Within reach but not so reachable: Obstacles matter in visual perception of distances

A large number of studies have shown that effort influences the visual perception of reaching distance. These studies have mainly focused on the effects of reach-relevant properties of the body and of the objects that people intend to reach. However, any influence of the reach-relevant properties of the surrounding environment remains still speculative. We investigated this topic in terms of the role of obstacle width in perceiving distances. Participants had to estimate the straight-line distance to a cylinder located just behind a transparent barrier of varying width. The results showed that participants perceived the straight-line distance to the cylinder as being longer when they intended to grasp the cylinder by reaching around a wide transparent barrier rather than by reaching around narrower ones. Interestingly, this effect might be due to the anticipated effort involved in reaching. Together, our results show that reach-relevant properties of the surrounding environment influence perceived distances, thereby supporting an embodied view of the visual perception of space.     

Dissociation of sensory facilitation and decision bias in statistical learning

ABSTRACT

The detection of regularities in the sensory environment, known as statistical learning, is an important brain function that has been observed in many experimental contexts. In these experiments, statistical learning of patterned sensory stimulation leads to improvements in the speed and/or accuracy with which subsequent stimuli are recognized. That is, statistical learning facilitates the transformation of sensory stimuli into motor responses, but the mechanism by which this occurs is unclear. Statistical learning could improve the efficiency of sensory processing, or it could bias responses toward particular outcomes. The distinction is important, as these different hypotheses imply different functions and different neural substrates for statistical learning. Here we address this problem by studying statistical learning as a decision-making process, which allows us to leverage the extensive computational literature on this topic. Specifically we describe a method for applying the Diffusion Decision Model (DDM) to isolate different sensory and cognitive processes associated with decision-making. The results indicate that statistical learning improves performance on a visual learning task in two distinct ways: by altering the efficiency of sensory processing and by introducing biases in the decision-making process. By fitting the parameters of the DDM to data from individual subjects, we find that the prominence of these two factors differed substantially across the population, and that these differences were predictive of individual performance on the psychophysical task. Overall, these results indicate that different cognitive processes can be recruited by statistical learning, and that the DDM is a powerful framework for detecting these influences.     

Hemispheric lateralization in aging: Interest of the verbal-manual concurrency paradigm

ABSTRACT

Introduction: The aim of this study was to evaluate whether the classic asymmetry seen in hemispheric functioning is modified in older adults by using a verbal-manual concurrency task. Method: Thirty-five right-handed participants divided into two groups according to age (15 older participants, mean age: 68 ± 8 years, without cognitive decline and 20 younger participants, mean age: 23 ± 2 years) had to perform a 30-second uni-manual tapping task, in both a single task (tapping alone) and dual task (tapping and performing a letter fluency task together) condition. Results: In younger participants, the letter fluency task disrupted the right hand more than the left hand whereas, in older participants, the letter fluency task disrupted both hands equally. Conclusion: These results should be considered preliminary data using a behavioral dual task condition, which might be useful for studying lateralized hemispheric functioning and the processes of divided attention during aging.     

Discounting in causality and covariation judgements

In two experiments, humans were asked to judge the strength of a moderate contingency between a cue and an outcome in the presence of a second strong contingency between another cue and the outcome. The first experiment replicated the discounting effect whereby a strong contingency causes subjects to reduce or discount judgements of a moderate contingency. This experiment used a video-game procedure in which subjects camouflaged a tank to make it safe from mines. The second causal cue was the presence or absence of a spotter plane. Experiment 1 also ruled out the possibility that judgements might be determined by the number of co-occurrences of the cue and outcome as opposed to the level of contingency. The second experiment used an abstract scenario in which discounting was demonstrated when subjects were asked to judge the relationship between the occurrence of geometric objects. The instructions were neutral to discourage causal hypotheses. These results support the notion that judgements result from associative or connectionist processes and not from a two-step cognitive retrospective process in which an estimate of covariation is calculated between cue and outcome and then in a second step this information is used in a normative manner when a decision is made.     

Edmund Husserl, <Emphasis Type="Italic">Logical Investigations. Volume I. Prolegomena to Pure Logic</Emphasis>

This is a translation from Russian to English of Nikolai Onufriyevich Lossky’s review of the first Russian translation of volume one of Husserl’s Logische Untersuchungen (the “Prolegomena to Pure Logic”), which was translated by E. A. Berstein and published in 1909 by a Petersburgian editor. The review appeared in the Muscovite philosophical journal Pyccкaя мыcль (Russian Thought) in 1909. In this short text, Lossky expresses his agreement with Husserl’s early anti-psychologism in logic. He also manifests his stance against logical and axiological relativism and naturalism. As an ontological realist, Lossky thought he had found in the author of the Logische Untersuchungen an ally against the subjectivistic trends then still prevalent in Germany. The review is significant in intellectual history for its vanguard role in the Rezeptionsgeschichte of Husserl’s thought in Russia. (Frédéric Tremblay)     

Cognitive events in a problem-solving task: a qualitative method for investigating interactivity in the 17 Animals problem

Outside the cognitive psychologist's laboratory, problem-solving is an activity that takes place in a rich web of interactions involving people and artefacts. This interactivity is constituted by fine-grained action–perception cycles, and it allows a reasoner's comprehension of the problem to emerge from a coalition of internal and external resources. Taking an ecological approach to problem-solving, this paper introduces a qualitative method, Cognitive Event Analysis, for studying the fine-grained interactivity between a problem-solving agent and his/her environment. To demonstrate the potential of this method, it is used to study a single subject solving the so-called 17 Animals problem using a material model. The fine-grained procedure allows tracking the solution to a serendipity that was brought about because of the participant's aesthetic considerations and a change in her perceptual figure-ground configuration. While a qualitative single-case method cannot prove specific models of problem-solving, it questions prevalent mentalist models, and it generates new hypotheses on insight problem-solving, because it allows the researcher to attend to outliers and to variability on a fast and fine-grained between-measurement timescale.     

Quelle juridiction est compétente pour juger des faits commis par un professeur des universités-praticien hospitalier qui sont en rapport avec son activité d’enseignement ?

Constituted courts of ordinal authorities are not competent to judge facts committed by a university professor-hospital practitioner, which are related to his teaching activity. Only the court specific to hospital teachers, which is seized by the ministries of health and higher education, is competent to judge those facts.     

The influence of natural contour and face size on the spatial frequency tuning for identifying upright and inverted faces

Psychological Research - It has previously been proposed that holistic face processing is based on low spatial frequencies (SFs) whereas featural processing relies on higher SFs, a hypothesis still...     

Short-term memory performances during sustained wakefulness in patients with obstructive sleep apnea-hypopnea syndrome

Both working and immediate memories were assessed every 4h by specific short-term memory tasks over sustained wakefulness in 12 patients with obstructive sleep apnea and hypopnea syndrome (OSAHS) and 10 healthy controls. Results indicated that OSAHS patients exhibited lower working memory performances than controls on both backward digit span and complex Sternberg tasks. Speed and accuracy on Sternberg tasks were affected by memory load in both groups. However, immediate memory was not impaired in OSAHS patients. Diurnal and nocturnal SaO(2) were correlated with speed and accuracy high-speed memory scanning performance on Sternberg tasks in patients. These results suggest specific working memory deficits associated with OSAHS over sustained wakefulness with a possible deficiency in the central executive responsible for the higher information processing, in addition to a potentially insufficient storage capacity. Among OSAHS patients, working memory ability involved in high-speed memory scanning may be impaired by chronic hypoxemia.