Frequency Coding of Multisensory Integration in the Local Field Potentials of the Medial Pulvinar.

The pulvinar is a posterior thalamic nucleus, with a heterogeneous anatomo-functional organization. It is divided into four parts, including the medial pulvinar, which is densely connected with primary unisensory and multisensory cortical regions, and subcortical structures, including the superior colliculus. Based on this connectivity, the medial pulvinar may play an important role in sensory processing and multisensory integration.

Oscillatory Traveling Waves Provide Evidence for Predictive Coding Abnormalities in Schizophrenia.

Background: The computational mechanisms underlying psychiatric disorders are hotly debated. One hypothesis, grounded in the Bayesian predictive coding framework, proposes that patients with schizophrenia have abnormalities in encoding prior beliefs about the environment, resulting in abnormal sensory inference, which can explain core aspects of the psychopathology, such as some of its symptoms.

Methods: Here, we tested this hypothesis by identifying oscillatory traveling waves as neural signatures of predictive coding.

What Makes the Detection of Movement Different Within the Autistic Traits Spectrum? Evidence From the Audiovisual Depth Paradigm.

Atypical sensory processing is now considered a diagnostic feature of autism. Although multisensory integration (MSI) may have cascading effects on the development of higher-level skills such as socio-communicative functioning, there is a clear lack of understanding of how autistic individuals integrate multiple sensory inputs. Multisensory dynamic information is a more ecological construct than static stimuli, reflecting naturalistic sensory experiences given that our environment involves moving stimulation of more than one sensory modality at a time.

Regular rhythmic and audio-visual stimulations enhance procedural learning of a perceptual-motor sequence in healthy adults: A pilot study.

Procedural learning is essential for the effortless execution of many everyday life activities. However, little is known about the conditions influencing the acquisition of procedural skills. The literature suggests that sensory environment may influence the acquisition of perceptual-motor sequences, as tested by a Serial Reaction Time Task.

A multisensory perspective onto primate pulvinar functions.

Perception in ambiguous environments relies on the combination of sensory information from various sources. Most associative and primary sensory cortical areas are involved in this multisensory active integration process. As a result, the entire cortex appears as heavily multisensory.

The interplay between multisensory integration and perceptual decision making.

Facing perceptual uncertainty, the brain combines information from different senses to make optimal perceptual decisions and to guide behavior. However, decision making has been investigated mostly in unimodal contexts. Thus, how the brain integrates multisensory information during decision making is still unclear.

Children with Dyslexia Have Altered Cross-Modal Processing Linked to Binocular Fusion. A Pilot Study.

Introduction: The cause of dyslexia, a reading disability characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities, is unknown. A considerable body of evidence shows that dyslexics have phonological disorders. Other studies support a theory of altered cross-modal processing with the existence of a pan-sensory temporal processing deficit associated with dyslexia.

Electrophysiological correlates of visual backward masking in high schizotypic personality traits participants.

Visual backward masking is strongly deteriorated in patients with schizophrenia. Masking deficits are associated with strongly reduced amplitudes of the global field power in the EEG. Healthy participants who scored high in cognitive disorganization (a schizotypic trait) were impaired in backward masking compared to participants who scored low.

The variability of multisensory processes of natural stimuli in human and non-human primates in a detection task.

Background: Behavioral studies in both human and animals generally converge to the dogma that multisensory integration improves reaction times (RTs) in comparison to unimodal stimulation. These multisensory effects depend on diverse conditions among which the most studied were the spatial and temporal congruences. Further, most of the studies are using relatively simple stimuli while in everyday life, we are confronted to a large variety of complex stimulations constantly changing our attentional focus over time, a modality switch that can impact on stimuli detection.

Schizophrenia patients and 22q11.2 deletion syndrome adolescents at risk express the same deviant patterns of resting state EEG microstates: A candidate endophenotype of schizophrenia.

Schizophrenia is a complex psychiatric disorder and many of the factors contributing to its pathogenesis are poorly understood. In addition, identifying reliable neurophysiological markers would improve diagnosis and early identification of this disease. The 22q11.

Crowding, grouping, and gain control in schizophrenia.

Visual paradigms are versatile tools to investigate the pathophysiology of schizophrenia. Contextual modulation refers to a class of paradigms where a target is flanked by neighbouring elements, which either deteriorate or facilitate target perception. It is often proposed that contextual modulation is weakened in schizophrenia compared to controls, with facilitating contexts being less facilitating and deteriorating contexts being less deteriorating.

Is there a common factor for vision?

In cognition, common factors play a crucial role. For example, different types of intelligence are highly correlated, pointing to a common factor, which is often called g. One might expect that a similar common factor would also exist for vision.

The contributions of sensory dominance and attentional bias to cross-modal enhancement of visual cortex excitability.

Approaching or looming sounds (L-sounds) have been shown to selectively increase visual cortex excitability [Romei, V., Murray, M. M.

Cognitive disorganisation in schizotypy is associated with deterioration in visual backward masking.

To understand the causes of schizophrenia, a search for stable markers (endophenotypes) is ongoing. In previous years, we have shown that the shine-through visual backward masking paradigm meets the most important characteristics of an endophenotype. Here, we tested masking performance differences between healthy students with low and high schizotypy scores as determined by the self-report O-Life questionnaire assessing schizotypy along three dimensions, i.

Electrical neuroimaging of memory discrimination based on single-trial multisensory learning.

Multisensory experiences influence subsequent memory performance and brain responses. Studies have thus far concentrated on semantically congruent pairings, leaving unresolved the influence of stimulus pairing and memory sub-types. Here, we paired images with unique, meaningless sounds during a continuous recognition task to determine if purely episodic, single-trial multisensory experiences can incidentally impact subsequent visual object discrimination.

Looming signals reveal synergistic principles of multisensory integration.

Multisensory interactions are a fundamental feature of brain organization. Principles governing multisensory processing have been established by varying stimulus location, timing and efficacy independently. Determining whether and how such principles operate when stimuli vary dynamically in their perceived distance (as when looming/receding) provides an assay for synergy among the above principles and also means for linking multisensory interactions between rudimentary stimuli with higher-order signals used for communication and motor planning.

Auditory-visual multisensory interactions in humans: timing, topography, directionality, and sources.

Current models of brain organization include multisensory interactions at early processing stages and within low-level, including primary, cortices. Embracing this model with regard to auditory-visual (AV) interactions in humans remains problematic. Controversy surrounds the application of an additive model to the analysis of event-related potentials (ERPs), and conventional ERP analysis methods have yielded discordant latencies of effects and permitted limited neurophysiologic interpretability.

Auditory-somatosensory multisensory interactions in humans: dissociating detection and spatial discrimination.

Simple reaction times (RTs) to auditory-somatosensory (AS) multisensory stimuli are facilitated over their unisensory counterparts both when stimuli are delivered to the same location and when separated. In two experiments we addressed the possibility that top-down and/or task-related influences can dynamically impact the spatial representations mediating these effects and the extent to which multisensory facilitation will be observed. Participants performed a simple detection task in response to auditory, somatosensory, or simultaneous AS stimuli that in turn were either spatially aligned or misaligned by lateralizing the stimuli.

The behavioral relevance of multisensory neural response interactions.

Sensory information can interact to impact perception and behavior. Foods are appreciated according to their appearance, smell, taste and texture. Athletes and dancers combine visual, auditory, and somatosensory information to coordinate their movements.

Multisensory facilitation of behavior in monkeys: effects of stimulus intensity.

Multisensory stimuli can improve performance, facilitating RTs on sensorimotor tasks. This benefit is referred to as the redundant signals effect (RSE) and can exceed predictions on the basis of probability summation, indicative of integrative processes. Although an RSE exceeding probability summation has been repeatedly observed in humans and nonprimate animals, there are scant and inconsistent data from nonhuman primates performing similar protocols.

Preperceptual and stimulus-selective enhancement of low-level human visual cortex excitability by sounds.

Evidence of multisensory interactions within low-level cortices and at early post-stimulus latencies has prompted a paradigm shift in conceptualizations of sensory organization. However, the mechanisms of these interactions and their link to behavior remain largely unknown. One behaviorally salient stimulus is a rapidly approaching (looming) object, which can indicate potential threats.

Early, low-level auditory-somatosensory multisensory interactions impact reaction time speed.

Several lines of research have documented early-latency non-linear response interactions between audition and touch in humans and non-human primates. That these effects have been obtained under anesthesia, passive stimulation, as well as speeded reaction time tasks would suggest that some multisensory effects are not directly influencing behavioral outcome. We investigated whether the initial non-linear neural response interactions have a direct bearing on the speed of reaction times.

The thalamocortical projection systems in primate: an anatomical support for multisensory and sensorimotor interplay.

Multisensory and sensorimotor integrations are usually considered to occur in superior colliculus and cerebral cortex, but few studies proposed the thalamus as being involved in these integrative processes. We investigated whether the organization of the thalamocortical (TC) systems for different modalities partly overlap, representing an anatomical support for multisensory and sensorimotor interplay in thalamus. In 2 macaque monkeys, 6 neuroanatomical tracers were injected in the rostral and caudal auditory cortex, posterior parietal cortex (PE/PEa in area 5), and dorsal and ventral premotor cortical areas (PMd, PMv), demonstrating the existence of overlapping territories of thalamic projections to areas of different modalities (sensory and motor).