Automatic versus volitional orienting and the production of the inhibition-of-return effect.

Abstract

A single, to-be-ignored peripheral flash (i.e., cue) reflexively attracts an orienting response (oculomotor/attention/head turn) that ultimately causes reaction time delays to target stimuli that later arise at this cued location, in relation to when the target appears at a new position (i.e., the inhibition-of-return [IOR] effect). The basic question posed here dealt with whether an IOR effect is also produced following volitional orienting. Results from paired cue-trial stimulations, one a distractor and one a target (nonsalient/salient) event, positioned more or less symmetrically on either side of fixation, supported the net vector model of IOR (R. Klein, J. Christie, & E. P. Morris, 2005). Automatic orienting did not yield an IOR effect at the stimulated positions. When the need to later report cue-trial target location was added, an IOR effect appeared at distractor-occupied, but not at target-occupied, locations. Seemingly, an IOR effect can follow volitional orienting. In this instance, the IOR process seems capable of undergoing modulation; however, such modulation was not evident following automatic orienting.

Spatial Negative Priming, but Not Inhibition of Return, with Central (Foveal) Displays

“…This version of IOR production may be viewed as somewhat controversial in that it does not stipulate the conventional view that the cued location itself is inhibited, which then contributes to IOR generation. It is, nonetheless, a version that acknowledges findings reported by Klein, Christie, and Morris (2005), and subsequently replicated by Fitzgeorge and Buckolz (2009). We present this work later.…”

“…This report requirement does not eliminate either the IOR (Fitzgeorge & Buckolz, 2009) or SNP-central effects . Subjects accurately reported the position of the prime event about 97% of the time and so had undertaken location differentiation.…”

“…So, on this account as well, their data do not unequivocally point to a common mechanism for IOR and SNP-central. Klein et al (2005) were the first to report that when simultaneously presented distractor events were symmetrically positioned on either side of midline in the visual periphery, IOR effects failed to materialize at these stimulated locations (Fitzgeorge & Buckolz, 2009). This failure is further evidence that distractor-occupied locations are not themselves inhibited, albeit peripheral locations in this case.…”

“…Although smaller in size than for the usual distractor-target trial, an IOR effect does materialize at responded-to, prime-trial target locations (i.e., called "target-target" trials) [e.g., Coward et al, 2004;Fitzgeorge & Buckolz, 2009;Taylor & Klein, 2000;Welsh & Pratt, 2006]. Presumably, the latency benefits of repetition (and/or inhibition absence) counter but do not fully offset the inhibitory after-effects attributed to orientation inhibition on target repeat trials.…”

The role of probe trial distractors in the production/removal of the spatial negative priming effect

“…Given the SNP disengagement success of the .25/.75 probe distractor manipulation in past work Fitzgeorge, 2009), an obvious possibility for its failure to do so in this study is that the SNP disengagement motivation influence of the .25/.75 manipulation is subject specific. Accordingly, the target-only probe trial data was examined for each subject.…”