Erschienen in:
01.02.2012 | Research Article
The prior-antisaccade effect influences the planning and online control of prosaccades
verfasst von:
Jeffrey Weiler, Matthew Heath
Erschienen in:
Experimental Brain Research
|
Ausgabe 4/2012
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Abstract
The latency of a prosaccade is increased when completed following an antisaccade (the prior-antisaccade effect). This finding has been attributed to the inhibition of the oculomotor networks necessary for an antisaccade engendering a persistent response set that delays a to-be-executed prosaccade. The goal of the present investigation was to determine whether the prior-antisaccade effect influences not only the planning but also the control of an unfolding prosaccade trajectory. To accomplish that objective, we employed a task-switching paradigm wherein participants alternated between pro- and antisaccades on every second trial (i.e., AABB paradigm). Importantly, trajectory control was evaluated by computing the proportion of variance (R
2 values) explained by the spatial position of the eye at decile increments of movement time relative to the response’s ultimate movement endpoint: small R
2 values indicate a response that unfolds with error-reducing trajectory amendments (i.e., online control), whereas larger R
2 values reflect a response that unfolds with few—if any—online corrections. As expected, results showed a prior-antisaccade effect for response planning; that is, prosaccade latencies were increased when completed after an antisaccade. Moreover, prosaccades completed after an antisaccade elicited larger R
2 values and less accurate endpoints than trials wherein a prosaccade was completed after another prosaccade. These results provide first evidence of a prior-antisaccade effect for trajectory control and indicate that the persistent and inhibitory response set arising from an antisaccade diminishes the online corrections, and thus endpoint accuracy, of a subsequent prosaccade.