Publication Summary and Abstract
Yates, D.J. and Stafford, T. (2011), Insights into the function and mechanism of saccadic decision making from targets scaled by an estimate of the cortical magnification factor, Cognitive Computation, 3,89-93.
Here we address the shape of the saccadic latency eccentricity function. Previously it has been proposed that the bowl-shaped nature of this function is a by-product of diminished stimulus representation in the periphery. A direct prediction of this theory is that saccadic latencies in the periphery should be speeded if stimuli are increased in size in proportion to the cortical magnification factor (M-scaling) Using a target-elicited saccade paradigm, ten subjects were shown M-scaled and unscaled Gaussian targets over a horizontal range of ±40 degrees. Saccadic latencies increased at an equal rate for peripheral targets regardless of whether targets were M-scaled or not. This suggests that the changes of latency with eccentricity are not a by-product of resource devoted to stimulus representation, but instead are a functional adaptation which takes account of the likelihood of saccades of each amplitude in the natural environment.
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