Sustained Attention

The vigilance decrement reflects limitations in effortful attention not mindlessness.

by Rebecca Grier

Coauthored with  Warm, J.S., Dember, W.N., Mathews, G., Galinsky, T.L., Szalma, J.L., & Parasuraman, R. Published in Human Factors, 45, 349-359.

Reduced electrodermal response to errors predicts poor sustained attention performance in attention deficit hyperactivity disorder

by Redmond O'Connell

Uncovering the neural signature of lapsing attention: electrophysiological signals predict errors up to 20 s before they occur

by Redmond O'Connell

Redmond G. O’Connell, Paul M. Dockree, Ian H. Robertson, Mark A. Bellgrove, John J. Foxe and Simon P. Kelly
The Journal of Neuroscience, 2009

The extent to which changes in brain activity can foreshadow human error is uncertain yet has important theoretical... more The extent to which changes in brain activity can foreshadow human error is uncertain yet has important theoretical and practical implications. The present study examined the temporal dynamics of electrocortical signals preceding a lapse of sustained attention. Twenty-one participants performed a continuous temporal expectancy task, which involved continuously monitoring a stream of regularly alternating patterned stimuli to detect a rarely occurring target stimulus whose duration was 40% longer. The stimulus stream flickered at a rate of 25 Hz to elicit a steady-state visual-evoked potential (SSVEP), which served as a continuous measure of basic visual
processing. Increasing activity in the alpha band (8 –14 Hz) was found beginning 20 s before a missed target. This was followed by decreases in the amplitude of two event-related components over a short pretarget time frame: the frontal P3 (3– 4 s) and contingent-negative variation (during the target interval). In contrast, SSVEP amplitude before hits and misses was closely matched, suggesting that the efficacy of ongoing basic visual processing was unaffected. Our results show that the specific neural signatures of attentional lapses are registered in the EEG up to 20 s before an error.

Two types of action error: electrophysiological evidence for separable inhibitory and sustained attention neural mechanisms producing error on go/no-go tasks

by Redmond O'Connell

Redmond G. O’Connell, Paul M. Dockree, Mark A. Bellgrove, Alessandra Turin, Seamus Ward, John J. Foxe and Ian H. Robertson
Journal of Cognitive Neuroscience, 2009

Disentangling the component processes that contribute to
human executive control is a key challenge for cognitive... more Disentangling the component processes that contribute to
human executive control is a key challenge for cognitive neuroscience. Here, we employ event-related potentials to provide electrophysiological evidence that action errors during a go/no-go task can result either from sustained attention failures
or from failures of response inhibition, and that these two processes are temporally and physiologically dissociable, although the behavioral error—a nonintended response—is the same. Thirteen right-handed participants performed a version of a
go/no-go task in which stimuli were presented in a fixed and
predictable order, thus encouraging attentional drift, and a
second version in which an identical set of stimuli was presented
in a random order, thus placing greater emphasis on response inhibition. Electrocortical markers associated with goal maintenance (late positivity, alpha synchronization) distinguished correct and incorrect performance in the fixed condition, whereas errors in the random condition were linked to
a diminished N2–P3 inhibitory complex. In addition, the amplitude of the error-related negativity did not differ between
correct and incorrect responses in the fixed condition, consistent
with the view that errors in this condition do not arise from a failure to resolve response competition. Our data provide
an electrophysiological dissociation of sustained attention
and response inhibition.

Unconscious orientation processing depends on perceptual load

by David Carmel

Perceptual load alters visual excitability

by David Carmel

Increasing perceptual load reduces the processing of visual stimuli outside the focus of attention, but the mechanism... more Increasing perceptual load reduces the processing of visual stimuli outside the focus of attention, but the mechanism underlying these effects remains unclear. Here we tested an account attributing the effects of perceptual load to modulations of visual cortex excitability. In contrast to stimulus competition accounts, which propose that load should affect simultaneous, but not sequential, stimulus presentations, the visual excitability account makes the novel prediction that load should affect detection sensitivity for both simultaneous and sequential presentations. Participants fixated a stimulus stream, responding to targets defined by either a color (low load) or color and orientation conjunctions (high load). Additionally, detection sensitivity was measured for a peripheral critical stimulus (CS) presented occasionally. Increasing load at fixation reduced sensitivity to the peripheral CSs; this effect was similar regardless of whether CSs were presented simultaneously with central stimuli or during the (otherwise empty) interval between them. Controls ruled out explanations of the results in terms of strategic task prioritization. These findings support a cortical excitability account for perceptual load, challenging stimulus competition accounts.
tition accounts.