Biology subjects

Clavagnier, S.

Publications and source records attributed to Clavagnier, S..

3 recordsLinked to original sources

bioRxiv2022

Macaque amygdala, claustrum and pulvinar support the cross-modal association of social audio-visual stimuli based on meaning

Social communication draws on several cognitive functions such as perception, emotion recognition and attention. In a previous study, we demonstrated that macaques associate audiovisual information when processing their species-specific communicative signals. Specifically, cortical activation is inhibited when there is a mismatch between vocalisations and social visual information whereas activation is enhanced in the lateral sulcus, superior temporal sulcus as well as a larger network composed of early visual and prefrontal areas when vocalisations and social visual information match. Here, we use a similar task and functional magnetic resonance imaging to assess the role of subcortical structures. We identify three subcortical regions involved in audio-visual processing of species-specific communicative signal: the amygdala, the claustrum and the pulvinar. Like the cortex, these subcortical structures are not activated when there is a mismatch between visual and acoustic information. In contrast, the amygdala and claustrum are activated by visual, auditory congruent and audio-visual stimulations. The pulvinar responds in a task-dependent manner, along a specific spatial sensory gradient. Anterior pulvinar responds to auditory stimuli, medial pulvinar is activated by auditory, audio-visual and visual stimuli and the dorsal lateral pulvinar only responds to visual stimuli in a pure visual task. The medial pulvinar and the amygdala are the only subcortical structures integrating audio-visual social stimuli. We propose that these three structures belong to a multisensory network that modulates the perception of visual socioemotional information and vocalizations as a function of the relevance of the stimuli in the social context. Significance StatementUnderstanding and correctly associating socioemotional information across sensory modalities, such that happy faces predict laughter and escape scenes screams, is essential when living in complex social groups. Using functional magnetic imaging in the awake macaque, we identify three subcortical structures - amygdala, claustrum and pulvinar - that only respond to auditory information that matches the ongoing visual socioemotional context, such as hearing positively valenced coo calls and seeing positively valenced grooming monkeys. We additionally describe task-dependent activations in the pulvinar, organizing along a specific spatial sensory gradient, supporting its role as a network regulator.

neuroscience↗

bioRxiv2021

Non-invasive real-time access to spatial attention information from 3T fMRI BOLD signals

Access to higher cognitive functions in real-time remains very challenging, because these functions are internally driven and their assessment is based onto indirect measures. In addition, recent finding show that these functions are highly dynamic. Previous studies using intra-cortical recordings in monkeys, succeed to access the (x,y) position of covert spatial attention, in real-time, using classification methods applied to monkey prefrontal multi-unit activity and local field potentials. In contrast, the direct access to attention with non-invasive methods is limited to predicting the attention localisation based on a quadrant classification. Here, we demonstrate the feasibility to track covert spatial attention localization using non-invasive fMRI BOLD signals, with an unprecedented spatial resolution. We further show that the errors produced by the decoder are not randomly distributed but concentrate on the locations neighbouring the cued location and that behavioral errors correlate with weaker decoding performance. Last, we also show that the voxels contributing to the decoder precisely match the visual retinotopic organization of the occipital cortex and that single trial access to attention is limited by the intrinsic dynamics of spatial attention. Taken together, these results open the way to the development of remediation and enhancement neurofeedback protocols targeting the attentional function.

neuroscience↗

bioRxiv2021

Neural correlates of audio-visual integration of socially meaningful information in macaque monkeys

Social interactions rely on the ability to interpret semantic and emotional information, often from multiple sensory modalities. In human and nonhuman primates, both the auditory and visual modalities are used to generate and interpret communicative signals. In individuals with autism, not only are there deficits in social communication, but in the integration of audio-visual information. At present, we know little about the neural mechanisms that subserve the interpretation of complex social events, including the audio-visual integration that is often required with accompanying communicative signals. Based on heart rate estimates and fMRI in two macaque monkeys (Macaca mulatta), we show that individuals systematically associate affiliative facial expressions or social scenes with corresponding affiliative vocalizations, aggressive facial expressions or social scenes with corresponding aggressive vocalizations and escape visual scenes with scream vocalizations. In contrast, vocalizations that are incompatible with the visual information are fully suppressed, suggesting top-down regulation over the processing of sensory input. The process of binding audio-visual semantic and contextual information relies on a core functional network involving the superior temporal sulcus (STS) and lateral sulcus (LS). Peak activations in both sulci co-localize with face or voice patches that have been previously described. While all of these regions of interest (ROIs) respond to both auditory and visual information, LS ROIs have a preference for auditory and audio-visual congruent stimuli while STS ROIs equally respond to auditory, visual and audio-visual congruent stimuli. To further specify the cortical network involved in the control of this semantic association, we performed a whole brain gPPI functional connectivity analysis on the LS and STS cumulated ROIs. This gPPI analysis highlights a functional network connected to the LS and STS, involving the anterior cingulate cortex (ACC), area 46 in the dorsolateral prefrontal cortex (DLPFC), the orbitofrontal cortex (OFC), the intraparietal sulcus (IPS), the insular cortex and subcortically, the amygdala and the hippocampus. Comparing human and macaque results, we propose that the integration of audio-visual information for congruent, meaningful social events involves homologous neural circuitry, specifically, an emotional network composed of the STS, LS, ACC, OFC, and limbic areas, including the amygdala, and an attentional network including the STS, LS, IPS and DLPFC. As such, these networks are critical to the amodal representation of social meaning, thereby providing an explanation for some of deficits observed in autism.

neuroscience↗