The preservation of response inhibition aftereffects in a location-based spatial negative priming task: younger versus older adults.

Younger (M = 21 years) and older (M = 74 years) adults completed a spatial negative priming (SNP) task where (central) events (i.e., target or distractor) are presented in trial pairs: first the prime and then the probe. Free-choice trials were included (1 location: 2 permissible responses), which allowed us to isolate response inhibition and its consequent inhibitory aftereffects (i.e., current inhibition interferes with later related processing-e.g., SNP). The inhibitory aftereffects associated with the suppression of responses activated by distractor-occupied locations were highly comparable for younger and older adults; including similar SNP effect sizes, a significant tendency to select against former distractor (inhibited) responses (within-hand finger options) on free-choice trials, and latency delays attributable solely to the use of self-selected distractor responses. Aftereffects generated by target-occupied prime trials locations were also the same for both age groups; recently executed target responses were selected for and produced faster responding (within hand). Aftereffects were absent on between-hand free-choice trials and, overall, response selection determinants on free-choice trials matched for older and younger adults.

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

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.

Freely-selected and forced-choice responses bind with relevant object-occupied locations in visuospatial tasks.

Past work has shown that cued manual responses in visuo-identity tasks bind to irrelevant stimulus features, present at the time these responses were executed (prime trial). These response bindings manifested their existence via impacts on later related processing (probe trial). Here, we extended this prior research by showing that response binding is likely a pervasive processing characteristic. We saw that uncertain prime-trial responses (i.e., free-choice, forced-choice) did bind to the relevant "location" feature of the prime stimulus in a visuospatial task (i.e., R-L binding). Overall, R-L binding evidence was better for within-hand than for between-hand probe-trial finger competitions and better for probe trial response selection preferences than for their reaction time (RT) data. R-L binding evidence was entirely absent, however, for forced-choice probe trials. Evidence that the prime response binds to irrelevant prime display features (i.e., prime stimulus identity [R-I binding]) was virtually absent. Other results indicated that R-I likely exists, but that its probe-trial manifestation is prevented by the involvement of R-L binding. Response binding impacts on later processing should be considered when interpreting RT data. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The influence of advance information on the response complexity effect in manual aiming movements.

The relation between reaction time and the number of elements in a response has been shown to depend on whether simple or choice RT paradigms are employed. The purpose of the present study was to investigate whether advance information about the number of elements is the critical factor mediating the influence between reaction time and response elements. Participants performed aiming movements that varied in terms of the number of elements and movement amplitude. Prior to the stimulus, advance information was given about the number of elements and movement amplitude, movement amplitude only, number of elements only, or no information about the response. Reaction time and movement time to the first target increased as a function of number of elements only when the full response or the number of elements was specified in advance of the stimulus. The implication of these results for current models of motor programming and sequential control of aiming movements are discussed.

The contribution of peripheral and central vision in the control of movement amplitude.

Past research has revealed that central vision is more important than peripheral vision in controlling the amplitude of target-directed aiming movements. However, the extent to which central vision contributes to movement planning versus online control is unclear. Since participants usually fixate the target very early in the limb trajectory, the limb enters the central visual field during the late stages of movement. Hence, there may be insufficient time for central vision to be processed online to correct errors during movement execution. Instead, information from central vision may be processed offline and utilised as a form of knowledge of results, enhancing the programming of subsequent trials. In the present research, variability in limb trajectories was analysed to determine the extent to which peripheral and central vision is used to detect and correct errors during movement execution. Participants performed manual aiming movements of 450 ms under four different visual conditions: full vision, peripheral vision, central vision, no vision. The results revealed that participants utilised visual information from both the central and peripheral visual fields to adjust limb trajectories during movement execution. However, visual information from the central visual field was used more effectively to correct errors online compared to visual information from the peripheral visual field.

The locus of location repetition latency effects.

We examined the processing locus (location vs. response) of location repetition effects in terms of the event [target (t) or distractor (d)] that initially occupied and then re-occupied the repeated location (i.e., t-to-t, t-to-d, d-to-t, d-to-d). Trials were presented in pairs (prime, then probe) and 2:1 location-to-response mappings were used. Generally, for all repetition conditions, perceptual processing at the repeated location itself was facilitated (location locus), while re-activated responses delayed output production (response locus). More specifically, perceptual facilitation observed for a repeated location was independent of the kind of processing (i.e., t or d) that occurred earlier, suggesting that it is not the labeling of locations as relevant or irrelevant that determines location repetition effects. Response production was significantly slowed only when a just-inhibited response had then to be executed, which supported the view that the spatial negative priming effect has a response locus.

The integration of sequential aiming movements: Switching hand and direction at the first target.

Movement times to a single target are typically shorter compared to when movement to a second target is required. This one target movement time advantage has been shown to emerge when participants use a single hand throughout the target sequence and when there is a switch between hands at the first target. Our goal was to investigate the lacuna in the movement integration literature surrounding the interactive effects between switching hands and changing movement direction at the first target. Participants performed rapid hand movements in five conditions; movements to a single target; two target movements with a single hand in which the second target required an extension or reversal in direction; and movements to two targets where the hands were switched at the first target and the second target required an extension or reversal in direction. The significance of including these latter two (multiple hand-multiple direction) movements meant that for the first time research could differentiate between peripheral and central processes within movement integration strategies. Reaction times were significantly shorter in the single task compared to the two target tasks. More importantly, movement times to the first target were significantly shorter in the single target task compared to all two target tasks (reflecting the so-called one target advantage), except when the second movement was a reversal movement with the same hand. These findings demonstrate for the first time the contrasting effects of movement integration at central and peripheral levels.

The influence of distractor-only prime trials on the location negative priming mechanism.

Two experiments were conducted that examined the influence of distractor-only prime trials on the "location" negative priming (NP) effect. In all experiments, the probe trial always lacked a distractor. We showed that the predictable absence of a probe distractor caused the elimination of the location NP effect when the prime trial contained both a target and a distractor event (T + D-->T), but not when the prime contained only a to-be-ignored distractor event (D-->T) (Milliken, Tipper, Houghton, & Lupianez, 2000). The preservation of the NP effect seen with the distractor-only prime trials (D-->T) was not the result of its lacking a prime-trial selection, nor was it the consequence of its representing a higher level of episodic similarity than the T + D-->T condition. Finally, the location NP effect observed for the D-->T condition is seemingly consistent with the view that location NP and the inhibition-of-return effects share a common underlying process (Milliken et al., 2000).

Influence of probe-trial selection on the location negative priming effect.

Using the location variant of the typical negative priming procedure, participants were cued (100% reliable) before (Experiment 1) or after (Experiment 2) the prime trial as to whether a distractor would or would not accompany the target on the probe trial. The crucial results were that on cued trials, the predictable absence, produced the removal of the negative priming effect (disengagement), and that this disengagement of the priming process, motivated by the predictable absence of a probe-trial distractor, could take place on-line. These findings demonstrated the "selection-state" dependency (probe trial) of the location negative priming process, supporting inhibition-based and episodic retrieval models in their contention that the ultimate function of this process is to enhance the efficiency of future distractor processing, and hence selection. The disengagement results revealed an adaptive feature of a process that can be detrimental or irrelevant to upcoming processing.

The error protection impact of inhibitory after-effects in a location-based task and its preservation with practice.

In location-based tasks, responses related to (prime trial) distractor-occupied locations automatically undergo activation, followed by inhibition, which causes these responses to become execution-resistant (ER). Distractor-response ER takes time to override, delaying target reactions that later require this response (e.g., probe, ignored-repetition trials), causing the spatial negative priming (SNP) phenomenon. We learned in this study that distractor-response ER affords this output a degree of error protection. Specifically, when the probe target appeared at a new location, former (prime) distractor responses were used erroneously significantly less often than their control response counterparts, likely due to their ER feature, which discourages their inappropriate selection (i.e., "ER" provides error protection). This error protection also was evident when a previous distractor response was activated by a distractor on the probe (i.e., distractor-repeat trial). Notably, error protection remained effective over extensive practice, as did SNP size (i.e., ER override time) after an initial decline.

Sequential aiming with one and two limbs: effects of target size.

It is well reported that movement times to the first target in a two-target sequence are slower than when a single target response is required. This one-target advantage has been shown to emerge when the two-target sequence is performed with the same limb and when the first and second segments within the sequence are performed with different limbs (i.e., when there is a switch between limbs at the first target). The present study examined the functional dependency between response segments in both single and two limb sequential aiming by varying the accuracy demands at the first and second target. Results revealed that, for both one and two limb conditions, the one-target advantage was present with large first targets but not with small first targets. Additionally, when the first target was large and the second target was small, spatial variability at the first target was significantly less (or constrained more) in both one and two limb conditions compared to conditions requiring only a single target response. These findings suggest that similar principles underlie the one-target advantage in both single and two limb sequential movements.

Inhibited prime-trial distractor responses solely produce the visual spatial negative priming effect.

Responding to a target's current (probe trial) location is slower when it appears at a former distractor-occupied position (i.e., ignored-repetition [IR] trial), relative to when it arises at a new location (i.e., control trial). This RT(IR) > RT(Control) inequality defines the spatial negative priming (SNP) effect in latency terms. It is uncertain whether the elevated RT(IR) is due to the inhibition of the distractor-occupied location or to the inhibition of this location's assigned manual response (SNP locus issue). The main aim here was to examine the SNP locus issue. Notably, our SNP design used centrally presented visual events and included having two locations share a common response (many:1 location-to-response mapping) and the use of informative (70 % validity) or uninformative probe-trial response cues. The many:1 mapping trials allowed for the detection of location and response inhibition presence. Results showed that the latter, but not the former, causes inhibitory aftereffects (e.g., SNP) following uninformative response cues. Consistent with this finding, when the informative response cue was valid and was assigned to the many:1 probe response that had just served as the prime distractor response, inhibitory aftereffects were eliminated, when the probe target appeared at the prime distractor position (IR trial) or at a new location (distractor-response repeat trial). Blocked retrieval of stored distractor-processing representations was proposed as the mechanism for inhibitory aftereffect prevention.

Recently inhibited responses are avoided for both masked and nonmasked primes in a spatial negative priming task.

Responding to the location of a target is delayed when the target arises at a position previously occupied by a distractor (ignored-repetition trial), relative to when it occurs at a formerly unoccupied location (control trial) [i.e., the spatial negative priming (SNP) effect]. Speculation has held that recently inhibited (distractor) responses resist future execution (i.e., execution resistance [ER]), and thus cause SNP. Evidence for ER has been reported for identity-based tasks using masked prime distractor events. The purpose of this study was to examine the potential impact of ER on response selection in an SNP task for both nonmasked (traditional) and masked primes. We employed a modified SNP task that included nonmasked and masked target-only and distractor-only visual primes (first trial), along with forced choice and free choice probes (second trial). On free choice trials, a selection bias against the prime-distractor-assigned response was evident (same-hand competition, for both nonmasked and masked primes). This selection avoidance was held to reflect ER operating with inhibited prime distractor responses. Further, inhibitory aftereffect patterns were the same for nonmasked and masked distractor primes, and masking target primes transformed a positive to a negative aftereffect, as predicted by the self-inhibition model of mask function set out by Schlaghecken and Eimer (Psychonomic Bulletin & Review, 11, 463-468, 2004).

Sequential aiming with two limbs and the one-target advantage.

Movement times to the first target in a 2-target sequence are typically slower than in 1-target aiming tasks. The 1-target movement time advantage has been shown to emerge regardless of hand preference, the hand used, the amount of practice, and the availability of visual feedback. The authors tested central and peripheral explanations of the 1-target advantage, as postulated by the movement integration hypothesis, by asking participants to perform single-target movements, 2-target movements with 1 limb, and 2-target movements in which they switched limbs at the first target. Reaction time and movement time data showed a 1-target advantage that was similar for both 1- and 2-limb sequential aiming movements. This outcome demonstrates that the processes underlying the increase in movement time to the 1st target in 2-target sequences are not specific to the limb, suggesting that the 1-target advantage originates at a central rather than a peripheral level.

The influence of response grouping on free-choice decision making in a response selection task.

Previous research has demonstrated an advantage for the preparation of fingers on one hand over the preparation of fingers on two hands, and for the preparation of homologous fingers over that of non-homologous fingers. In the present study, we extended the precuing effects observed with finger responses to response selection under free-choice conditions. Participants were required to choose from a range of possible responses following the presentation of a precue that indicated which response to prepare (go-to precue) or prevent (no-go-to precue). In Experiment 1 the choice was between homologous and non-homologous finger responses on the hand opposite to the precue while in Experiment 2 the choice was between finger responses on the same or different hand to the precue. In the go-to precue condition, the frequency of homologous finger choices was more frequent than non-homologous finger responses. Similarly, participants chose finger responses on the same hand as the precue regardless of whether they were instructed to prepare or prevent the precued response. The hand effect bias was stronger than the finger effect bias. These findings are consistent with the Grouping Model (Adam, Hommel, & Umilta, 2003).

Prime-trial processing demands and their impact on distractor processing in a spatial negative priming task.

A spatial negative priming (NP) paradigm was used where trials were presented in pairs, first the 'prime' and then the 'probe', and where participants responded manually to a target's location. In Experiment 1, three prime-trial types were used: distractor-plus-target, predictable distractor-only, and unpredictable distractor-only, with prime-probe trial onset delays of 2, 5 or 10 s (NP longevity). In Experiment 2, the latter two prime-trials were employed with onset delays of 75 and 750 ms (distractor response activation-inhibition sequence). With the exception of the 10 s onset delay, the spatial NP effect data (NP size, longevity, distractor response activation-inhibition sequence) was the same for all three prime-trial types. Thus, the varying processing demands associated with each of the prime-trial types (e.g., selection, intervening response) did not alter prime distractor processing so that they differentially contributed to the spatial NP process. The three prime-trial types can be used interchangeably, within limits, to study the NP process.

The locus and modulation of the location negative priming effect.

Responding to the location of a target is slower when it appears at a recent distractor location [ignored-repetition (IR) trial] than when it arises at a new position [control (CO) trial], defining the location negative priming (NP) effect. On IR trials, both the distractor location and response are from the prior trial, and the locus question asks whether the delayed responding that arises is caused by the reused distractor position (i.e., a location locus) or the need to execute a distractor output (i.e., a response locus). A location NP procedure was used, incorporating a many:1 location-to-response mapping design, along with a response cue on some trials. A response locus for the location NP effect was indicated. Distractor-turned-target responses took longer to initiate than new outputs (many:1 paradigm), and valid response cues reduced distractor response interference and the location NP effect. Importantly, a possible S-R compatibility problem within the many:1 S-R paradigm was not supported.

Can the location negative priming process operate in a proactive manner?

The location negative priming (NP) effect refers to the fact that the processing of a current target stimulus (probe trial) is delayed when it appears at a location that has recently contained a distractor event (prime trial), relative to when it occurs at a previously unoccupied position. One view is that the process causing the NP effect involves the inhibition of the internal representation of the prime-distractor event, and that the future processing of target stimuli that involve this event are prolonged because this distractor inhibition is persistent. In this study, we examined the possibility that the NP process (inhibition) could act proactively; specifically asking whether inhibition could be allocated to a location merely predicted to hold a future distractor event. To do this, we cued the probe distractor's location using an otherwise traditional location NP paradigm. No evidence of a proactive NP process was obtained. Probe-trial target latency was the same whether it appeared at the cued distractor location or at a new location, but was delayed when it occupied the prime-distractor location (NP effect). The location NP process is seemingly a reactive one, applying inhibition only when an actual distractor is present, much as past theories have implied.

Programming strategies for rapid aiming movements under simple and choice reaction time conditions.

Increases in reaction time (RT) as a function of response complexity have been shown to differ between simple and choice RT tasks. Of interest in the present study was whether the influence of response complexity on RT depends on the extent to which movements are programmed in advance of movement initiation versus during execution (i.e., online). The task consisted of manual aiming movements to one or two targets (one- vs. two-element responses) under simple and choice RT conditions. The probe RT technique was employed to assess attention demands during RT and movement execution. Simple RT was greater for the two- than for the single-target responses but choice RT was not influenced by the number of elements. In both RT tasks, reaction times to the probe increased as a function of number of elements when the probe occurred during movement execution. The presence of the probe also caused an increase in aiming errors in the simple but not choice RT task. These findings indicated that online programming was occurring in both RT tasks. In the simple RT task, increased executive control mediated the integration between response elements through the utilization of visual feedback to facilitate the implementation of the second element.

The use of a distractor-assigned response slows later responding in a location negative priming task.

Responding to a target's location takes longer when that location has recently contained a distractor event (ignored-repetition [IR] trial) relative to when it has been unoccupied (control trial). This is known as the location negative priming (NP) effect. We aimed to determine whether the elevated reaction time observed for IR trials was due to the reuse of a distractor location (location locus) and/or to the need to execute a (just inhibited) distractor response (response locus). We isolated these loci latency effects by using many-to-one and one-to-many location-response assignments. Our results showed that reusing a distractor location hastened target processing at that position (facilitative location locus), whereas the production of a distractor response was associated with a time cost (interfering response locus). Accordingly, part of the latency elevation seen with IR trials results from the need on these occasions to execute ajust inhibited (distractor) response, and, hence, the location NP effect has a response locus.