C - Attention

Question 1

Theories of attention

Answer 1

Treisman’s attenuation theory (1960)
- subjects de-emphasize but not filter out the unattended message. Listeners engaged in verbal shadowing occasionally say words presented to the unattended ear and some subjects switched ears even when told not to, following the semantic content.

• These breakthroughs occur when unattended messages are relevant (e.g. fit semantic context or expectations).
• Top-down driven.

Late selection theory (Deutsch, 1963)
- The limitation is in the response system, not at the level of perception.
- Both messages are perceived in terms of meaning, but only one can be shadowed at a time.
- The selection criterion for what to say can change – based on ear or meaning.

Question 2

Space based attention vs Object based theory

Answer 2

SBA
Spotlight: attenetion to locations in a space and process whatever is there, moving eyes changes area of spotlight
Zoom lens: can be broad or narrow, broad areas are less well processed

OBA
Attention often focused on certain objects even if FOV is larger

Question 3

Two components of active attention

Answer 3

1. Focused (selective) attention: only focuses on one source of information while other stimuli are ignored
2. Divided attention: Two or more tasks performed simultaneously (multitasking).

Question 4

Empirical studies for auditory attention

Answer 4

• ‘Cocktail party’ problem: many sounds at once in a party, how do we pick out the relevant sounds?

Colin Cherry (1953)
- Dichotic listening task: a different message is presented to each ear and ppts asked to attend to only one
Findings: people did not remember content of unattended ear, ppts screened out unwanted info and only noticed physical characteristics
- Verbal shadowing: repeating the attended message aloud as it is presented

Question 5

Feature integration theory

Answer 5

Visual search is a two-stage process:
1. Pre-attentive: rapid, parallel processing across a visual scene (single features ‘pop out’, bottom-up detection.
2. Attentive: slow, serial processing while searching for conjunctive features that make up an object.

• Binding features together to form an object requires focused attention.
• In the absence of focused attention, features are miscombined, resulting in ILLUSORY CONJUNCTIONS.

Question 6

The processes required in visual search

Answer 6

Visual search involves processing object features (colour, size, line orientation) and objects as a whole.