The influence of infant-directed speech on 12-month-olds' intersensory perception of fluent speech

The present study examined whether infant-directed (ID) speech facilitates intersensory matching of audio--visual fluent speech in 12-month-old infants. German-learning infants\^a audio--visual matching ability of German and French fluent speech was assessed by using a variant of the intermodal matching procedure, with auditory and visual speech information presented sequentially. In Experiment 1, the sentences were spoken in an adult-directed (AD) manner. Results showed that 12-month-old infants did not exhibit a matching performance for the native, nor for the non-native language. However, Experiment 2 revealed that when ID speech stimuli were used, infants did perceive the relation between auditory and visual speech attributes, but only in response to their native language. Thus, the findings suggest that ID speech might have an influence on the intersensory perception of fluent speech and shed further light on multisensory perceptual narrowing

Sex categorization of faces: The effects of age and experience

The face own-age bias effect refers to the better ability to recognize the face from one's own age compared with other age groups. Here we examined whether an own-age advantage occurs for faces sex categorization. We examined 7- and 9-year-olds' and adults' ability to correctly categorize the sex of 7- and 9-year-olds and adult faces without external cues, such as hair. Results indicated that all ages easily classify the sex of adult faces. They succeeded in classifying the sex of child faces, but their performance was poorer than for adult faces. In adults, processing time increased, and a response bias (male response) was elicited for child faces. In children, response times remained constant, and no bias was observed. Experience with specific category of faces seems to offer some advantage in speed of processing. Overall, sex categorization is more challenging for child than for adult faces due to their reduced sexual dimorphic facial characteristics

Female face preference in 4-month-olds: The importance of hairline

At 3–4 months of age, infants respond to gender information in human faces. Specifically, young infants display a visual preference toward female over male faces. In three experiments, using a visual preference task, we investigated the role of hairline information in this bias. In Experiment 1, we presented male and female composite faces with similar hairstyles to 4-month-olds and observed a preference for female faces. In Experiment 2, the faces were presented, but in this instance, without hairline cues, and the preference was eliminated. In Experiment 3, using the same cropping to eliminate hairline cues, but with feminized female faces and masculinized male faces, infants’ preference toward female faces was still not in evidence. The findings show that hairline information is important in young infants’ preferential orientation toward female face

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Apprentissage multisensoriel de lettres et de formes abstraites chez les jeunes enfants et les adultes

Learning to read in an alphabetic system requires children to understand that letters (graphemes) in written language correspond to sounds (phonemes) in oral language. To learn these novel associations requires several years of specific instruction. Using some methods early on to prepare children for this seems efficient, where the methods are designed to reinforce the link observed between perceptive and motor abilities during reading and handwriting acquisition. The main goal of this work was to understand the way manual haptic exploration of cursive letters can enhance pseudo-words decoding and handwriting fluidity in letters production in senior kindergarten children. To do so, we compared multisensory trainings involving haptic and visual modalities, in the proposed motor activities around the letters, to visual or haptic unisensory tranings. This work was realised according to two axes: for the first, in senior kindergarten children shown graphemes and phonemes, and for the second, in adults shown a new learning of unseen abstract forms and auditory stimuli. Results reveal that motor activity around letters and abstract forms does not enhance participant's memorisation despite exploratory motions intimately related to their shapes. Nevertheless, we showed in a robust way a more important associative learning of letters and sounds after a visuo-haptic exploration of letters. In addition, this enhancement is not only due to a more sequential exploration induced by the haptic modality but more to the motor activity per se. Haptic modality could be at the origin of a "binding" effect between visual and auditory stimuli. Finally, getting children into the habit of handwriting motion of cursive letters via a haptic exploration (arm robot device), enhances their handwriting fluidity. Demonstration of a static and dynamic model of letters could help children in the acquisition of some motor rules production (as strokes order and kinematics) and in the construction of more complete motor representations of letters. Taken together, results suggest a significant impact of the haptic exploration of letters in acquiring the skills of reading and handwriting and add weight to the suggestion that haptic exploration should be used in training programs designed to prepare children for acquiring these skillsPour apprendre à lire dans un système d'écriture alphabétique, les enfants doivent comprendre que les lettres (graphèmes) de l'écrit représentent les sons (phonèmes) de l'oral. Comprendre et apprendre ces nouvelles associations ainsi qu'automatiser leur utilisation nécessite plusieurs années d'enseignement spécifique. Des études ont montré que des méthodes précoces de préparation aux apprentissages qui renforcent les liens entre les compétences perceptives et motrices sollicitées lors de l'apprentissage conjoint de la lecture et de l'écriture seraient particulièrement efficaces. L'objectif principal de ce travail a été de comprendre la manière dont une exploration manuelle haptique de lettres cursives favorisait le décodage de pseudo-mots et la fluidité des tracés chez des enfants de grande section de maternelle. Nous avons donc comparé des entraînements multisensoriels, impliquant la modalité haptique et visuelle dans le travail d'exploration des lettres, à des entraînements unimodaux visuel ou haptique. Ce travail a été réalisé à travers deux axes : d'une part, chez des enfants de grande section de maternelle confrontés aux graphèmes et phonèmes, et d'autre part, chez des adultes confrontés à un nouvel apprentissage de formes abstraites et stimuli auditifs totalement inédits. Les résultats révèlent que l'activité motrice autour des lettres et des formes abstraites ne permet pas, malgré des mouvements d'exploration intimement liés à leur configuration spatiale, de favoriser leur mémorisation. Toutefois, nous mettons en évidence de manière robuste un meilleur apprentissage des associations entre les formes et les sons après une exploration visuelle et haptique des formes. De surcroît, cette amélioration ne serait pas uniquement due à la séquentialité de l'exploration induite par la modalité haptique, mais bien à la motricité elle-même. La modalité haptique pourrait donc servir de " ciment " entre les stimuli visuels et auditifs. Enfin, familiariser les enfants au geste d'écriture de lettres cursives, via une exploration haptique guidée (par un bras robot à retour de force), permet d'améliorer la fluidité de l'écriture. Présenter un patron de lettre à la fois statique et dynamique permettrait aux enfants d'assimiler certaines règles motrices de production (ordre de production, cinématique) et d'acquérir une représentation motrice plus complète de la lettre. L'ensemble des résultats suggère une influence significative de l'exploration haptique de lettres dans l'apprentissage de la lecture et de l'écriture et encourage donc sa prise en compte dans des entraînements visant à préparer ces apprentissages

Saccadic "Adaptation" at Late Target Reappearance

International audienc

Empirical validation of Quest+

Raw data collected for the empirical validation of Quest+ in three visual discrimination task

Empirical validation of Quest+ in PSE and JND estimations in visual discrimination tasks

International audienceOne of the most precise methods to establish psychometric functions and estimate threshold and slope parameters is the constant stimuli procedure. In this procedure the distribution of stimulus values presented to the participants is specified before the experiment. This distribution is composed of a large range of stimulus values, which enables to fully develop the psychometric function, but requires a large number of trials. Adaptive procedures (e.g., non-parametric staircases, Bayesian procedures...) enable reliable threshold estimation while reducing the number of trials by concentrating stimulus presentations around observers' supposed threshold. Here, the stimulus value for the next trial depends on observer's responses to the previous trials. One recent substantial improvement of Bayesian procedures is to also estimate the slope (related to discrimination sensitivity). The Bayesian Quest+ procedure (Watson, 2017), a generalization and extension of Watson and Pelli's (1983) Quest procedure, includes this refinement. Surprisingly, this procedure is barely used. Our goal was to assess the efficacy of this procedure empirically, in four yes-no tasks evaluating size (Expt. 1A and 1B), orientation (Expt. 2), or temporality (Expt. 3). We compared points of subjective equivalence (PSEs) and discrimination sensitivity obtained in 91 adult participants in total with the Quest+, constant stimuli and simple up-down staircase procedures. While PSEs did not differ between procedures, sensitivity estimates obtained with the 64-trials Quest+ procedure were overestimated (i.e., just noticeable differences, or JNDs, were underestimated). Correlations between PSEs and between JNDs of the Quest+ and constant stimuli procedures were significant in three experiments (r range: .52-.85, p range: <.001-.024). Overall, this study empirically confirmed that the Quest+ procedure can be considered as a method of choice to accelerate PSE estimation, while keeping in mind that sensitivity estimation should be handled with caution

Action-Perception Relationship: Peripheral Objects' Magnification Occurs Before the Saccadic Compression Timeframe

International audienceVisual attention is known to enhance perception of saccadic targets’ orientation, contrast and spatial resolution. In this study, we evaluated whether preparing a saccade could improve size perception of objects appearing before the saccadic compression timeframe. Participants (N=19) performed a judgment task in which they had to compare a test disk of varying size briefly presented in peripheral vision to a reference disk appearing about 550 ms later in foveal vision. Psychometric function parameters were computed. When no saccade was made toward the test disk location, its size was underestimated, as expected for objects presented in the periphery. However, Points of Subjective Equality were near objective equality when participants initiated saccades 200 ms after the extinction of the test disk. This refinement in size perception seems to indicate that attention coupled to saccade preparation could overcome perceptual distortion (size-eccentricity effect) in the visual field likely by magnifying peripheral objects’ size