Effect of visuomotor calibration and uncertainty on the perception of peripersonal space

Target selection for action depends not only on the egocentric location of objects estimated from retinal and extraretinal variables, but also on the assessment of current action possibilities. In the present study, we investigated the effect of altering sensorimotor anticipation processes on subsequent perceptual estimates of reachability. To do so, we conducted two experiments in which we changed the relation between visual distance and movement amplitude. Experiment 1 showed that iterative visuomotor adaptation to distorted visual feedback (in steps of ±15?mm, up to a total adaptation of ±75?mm) led to a congruent variation of perceived reachable space, although the first introduction of the shifted visual feedback produced a reduction of perceived reachable space whatever the direction of the feedback shift. Experiment 2 showed that increasing uncertainty about visuomotor performances, by providing a visual feedback randomly shifted in depth (±7.5?mm), produced the same reduction of perceived reachable space in the absence of visuomotor adaptation. Taken together, these data suggest that the visual perception of reachable space depends on a motor-related perceptual system, which is affected by both visuomotor recalibration and reliability of the visuomotor system.     

Analysis of the learned irrelevance effect in appetitive Pavlovian conditioning

In Experiments 1 and 2 rats received uncorrelated presentations of a light conditioned stimulus (CS) and a food unconditioned stimulus (US) on each day of a preexposure phase. Control subjects received the same number of USs during the first half of preexposure and the same number of CSs during the second. Uncorrelated preexposure retarded inhibitory conditioning. Experiment 3 showed, however, that the different patterns of US preexposure experienced by the two groups could in itself influence the course of subsequent inhibitory conditioning. When this factor was equated by restricting the uncorrelated treatment to the first half of the pre-exposure phase (Experiment 2) or by extending the control treatment throughout the phase (Experiment 4) it was found that uncorrelated preexposure retarded excitatory conditioning, but facilitated inhibitory conditioning. This outcome challenges an interpretation in terms of the concept of learned irrelevance, which predicts that uncorrelated preexposure should retard both forms of conditioning.     

Determination of target distance in a structured environment: Selection of visual information for action

In the literature relating to visuo-motor control, controversial data are found concerning the consequence of enriching the visual scene in the specification of the target's spatial coordinates. In this paper four experiments were carried out to unravel this issue. Based on spatio-temporal analysis of pointing movements carried out in an open loop condition, the effect of appending contextual elements in the vicinity of a visual target was investigated, taking into account (1) their location in the visual field, (2) the extent of the movement, and (3) their presence during the planning and/or execution period of the movement. Taken as a whole, results showed that enriching the visual scene gave rise to a decrease of perceptual underestimation of distance (with no effect on the direction parameter), as otherwise observed (dark environment). Though not deeply affecting reaction and movement time, this effect held whatever the target position, provided that the contextual elements were situated between the initial and terminal position of the hand trajectory. The magnitude of the effect was, however, dependent upon the space conferred to the visual context. Furthermore, a higher spatial performance was observed when the latter was provided during the planning of execution period of the movement. Both effects combined when contextual elements were provided during the entire movement, which suggests a continuous updating of target coordinates during the whole motor performance. Altogether these findings underline a dynamic aspect of space perception, originating, in part, in the functional use of contextual cues in the coding of target distance. They also suggest that, provided the visual environment is structured, the retinal signal is widely used in the perception of target distance in visuo-manual tasks.     

Sex differences in the expression of depression in adolescents

The purpose of the present study is to examine the patterns of depressive response of adolescents on The Beck Depression Inventory (BDI). Subjects, who were registered at the Western Québec Regional School Board (Grades 7–12), completed the BDI in the context of intact classes. Out of 1015 subjects, 249 (152 females, 97 males) met the cut-off score of 15 and above on the BDI, and were retained for the study. Sixty-three percent were francophone and 37 percent were anglophone. Ages ranged from 12 to 17 years. Results did not reveal any difference in the BDI scores as a function of either sex, age, or language. However, a significant discriminant function was obtained from subjects' responses that correctly differentiates depressed males from depressed females in 67.8% of the cases. These differential patterns of depressive responding are compared with those observed in depressed college students and adult psychiatric patients, and discussed in light of the literature on adolescent depression.This is an extended version of a poster paper presented at the 48th annual meeting of the Canadian Psychological Association, Vancouver, June 1987.     

The Epistemic Edge of Majority Voting Over Lottery Voting

I aim to explain why majority voting can be assumed to have an epistemic edge over lottery voting. This would provide support for majority voting as the appropriate decision mechanism for deliberative epistemic accounts of democracy. To argue my point, I first recall the usual arguments for majority voting: maximal decisiveness, fairness as anonymity, and minimal decisiveness. I then show how these arguments are over inclusive as they also support lottery voting. I then present a framework to measure accuracy so as to compare the two decision mechanisms. I go over four arguments for lottery voting and three arguments for majority voting that support their respective accuracy. Lottery voting is then shown to have, compared to majority voting, a decreased probability of discrimination. That is, I argue that with lottery voting it is less probable under conditions of normal politics that if the procedure selects X, X is reasonable. I then provide two case scenarios for each voting mechanism that illustrate my point.     

Costs and benefits of tool-use on the perception of reachable space

Previous studies have shown that using a tool modifies in a short time-scale both near-body space perception and arm-length representation in the body schema. However, to date no research has specifically investigated the effect of tool-use on an action-related perceptual task. We report here a study assessing the effect of tool-use on the perception of reachable space for perceptual estimates made in reference to either the tool or the hand. Using the tool on distal objects resulted in an extension of perceived reachable space with the tool and reduced the variability of reachability estimates. Tool use also extended perceived reachable space with the hand, but with a concomitant increase of the variability of reachability estimates. These findings suggest that tool incorporation into the represented arm following tool-use improves the anticipation of action possibilities with the tool, while hand representation becomes less accurate.     

Longitudinal effects of two individual career counseling interventions on clients’ career decision-making during the COVID-19 pandemic over a 1-year follow-up

This study assessed the effects of two individual career counseling interventions during the COVID-19 pandemic over a 1-year follow-up. Participants (n = 71) engaged either in four individual humanistic–psychodynamic (during winter 2021) or cognitive career counseling (during winter 2022) sessions at a university counseling clinic. Latent growth models indicated that clients experienced a significant reduction in their career decision difficulties and psychological distress and a significant increase in their life satisfaction over sessions and the 12 months following. Clients who received cognitive career counseling sessions experienced larger effects. Results highlight the utility of individual career counseling in times of crisis.     

Le geste suicidaire et la faute inexcusable de l’employeur

When a suicidal act is attributed to work, in addition to the qualification of a work accident, the employer's inexcusable fault, based on his obligation of safety, can be retained if the latter was aware of the danger incurred by his subordinate and did not take the necessary measures to protect him. Two points stand out. On the one hand, the risk of suicide is not always predictable, which leads to a more general thinking on its prevention. On the other hand, since 2015, two conceptions regarding the obligation of security have coexisted, new in labour law and, constant in social security law, with litigation falling under two separate chambers of the High Court. Three judgments from October 8, issued by the second civil chamber of the High Court appear to be moving towards a harmonization of case law. Consequently, their scope should be assessed, in particular regarding the preventive measures expected from the employer.