Cerebral Correlates of Emotional and Action Appraisals During Visual Processing of Emotional Scenes Depending on Spatial Frequency: A Pilot Study.

International audienceVisual processing of emotional stimuli critically depends on the type of cognitive appraisal involved. The present fMRI pilot study aimed to investigate the cerebral correlates involved in the visual processing of emotional scenes in two tasks, one emotional, based on the appraisal of personal emotional experience, and the other motivational, based on the appraisal of the tendency to action. Given that the use of spatial frequency information is relatively flexible during the visual processing of emotional stimuli depending on the task's demands, we also explored the effect of the type of spatial frequency in visual stimuli in each task by using emotional scenes filtered in low spatial frequency (LSF) and high spatial frequencies (HSF). Activation was observed in the visual areas of the fusiform gyrus for all emotional scenes in both tasks, and in the amygdala for unpleasant scenes only. The motivational task induced additional activation in frontal motor-related areas (e.g. premotor cortex, SMA) and parietal regions (e.g. superior and inferior parietal lobules). Parietal regions were recruited particularly during the motivational appraisal of approach in response to pleasant scenes. These frontal and parietal activations, respectively, suggest that motor and navigation processes play a specific role in the identification of the tendency to action in the motivational task. Furthermore, activity observed in the motivational task, in response to both pleasant and unpleasant scenes, was significantly greater for HSF than for LSF scenes, suggesting that the tendency to action is driven mainly by the detailed information contained in scenes. Results for the emotional task suggest that spatial frequencies play only a small role in the evaluation of unpleasant and pleasant emotions. Our preliminary study revealed a partial distinction between visual processing of emotional scenes during identification of the tendency to action, and during identification of personal emotional experiences. It also illustrates flexible use of the spatial frequencies contained in scenes depending on their emotional valence and on task demands

Multimodal Perception of Prosodic Contrastive Focus in French: A Preliminary fMRI Study

http://www.zas.gwz-berlin.de/events/summerschool_2007/index.htmInternational audienceContrastive focus is used to emphasize a word or group of words in an utterance as opposed to another. In French, it can be conveyed by prosody using a specific intonational contour on the constituent pointed at (XXXf a mangé la pomme. 'XXXf ate the apple.'). It remains unclear what neural processes underlie the perception of prosodic focus. Meanwhile studies have shown that prosodic processing in general cannot be restricted to the right hemisphere (see [1] for review). Moreover it appears ([2]) that even though the perception of prosodic focus was often considered as uniquely auditory, it is possible to perceive prosodic focus visually and the visual modality can enhance perception when prosodic auditory cues are degraded (whispered speech). This finding emphasizes the necessity to consider the perception of prosodic contrastive focus and speech prosody in general as multimodal. The aim of this study is to analyze the neural processing of prosodic focus from a multimodal point of view

Cerebral correlates of multimodal pointing: An fmri study of prosodic focus, syntactic extraction, digital- and ocular- pointing

International audienceDeixis or pointing plays a crucial role in language acquisition and speech communication and can be conveyed in several modalities. The aim of this paper is to explore the cerebral substrate of multimodal pointing actions. We present an fMRI study of pointing including: 1) index finger pointing, 2) eye pointing, 3) prosodic focus production, 4) syntactic extraction (during speech production). Fifteen subjects were examined while they gave digital, ocular and oral responses inside the 3T imager. Results of a random effect group analysis show that digital and prosodic pointings recruit the parietal lobe bilaterally, while ocular and syntactic pointings do not. A grammaticalization process is suggested to explain the lack of parietal activation in the syntactic condition. Further analyses are carried out on the link between digital and prosodic parietal activations

Retinotopic and lateralized processing of spatial frequencies in human visual cortex during scene categorization.

International audienceUsing large natural scenes filtered in spatial frequencies, we aimed to demonstrate that spatial frequency processing could not only be retinotopically mapped but could also be lateralized in both hemispheres. For this purpose, participants performed a categorization task using large black and white photographs of natural scenes (indoors vs. outdoors, with a visual angle of 24° × 18°) filtered in low spatial frequencies (LSF), high spatial frequencies (HSF), and nonfiltered scenes, in block-designed fMRI recording sessions. At the group level, the comparison between the spatial frequency content of scenes revealed first that, compared with HSF, LSF scene categorization elicited activation in the anterior half of the calcarine fissures linked to the peripheral visual field, whereas, compared with LSF, HSF scene categorization elicited activation in the posterior part of the occipital lobes, which are linked to the fovea, according to the retinotopic property of visual areas. At the individual level, functional activations projected on retinotopic maps revealed that LSF processing was mapped in the anterior part of V1, whereas HSF processing was mapped in the posterior and ventral part of V2, V3, and V4. Moreover, at the group level, direct interhemispheric comparisons performed on the same fMRI data highlighted a right-sided occipito-temporal predominance for LSF processing and a left-sided temporal cortex predominance for HSF processing, in accordance with hemispheric specialization theories. By using suitable method of analysis on the same data, our results enabled us to demonstrate for the first time that spatial frequencies processing is mapped retinotopically and lateralized in human occipital cortex

Le grand parc des boucles de l'Isère: Parcours sonore en descendant la rivière

Parcours sonore en descendant l'Isère, de l'espace Naturel Sensible du Bois de la Bâtie (Le Versoud) au Pont de Chartreuse (Grenoble) – Séquence courte de 20 minutes – Enregistré en janvier 2023.Enregistré sur 18 points placés le long des berges de l'Isère.Prises de son : Léa Sammuri / Cédric PichatMatériel : Micros Schoeps CCM4 stéréo avec bonnette Cinela Albert / Parabole Telinga Modular Kit avec micro stéréo Primo EM272Réalisation / Montage : Cédric PichatDirecteur scientifique : Nicolas TixierLes enregistrements sonores et leurs fiches descriptives sont disponibles sur l’entrepôt Nakala

Effective connectivity in the cerebral network underlying visual scene categorization. A dynamic causal modeling study

International audienceAccording to current models of visual perception (Kauffmann, Ramanoël, & Peyrin, 2014; Schyns & Oliva, 1994) scenes are processed in terms of spatial frequencies following a predominantly coarse-to-fine processing sequence. Low spatial frequencies (LSF) reach high-order areas rapidly in order to activate plausible interpretations of the visual input. This triggers top-down facilitation that guides subsequent processing of high spatial frequencies (HSF) in lower-level areas such as the inferotemporal and occipital cortices (Bar et al., 2006; Bullier, 2001; Peyrin et al., 2010). However, dynamic interactions underlying top-down influences on the occipital cortex have never been systematically investigated. The present fMRI study aimed to further explore the neural bases and effective connectivity underlying coarse-to-fine processing of scenes, particularly the role of the occipital cortex.We used sequences of six filtered scenes as stimuli depicting coarse-to-fine or fine-to-coarse processing of scenes. Participants performed a categorization task on these stimuli (indoor vs. outdoor). Firstly, we showed that coarse-to-fine (compared to fine-to-coarse) sequences elicited stronger activation in the inferior frontal gyrus (in the orbitofrontal cortex), the inferotemporal cortex (in the fusiform and parahippocampal gyri), and the occipital cortex (in the cuneus). Dynamic causal modeling (DCM; Friston, Harrison, & Penny, 2003) was then used to infer effective connectivity between these regions.DCM results revealed that coarse-to-fine processing resulted in increased connectivity from the occipital cortex to the inferior frontal gyrus and from the inferior frontal gyrus to the inferotemporal cortex. Critically, results also revealed an increase in connectivity strength from both the inferior frontal gyrus and the inferotemporal cortex to the occipital cortex, suggesting top-down influences from these areas that may guide processing of incoming signals.The present results support influential models of visual perception and refine them by emphasizing the role of the occipital cortex as a cortical site for feedback projections in the neural network underlying coarse-to-fine processing of scenes

Effective connectivity in the neural network underlying coarse-to-fine categorization of visual scenes. A dynamic causal modeling study.

International audienceAccording to current models of visual perception scenes are processed in terms of spatial frequencies following a predominantly coarse-to-fine processing sequence. Low spatial frequencies (LSF) reach high-order areas rapidly in order to activate plausible interpretations of the visual input. This triggers top-down facilitation that guides subsequent processing of high spatial frequencies (HSF) in lower-level areas such as the inferotemporal and occipital cortices. However, dynamic interactions underlying top-down influences on the occipital cortex have never been systematically investigated. The present fMRI study aimed to further explore the neural bases and effective connectivity underlying coarse-to-fine processing of scenes, particularly the role of the occipital cortex. We used sequences of six filtered scenes as stimuli depicting coarse-to-fine or fine-to-coarse processing of scenes. Participants performed a categorization task on these stimuli (indoor vs. outdoor). Firstly, we showed that coarse-to-fine (compared to fine-to-coarse) sequences elicited stronger activation in the inferior frontal gyrus (in the orbitofrontal cortex), the inferotemporal cortex (in the fusiform and parahippocampal gyri), and the occipital cortex (in the cuneus). Dynamic causal modeling (DCM) was then used to infer effective connectivity between these regions. DCM results revealed that coarse-to-fine processing resulted in increased connectivity from the occipital cortex to the inferior frontal gyrus and from the inferior frontal gyrus to the inferotemporal cortex. Critically, we also observed an increase in connectivity strength from the inferior frontal gyrus to the occipital cortex, suggesting that top-down influences from frontal areas may guide processing of incoming signals. The present results support current models of visual perception and refine them by emphasizing the role of the occipital cortex as a cortical site for feedback projections in the neural network underlying coarse-to-fine processing of scenes

The neural basis of the paired-object affordance effect

International audienceRecent behavioral studies indicate that right-handed individuals make faster action decisions on object pairs that appear in standard co-location for right-handed actions in comparison to object pairs that appear in a mirror location. In this fMRI study, we aimed to investigate the neural correlates of visual processing of thematic relations between co-acting objects (frying pan and spatula), depending of their co-location for right-handed actions. Fourteen right-handed participants made decisions about thematically related and unrelated object pairs. Pairs were either positioned in a standard location for a right-handed action (with the active object - spatula in the right visual hemifield, and the passive object - frying pan in the left visual hemifield), or in the reverse location. Behavioral results showed a benefit of positioning thematically related pairs in standard co-location when an action decision was made (deciding if the two objects are usually used together), but not when a more general contextual decision was made (deciding if the two object are typically found in the kitchen). Neuroimaging results showed that the left lateral occipital complex was more activated for standard than reverse locations. Our results provide novel evidence of close interrelations between thematic and action processing in the posterior semantic system

Dorsal and ventral stream contribution to the paired-object affordance effect

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