7.4 Neural Mechanisms of Attention and Perceptual Selection

Question 1

Visuospatial attention

Answer 1

nvolves selecting a stimulus on the basis of its spatial location. It can be voluntary, or it can be reflexive,

Question 2

Spatial attention

Answer 2

influences the processing of visual inputs: attended stimuli produce greater neural responses than do ignored stimuli, and this process takes place in multiple visual cortical areas.

Question 3

simple cells

Answer 3

exhibit orientation tuning and respond to contrast borders.

Question 4

biased competition model for selective attention

Answer 4

This model may help answer two questions: (1) why are the effects of attention larger when multiple competing stimuli fall within a neuron’s receptive field, (2) how does attention operate at different levels of the visual hierarchy as neuronal receptive fields change their properties? In this model the idea is that when different stimuli in a visual scene fall within the receptive field of a visual neuron, the bottom-up signals from the two stimuli compete like two snarling dogs to control these neuron’s firing. Attention can help resolve this competition by favoring one stimulus.

Question 5

reflexive cuing or exogenous cuing

Answer 5

Also exogenous cuing. An experimental method that uses an external (i.e., exogenous) sensory stimulus (e.g., flash of light) to automatically att act attention without voluntary control.

Question 6

inhibition of return (IOR)

Answer 6

Also inhibitory after effect. The phenomenon, observed in an exogenously cued spatial attention task, where after the attention is reflexively attracted to a location by the exogenous cue, there is a slower behavioral response to stimuli in that location that are presented later than 300 ms aft er the exogenous cue.