Attention Configures Synchronization Within Local Neuronal Networks for Processing of the Behaviorally Relevant Stimulus.

The need for fast and dynamic processing of relevant information imposes high demands onto the flexibility and efficiency of the nervous system. A good example for such flexibility is the attention-dependent selection of relevant sensory information. Studies investigating attentional modulations of neuronal responses to simultaneously arriving input showed that neurons respond, as if only the attended stimulus would be present within their receptive fields (RF).

Attention Selectively Gates Afferent Signal Transmission to Area V4.

Selective attention allows focusing on only part of the incoming sensory information. Neurons in the extrastriate visual cortex reflect such selective processing when different stimuli are simultaneously present in their large receptive fields. Their spiking response then resembles the response to the attended stimulus when presented in isolation.

A multi-channel, flex-rigid ECoG microelectrode array for visual cortical interfacing.

High-density electrocortical (ECoG) microelectrode arrays are promising signal-acquisition platforms for brain-computer interfaces envisioned, e.g., as high-performance communication solutions for paralyzed persons.

Toward high performance, weakly invasive brain computer interfaces using selective visual attention.

Brain-computer interfaces have been proposed as a solution for paralyzed persons to communicate and interact with their environment. However, the neural signals used for controlling such prostheses are often noisy and unreliable, resulting in a low performance of real-world applications. Here we propose neural signatures of selective visual attention in epidural recordings as a fast, reliable, and high-performance control signal for brain prostheses.

Switching neuronal inputs by differential modulations of gamma-band phase-coherence.

Receptive fields (RFs) of cortical sensory neurons increase in size along consecutive processing stages. When multiple stimuli are present in a large visual RF, a neuron typically responds to an attended stimulus as if only that stimulus were present. However, the mechanism by which a neuron selectively responds to a subset of its inputs while discarding all others is unknown.

Optimality of human contour integration.

For processing and segmenting visual scenes, the brain is required to combine a multitude of features and sensory channels. It is neither known if these complex tasks involve optimal integration of information, nor according to which objectives computations might be performed. Here, we investigate if optimal inference can explain contour integration in human subjects.

Rapid contour integration in macaque monkeys.

Integration of oriented elements into a contour has been investigated extensively in human psychophysics whereas electrophysiological experiments exploring the neuronal mechanism of contour integration were most often done with macaque monkeys. To bridge the gap between human psychophysics and physiology we estimated spatial and temporal constraints of contour integration in two macaque monkeys. Our results show that contour integration in monkeys depends in a similar way on element distance and alignment between contour path and contour elements as in human subjects.

Oscillatory synchrony in the monkey temporal lobe correlates with performance in a visual short-term memory task.

Oscillatory synchrony has been proposed to dynamically coordinate distributed neural ensembles, but whether this mechanism is effectively used in neural processing remains controversial. We trained two monkeys to perform a delayed matching-to-sample task using new visual shapes at each trial. Measures of population-activity patterns (cortical field potentials) were obtained from a chronically implanted array of electrodes placed over area V4 and posterior infero-temporal cortex.