Voluntary attention improves performance similarly around the visual field

Area of Science:

• Visual perception
• Cognitive neuroscience
• Human psychophysics

Background:

• The visual system exhibits performance fields (PF) with horizontal-vertical anisotropy (HVA) and vertical meridian asymmetry (VMA).
• Exogenous (involuntary) spatial attention does not alter the PF shape, improving performance uniformly across polar angles.

Purpose of the Study:

• To investigate if endogenous (voluntary) spatial attention can reduce perceptual asymmetries in the visual performance field.
• To determine if the flexible nature of voluntary attention can overcome known limitations in visual processing.

Main Methods:

• Twenty participants completed an orientation discrimination task.
• Endogenous attention was manipulated by directing it to the target or distributing it broadly.
• Stimulus contrast was either constant or individually titrated to equate task difficulty across locations.

Main Results:

• Endogenous attention improved performance across all polar angles, irrespective of attention allocation.
• The canonical performance field shape, including its asymmetries, was maintained under voluntary attention.
• Task difficulty adjustments did not alter the effect of attention on PF shape.

Conclusions:

• Endogenous spatial attention, despite its voluntary nature, does not attenuate perceptual asymmetries in the visual performance field.
• Similar to exogenous attention, voluntary attention improves performance globally without altering the fundamental shape of the performance field.
• Perceptual asymmetries at isoeccentric locations appear robust to modulation by spatial attention.