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Colored grating patterns were presented to 8 participants in a passive oddball condition (standard, 87.5% and deviant, 12.5%, differing in their color). In the corresponding multicolor condition, grating patterns of eight different colors were presented, their probabilities set equal both to each other and to that of the deviant in the oddball task.(More)
Infrequent colored patterns within sequences of patterns of frequent color elicited a posterior negative event-related potential component only in case of lower half-field stimulation. This negativity in the 140-200 ms latency range is considered as a correlate of automatic visual change detection (visual mismatch negativity, vMMN). Retinotopic prestriate(More)
We investigated the role of attention in feature binding in the auditory and the visual modality. One auditory and one visual experiment used the mismatch negativity (MMN and vMMN, respectively) event-related potential to index the memory representations created from stimulus sequences, which were either task-relevant and, therefore, attended or(More)
We studied whether, similarly to the auditory modality, short-period temporal integration processes occur in vision. Event-related potentials (ERP) were recorded for occasional stimulus omissions from sequences of patterned visual stimuli. A posterior negative component emerged only when the constant stimulus onset asynchrony (SOA) was shorter than 150 ms.(More)
Younger and older participants (n=8 in each age group) performed a letter-matching task, where they had to respond to identical letters (P=0.15). Task-relevant (target and non-target) letters were presented on two corners of an imagery square, while on the other two corners irrelevant letters were presented. In some trials (P=0.05), pictures of visual(More)
Age-related change of event-related potentials to novel visual stimuli was investigated while participants attended to both auditory and visual stimulation. Meaningful but irrelevant pictures (novel stimuli) were presented to younger (mean=21.8, range=18-26 years) and older (mean=70.0, range=60-78) participants (10 in each group). The participants were(More)
A set of scaling feedforward filters is developed in an unsupervised way via inputting pixel-discretized extended objects into a winner-take-all artificial neural network. The system discretizes the input space by both position and size. Depending on the distribution of input samples and below a certain number of neurons the spatial filters may form groups(More)
We investigated whether visual orientation anisotropies (known as oblique effect) exist in non-attended visual changes using event-related potentials (ERP). We recorded visual mismatch negativity (vMMN) which signals violation of sequential regularities. In the visual periphery unattended, task-irrelevant Gábor patches were displayed in an oddball sequence(More)
It is shown that local. extended objects of a metrical topological space shape the receptive fields of competitive neurons to local fi lters. Self-orl!,anized topolol!,Y learninl!, is then solved with the help of Hebbian learninl!, tOl!,ether with extended objecttl that provide unique illfonnaLion about neighborhood relaLiolltl. A topo­ graphic, al Illap(More)
The aim of this study was to investigate how information carried by a cue stimulus modulate event-related potentials (ERPs) to a subsequent target stimulus which either calls for an overt response (Go stimulus) or no response (Nogo stimulus). One of the cues predicted the likely appearance of the Go stimulus (Go cue) whereas the other cue predicted the(More)