Vision Research. In Press
Carrasco, M., Giordano, A.M., & McElree, B. (2003). Temporal performance
fields: Visual and attentional factors.
This study is the first to investigate: a) 'temporal performance fields,'
whether the speed of information accrual differs for different locations
at a fixed eccentricity, and b) whether covert attention modulates temporal
dynamics differentially at isoeccentric locations. Using the speed accuracy
tradeoff (SAT) procedure, we derived conjoint measures of how isoeccentric
locations and precueing target location affect speed and accuracy in a
search task. The results demonstrate the existence of temporal performance
fields, analogous to spatial performance fields: Information accrual was
fastest for target on the horizontal meridian, intermediate for targets
at the intercardinal locations, slow for targets on the vertical meridian,
and slowest for targets at the North (N) location (accrual time pattern:
E & W < intercardinal < S < N). Surprisingly, in contrast
to spatial performance fields, where covert attention enhanced discriminability
at all locations to a similar degree, attention differentially sped up
processing at the slower locations, with a greater benefit evident along
the vertical than the horizontal meridian, particularly at the N location,
and an intermediate benefit seen at intercardinal locations (viz., N >
S > intercardinal > E & W). Hence, the compensatory effect of
attention eliminated the temporal asymmetries across isoeccentric locations.