No description available.

Le phénomène de Clignement Attentionnel (Attentional Blink, AB), fait référence à une diminution transitoire du rapport exact d’une deuxième cible (C2) si celle-ci est présentée trop tôt après une première cible (C1) lors d’une présentation visuelle sérielle rapide (rapid serial visual presentation, RSVP), et ce, quand les deux cibles doivent être rapportées. Cette étude a examiné l’existence possible d’asymétries hémisphèriques dans le traitement attentionnel ainsi que l’éventualité que la présentation de cibles à deux hémisphères différents puisse diminuer le AB chez des participants neurologiquement sains et l’abolir dans le cas d’un patient callosotomisé. Pour ce faire, nous avons employé un paradigme modifié du AB dans lequel les cibles pouvaient apparaître dans n’importe quelle de quatre RSVP, une dans chaque quadrant du champ visuel, pour permettre des essais dans lesquels les deux cibles puissent être présentées au même hémisphère et d’autres où chaque cible était présentée à un hémisphère différent. Bien que nous n’ayons trouvé aucune diminution de l’effet AB lors de présentation inter-hémisphérique, dans les deux populations à l’étude, le taux de bonnes réponses globales à la deuxième cible était plus élevé quand les cibles étaient présentées à des hémisphères différents. Nous avons également trouvé un avantage de l’hémisphère gauche chez le patient callosotomisé. / The Attentional Blink (AB) refers to a transient impairment in the accurate report of a second target (T2) if it closely follows the presentation of a first target (T1) in a rapid serial visual presentation (RSVP), when both targets must be reported. This study investigated both the possibility of hemispheric asymmetries of attentional processes as well as the possibility that presenting targets to different hemispheres could diminish the AB in neurologically intact participants and abolish it in the case of a split-brain patient. To do so, a modified AB paradigm was used in which targets could appear in any of four simultaneous RSVP streams, one in each quadrant of the visual field, so as to have trials in which both targets were presented to the same hemispheres and trials in which targets were presented to different hemispheres. Although no evidence of a diminished AB was observed by presenting targets to separate hemispheres, in both neurologically intact individuals and the split-brain patient, overall accuracy was higher when targets were presented to separate hemispheres. A left hemisphere advantage was only observed in the split-brain patient.

L’influence de la couleur dans les mécanismes perceptuels et attentionnels a été étudiée. Quatre couleurs (le rouge, le vert, le bleu et le jaune) ont été calibrées individuellement à travers la technique heterochromatic flicker photometry. Suivant cela, les participants ont déployé leur attention à une cible (un cercle de couleur avec une ligne orientée). Les données électrophysiologiques ont été enregistrées pendant que les sujets performaient la tâche de recherche visuelle, et les analyses ont été basées sur les potentiels évoqués (PÉs). Trois composantes des PÉs ont été examinées : la posterior contralateral positivity (Ppc); la N2pc, reflétant le déploiement de l’attention visuo-spatiale et la temporal and contralateral positivity (Ptc). Des conditions dans lesquelles la cible était bleu ou rouge, lorsque comparées à des conditions avec une cible jaune ou verte suscitaient une N2pc plus précoce. Une amplitude plus élevée est aussi observée pour les cibles rouges pour les composantes Ppc et Ptc, reflétant une sélectivité pré-attentionelle. Ces résultats suggèrent de la prudence dans l’interprétation de données comparant des cibles de différentes couleurs dans des tâches de PÉs, et ce même lorsque les couleurs sont équiluminantes. / We investigated how target color affected behavioral and electrophysiological results in a visual search task. Perceptual and attentional mechanisms were tracked using the N2pc component of the event-related potential and other lateralized components. Four colors (red, green, blue, or yellow) were calibrated for each participant for luminance through heterochromatic flicker photometry and equated to the luminance of grey distractors. Each visual display contained 10 circles, 1 colored and 9 grey, each of which contained an oriented line segment. The task required deploying attention to the colored circle, which was either in the left or right visual hemifield. Three lateralized ERP components relative to the side of the lateral colored circle were examined: a posterior contralateral positivity (Ppc) prior to N2pc, the N2pc, reflecting the deployment of visual spatial attention, and a temporal and contralateral positivity (Ptc) following N2pc. Red or blue stimuli, as compared to green or yellow, had an earlier N2pc. Both the Ppc and Ptc had higher amplitudes to red stimuli, suggesting particular selectivity for red. The results suggest that attention may be deployed to red and blue more quickly than to other colors and suggests special caution when designing ERP experiments involving stimuli in different colors, even when all colors are equiluminant.

Existem evidências que jogar videogames de ação (AVG) aperfeiçoa habilidades perceptuais, atentivas e cognitivas, como por exemplo, recuperação mais rápida da atenção visual e aprimoramento das dinâmicas temporais da percepção visual. Estudos correlacionais sugerem que estes aprimoramentos temporais se aplicam também ao processamento visual de baixa ordem, contudo evidências mais contundentes são necessárias. Ademais, no campo da multimídia computacional estudos apontam que a resolução temporal na qual o videogame é apresentado na tela, correspondente a taxa de quadros por segundo (QPS), afeta o desempenho e o entretenimento de jogadores. Entretanto ainda não se sabe como aspectos técnicos dos AVG, como a taxa de QPS, influenciam nos aperfeiçoamentos cognitivos citados anteriormente. Para esclarecer tais lacunas, delineou-se um estudo para verificar se AVG jogados em diferentes QPS afetam a recuperação temporal da atenção, medidos pela tarefa de Supressão Atencional (SA), e se há alterações nos limiares da resolução temporal visual, medidas através da frequência crítica de fusão e oscilação da visão (CFF). Trinta e dois (16M, 16F) participantes não jogadores de videogame voluntariaram-se para um experimento longitudinal. Inicialmente os voluntários foram separados em quatro grupos (4M, 4F) e todos eles no primeiro dia foram submetidos a uma tarefa de mensuração de CFF na região visual central e uma tarefa de SA. No dia seguinte e depois nos sete dias conseguintes dois grupos, intitulados experimentais, realizaram um treinamento com videogames de ação, sendo que cada um dos grupos treinou em diferentes resoluções temporais, um a 15 QPS e outro a 120 QPS. Simultaneamente um terceiro grupo, treinou com um videogame controle sem elementos de ação. E o quarto grupo, controle, não teve treinamento. O total de tempo de treinamento foi de 10 horas, distribuído em 8 dias, exceto para o grupo sem treino. No dia posterior ao último dia de treinamento todos os participantes foram submetidos novamente a tarefas de SA e CFF. De modo geral o CFF aumentou para todos os participantes entre pré e pós-teste, particularmente para o grupo sem treino, não houve efeito de grupo. Desempenho no SA melhorou somente no para lag2 (212ms) para participantes que treinaram AVG na taxa de QPS mais baixa. Estes resultados sugerem que treinamento com AVG não aumenta o limiar do CFF na região visual central, se não o oposto, e que o aprimoramento temporal da atenção beneficia-se com um treinamento com AVG em baixa resolução temporal, mas não de alta taxa de QPS, ao menos nas 10 horas iniciais de treino / Action video game play enhances perceptual, attentional, and cognitive skills, such as leading to faster recovery of visual attention over time and improvement of temporal dynamics of visual perception. Correlational data suggest that these temporal enhancements extend to low-level vision processes, but stronger evidence is needed. Also, in the multimedia computing field it was pointed out that video game screen frame rate affects players performance and enjoyment, but it is unclear how such technical aspects of the games play a role in cognitive augmentations. To shed more light on these issues, we tested whether action video game play and the frame rate at which they are played affects flicker detection in the central visual field and performance in attentional blink task. Thirty two (16 M, 16F) non-video game players volunteered to a longitudinal experiment. They were randomly split into four groups (4M, 4F). All of the groups performed a critical flicker-fusion frequency task (by method of limits) and attentional blink task at the first day of the experiment. Two experimental groups underwent action video-game training with different screen frame-rate caps each (15 and 120 frames per second, respectively). And one control group trained with a control game and a second control group had no training. The total amount of time in video-game training was 10 hours (75 min per day for consecutive 8 days), except for the no-training group. On the 10th day, all participants performed the flicker-detection and attentional blink tasks (post-test). Generally, critical flicker-fusion thresholds increased at the post-test for all groups, particularly for the non-training group, there were no group effect. Only marginal increased were observed in lag 2 for participant trained in low-frame-rate action video games. Our data suggest that playing video games do not increase flicker sensitivity threshold, it may actually prevent increase. And lower frame rate training produce transfer effects to Attentional Blink task, but not the higher frame rate training, at least in the first 10 hours

Existem evidências que jogar videogames de ação (AVG) aperfeiçoa habilidades perceptuais, atentivas e cognitivas, como por exemplo, recuperação mais rápida da atenção visual e aprimoramento das dinâmicas temporais da percepção visual. Estudos correlacionais sugerem que estes aprimoramentos temporais se aplicam também ao processamento visual de baixa ordem, contudo evidências mais contundentes são necessárias. Ademais, no campo da multimídia computacional estudos apontam que a resolução temporal na qual o videogame é apresentado na tela, correspondente a taxa de quadros por segundo (QPS), afeta o desempenho e o entretenimento de jogadores. Entretanto ainda não se sabe como aspectos técnicos dos AVG, como a taxa de QPS, influenciam nos aperfeiçoamentos cognitivos citados anteriormente. Para esclarecer tais lacunas, delineou-se um estudo para verificar se AVG jogados em diferentes QPS afetam a recuperação temporal da atenção, medidos pela tarefa de Supressão Atencional (SA), e se há alterações nos limiares da resolução temporal visual, medidas através da frequência crítica de fusão e oscilação da visão (CFF). Trinta e dois (16M, 16F) participantes não jogadores de videogame voluntariaram-se para um experimento longitudinal. Inicialmente os voluntários foram separados em quatro grupos (4M, 4F) e todos eles no primeiro dia foram submetidos a uma tarefa de mensuração de CFF na região visual central e uma tarefa de SA. No dia seguinte e depois nos sete dias conseguintes dois grupos, intitulados experimentais, realizaram um treinamento com videogames de ação, sendo que cada um dos grupos treinou em diferentes resoluções temporais, um a 15 QPS e outro a 120 QPS. Simultaneamente um terceiro grupo, treinou com um videogame controle sem elementos de ação. E o quarto grupo, controle, não teve treinamento. O total de tempo de treinamento foi de 10 horas, distribuído em 8 dias, exceto para o grupo sem treino. No dia posterior ao último dia de treinamento todos os participantes foram submetidos novamente a tarefas de SA e CFF. De modo geral o CFF aumentou para todos os participantes entre pré e pós-teste, particularmente para o grupo sem treino, não houve efeito de grupo. Desempenho no SA melhorou somente no para lag2 (212ms) para participantes que treinaram AVG na taxa de QPS mais baixa. Estes resultados sugerem que treinamento com AVG não aumenta o limiar do CFF na região visual central, se não o oposto, e que o aprimoramento temporal da atenção beneficia-se com um treinamento com AVG em baixa resolução temporal, mas não de alta taxa de QPS, ao menos nas 10 horas iniciais de treino / Action video game play enhances perceptual, attentional, and cognitive skills, such as leading to faster recovery of visual attention over time and improvement of temporal dynamics of visual perception. Correlational data suggest that these temporal enhancements extend to low-level vision processes, but stronger evidence is needed. Also, in the multimedia computing field it was pointed out that video game screen frame rate affects players performance and enjoyment, but it is unclear how such technical aspects of the games play a role in cognitive augmentations. To shed more light on these issues, we tested whether action video game play and the frame rate at which they are played affects flicker detection in the central visual field and performance in attentional blink task. Thirty two (16 M, 16F) non-video game players volunteered to a longitudinal experiment. They were randomly split into four groups (4M, 4F). All of the groups performed a critical flicker-fusion frequency task (by method of limits) and attentional blink task at the first day of the experiment. Two experimental groups underwent action video-game training with different screen frame-rate caps each (15 and 120 frames per second, respectively). And one control group trained with a control game and a second control group had no training. The total amount of time in video-game training was 10 hours (75 min per day for consecutive 8 days), except for the no-training group. On the 10th day, all participants performed the flicker-detection and attentional blink tasks (post-test). Generally, critical flicker-fusion thresholds increased at the post-test for all groups, particularly for the non-training group, there were no group effect. Only marginal increased were observed in lag 2 for participant trained in low-frame-rate action video games. Our data suggest that playing video games do not increase flicker sensitivity threshold, it may actually prevent increase. And lower frame rate training produce transfer effects to Attentional Blink task, but not the higher frame rate training, at least in the first 10 hours

Le phénomène de Clignement Attentionnel (Attentional Blink, AB), fait référence à une diminution transitoire du rapport exact d’une deuxième cible (C2) si celle-ci est présentée trop tôt après une première cible (C1) lors d’une présentation visuelle sérielle rapide (rapid serial visual presentation, RSVP), et ce, quand les deux cibles doivent être rapportées. Cette étude a examiné l’existence possible d’asymétries hémisphèriques dans le traitement attentionnel ainsi que l’éventualité que la présentation de cibles à deux hémisphères différents puisse diminuer le AB chez des participants neurologiquement sains et l’abolir dans le cas d’un patient callosotomisé. Pour ce faire, nous avons employé un paradigme modifié du AB dans lequel les cibles pouvaient apparaître dans n’importe quelle de quatre RSVP, une dans chaque quadrant du champ visuel, pour permettre des essais dans lesquels les deux cibles puissent être présentées au même hémisphère et d’autres où chaque cible était présentée à un hémisphère différent. Bien que nous n’ayons trouvé aucune diminution de l’effet AB lors de présentation inter-hémisphérique, dans les deux populations à l’étude, le taux de bonnes réponses globales à la deuxième cible était plus élevé quand les cibles étaient présentées à des hémisphères différents. Nous avons également trouvé un avantage de l’hémisphère gauche chez le patient callosotomisé. / The Attentional Blink (AB) refers to a transient impairment in the accurate report of a second target (T2) if it closely follows the presentation of a first target (T1) in a rapid serial visual presentation (RSVP), when both targets must be reported. This study investigated both the possibility of hemispheric asymmetries of attentional processes as well as the possibility that presenting targets to different hemispheres could diminish the AB in neurologically intact participants and abolish it in the case of a split-brain patient. To do so, a modified AB paradigm was used in which targets could appear in any of four simultaneous RSVP streams, one in each quadrant of the visual field, so as to have trials in which both targets were presented to the same hemispheres and trials in which targets were presented to different hemispheres. Although no evidence of a diminished AB was observed by presenting targets to separate hemispheres, in both neurologically intact individuals and the split-brain patient, overall accuracy was higher when targets were presented to separate hemispheres. A left hemisphere advantage was only observed in the split-brain patient.

L’influence de la couleur dans les mécanismes perceptuels et attentionnels a été étudiée. Quatre couleurs (le rouge, le vert, le bleu et le jaune) ont été calibrées individuellement à travers la technique heterochromatic flicker photometry. Suivant cela, les participants ont déployé leur attention à une cible (un cercle de couleur avec une ligne orientée). Les données électrophysiologiques ont été enregistrées pendant que les sujets performaient la tâche de recherche visuelle, et les analyses ont été basées sur les potentiels évoqués (PÉs). Trois composantes des PÉs ont été examinées : la posterior contralateral positivity (Ppc); la N2pc, reflétant le déploiement de l’attention visuo-spatiale et la temporal and contralateral positivity (Ptc). Des conditions dans lesquelles la cible était bleu ou rouge, lorsque comparées à des conditions avec une cible jaune ou verte suscitaient une N2pc plus précoce. Une amplitude plus élevée est aussi observée pour les cibles rouges pour les composantes Ppc et Ptc, reflétant une sélectivité pré-attentionelle. Ces résultats suggèrent de la prudence dans l’interprétation de données comparant des cibles de différentes couleurs dans des tâches de PÉs, et ce même lorsque les couleurs sont équiluminantes. / We investigated how target color affected behavioral and electrophysiological results in a visual search task. Perceptual and attentional mechanisms were tracked using the N2pc component of the event-related potential and other lateralized components. Four colors (red, green, blue, or yellow) were calibrated for each participant for luminance through heterochromatic flicker photometry and equated to the luminance of grey distractors. Each visual display contained 10 circles, 1 colored and 9 grey, each of which contained an oriented line segment. The task required deploying attention to the colored circle, which was either in the left or right visual hemifield. Three lateralized ERP components relative to the side of the lateral colored circle were examined: a posterior contralateral positivity (Ppc) prior to N2pc, the N2pc, reflecting the deployment of visual spatial attention, and a temporal and contralateral positivity (Ptc) following N2pc. Red or blue stimuli, as compared to green or yellow, had an earlier N2pc. Both the Ppc and Ptc had higher amplitudes to red stimuli, suggesting particular selectivity for red. The results suggest that attention may be deployed to red and blue more quickly than to other colors and suggests special caution when designing ERP experiments involving stimuli in different colors, even when all colors are equiluminant.

Syfte: Syftet med den här studien var att undersöka om Spontaneous Eye Blink Rate (SEBR) skiljde sig åt vid läsning på utskrivet papper, surfplatta eller smartphone. Det jämfördes också huruvida fullständiga och ofullständiga blinkningar skiljde sig åt vid läsning på de olika medierna. Metod: Deltagarna (n=29) fick läsa tre olika texter på utskrivet papper, surfplatta och smartphone samtidigt som de filmades. I efterhand granskades samtliga videos två gånger för att räkna fullständiga blinkningar, ofullständiga blinkningar och totalt antal blinkningar (SEBR). Resultat: Den här studien visade att där finns en signifikant skillnad av totalt antal blinkningar vid läsning på utskrivet papper och surfplatta (p=0,03), där blinkningar/minut sjönk med 14,9% vid läsning på utskrivet papper, jämfört med surfplatta. För ofullständiga blinkningar fanns en statistiskt signifikant skillnad mellan utskrivet papper och surfplatta (p=0,02), där antalet ofullständiga blinkningar/minut ökade med 30,0% vid läsning på surfplatta, jämfört med utskrivet papper. Vid läsning på surfplatta och smartphone fanns en signifikant skillnad gällande ofullständiga blinkningar (p=0,01), där antalet ofullständiga blinkningar/minut ökade med 42% vid läsning på surfplattan, jämfört med smartphone.  Slutsats: Spontaneous Eye Blink Rate skiljer sig vid läsning på papper och surfplatta. Ofullständiga blinkningar är flest vid läsning på surfplatta. Inga signifikanta skillnader finns mellan utskrivet papper och smartphone. / Purpose: The purpose of this study was to evaluate whether Spontaneous Eye Blink Rate (SEBR) differ when reading on hard copy, tablet or smartphone. Complete and incomplete blinks were also evaluated to see if there were any differences regarding the hard copy, tablet and smartphone.  Methods: The participants read three different texts on hard copy, tablet and smartphone while they were being filmed. Afterwards, each video was analysed twice in order to count complete blinks, incomplete blinks and total blink rate (SEBR). Results: This study showed that there is a significant difference in total blink rate between reading on hard copy and tablet (p=0.03), where blinks/minute decreased by 14.9% for the hard copy condition. There was also a significant difference in incomplete blinks regarding the two devices (p=0.02), where incomplete blinks increased by 30.0% when reading on tablet. Tablet and smartphone reading also resulted in a significant difference, where incomplete blinks increased  by 42% when reading on tablet (p=0.01). Conclusion: Spontaneous Eye Blink Rate differ when reading on hard copy and tablet. Incomplete blinks increase when reading on tablet. No significant differences are found between hard copy and smartphone.

No description available.

Une des théories actuellement prépondérante pour expliquer le déclin cognitif observé chez les personnes âgées est une perte généralisée de la fonction inhibitrice. En revanche, de plus en plus d’études révèlent un maintien et même un gain sur le plan émotionnel chez les âgés. Afin de caractériser l’effet de l’âge sur la fonction inhibitrice et sur les émotions, nous avons utilisé le paradigme bien connu du réflexe acoustique de sursaut et de son inhibition par le prépulse, un phénomène reconnu comme reflétant le filtrage sensorimoteur, soit une mesure pré-attentionnelle d’inhibition. Le réflexe acoustique de sursaut est une réponse du corps tout entier à un bruit fort et inattendu et a été mesuré via la magnitude et la latence du clignement des yeux. La présentation d’un son faible (prépulse) quelques millisecondes avant le bruit de sursaut réduit la réponse de sursaut. Deux groupes de participants (jeunes adultes et âgés) ont visionné des images plaisantes, neutres et déplaisantes issues du International Affective Picture System (IAPS), lesquelles étaient associées à des stimuli auditifs évaluant le réflexe acoustique de sursaut et son inhibition par le prépulse. Les résultats démontrent que le réflexe de sursaut est modulé différemment par les émotions chez les jeunes adultes et les âgés. Plus particulièrement, les adultes âgés ont un plus grand réflexe de sursaut que les jeunes adultes lorsqu’ils visionnent des images plaisantes et neutres. Le processus d’inhibition par le prépulse est également modulé différemment par les émotions chez les âgés et les jeunes adultes: les âgés ont une plus grande inhibition du réflexe de sursaut que les jeunes adultes lorsqu’ils visionnent des images plaisantes et déplaisantes, mais ils ne diffèrent pas des jeunes adultes pour les images neutres. Dans l’ensemble, les résultats obtenus ne sont pas compatibles avec une perte d’inhibition chez les adultes âgés, et supportent plutôt un biais émotionnel positif. / Aging is often characterized by a decline in cognitive abilities and a loss of inhibitory function. At the same time there is promising, yet limited to date, evidence of a better emotion regulation with aging. In order to characterize the effect of age on inhibitory function and emotions, in this study the well-known acoustic startle paradigm and its inhibition by a prepulse, a phenomenon known to engage sensorimotor gating, were used. The acoustic startle reflex, a whole-body reflex in response to a loud and unexpected sound, was measured through eye blink magnitude and latency. The inhibition of this acoustic startle response by the presentation of a weak sound, a prepulse, was also measured. Two groups of 30 adults (young and older adults) viewed pleasant, neutral, and unpleasant images from the International Affective Picture System (IAPS) while startle and prepulse trials were presented. The results show that the startle response is differently modulated in the two groups, with the elderly displaying a greater startle reflex while viewing pleasant and neutral pictures compared to young adults. Prepulse inhibition is also differently modulated by emotions in young adults and their older counterparts, with the latter exhibiting a greater inhibition of the startle reflex when viewing pleasant and unpleasant pictures (but not for neutral pictures) compared to young adults. In summary, the present data do not support a decline of the inhibitory function with increasing age, but rather support a positivism effect.