C E Schroeder

..These instrumental functions of low-frequency oscillations support a conceptual framework that integrates numerous earlier findings...

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..Finally, we consider the functional implications of multisensory integration in early sensory processing...

..These observations outline the essentials of an Active Sensing paradigm, and argue for increased emphasis on the study of sensory processes as specific to the dynamic motor/attentional context in which inputs are acquired...

..Our hypothesis makes testable predictions for future studies and emphasizes the idea that 'background' oscillatory activity is instrumental to cortical sensory processing...

..Each mode has costs and benefits, and the brain shifts dynamically between them in accord with task demands...

..In addition to enriching current models of multisensory processing and perceptual functions, these new findings require a revision in our thinking about unisensory processing in low level cortical areas...

..We review the evidence for early sensory selection by oscillatory phase-amplitude modulations, its mechanisms and its perceptual and behavioral consequences...

..Critical in such a model is the recognition that processing within a location typically entails multiple temporal components or 'waves' of activity, driven by input conveyed over heterogeneous pathways from the retina...

..No somatosensory responses were observed in A1. These findings suggest a potential neural substrate for multisensory integration at an early stage of auditory cortical processing...

..Interaction effects place an upper limit on the time required for neuronal ensembles to combine inputs from different quadrants of visual space ( approximately 72 ms for unilateral and approximately 82 ms for bilateral conditions)...

..Both the topography and timing of these interactions are consistent with multisensory integration early in the cortical processing hierarchy, in brain regions traditionally held to be unisensory...

..By demonstrating super- and sub-additive effects, our analyses showed that this approach is a valuable metric for studying multisensory interactions reflected in induced oscillatory responses...

..In fact, it seems that the question is no longer whether low level, putatively unisensory cortex is accessible to multisensory influences, but how...

..The present study investigates P1 and N1 refractoriness in the awake monkey in order to investigate underlying mechanisms...

..That the earliest priming-related activity occurs over LO complex, suggests that the sensory trace itself may reside in these object recognition areas...

..Finally, it is increasingly evident that we can and should analyze temporal patterns of attentional modulation, both within and across brain areas. These patterns provide critical information on the dynamics of attention...

..Our observations raise the possibility that, rather than being initiators of epileptiform activity, fast ripples may be markers of a secondary local response...

..These findings are in accord with the multiplicity of visual inputs to frontal cortex and are discussed in terms of frontal lobe functions as may be required in these tasks...

..These findings support a "Framing" Model of ventral stream visual processing in which rapidly conducted inputs, mediated by one or more accessory pathways, modulate the processing of more slowly conducted feedforward inputs...

..Dissociation of broadband noise and pure tone latencies may reflect the use of parallel anatomical routes into belt regions...

..We propose that the hierarchical organization of ambient oscillatory activity allows auditory cortex to structure its temporal activity pattern so as to optimize the processing of rhythmic inputs...

..Schizophrenia is associated with deficits in higher-order processing of visual information. This study evaluated the integrity of early visual processing in order to evaluate the overall pattern of visual dysfunction in schizophrenia...

..The selective localization of these connections to peripheral visual areas and caudal auditory cortex suggests that they are involved in spatial localization...

..The timing and laminar profile of the multisensory interactions in A1 indicate that nonspecific thalamic systems may play a key role in the effect...

..Despite remaining mechanistic questions, it appears that analysis of fixation-related responses may be useful in studying natural vision...

..Thus, multisensory interactions can occur across wide peripersonal spatial separations remarkably early in sensory processing and in cortical regions traditionally considered unisensory...

..This RT facilitation could not be accounted for by probability summation, as evidenced by violation of the 'race' model, providing compelling evidence that auditory-visual neural interactions give rise to this RT effect...

..They also illustrate the value of combined CSD and fMRI analyses in monkeys for defining hidden aspects of sensory function and for investigating the neuronal processes generating fMRI signals...

..NMDA-mediated enhancement of excitatory responses in the supragranular laminae of neocortex is believed to play a role in normal signal processing, as well as in epileptic manifestations...

..We suggest that simultaneous activation of both types of subregions in conflict conditions may account the ubiquitous ACC activation observed with fMRI and ERP in those conditions...

..These findings outline a supramodal mechanism by which attention can control neurophysiological context, thus determining the representation of specific sensory content in primary sensory cortex...

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..The differential connections of CM compared with adjacent areas provide additional evidence for the functional specialization of the individual auditory belt areas...

..Alternative, and we believe, more parsimonious interpretations of the data are also proposed...

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..For example, it is plausible that spatial attention mechanisms could operate primarily through the M system and that as such C1 may not always represent an adequate dependent measure in such studies...

..Taken together, the results of this series of studies suggest that these parietal regions are capable of integrating sensory cues from multiple sensory modalities in order to program the subsequent deployment of visual attention...

..We interpret this to represent contributions from global stimulus parameters to scene analysis. In contrast to the IC effect, the topography of the configuration effect was restricted to central parieto-occipital scalp...

..The authors hypothesize that microdischarges and microseizures are generated by small cortical domains that form the substrate of epileptogenic cortex and play important roles in seizure initiation and propagation...

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..This work may help to reconcile some of the diverse findings and conclusions on the functional significance of alpha band oscillations in the visual system...

..Somatosensory inputs may reach CM and CL through MGm or the multisensory nuclei but not VP...

..Indeed, the multisensory nature of most, possibly all, of the neocortex forces us to abandon the notion that the senses ever operate independently during real-world cognition...

..Finally, we apply dVCA to neural ensemble activity recorded from an awake, behaving macaque-demonstrating that dVCA is an important tool for identifying and characterizing multiple components in the single trial...

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..Since, these techniques could be adapted for exploration of areas within other sulci, the approach represents an important advance in efforts to elucidate the functional organization of the primate cerebral cortex...

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..The present data add to growing evidence of multisensory convergence in cortical areas previously considered to be 'unimodal', and also indicate that auditory cortical areas differ in this respect...

..3-To identify cortical regions, and physiological processes generating object-related ERPs shown to be abnormal in schizophrenic patients. ..

..This will help to bridge-the-gap between a vast single unit literature in monkeys, and a developing understanding of somatosensory structure and function in humans. ..

..Because of our unique combination of methods we can bridge the gap between incisive findings from in-vitro cellular-level experiments and effects noted by electromagnetic and hemodynamic imaging studies in humans. ..

..This "translational" emphasis will be reflected in this competing renewal proposal. ..

..This "translational" emphasis will be reflected in this competing renewal proposal. ..

..abstract_text> ..

..These experiments will evaluate the hypotheses that the caudal belt and parabelt regions of auditory cortex are involved in auditory localization and that somatosensory-auditory interactions contribute to this function. ..

..impairment specific to hearing disorders, and in a spectrum of disorders including ADHD, autism and schizophrenia, where defects in normal connectivity, disruptions of neuronal synchrony and attentional impairments are prominent ..