04 Attention

Question 1

overt vs. covert attention

Answer 1

• overt: attention is focused by physically directing the eyes to the stimulus of interest
• covert: ability to select a region of visual space for in-depth processing without moving the eyes, decoupling of attentional focus and gaze
• eye movements and attention are controlled by highly similar networs in parietal (IPS) and frontal cortex (FEF)

Question 2

exogenous vs. endogenous attention

Answer 2

• exogenous: bottom-up capture of attention by saliency (involuntary), ventral network (TPJ (IPL/STG), VFC (IFg/MFg))
• endogenous: top-down orientation of attention (voluntary), dorsal network (FEF, IPs/SPL)

Question 3

Early vs. late selection models

Answer 3

• early selection: selection prior to semantic analysis, e.g. Broadbent’s filter model
• evidence: dichotic hearing experiments: participants reported change in voice but not in language on the unattended ear
• late selection: selection during/after semantic analysis, e.g. cocktail party phenomenon

Question 4

parallel vs. serial visual search

Answer 4

• parallel search: singleton, pop-out, preattentive, RT constant
• serial search: feature conjunction, attention required, RT increases with set size

Question 5

Treisman’s feature-integration theory

Answer 5

• different cortical maps for different features
• features are processed in parallel
• feature conjunction requires attention to bind different features across different maps