The upper spatial limit for perception of displacement is affected by preceding motion.

The upper spatial limit D(max) for perception of apparent motion of a random dot pattern may be strongly affected by another, collinear, motion that precedes it [Mateeff, S., Stefanova, M., &.

Flanker interference in young and older participants as reflected in event-related potentials.

The present study investigates behavioural and event-related potential (ERP) differences between young and older participants in two variants of a flanker task. Flankers preceded the target by 100 ms (Experiment 1) or were presented simultaneously with the target (Experiment 2). In both experiments the response times showed an age-related slowing and a compatibility effect, which did not differ significantly across age.

Perceived global direction of a compound of real and apparent motion.

We presented a random dot pattern that moved horizontally for 1.6s within a stationary invisible aperture. The dots were periodically visible for 50 ms (visible phase) with lengths of the real motion 0-1.

Effects of ageing on cognitive task preparation as reflected by event-related potentials.

Objective: The anticipation of complex cognitive tasks involves effortful preparation being reflected in the contingent negative variation (CNV) of the event-related potential. In the literature there are contradictory results concerning the effect of age on this potential. We wanted to investigate effects of age, time-on-task, and task difficulty on the CNV.

Visual analysis of changes of motion in reaction-time tasks.

Subjects observed a random-dot pattern moving uniformly in the vertical direction (vector V1). The motion vector abruptly changed to V2, both in speed and direction simultaneously. It was found that the time of simple reaction to such changes V1 --> V2 can be described by a function of a single variable, [w(V1 - V2c) + (1 - w) V2N], 0 < w < 0.

Central and parietal event-related lateralizations in a flanker task.

Recently Wascher et al. (1999) reported that in a flanker task with arrow stimuli not only the known lateralized readiness potential (LRP) that reflects lateralized response activation was induced, but also a parietal lateralized activation (direction encoding lateralization; DEL) that was interpreted as reflecting an earlier coding of a response side. However, the Wascher study did not exclude that the DEL could have also been due to lateralized stimulus- or attention-related factors.

Effects of spatial attention on the brain stem frequency-following potential.

Can spatial attention or orienting affect human auditory information processing as peripheral as on the brain stem level? More specifically, is the reduction of the latency of the frequency-following potential (FFP; an evoked lower brain stem response) that we described in an earlier Neuroreport article really specifically attention-related? Here we demonstrate that, indeed, exogenous intramodal (auditory) spatial orienting, but not a transient modulation of general arousal, reduced the latency of the FFP by 27 micros; there were no effects on the FFP-amplitude. Although it might seem small, this reduction may be relevant in spatial hearing. We conclude that under certain conditions spatial attention can affect auditory information processing already on the brain stem level.

Parallel systems of error processing in the brain.

Major neurophysiological principles of performance monitoring are not precisely known. It is a current debate in cognitive neuroscience if an error-detection neural system is involved in behavioral control and adaptation. Such a system should generate error-specific signals, but their existence is questioned by observations that correct and incorrect reactions may elicit similar neuroelectric potentials.

Short-term mobilization of processing resources is revealed in the event-related potential.

This study investigates whether an occasional effortful improvement of performance, as asked for by a precue, is reflected in event-related potential (ERP) changes. To estimate the limits of possible effort-induced behavioral and ERP changes, we manipulated the time between precue and imperative stimulus (IS; precue interval, PCI). The subjects could, in fact, improve their performance in the effort trials, with all but the shortest PCI.

Sensorimotor slowing with ageing is mediated by a functional dysregulation of motor-generation processes: evidence from high-resolution event-related potentials.

The objective of the present study was to identify the origin(s) of ageing-related behavioural slowing in sensorimotor tasks. For this aim, event-related potentials (ERPs) were analysed at 64 electrodes to evaluate the strength and timing of different stages of information processing in the brain. Electrophysiological indices of stimulus processing, sensorimotor integration/response selection and motor-related processing were used to compare the processing speed of young (n = 13, mean age = 22.