Does a visual mask need to be perceptually present to disrupt processing? In the present research, we proposed to explore the link between perceptual and memory mechanisms by demonstrating that a typical sensory phenomenon (visual masking) can be replicated at a memory level. Experiment 1 highlighted an interference effect of a visual mask on the categorization of auditory targets and confirmed the multimodal nature of knowledge. In Experiment 2, we proposed to reactivate this mask in a categorization task on visual targets. Results showed that the sensory mask has disrupted (slower reaction times) the processing of the targets whether the mask was perceptually present or reactivated in memory. These results support a sensory-based conception of memory processing and suggest that the difference between perceptual processes and memory processes is characterized by the presence (perception) or the absence (memory) of the sensory properties involved in the activity.

Objectives: In the context of growing interest in real-time driver stress detection systems, we question the value of using heart rate change over short time periods to detect driver stress and hazard anticipation. Methods:To this end, we explored changes in heart rate and speed as well as perceived stress in 27 drivers in a driving simulator. Driver stress was triggered by using hazardous road events, while hazard anticipation was manipulated using three levels of hazard predictability: unpredictable (U), predictable (P), and predictable and familiar (PF). Results:The main results indicate that using heart rate change (1) is a good indicator for detecting driver stress in real time, (2) provides a cardiac signature of hazard anticipation, and (3) was affected by perceived stress groups. Further investigation is needed to validate the lack of relationship between increased anticipation/predictability and strengthened cardiac signature. Conclusions:These results support the use of heart rate change as an indicator of realtime driver stress and hazard anticipation.

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International audienceWith the increased popularity of touch-sensitive surfaces, much attention has been drawn to their security-related issues, as they currently rely only on the visual sense for feedback. To improve operability, vibrotactile signals may be delivered to the finger on screen interaction. The way vibrotactile signals affect human perception is examined via three measured variables, related to their energy, velocity, and spectral complexity, and which are analytically defined in this paper. It is shown that these variables accurately account for the psychophysical properties of the tactile sense. Based on this, a psychophysical fuzzy rule-based model of vibrotactile perception is introduced to forecast the comfort values of the vibrational signals provided by an automobile haptic screen. Using an efficient rule-based generation method, a Mamdani fuzzy inference system is proposed; it achieves a mean error rate of 14% for the train set and 17% for the test set, while correctly classifying most of the signals within a reasonable tolerance, related to human evaluation imprecision. The system also produces a comprehensible linguistic rule structure, which allows behavioral patterns to be detected

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Background: The link between driving performance impairment and driver stress is well-established. Identifying and understanding driver stress is therefore of major interest in terms of safety. Although many studies have examined various physiological measures to identify driver stress, none of these has as yet been definitively confirmed as offering definitive all-round validity in practice.Aims: Based on the data available in the literature, our main goal was to provide a quantitative assessment of the sensitivity of the physiological measures used to identify driver stress. The secondary goal was to assess the influence of individual factors (i.e., characteristics of the driver) and ambient factors (i.e., characteristics of the context) on driver stress. Age and gender were investigated as individual factors. Ambient factors were considered through the experimental apparatus (real-road vs. driving simulator), automation driving (manual driving vs. fully autonomous driving) and stressor exposure duration (short vs. long-term).Method: Nine meta-analyses were conducted to quantify the changes in each physiological measure during high-stress vs. low-stress driving. Meta-regressions and subgroup analyses were performed to assess the moderating effect of individual and ambient factors on driver stress.Results: Changes in stress responses suggest that several measures are sensitive to levels of driver stress, including heart rate, R-R intervals (RRI) and pupil diameter. No influence of individual and ambient factors was observed for heart rate.Applications and Perspective: These results provide an initial guide to researchers and practitioners when selecting physiological measures for quantifying driver stress. Based on the results, it is recommended that future research and practice use (i) multiple physiological measures, (ii) a triangulation-based methodology (combination of measurement modalities), and (iii) a multifactorial approach (analysis of the interaction of stressors and moderators).

International audienceNowadays tactile surfaces are slowly replacing the mechanical interfaces of our electronic devices, and the actual trend is toward a quasi-total touch interaction. This transition has however one important side effect, i.e the lack of feedback from the device, which in certain situations can be crucial. In order to overcome this, it has been suggested that feedback has to be delivered to the finger through vibrations that should be both detectable and comfortable. This paper aims to define a perception model for the sensory evaluations of the vibrotactile signals using fuzzy set theory. First of all, the hypothesis that haptic perception is strongly related to physical characteristics of the signals was evaluated and confirmed with a 93% correlation rate, based on psychophysical studies of the tactile sense. Secondly, using the previous analysis as a knowledge base we have implemented a fuzzy inference system which forecasts the preference values for vibrotactile signals. The preliminary results show that for 15 out of 18 signals, the preference is correctly predicted within a reasonable uncertainty interval

Based on claims resulting from grounded cognition theory that perceptual and memory processes are using the same distributed systems, the present study investigated the temporal aspect of access to memory traces through haptic and auditory modalities. Unlike in the case of visual or auditory components, the perception of a vibrotactile component is more sequential in nature and therefore cannot be fully processed before the end of the signal. The present study explores the dynamic of components activation in a situation of audio-vibrotactile asynchrony. We used a short-term priming paradigm consisting of an association phase (between a vibration and sound) and a test phase testing priming effect of a vibrotactile stimulation on the processing of a target sound. Results showed an interference with a simultaneous processing and a facilitation with a sequential processing. The temporality process of perceptual components is also important at a memory level.