Chapter 2: Visual and Auditory Recognition

Question 1

Define perception.

Answer 1

Perception involves using previous knowledge to gather and interpret the stimuli registered by the senses.

Question 2

Define object recognition.

Answer 2

Object recognition (aka pattern recognition) is when you perceive a pattern as separate from its background in a complex arrangement of sensory stimuli.

Question 3

Define distal stimulus.

Answer 3

A distal stimulus is the object that is in the environment that is being perceived during visual processing.

Question 4

Define proximal stimulus.

Answer 4

A proximal stimulus is the information registered on your sensory receptors on your retina that registers and transmits visual information from the environment (i.e. the distal stimulus).

Question 5

What is sensory memory?

Answer 5

Sensory memory is a large-capacity storage system that records information from each of the senses with reasonable accuracy.

Question 6

How does visual sensory memory work?

Answer 6

Iconic memory (or visual sensory memory) preserves an image of a visual stimulus for a brief period after the stimulus has disappeared.

Question 7

Describe the primary visual cortex.

Answer 7

It is located in the occipital lobe and is concerned with the basic processing of visual stimuli. Visual information registered on the retina makes its way through a set of neurons to the primary visual cortex where the information from each eye is combined. The primary visual cortex is the first stop within the cortex for visual perception.

Question 8

Describe the ambiguous figure-ground illusion.

Answer 8

The ambiguous figure-ground illusion happens when the figure (distinct shape with clearly defined edges) and the ground (background region) reverse from time to time such that one portion stands out while the other recedes into the background. Due to the ambiguous situation, the figure and ground exchange places back and forth.

Question 9

Describe the illusory contour effect.

Answer 9

The illusory contour (aka subjective contour) effect happens when a figure-ground relationship is perceived even though there is no clear-cut boundary between the figure and the ground in the stimulus.

Question 10

What do the ambiguous figure-ground illusion and the illusory contour effect indicate about visual processing?

Answer 10

These illusions indicate that humans “fill in the blanks.” Human perception is more than the sum of the information in the distal stimulus.

Question 11

Describe the template matching theory of object recognition.

Answer 11

Templates are specific patterns stored in memory that our visual system compares stimuli to. When the stimuli matches a template we recognize the object.

It does not account for the flexibility with which people can recognize complex objects in the visual world that differ substantially from the template (e.g., recognizing the same word written in different handwriting).

Question 12

Describe the feature-analysis models of object recognition.

Answer 12

Feature-analysis models propose that visual stimuli are composed of a small number of characteristics or components (called distinctive features) and the visual system notes the absence or presence of these features and compares them to a list of features stored in memory in order to recognize objects. They explain how two-dimensional patterns are perceived.

They offer an explanation for how people can recognize objects that may differ from a template because the distinctive features stay constant. But the research focuses on numbers and letters and is largely untested with more complex visual stimuli.

Question 13

Describe the recognition by components model of object recognition.

Answer 13

The recognition-by-components model offers an explanation for how humans recognize 3-dimensional shapes. A specific view of an object can be represented as an arrangement of geons (3D shapes). Geons can be combined in different ways to make meaningful objects. Generally, 3 geons are needed to classify an object.

There is insufficient research to explain how complex, real-world objects and scenes are recognized.

Question 14

What is bottom-up processing?

Answer 14

Bottom-up processing is when the physical stimuli from the environment are registered on the sensory receptors. Then this information is passed on from the sensory receptors to the cognitive regions of the brain for object recognition.

Question 15

What is top-down processing?

Answer 15

Top-down processing is when higher-level mental processes like a person’s concepts, expectations, and memory influence object recognition.

Question 16

How does top-down processing affect object recognition?

Answer 16

It is strong when stimuli are incomplete or ambiguous and uses context and existing knowledge to fill in the missing information.

Question 17

What is the word superiority effect?

Answer 17

The word superiority effect describes people’s ability to identify a single letter faster and more accurately when it appears in a meaningful word compared to when it appears alone or in a meaningless string of letters. It is an example of top-down processing.

Question 18

What is change blindness?

Answer 18

Change blindness occurs when a person fails to detect a change in an object or a scene because their top-down processing encourages them to assume that the basic meaning of the scene will remain stable. As a result, people often miss obvious changes when those changes are unimportant.

Question 19

What is inattentional blindness?

Answer 19

Inattentional blindness occurs when people fail to notice that a new object has appeared. This may happen because the new object is not consistent with their concepts, expectations, and memory, because they were paying attention to other visual stimuli, or because they were simultaneously completing a cognitive demanding task.

Question 20

What do change blindness and inattentional blindness say about top-down processing and the visual system?

Answer 20

The visual system uses top-down processes in daily life to create accurate general interpretations of our visual environment without becoming overwhelmed by the precise details of all the stimuli around us and the moment-to-moment trivial changes in them. Also, cognitive errors can often be traced back to a rational strategy.

Question 21

How is face perception different from normal object recognition?

Answer 21

Research evidence suggests that faces have a special status in our perceptual system. Evidence includes infants’ preference for faces over other stimuli and the tendency for people to perceive faces in terms of their gestalt.

Question 22

Define prosopagnosia.

Answer 22

Prosopagnosia is the term used to describe people who cannot recognize human faces even though they are able to perceive other objects relatively normally.

Question 23

What does the neuroscience research on face recognition indicate?

Answer 23

People with prosopagnosia only have difficulty perceiving faces, not common objects. This has been taken as evidence for the existence of special mechanisms underlying face processing. Cells in the inferotemporal cortex play a role in perceiving faces which offers a possible location for these special mechanisms.

Question 24

What are the four characteristics of speech perception?

Answer 24

1. word boundaries
2. variability in phoneme pronunciation
3. context and speech perception
4. visual cues as an aid to speech perception

Question 25

What do the four characteristics of speech perception reveal about the complexity of speech perception?

Answer 25

People overcome less-than-ideal speech stimulus information to perceive speech with considerable speed and accuracy. This is done by ignoring variability in phoneme pronunciation and using context and visual cues to resolve ambiguous phonemes.

Question 26

What are the two theories of speech perception?

Answer 26

1. special mechanism approach

2. general mechanism approaches

Question 27

Explain the special mechanism approach.

Answer 27

Humans have a specialized device for decoding speech stimuli that we are born with called the phonetic module. The phonetic module is a special-purpose neural mechanism that processes all aspects of speech perception and no other auditory information. It functions independently of other general cognitive functions.

Question 28

Explain the general mechanism approaches.

Answer 28

The same neural mechanisms are used to process both speech and nonspeech sounds. There is no special neural mechanism for speech.