Chapter 4: Recognizing Objects

Question 1

Visual search tasks

Answer 1

Tasks in which study participants are asked to examine a display and judge whether a particular target is or is not present

I Spy, Where’s Waldo, etc.

Question 2

Test yourself

What is the difference between bottom-up and top-down processing?

Answer 2

Bottom-up processing refers to the process of starting with the stimulus itself while top-down is the process of starting with background knowledge

“Data driven” vs. relying on knowledge

Question 2

Bottom-up processing

Answer 2

Sequence of events governed by the stimulus input itself, often contrasted with top-down processing

Question 2

Tachistoscope

Answer 2

A device that allows the presentation of stimuli for precisely controlled amounts of time, including very brief presentations

Question 2

Word superiority effect (WSE)

Answer 2

We are better at recognizing letters if they appear in a word than if they appear in isolation

Question 2

Top-down processing

Answer 2

Sequence of events governed by the knowledge and expectations an individual brings to a situation, often contrasted with bottom-up processing

Question 2

Mask

Answer 2

Visual presentation used to interrupt the processing of another visual stimulus

Question 2

Priming

Answer 2

A process through which one input or cue prepares a person for an upcoming input or cue

Question 3

Repitition priming

Answer 3

A stimulus is presented again as a form of priming

Question 4

Test yourself

What is repetition priming and how is it demonstrated?

Answer 4

Repetition priming is a pattern of priming that occurs because the stimulus appears a second time

For example, if participants read a list of words aloud and are then presented with a series of words (some new some old), they’ll recognize the primed words at a higher rate

Question 5

Test yourself

What procedure demonstrates the WSE?

Word-superiority effect

Answer 5

Two-alternative forced-choice procedures

Question 6

Test yourself

What’s the evidence that word perception is somehow governed by rules of ordinary spelling?

Answer 6

• Errors are systematic
• Strong tendency to misread less-common letter sequences as if they were more-common sequences (Eg. “TPUM” as “TRUM”)

Question 7

Activation level

Answer 7

A measure of current status for a node or detector

Increased if the node or detector receives the appropriate input from its associated nodes or detectors

High if input received frequently or recently

Question 8

Feature nets

Answer 8

Systems for recognizing patterns involving a network of detectors

Detectors for features serve as the initial layer in each system

Question 9

Response threshold

Answer 9

Quantity of information/activation needed to trigger a response in a node or detector

AKA a response from a neuron

Question 10

Bigram detectors

Answer 10

Hypothetical units in a recognition system that respond or fire when a specific letter pair is in view

Dectors of pairs

Question 11

Locally represented

Answer 11

Mode of representation in which information is encoded in a small number of identifiable nodes

“One idea per node”

Contrast with distributed representation

Question 12

Distributed representation

Answer 12

There is no one node or specific group representing the content, and no one place where it is stored

Contrast with local representation

Question 13

Test yourself

How does a feature net explain the word-frequency effect?

Answer 13

Detectors reach their threshold faster if a word has been used recently/frequently

Question 14

Test yourself

How does a feature net explain the types of errors people make in recognizing words?

Answer 14

Some letters have very similar features, so if we see a nonword like “CQRN” briefly, it looks a lot like “CORN” and the feature net is based on recognizing these features

“Q” and “O” are nearly identical at a quick glance

Question 15

What are the benefits and what are the costs associated with the feature net’s functioning?

Answer 15

We easily recognize familar features

It is easy to mistake similar features at a glance

Question 16

The McClelland and Rumelhart model

Answer 16

Excitatory and inhibitory connections

Better able to identify characters in context as opposed to characters in isolation

Question 17

Excitatory connection

Answer 17

A link from one node/detector to another, such that activation of one activates the other

Contrast with inhibitory connection

Question 18

Inhibitory connection

Answer 18

A link from one node/detector to another, such that activation of one decreases that of another

Contrast with excitatory connection

Question 19

Recognition by components (RBC) model

Answer 19

A model of object recognition

Geons (hypothesized basic building blocks) compose all objects we recognize

Question 20

Geons (Geometric ions)

Answer 20

Basic shapes proposed as the building blocks of all complex 3D forms

Take the form of cylinders, cones, blocks, and the like, combining to create geon assemblies and then entire objects

Question 21

Prosopagnosia

Answer 21

Syndrome in which individuals lose the ability to recognize faces and to make other fine-grained discriminations within a highly familiar category

Other visual abilities seem intact

Question 22

Inversion effect

Answer 22

We have a much harder time recognizing an upside-down face than a rightside-up one

The effect is much less pronounced for objects compared to faces interestingly

Question 23

Holistic perception

Answer 23

Ability to identify an object depends on the whole rather than its parts

Question 24

The composite effect

Answer 24

When asked to id the top half of a face, participants have difficulty focusing on just the top instead of the whole

Question 25

Test yourself

What’s the evidence that word recognition is influenced by processes separate from what has been seen recently or frequently?

Answer 25

We rely on outside information, context to develop a complete understanding