Modification de la formule de Dalton à partir d'une nouvelle formulation du flux chaleur sensible en conditions suradiabatiques

Utilisant une nouvelle méthode de formulation des flux turbulents, les auteurs proposent une modification de la formule de Dalton qui tienne compte de façon explicite de l'instabilité et qui est vérifiée expérimentalement par des résultats obtenus dans le Sud-Tunisien. La formule traditionnelle de Dalton est discutée à partir de cette nouvelle expression. (Résume d'auteur

Attention Capture by Direct Gaze is Robust to Context and Task Demands

The final publication is available at Springer via https://dx.doi.org/10.1007/s10919-011-0128-z.Eye-tracking was used to investigate whether gaze direction would influence the visual scanning of faces, when presented in the context of a full character, in different social settings, and with different task demands. Participants viewed individual computer agents against either a blank background or a bar scene setting, during both a free-viewing task and an attractiveness rating task for each character. Faces with a direct gaze were viewed longer than faces with an averted gaze regardless of body context, social settings, and task demands. Additionally, participants evaluated characters with a direct gaze as more attractive than characters with an averted gaze. These results, obtained with pictures of computer agents rather than real people, suggest that direct gaze is a powerful attention grabbing stimulus that is robust to background context or task demands.103305-1/Canadian Institutes of Health Research89822-1/Canadian Institutes of Health Research103305-1/PHS HHS/United States89822-1/PHS HHS/United State

Is the rapid adaptation paradigm too rapid? Implications for face and object processing

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.neuroimage.2012.03.065. © 2012. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Rapid adaptation is an adaptation procedure in which adaptors and test stimuli are presented in rapid succession. The current study tested the validity of this method for early ERP components by investigating the specificity of the adaptation effect on the face-sensitive N170 ERP component across multiple test stimuli. Experiments 1 and 2 showed identical response patterns for house and upright face test stimuli using the same adaptor stimuli. The results were also identical to those reported in a previous study using inverted face test stimuli (Nemrodov and Itier, 2011). In Experiment 3 all possible adaptor-test combinations between upright face, house, chair and car stimuli were used and no interaction between adaptor and test category, expected in the case of test-specific adaptation, was found. These results demonstrate that the rapid adaptation paradigm does not produce category-specific adaptation effects around 170-200 ms following test stimulus onset, a necessary condition for the interpretation of adaptation results. These results suggest the rapid categorical adaptation paradigm does not work.103305-1/Canadian Institutes of Health Research89822-1/Canadian Institutes of Health ResearchMOP-89822/Canadian Institutes of Health Researc

Searching for a perceived gaze direction using eye tracking

The purpose of the current study was to use eye tracking to better understand the “stare-in-the-crowd effect”—the notion that direct gaze is more easily detected than averted gaze in a crowd of opposite-gaze distractors. Stimuli were displays of four full characters aligned across the monitor (one target and three distractors). Participants completed a visual search task in which they were asked to detect the location of either a direct gaze or an averted gaze target. Reaction time (RT) results indicated faster responses to direct than averted gaze only for characters situated in the far peripheral visual fields. Eye movements confirmed a serial search strategy (definitely ruling out any pop-out effects) and revealed different exploration patterns between hemifields. The latency before the first fixation on target strongly correlated with response RTs. In the LVF, that latency was also faster for direct than averted gaze targets, suggesting that the response asymmetry in favor of direct gaze stemmed from faster direct gaze target detection. In the RVF, however, the response bias to direct gaze seemed not due to a faster visual detection but rather to a different cognitive mechanism. Direct gaze targets were also responded to even faster when their position was congruent with the direction of gaze of distractors. These findings suggest that the detection asymmetry for direct gaze is highly dependent on target position and influenced by social contexts.This study was funded by CIHR (MOP-87393, MOP-89822, and NSP-94824), CFI, and the CRC Program to R. J. Itier

The role of eyes in early face processing: a rapid adaptation study of the inversion effect.

This is the peer reviewed version of the following article: Nemrodov, D. and Itier, R. J. (2011), The role of eyes in early face processing: A rapid adaptation study of the inversion effect. British Journal of Psychology, 102: 783–798. doi:10.1111/j.2044-8295.2011.02033.x, which has been published in final form at https://dx.doi.org/10.1111/j.2044-8295.2011.02033.x. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.The current study employed a rapid adaptation procedure to test the neuronal mechanisms of the face inversion effect (FIE) on the early face-sensitive event-related potential (ERP) component N170. Five categories of face-related stimuli (isolated eyes, isolated mouths, eyeless faces, mouthless faces, and full faces) and houses were presented in upright and inverted orientations as adaptors for inverted full face test stimuli. Strong adaptation was found for all face-related stimuli except mouths. The adaptation effect was larger for inverted than upright stimuli, but only when eyes were present. These results underline an important role of eyes in early face processing. A mechanism of eye-dependent orientation sensitivity during the structural encoding stage of faces is proposed.103305-1/Canadian Institutes of Health Research89822-1/Canadian Institutes of Health ResearchMOP-89822/Canadian Institutes of Health Researc

Eye gaze and head orientation modulate the inhibition of return for faces

The final publication is available at Springer via https://dx.doi.org/10.3758/s13414-015-0961-y.The present study used an inhibition of return (IOR) spatial cueing paradigm to examine how gaze direction and head orientation modulate attention capture for human faces. Target response time (RT) was measured after the presentation of a peripheral cue, which was either a face (with frontfacing or averted gaze, in either frontal head view or averted head view) or a house (control). Participants fixated on a centred cross at all times and responded via button press to a peripheral target after a variable stimulus onset asynchrony (SOA) from the stimulus cue. At the shortest SOA (150 ms), RTs were shorter for faces than houses, independent of an IOR response, suggesting a cue-based RT advantage elicited by faces. At the longest SOA (2400 ms), a larger IOR magnitude was found for faces compared to houses. Both the cue-based RT advantage and later IOR responses were modulated by gaze-head congruency; these effects were strongest for frontal gaze faces in frontal head view, and for averted gaze faces in averted head view. Importantly, participants were not given any specific information regarding the stimuli, nor were they told the true purpose of the study. These findings indicate that the congruent combination of head and gaze direction influence the exogenous attention capture of faces during inhibition of return.These findings indicate that the congruent combination of head and gaze direction influence the exogenous attention capture of faces during inhibition of return.||the Ontario government (Early Researcher Award||ER11-08-172), the Canada Foundation for Innovation (CFI, #213322)||and the Canada Research Chair (CRC, #959-213322) program to RJI||as well as by a doctoral NSERC grant to KNN

EMOTIONAL MODULATION OF ATTENTION ORIENTING BY GAZE VARIES WITH DYNAMIC CUE SEQUENCE.

This is the author accepted manuscript. The final version is available from Taylor & Francis via http://dx.doi.org/10.1080/13506285.2015.1083067Recent gaze cueing studies using dynamic cue sequences have reported increased attention orienting by gaze with faces expressing fear, surprise or anger. Here, we investigated whether the type of dynamic cue sequence used impacted the magnitude of this effect. When the emotion was expressed before or concurrently with gaze shift, no modulation of gaze-oriented attention by emotion was seen. In contrast, when the face cue averted gaze before expressing an emotion (as if reacting to the object after first localizing it), the gaze orienting effect was clearly increased for fearful, surprised and angry faces compared to neutral faces. Thus, the type of dynamic sequence used, and in particular the order in which the gaze shift and the facial expression are presented, modulate gaze-oriented attention, with maximal modulation seen when the expression of emotion follows gaze shift

Facial expression discrimination varies with presentation time but not with fixation on features: A backward masking study using eye-tracking

This is an Accepted Manuscript of an article published by Taylor & Francis in Cognition and Emotion on 23 Sep 2013, available online: http://www.tandfonline.com/10.1080/02699931.2013.812557.The current study investigated the effects of presentation time and fixation to expression-specific diagnostic features on emotion discrimination performance, in a backward masking task. While no differences were found when stimuli were presented for 16.67 ms, differences between facial emotions emerged beyond the happy-superiority effect at presentation times as early as 50 ms. Happy expressions were best discriminated, followed by neutral and disgusted, then surprised, and finally fearful expressions presented for 50 and 100 ms. While performance was not improved by the use of expression-specific diagnostic facial features, performance increased with presentation time for all emotions. Results support the idea of an integration of facial features (holistic processing) varying as a function of emotion and presentation time.This study was supported by the Canadian Institutes for Health Research (CIHR)the Canada Foundation for Innovation (CFI)the Ontario Research Fund (ORF)and the Canada Research Chair (CRC) program to RJI

Is the rapid adaptation paradigm too rapid? Implications for face and object processing

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.neuroimage.2012.03.065. © 2012. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Rapid adaptation is an adaptation procedure in which adaptors and test stimuli are presented in rapid succession. The current study tested the validity of this method for early ERP components by investigating the specificity of the adaptation effect on the face-sensitive N170 ERP component across multiple test stimuli. Experiments 1 and 2 showed identical response patterns for house and upright face test stimuli using the same adaptor stimuli. The results were also identical to those reported in a previous study using inverted face test stimuli (Nemrodov and Itier, 2011). In Experiment 3 all possible adaptor-test combinations between upright face, house, chair and car stimuli were used and no interaction between adaptor and test category, expected in the case of test-specific adaptation, was found. These results demonstrate that the rapid adaptation paradigm does not produce category-specific adaptation effects around 170-200 ms following test stimulus onset, a necessary condition for the interpretation of adaptation results. These results suggest the rapid categorical adaptation paradigm does not work.103305-1/Canadian Institutes of Health Research89822-1/Canadian Institutes of Health ResearchMOP-89822/Canadian Institutes of Health Researc