Andreas K. Kreiter

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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(More)
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(More)
Selective attention improves perception and modulates neuronal responses, but how attention-dependent changes of cortical activity improve the processing of attended objects is an open question. Changes in total signal strength or enhancements in signal-to-noise ratio have been proposed as putative mechanisms. However, it is still not clear whether, and to(More)
Feature-directed attention has been recently studied in various psychophysical, electrophysiological, and imaging studies. Convincing evidence has been obtained for its global effectiveness, but there is a debate about the processing fate of non-attended target features. A number of studies demonstrated feature-directed attention being associated with(More)
Remarkable alterations of perception during long-lasting attentional processes have been described in several recent studies. Although these findings have gained much interest, almost nothing is known about the modulation of neuronal responses during sustained attention. Therefore, we investigated the effect of prolonged selective attention on neuronal(More)
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(More)
The study of neural population codes relies on massively parallel recordings in combination with theoretically motivated analysis tools. We applied two multi-site recording techniques to record from cells throughout cortical depth in a minimally invasive way. The feasibility of such experiments in area 17 of the anesthetized rat is demonstrated. Bayesian(More)
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(More)
In monkeys, long-term recordings with chronically implanted microelectrodes frequently suffer from a continuously decreasing probability to record single units or even small multiunit clusters. This problem is associated with two technical limitations of the available devices: first, restrictions for electrode movement, and second, absent possibility to(More)