Audiovisual timing perception can recalibrate following prolonged exposure to asynchronous auditory and visual inputs. It has been suggested that this might contribute to achieving perceptual synchrony for auditory and visual signals despite differences in physical and neural signal times for sight and sound. However, given that people can be concurrently exposed to multiple audiovisual stimuli...

The brain seeks to combine related inputs from different senses (e.g., hearing and vision), via multisensory integration. Temporal information can indicate whether stimuli in different senses are related or not. A recent human fMRI study (Noesselt et al. [2007]: J Neurosci 27:11431-11441) used auditory and visual trains of beeps and flashes with erratic timing, manipulating whether auditory and...

In the search for the neural correlate of visual awareness, much controversy exists about the role of primary visual cortex. Here, the neurophysiological data from V1 recordings in awake monkeys are examined in light of two general classes of models of visual awareness. In the first model type, visual awareness is seen as being mediated either by a particular set of areas or pathways, or altern...

The visual system analyses information by decomposing complex objects into simple components (visual features) widely distributed across the cortex [1, 2] When several objects are simultaneously present in the visual eld, a mechanism is required to group (bind) together visual features belonging to each object and to separate (segment) them from features of other objects. An attractive scheme f...

Visual signals converge through the layers of the retinal circuitry from the photoreceptor cells to the retinal ganglion cells such that nearby ganglion cells are driven by essentially the same visual stimulus. We use computational modeling to address the question whether the experimentally observed degree of synchrony in nearby ganglion cells is due to the common visual stimulus or whether act...

We discuss the role of synchrony of activation in higher-level cognitive processes. In particular, we analyze the question of whether synchrony of activation provides a mechanism for compositional representation in neural systems. We will argue that synchrony of activation does not provide a mechanism for compositional representation in neural systems. At face value, one can identify a level of...

Disturbance in the integration of visual information is one of the hallmarks of schizophrenia. In the spatial domain, visual integration is compromised, resulting in impaired perceptual grouping and contour integration. In the time domain, in contrast, visual integration is enhanced, as manifested by increased backward masking and lower ability of patients to detect successively presented visua...

The synchrony of neurons in extrastriate visual cortex is modulated by selective attention even when there are only small changes in firing rate (Fries, Reynolds, Rorie, & Desimone, 2001). We used Hodgkin-Huxley type models of cortical neurons to investigate the mechanism by which the degree of synchrony can be modulated independently of changes in firing rates. The synchrony of local networks ...

Recordings from area V4 of monkeys have revealed that when the focus of attention is on a visual stimulus within the receptive field of a cortical neuron, two distinct changes can occur: The firing rate of the neuron can change and there can be an increase in the coherence between spikes and the local field potential (LFP) in the gamma-frequency range (30–50 Hz). The hypothesis explored here is...

Recordings from area V4 of monkeys have revealed that when the focus of attention is on a visual stimulus within the receptive field of a cortical neuron, two distinct changes can occur: The firing rate of the neuron can change and there can be an increase in the coherence between spikes and the local field potential (LFP) in the gamma-frequency range (30–50 Hz). The hypothesis explored here is...