

Frontal lobe

Answer 7

Receiving signals from all the senses, the frontal lobe play an important role in perceptions that involve the coordination of information received through two or more senses. It also serves functions such as language, thought, memory, and motor functioning.

Question 8

Knowledge

Answer 8

Any information that the perceiver brings to a situation.

Question 9

Magnitude estimation

Answer 9

A psychophysical method in which the subject assigns numbers to a stimulus that are proportional to the subjective magnitude of the stimulus.

Question 10

Method of adjustment

Answer 10

A psychophysical method in which the experimenter or observer adjusts the stimulus intensity in a continous manner until the observer detects the stimulus.

Question 11

Method of constant stimuli

Answer 11

A psychophysical method in which a number of stimuli with different intensities are presented repeatedly in a random order.

Question 12

Method of limits

Answer 12

A psychophysical method for measuring threshold in which the experimenter presents sequences of stimuli in ascending and descending order.

Question 13

Neural processing

Answer 13

Operations that transform electrical signals within a network of neurones or that transform the response of individual neurones.

Question 14

Oblique effect

Answer 14

Enhanced sensitivity to vertically and horizontally oriented visual stimuli compared to obliquely oriented (slanted) stimuli. The effect has been demonstrated by measuring both perception and neural responding.

Question 15

Occipital lobe

Answer 15

A lobe at the back of the cortex that is the site of the cortical receiving area for vision.

Question 16

Optical system

Answer 16

The parts of the eye through which the physical energy of light passes and whose job is to focus the image for perception.

The parts of the optical system include the cornea, which is at the front of the eye, and the lens directly behind it.

Question 18

Parietal lobe

Answer 18

A lobe at the top of the cortex that is the site of the cortical receiving area for touch and is the termination point of the dorsal (where or how) stream for visual processing.

Question 19

Perceived magnitude

Answer 19

A perceptual measure of stimuli, such as light or sound, that indicates the magnitude of experience.

Question 20

Perception

Answer 20

Conscious sensory experience

Question 21

Perceptual process

Answer 21

A sequence of steps leading from the environment to perception of a stimulus, recognition of the stimulus, and action with regard to the stimulus.

Namely: 1. Environmental stimulus; 2. Transformation of energy; 3. Receptor processes; 4. Neural processing; 5. Perception; 6. Recognition; 7. Action

Question 22

Phenomenological method

Answer 22

Method of determining the relationship between stimuli and perception in which the observer describes what he or she perceives.

Question 23

Physiological approach to perception

Answer 23

Analysing perception by determining how a person’s perception is related to physiological processes that are occurring within the person. This approach focuses on determining between stimuli and physiological responding and between physiological responding and perception.

Question 24

Power function

Answer 24

A mathematical function of the form P=KSⁿ, where P is perceived magnitude, K is a constant, S is the stimulus intensity, and ⁿ is an exponent.

Question 25

Primary receiving areas

Answer 25

Areas of the cerebral cortex that first receives most of the signals initiated by a sense’s receptors. For example, the occipital cortex is the site of the primary receiving area for vision, and the temporal lobe is the site of the primary receiving area for hearing.

Question 26

Principle of representation

Answer 26

A principle of perception that states that everything a person perceives is based not on direct contact with stimuli but on representations of stimuli on the receptors and in the person’s nervous system.

Question 27

Principle of transformation

Answer 27

A principle of perception that states that stimuli and responses created by stimuli are transformed, or changed, between the environmental stimulus and perception.

Question 28

Psychophysical approach to perception

Answer 28

Analysing perception by determining how a person’s perception is related to stimuli in the environment. This approach focuses on determining the relationship between stimuli in the environment and perceptual responding.

Question 29

Psychophysics

Answer 29

Traditionally, the term psychophysics refers to quantitative methods for measuring the relationship between properties of the stimulus and the subject’s experience. In the book, all methods that are used to determine the relationship between stimuli and perception will be broadly referred to as psychophysical methods.

Question 30

Rat-man demonstration

Answer 30

The demonstration in which the presentation of a “ratlike” or “manlike” picture influences an observer’s perception of a second picture, which can be interpreted either as a rat or as a man. This demonstration illustrates an effect of top-down processing on perception.

Question 31

Reaction time

Answer 31

The time between presentation of a stimulus and an observer’s or listener’s response to the stimulus. Reaction time is often used in experiments as a measure of speed of processing.

Question 32

Recognition

Answer 32

The ability to place an object in a category that gives it meaning—for example, recognising a particular red object as a tomato.

Question 33

Response compression

Answer 33

The result when doubling the physical intensity of a stimulus less than doubles the subjective magnitude of the stimulus.

Question 34

Response criterion

Answer 34

In a signal detection experiment, the subjective magnitude of a stimulus above which the participant will indicate that the stimulus is present.

Question 35

Retina

Answer 35

A 0.4-mm thick network of nerve cells that covers the back of the eye and that contains the receptors for vision.

Question 36

Response expansion

Answer 36

The result when doubling the physical intensity of a stimulus more than doubles the subjective magnitude of the stimulus.

Question 38

Sensory receptors

Answer 38

Cells specialised to respond to environmental energy, with each sensory system’s receptors specialised to respond to a specific type of energy.

Question 39

Signal detection theory

Answer 39

A theory stating that the detection of a stimulus depends both on the participant’s sensitivity to the stimulus and on the participant’s response criterion

Question 40

Steven’s power law

Answer 40

A law concerning the relationship between the physical intensity of a stimulus and the perception of the subjective magnitude of the stimulus. The law states that P=KSⁿ, where P is perceived magnitude, K is a constant, S is the stimulus intensity, and ⁿ is an exponent.

Question 41

Temporal lobe

Answer 41

A lobe on the side of the cortex that is the site of the cortical receiving area for hearing and the termination point for the ventral, or what, stream for visual processing. A number of areas in the temporal lobe, such as the fusiform face area and the extrastriate body area, serve functions related to perceiving and recognising objects.

Question 42

Top-down processing

Answer 42

Processing that starts with the analysis of high-level information, such as the knowledge a person brings to a situation. Also called knowledge-based processing. Distinguished from bottom-up, or data-based processing, which is based on incoming data.

Question 43

Transduction

Answer 43

In the senses, the transformation of environmental energy into electrical energy. For example, the retinal receptors transduce light energy into electrical energy.

Question 44

Visual form agnosia

Answer 44

The inability to recognise objects.

Question 45

Visual pigment

Answer 45

A light-sensitive molecule contained in the rod and outer cone segments. The reaction of this molecule to light results in the generation of an electrical response in the receptors.

Question 46

Visual search

Answer 46

A procedure in which a person’s task is to find a particular element in a display that contains a number of elements.

Question 47

Weber fraction

Answer 47

The ratio of the difference threshold to the standard stimulus in Weber’s law.

Question 48

Weber’s law

Answer 48

A law stating that the ratio of the difference threshold (DL) to the value of the stimulus (S) is constant. According to this relationship, doubling the value of a stimulus will cause a doubling of the difference threshold. The ratio DL/S is called the Weber fraction.