The prior-antisaccade effect influences the planning and online control of prosaccades

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 (R2 values) explained by the spatial position of the eye at decile increments of movement time relative to the response's ultimate movement endpoint: small R2 values indicate a response that unfolds with error-reducing trajectory amendments (i.e., online control), whereas larger R2 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 R2 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.

The unidirectional prosaccade switch-cost: Electroencephalographic evidence of task-set inertia in oculomotor control

“…These results are in accord with an extensive literature and are taken as evidence that antisaccades require the top-down and time-consuming processes of response suppression and vector inversion (see [37]). Moreover, the present findings show that the completion of an antisaccade selectively delayed the RT of a subsequent prosaccade; that is, results demonstrate the unidirectional prosaccade switch-cost ( [6,10,[41][42][43][44][45]). As well, results showed that pro-and antisaccade endpoint accuracy and variability were not modulated across task-switch and task-repetition trials.…”

“…In addition to the above-mentioned behavioural and neural changes linked to the antisaccade task, a series of recent studies have shown that the execution of an antisaccade lengthens the RT of a subsequent prosaccade ( [6,7,10,41,[42][43][44][45]). More specifically, results from our group have shown that the RT of a prosaccade completed after an antisaccade (i.e., task-switch prosaccade) are between 10 and 20 ms longer than a prosaccade completed after a prosaccade (i.e., task-repetition prosaccades).…”

Response Suppression Delays the Planning of Subsequent Stimulus-Driven Saccades

“…Recently, our group has shown that a corollary of antisaccade pre-setting is a residual inhibition of stimulus-driven oculomotor networks [1], [2], [15]. In addressing this issue, participants alternated between pro- and antisaccades using a classic task-switching schedule (i.e., AABB) as well as a pseudo-randomized task-switching schedule (i.e., AABAABB…).…”

“…Thus, the present investigation sought to determine whether the unidirectional prosaccade switch-cost is a specific consequence of the antisaccade task (i.e., response suppression and vector inversion) or represents a more general phenomenon associated with response suppression. In accomplishing our objective, we had participants alternate between pro- and antisaccades using the task-switching schedule (i.e., AABB; task-switching block) employed in our group’s previous work [1], [2], [15], and in a separate block required that participants complete a series of prosaccades that were randomly interleaved with no-go catch-trials (i.e., go/no-go block). Most importantly, we were interested in contrasting the putative changes in prosaccade RT when preceded by an antisaccade and a no-go catch-trial.…”

“…The completion of an antisaccade selectively increases the reaction time (RT) of a subsequent prosaccade: a result that has been interpreted to reflect the residual inhibition of stimulus-driven saccade networks [1], [2]. In the present investigation we sought to determine whether the increase in prosaccade RT is contingent on the constituent antisaccade planning processes of response suppression and vector inversion or is limited to response suppression.…”