Our brain integrates the information provided by different sensory modalities into a coherent percept, and recent studies suggest that this process is not restricted to higher association areas. Here we evaluate hypothesis auditory cortical fields are involved in cross-modal processing probing individual neurons for audiovisual interactions. We find visual stimuli modulate both at level of field potentials single-unit activity already primary secondary fields. These interactions strongly...

Abstract We begin by reviewing the statistical framework of information theory as applicable to neuroimaging data analysis. A major factor hindering wider adoption this in is difficulty estimating theoretic quantities practice. present a novel estimation technique that combines copulas with closed form solution for entropy Gaussian variables. This results general, computationally efficient, flexible, and robust multivariate provides effect sizes on common meaningful scale, allows unified...

During online speech processing, our brain tracks the acoustic fluctuations in at different timescales. Previous research has focused on generic timescales (for example, delta or theta bands) that are assumed to map onto linguistic features such as prosody syllables. However, given high intersubject variability speaking patterns, a association between of activity and properties can be ambiguous. Here, we analyse tracking source-localised magnetoencephalographic data by directly focusing...

Merging the information from different senses is essential for successful interaction with real-life situations. Indeed, sensory integration can reduce perceptual ambiguity, speed reactions, or change qualitative experience. It widely held that occurs at later processing stages and mostly in higher association cortices; however, recent studies suggest convergence occur primary cortex. A good model early proved to be auditory cortex, which modulated by visual tactile stimulation; given large...

Anatomical studies propose that the primate auditory cortex contains more fields than have actually been functionally confirmed or described. Spatially resolved functional magnetic resonance imaging (fMRI) with carefully designed acoustical stimulation could be ideally suited to extend our understanding of processing within these fields. However, after numerous experiments in humans, many remain poorly characterized. Imaging macaque monkey is particular interest as species a richer set...

Oscillatory activity in sensory cortices reflects changes local excitation–inhibition balance, and recent work suggests that phase signatures of ongoing oscillations predict the perceptual detection subsequent stimuli. Low-frequency are also entrained by dynamic natural scenes, suggesting chance detecting a brief target depends on relative timing this to rhythm. We tested hypothesis humans implementing cocktail-party-like scenario requiring subjects detect embedded cacophony background...

Sensory perception is enhanced by the complementary information provided our different sensory modalities and even apparently task irrelevant stimuli in one modality can facilitate performance another. While general comprises both, detection of objects as well their discrimination recognition, most studies on audio-visual interactions have focused either these aspects. However, previous evidence, neuroanatomical projections between early cortices computational mechanisms suggest that sounds...

During continuous speech, lip movements provide visual temporal signals that facilitate speech processing. Here, using MEG we directly investigated how these interact with rhythmic brain activity in participants listening to and seeing the speaker. First, coherence between oscillatory speaker’s demonstrated significant entrainment cortex. We then used partial remove contributions of coherent auditory signal from lip-brain coherence. Comparing this synchronization different attention...

The claustrum receives afferent inputs from multiple sensory-related brain areas, prompting speculation about a role in integrating information across sensory modalities. Here we directly test this hypothesis by probing neurons the primate for functional characteristics of multisensory processing. To end recorded neuronal responses to naturalistic audio-visual stimuli claustra alert monkeys. Our results reveal existence distinct claustral zones comprised unimodal associated with auditory and...

Oscillations are pervasive in encephalographic signals and supposedly reflect cognitive processes sensory representations. While the relation between oscillation amplitude (power) sensory-cognitive variables has been extensively studied, recent work reveals that dynamic signature (phase pattern) can carry information about such to a greater degree than amplitude. To elucidate neural correlates of oscillatory phase patterns, we compared stimulus selectivity firing rates auditory-driven...

Human imaging studies implicate the insular cortex in processing complex sounds and vocal communication signals such as speech. In addition, lesions of insula often manifest deficits sound or speech recognition (auditory agnosia) production. While models acoustic perception assign an important role to insula, little is known about underlying neuronal substrate. Studying a primate, we identified predominantly auditory region caudal therein discovered neural representation conspecific sounds....

The entrainment of slow rhythmic auditory cortical activity to the temporal regularities in speech is considered be a central mechanism underlying perception. Previous work has shown that reduced when quality acoustic input degraded, but also linked at similar time scales encoding expectations. To understand these bottom-up and top-down contributions entrainment, we manipulated predictive structure by parametrically altering distribution pauses between syllables or words, thereby rendering...