Defining the boundary in a positioning task

Previous experiments have shown that overshoot rate in a linear positioning task is determined by the distance of the target from the boundary of the task in the direction of movement. Present experiments have served to specify distance more precisely as being relative rather than absolute, and as proximal rather than distal, and to show that the position of the boundary depends on the movements demanded by the task and not the visual and proprioceptive limits of the display. The operational boundary may be regarded as a cognitive construct by reference to which subjects locate targets.     

Role of the striatum and the cerebellum in motor skill acquisition

Motor skill acquisition was investigated in patients with Parkinson's disease (PD) or cerebellar dysfunction using two sensory-guided tracking tasks. The subjects had to learn to track a visual target (a square) on a computer screen by moving a joystick under two different conditions. In the unreversed task, the horizontal target movements were semi-predictable and could be anticipated. In the reversed task, the horizontal movements of a pointer which had to be kept within the target square were mirror-reversed to the joystick movements. PD patients showed intact learning of the semi-predictable task and reduced learning of the mirror-reversed task; patients with cerebellar dysfunction showed the opposite pattern. These findings are discussed in relation to the differential contribution of the cerebellum and the striatum to motor skill acquisition: the cerebellum appears to participate in the implementation of anticipatory movements, whereas the striatum may be critically involved in types of motor learning which require a high degree of internal elaboration.     

Role of the striatum and the cerebellum in motor skill acquisition

Motor skill acquisition was investigated in patients with Parkinson's disease (PD) or cerebellar dysfunction using two sensory-guided tracking tasks. The subjects had to learn to track a visual target (a square) on a computer screen by moving a joystick under two different conditions. In the unreversed task, the horizontal target movements were semi-predictable and could be anticipated. In the reversed task, the horizontal movements of a pointer which had to be kept within the target square were mirror-reversed to the joystick movements. PD patients showed intact learning of the semi-predictable task and reduced learning of the mirror-reversed task; patients with cerebellar dysfunction showed the opposite pattern. These findings are discussed in relation to the differential contribution of the cerebellum and the striatum to motor skill acquisition: the cerebellum appears to participate in the implementation of anticipatory movements, whereas the striatum may be critically involved in types of motor learning which require a high degree of internal elaboration.     

Multi-scale control influences sense of agency: Investigating intentional binding using event-control approach

Control exercised by humans through interactions with the environment is critical for sense of agency. Here, we investigate how control at multiple levels influence implicit sense of agency measured using intentional binding. Participants are asked to hit a moving target using a joystick with noisy control followed by an intentional binding task initiated by the target hitting action. Perceptual-motor level control was manipulated through noise in the joystick controller (experiment 1) and goal-level control in terms of feedback about successful hit (experiments 2a and 2b). In the first experiment, intentional binding increased with amount of joystick control only when goal was not achieved and independent otherwise suggesting that the two levels interact hierarchically. In the second experiment, the estimated duration was dependent on when participants knew about goal completion. The results are similar to those obtained with explicit measures of sense of agency indicating that multi-scale event control influences agency.     

Effects of competition on video-task performance in monkeys (Macaca mulatta)

The effects of competition on performance of a video-formatted task were examined in a series of experiments. Two rhesus monkeys (Macaca mulatta) were trained to manipulate a joystick to shoot at moving targets on a computer screen. The task was made competitive by requiring both animals to shoot at the same target and by rewarding only the animal that hit the target first each trial. The competitive task produced a significant and robust speed-accuracy trade-off in performance. The monkeys hit the target in significantly less time on contested than on uncontested trials. However, they required significantly more shots to hit the target on contested trials in relation to uncontested trials. This effect was unchanged when various schedules of reinforcement were introduced in the uncontested trials. This supports the influence of competition qua competition on performance, a point further bolstered by other findings of of behavioral contrast presented here.     

Implicit evaluation bias induced by approach and avoidance

We report a study in which faces with a neutral emotional expression were shown on a computer screen. By means of a joystick, participants pulled half of the faces closer (positive approach movement), and pushed the half away (negative avoidance movement). As a result, an operant evaluative conditioning effect occurred in a subsequent affective priming task: Participants responded more quickly to positive target words if they were preceded by a previously pulled face than a pushed face, and vice versa for negative target words. The effect became stronger the more often the faces had been trained to approach or to avoid. No effect was observed on explicit evaluations of the faces: Pushed faces were rated as sympathetic as pulled ones.     

A study of Fitts' law on goal-directed aiming task with moving targets

Most research based on Fitts' law define a log-linear relationship between temporal and spatial accuracy in goal-directed aiming tasks using stationary targets. Whether this relationship holds or not when the targets have varying velocities, and how the behavioral strategies and physical activities may change accordingly are of interest. The aim of this study was to investigate the relationship between temporal and spatial accuracy in goal-directed aiming tasks with moving targets. Participants were asked to aim at two target widths using a joystick. Results demonstrated that in a goal-directed aiming task there was a negative effect on performance when target velocity was increased or target width was decreased. Participants moved faster and then made more systematic errors in a high-velocity target condition. Results may be applicable to the complex perceptual-motor behavior of people who perform tasks using computers.     

Influence of body-centered information on the transfer of spatial learning from a virtual to a real environment

This study investigated the effects of body-centred information on the transfer of spatial learning using a wayfinding task and tasks that specifically probe the route and survey strategies of navigation. The subject learned a route in either a real or a virtual environment (VE; 3D scale model of a Bordeaux neighbourhood) and then reproduced it in the real environment. The involvement of body-based information was manipulated across the spatial learning conditions in the VE: participants learned with full body-based information (treadmill with rotation), with the translational component only (treadmill without rotation) or without body-based information (joystick). In the wayfinding task, the results showed a significant effect of the learning environment with the best scores obtained in the real and treadmill with rotation conditions. There was no significant difference between these two conditions, but the real condition was significantly different from the treadmill without rotation and joystick conditions. Also, the visual flow was sufficient to successfully perform the two egocentric tasks used as well as a direction estimation task (a survey task), in so far as there is no significant difference between the joystick and the treadmill conditions. By contrast, the distance estimates were improved by the treadmill condition including the translational component (but not the rotational component). Finally, our results show that treadmill with rotation promotes the transfer of spatial learning from a virtual to a real environment (compared to joystick and treadmill without rotation). Moreover, body-centred informations are more involved in allocentric (distance estimates) than egocentric navigational strategies.     

Aging affects motor learning but not savings at transfer of learning

Two important components of skill learning are the learning process itself (motor acquisition) and the ability to transfer what has been learned to new task variants (motor transfer). Many studies have documented age-related declines in the ability to learn new manual motor skills. In this study, I tested whether the degree of savings at transfer of learning is similarly affected by advancing age. Young and older adults made aiming movements with a joystick to hit targets presented on a computer screen, with real-time feedback display of their movement. They adapted to three different rotations of the feedback display in a sequential fashion, with return to the normal feedback display between each. Adaptation performance was better when it was preceded by other adaptive experiences, regardless of age.     

Macintosh analogue of the rotary pursuit task

Pursuit tracking, a perceptual motor-skill task, has had wide application in many areas of psychology. The task is usually administered with a mechanical device in which subjects try to maintain a contact between a stylus and a disk on a rotating platter. A pursuit-tracking task that can be administered on a Macintosh computer is described. Subjects try to keep a crosshair cursor on top of a moving circular target. The cursor can be controlled by commonly used Macintosh ADB devices such as a joystick. The computer version has several important advantages: it offers more task flexibility and more accurate dependent measures of performance, and it is inexpensive.     

New methodology applied to bonnet macaques (Macaca radiata) to address some contradictory evidence on manual asymmetries in Old World monkeys

Seven bonnet macaques (Macaca radiata) with strong hand preferences in performing a computer-generated joystick task that required directing a cursor to contact a small stationary target on a monitor were given comparable experience with each hand on the task over a 5-week period. Hand use was randomly restricted to either only the left or only the right hand across trials by automatically inputting into a computer the unique identification numbers of microchips implanted in the forearms of each macaque. Subsequent presentation of a novel task requiring maintenance of contact between a cursor and a moving target revealed no performance difference between preferred and nonpreferred hands or between left and right hands on the basis of number of errors or time to complete the task. The findings suggest that the strong hand preference for these tasks does not derive from a performance advantage for the preferred hand.     

The cognitive loci of the display and task-relevant set size effects on distractor interference: Evidence from a dual-task paradigm

The congruency effect of a task-irrelevant distractor has been found to be modulated by task-relevant set size and display set size. The present study used a psychological refractory period (PRP) paradigm to examine the cognitive loci of the display set size effect (dilution effect) and the task-relevant set size effect (perceptual load effect) on distractor interference. A tone discrimination task (Task 1), in which a response was made to the pitch of the target tone, was followed by a letter discrimination task (Task 2) in which different types of visual target display were used. In Experiment 1, in which display set size was manipulated to examine the nature of the display set size effect on distractor interference in Task 2, the modulation of the congruency effect by display set size was observed at both short and long stimulus-onset asynchronies (SOAs), indicating that the display set size effect occurred after the target was selected for processing in the focused attention stage. In Experiment 2, in which task-relevant set size was manipulated to examine the nature of the task-relevant set size effect on distractor interference in Task 2, the effects of task-relevant set size increased with SOA, suggesting that the target selection efficiency in the preattentive stage was impaired with increasing task-relevant set size. These results suggest that display set size and task-relevant set size modulate distractor processing in different ways.     

The effects of endogenous attention and stimulus onsets on encoding target location

The effects of endogenously attended and non-attended stimulus onsets on spatial stimulus encoding of a target were explored in a Simon task. In each experiment participants made speeded left or right key-press responses to the colour of a target that followed a cueing display consisting of several shapes. The target appeared within some shapes and not others. The target's spatial code as measured by a Simon task was its location relative to possible target positions and relative to the centre of the display. Target location was not coded relative to the positions of onset shapes that could not contain a target. These spatial coding effects were found at cue-target intervals of 50, 300, and 1000 ms. The data indicate that target location is defined relative to the distribution of endogenous attention and reference frames aligned with the centre of the display and that the spatial code assigned to a target is not affected when attention is shifted in the target's direction.     

Failures to induce implicit evaluations by means of approach-avoid training

Woud, Becker, and Rinck (2008) asked participants to repeatedly push pictures of certain faces away and to pull pictures of other faces towards them using a joystick. Performance in a subsequent affective priming task showed that previously pulled faces evoked more positive implicit evaluations then previously pushed faces. We report five studies in which we failed to find consistent evidence for the effect of approach-avoid training on implicit evaluations. We also failed to reproduce the effect reported by Woud et al. when reanalysing their data. An overall analysis that included our data, the data of Woud et al. and additional data provided by Woud and colleagues also did not reveal a significant effect of approach-avoid training on implicit evaluations. We conclude that the impact of approach-avoid training on implicit evaluations is subject to subtle boundary conditions.     

Boundary Distance Effects on Overshooting

Experiments with a subject-paced pursuit tracking task show that overshoot rate is dependent upon the distance between the target and the display boundary measured in the direction of movement, and that a previously noted inverse relationship with distance to the target is artifactual. The effect held for tasks with direct and reverse control-display relations, and for tasks with constant and variable target distances. The findings were consistent with Wetford’s (1968) hypothesis that a pursuit response is initiated with a ballistic, distance-covering, movement. Ralph Leonardo carried out extensive work in collecting data, Fred Hyde maintained the apparatus, and Georgie Green assisted in data analysis.     

The interaction of objective and subjective organizations in a localization search task

We investigated how both objective and subjective organizations affect perceptual organization and how this perceptual organization, in turn, influences observers’ performance in a localization search task. Two groups of observers viewing exactly the same stimuli (objective organization) performed in significantly different ways, depending on how they were induced to parse the display (subjective organization). In Experiments 1 and 2, the observers were asked to describe the location of a tilted target among a varying number of vertical or horizontal distractors. Subjective organization was induced by instructing observers to parse the display into either three horizontal regions (rows) or three vertical regions (columns). The position of the target was critical: location performance, as assessed by reaction time and errors, was consistently impaired at the locations adjacent to the boundaries defining the regions, producing what we refer to as thesubjective boundary effect. Furthermore, the extent of this effect depended on whether the stimulus-driven and conceptually driven information concurred or conflicted. This made location information more or less accessible. In Experiment 1, the strength of objective grouping was a function of the proximity of the items (near or far conditions) and their orientation in a 6×6 matrix. In Experiment 2, the strength of objective grouping was a function of similarity of color (items were color coded by rows or by columns) and the orientation of the items in a 9×9 matrix. The subjective boundary effect was more pronounced when the display promoted grouping in the direction orthogonal to that of the task (e.g., when observers parsed by rows but vertical distractors were closer together [Experiment 1] or color coded [Experiment 2] to induce global columns). In contrast, this effect decreased when the direction of both objective and subjective organizations was parallel (e.g., when observers parsed by rows and horizontal distractors were closer together [Experiment 1] or were color coded [Experiment 2] to induce global rows). A localization search task proved to be an ideal forum in which objective and subjective organizations interacted. We discuss how these results indicated that observers’ performance in a localization task was determined by the interaction of objective and subjective organizations, and that the resulting perceptual organization constrained coarse location information.     

Resources and dual-task performance; resource allocation versus task integration

This study aims at contributing to the explanation of dual-task performance in terms of either resource allocation or of task interference and integration. Twenty-four subjects carried out, single and in combination, a motor interval production task and a perceptual target detection task on the basis of combined memory and display search. The demands of the target detection task were varied by increasing or decreasing the presentation rate of successive search displays. Furthermore, the presentation rate was either constant or variable. The dual-task condition had a negative effect on interval production, the extent of which was unaffected by either rate or variability of display presentation. This means that there was no evidence for synchronizing interval production with display presentation, so that the major opportunity for task integration did not substantiate. It is suggested that the two tasks use different resource pools in addition to a common mechanism, the limited capacity of which causes a general interference in dual-task conditions.     

Effects of directionality in deductive reasoning: I. The comprehension of single relational premises

Four experiments involving 123 university students tested directionality effects in the comprehension of spatial relations, quantified statements, and propositional connectives with a sentence-picture verification task. Presentation of the referents of terms in the statements was separated by 1 s, and presentation order was congruent or incongruent with the order of terms in the statement. Some relations showed faster verification times for congruent display order, others for incongruent display order, and still others showed no directionality effect. The authors proposed a 2-step process model for the construction of semantic representations of relational statements, in which a reference object is established first, and then the second object is attached in relation to it. This theory explains the various directionality effects as a general preference to process information about the reference object before information about the target object.     

Failures to induce implicit evaluations by means of approach–avoid training

Woud, Becker, and Rinck (2008) asked participants to repeatedly push pictures of certain faces away and to pull pictures of other faces towards them using a joystick. Performance in a subsequent affective priming task showed that previously pulled faces evoked more positive implicit evaluations then previously pushed faces. We report five studies in which we failed to find consistent evidence for the effect of approach–avoid training on implicit evaluations. We also failed to reproduce the effect reported by Woud et al. when reanalysing their data. An overall analysis that included our data, the data of Woud et al. and additional data provided by Woud and colleagues also did not reveal a significant effect of approach–avoid training on implicit evaluations. We conclude that the impact of approach–avoid training on implicit evaluations is subject to subtle boundary conditions.     

Impulsivity and anxiety differences in cognitive inhibition

An identity negative priming task was employed to investigate cognitive inhibition in 245 undergraduates. The task presented consecutively a prime and a probe display that contained a target and a distractor. Negative priming is observed when subjects must respond to a target in the probe display that had been a distractor in the prime display. This task also served to study the Eriksen interference effect by comparing a condition in which the target and the distractor had the same identity with a condition in which they had different identities. Subjects completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire designed to measure Gray's anxiety and impulsivity dimensions. Results showed that impulsives had a lower cognitive inhibition than non-impulsives, whereas impulsive women also showed a greater Eriksen interference effect than non-impulsive women. Furthermore, no differences in task performance were found between anxious and non-anxious groups. Our discussion considers the importance of studying cognitive functioning in personality research.