Multisensory integration

…This process, known as multisensory integration, enhances the brain’s response to redundant congruent sensory cues and emerges gradually during the developmental period, based on our experience with cross-modal stimuli. Consequently, integrative abilities develop in an altered form in individuals subjected to atypical multisensory experiences during the developmental period, such as those on the autistic spectrum. However, to interact with and corre

Regression, understood as the loss of previously acquired behaviors, affects 20-30% of patients with Autism Spectrum Disorder (ASD). Nowadays, the mechanism behind this regressive process is still unknown. To improve our knowledge and find selected target treatments, it is important to establish a model with regressive features. Here, we showed that the Synapsin II Knockout (SynII KO) mouse loses previously acquired social and cognitive abilities in adulthood. Synapsin II is a presynaptic phosphoprotein belonging to the Synapsin family (Syns) involved in neuronal development and in the modulat

This study investigates multisensory integration in weakly electric fishes, Apteronotus albifrons and Eigenmannia virescens, during their natural refuge tracking behavior. Our goal is to examine and model the sensory reweighting that occurs in the midbrain in relation to changes in the sensory salience. Specifically, we manipulate illumination (light, dim light, dark), conductivity (low, medium, high), refuge structure (with/out windows), and refuge length (short, medium, high) and observe how the weights of visual and electrosensory systems are dynamically adjusted. We conducted a total of 27

…The integration of multisensory signals during passive rotation and the role of the presubiculum in merging vestibular and visual inputs are yet to be fully understood.We manipulated vestibular and visual cues using a novel paradigm. Head-fixed mice were rotated on a motorized platform in a pseudo-random fashion, covering all angles, while surrounded by a semi-transparent dome displaying visual cues. Using Neuropixel probes, we investigated the a

…they regulate their behavior during multisensory behavioral control. Specifically, we study multisensory integration in Eigenmannia virescens, a species of weakly electric fish du

The integration of sensory inputs from different senses is a crucial aspect of sensory perception and behavioral decisions. Whether such multisensory integration occurs at specific stages of neural processing remains unclear. Two brain regions, the anterolateral motor cortex (ALM) and the superior colliculus (SC) are important parts of a cortico-subcortical loop that transforms multisensory inputs into behavioral decisions. To study the role of these areas in multisensory integration and decision-making, we trained mice in a multisensory discrimination task, where animals had to integrate visu

The superior colliculus (SC) is a dorsal midbrain structure known for its roles in multisensory integration and motor responses and its dysfunction has been linked to neurodevelopmental diseases. SC is a highly organized structure composed of distinct laminae of diverse neuronal and glial cell types. However, the precise developmental principles instructing the generation of SC cell-type diversity are still unknown. To investigate this, we pursued lineage tracing using genetic MADM (Mosaic Analysis with Double Markers)-based clonal analysis with single cell sequencing (MADM-CloneSeq) and in si

Multisensory integration is a sensory processing mechanism that integrate input information from different sensory modalities, occurring during sensory reception and perception. However, the underlying neuronal circuit to integrate sensory information is still unknown. We featured anterolateral visual area (AL), which has axonal projection from primary sensory cortexes, and try to clarify the mechanism underpinning sensory information processing and integration in AL. We first visualized neuronal response to sensory input (whisker stimulation and auditory representation) in AL by in vivo Ca2+

…Thus, examining multisensory integration (MSI) necessitates the use of control-theoretic approaches and custom experimental systems that may shed light on their underlying mechanisms. Here, we built a custom refuge-tracking system for Eigenmannia virescens, a species of weakly electric fish. These fish hide within refuges and track their movement to remain h

Previous studies have suggested that the relative importance associated with redundant sensory signals should depends only on their relative noisiness, so as to optimize movement precision (Maximum Likelihood Principle, MLP). As a consequence, whether a goal-oriented hand movement is performed in a seated or standing position should not affect the visuo-proprioceptive sensory weights. To test this hypothesis, we asked healthy subjects to perform visuo-manual coordination tasks both seated and standing. Using virtual reality and quantifying the deviation of the subjects’ motor responses due to

The relative timing of different sensory input signals is an important factor in multisensory integration and perception. When multiple forms of sensory stimuli arise from a single source, the degree of synchrony in the arrival of these stimuli can provide distance cues. The difference between the velocities of light and sound introduces a distance dependent lag for auditory signals with respect to visual information. Audio-visual delays therefore carry information about the distance to the stimulus source. Here we investigated the representation of audio-visual delays in the mouse superior co

Multisensory integration requires transformations between coordinate systems. When an object is touched and seen at the same time, tactile signals from the snout’s vibrissae arrive in the somatotopically organized primary whisker somatosensory cortex (wS1) whereas visual signals arrive in the retinotopically organized primary visual cortex (V1). The posterior parietal cortex (PPC) in-between is a candidate cortical region for merging these two representations. However, how converging visual and tactile inputs of nearby objects are processed in these cortical areas remains unclear. To address t

…In biological networks, this process (multisensory integration) is implemented by multimodal neurons which are often thought to receive the information accumulated by unimodal areas, and to fuse this across channels; an algorithm we term accumulate-then-fuse. However, it remains an open question how well this theo

…events is vital to human perception, multisensory integration and action planning. For example, this allows us to follow and interact with the precise timing of speech and sports. Here we investigate how visual event timing is represented and transformed across the brain’s hierarchy: from sensory processing areas, through multisensory integration areas, to frontal action planning areas. We hypothesized that the dynamics of neural responses to sensory events in sensory processing areas allows derivation of event timing representati

…very few have been extended to include multisensory processing. We will present an extension of the Wong and Wang (2006) model, a system of non-linear differential equations, that simulates the neuronal and behavioural processes in a visual-vestibular heading speeded reaction time task. To replicate similar fin

Multisensory integration plays an important role during decision-making in naturalistic settings. Here, we dissect circuit mechanisms underlying multisensory integration in Drosophila melanogaster, focusing on neurons that directly drive and modulate mated female rejection behavior (ovipositor extrusion or OE) during courtship. DNp13 is a descending neuron that is both necessary and sufficient for OE (Wang et al. Current Biology, 2020); pC2l neurons, which are activated by male courtship song (Deutsch et al. Current Biology, 2019), provide direct presynaptic input to DNp13 (Wang et al. Current

…for the perception space, time and multisensory integration. In particular, I will show how results from a series of psychophysical experiments can be interpreted in the light of

Humans have a remarkable ability to figure out what happened and why. In this talk, I will shed light on this ability from multiple angles. I will present a computational framework for modeling causal explanations in terms of counterfactual simulations, and several lines of experiments testing this framework in the domain of intuitive physics. The model predicts people's causal judgments about a variety of physical scenes, including dynamic collision events, complex situations that involve multiple causes, omissions as causes, and causal responsibility for a system's stability. It also capture