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Pre-stimulus activity predicts the winner of top-down vs. bottom-up attentional selection.

Mazaheri A, DiQuattro NE, Bengson J, Geng JJ - PLoS ONE (2011)

Bottom Line: Our ability to process visual information is fundamentally limited.This leads to competition between sensory information that is relevant for top-down goals and sensory information that is perceptually salient, but task-irrelevant.We propose that the high frontal alpha reflects a disengagement of attentional control whereas the transient posterior alpha time-locked to the saccade indicates sensory inhibition of the salient distractor and suppression of bottom-up oculomotor capture.

View Article: PubMed Central - PubMed

Affiliation: Center for Mind and Brain, University of California Davis, Davis, California, United States of America. a.mazaheri@donders.ru.nl

ABSTRACT
Our ability to process visual information is fundamentally limited. This leads to competition between sensory information that is relevant for top-down goals and sensory information that is perceptually salient, but task-irrelevant. The aim of the present study was to identify, from EEG recordings, pre-stimulus and pre-saccadic neural activity that could predict whether top-down or bottom-up processes would win the competition for attention on a trial-by-trial basis. We employed a visual search paradigm in which a lateralized low contrast target appeared alone, or with a low (i.e., non-salient) or high contrast (i.e., salient) distractor. Trials with a salient distractor were of primary interest due to the strong competition between top-down knowledge and bottom-up attentional capture. Our results demonstrated that 1) in the 1-sec pre-stimulus interval, frontal alpha (8-12 Hz) activity was higher on trials where the salient distractor captured attention and the first saccade (bottom-up win); and 2) there was a transient pre-saccadic increase in posterior-parietal alpha (7-8 Hz) activity on trials where the first saccade went to the target (top-down win). We propose that the high frontal alpha reflects a disengagement of attentional control whereas the transient posterior alpha time-locked to the saccade indicates sensory inhibition of the salient distractor and suppression of bottom-up oculomotor capture.

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The latency of saccades.First saccade latencies in each experimental condition in A) group and B) individuals. Error bars on group data are standard error of the mean. First saccade latencies were significantly faster for fs-distractor trials in the distractor-salient condition. This suggests that the salient distractor produced automatic oculomotor capture.
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pone-0016243-g002: The latency of saccades.First saccade latencies in each experimental condition in A) group and B) individuals. Error bars on group data are standard error of the mean. First saccade latencies were significantly faster for fs-distractor trials in the distractor-salient condition. This suggests that the salient distractor produced automatic oculomotor capture.

Mentions: Fs-target trials were more efficient and this suggests that fs-distractor trials were due to a failure of top-down attentional control to direct the first saccade away from the salient item, which was known to be a non-target. Consistent with the notion that fs-distractor trials were due to involuntary oculomotor capture, saccades to the salient distractor had shorter latencies than any other trial type, including target-alone trials (all t(10)>10, p<.0001; Figure 2AB). This pattern was seen in all individuals (Figure 2B). Thus, despite individual differences in the likelihood of executing a saccade to the target versus the salient distractor first, fs-distractor trials represented instances where automatic bottom-up selection of the salient item won the competition for attention despite prior knowledge of its task-irrelevance. These results are similar to previous findings where behavioral and oculomotor responses from a similar paradigm are more fully explicated [13].


Pre-stimulus activity predicts the winner of top-down vs. bottom-up attentional selection.

Mazaheri A, DiQuattro NE, Bengson J, Geng JJ - PLoS ONE (2011)

The latency of saccades.First saccade latencies in each experimental condition in A) group and B) individuals. Error bars on group data are standard error of the mean. First saccade latencies were significantly faster for fs-distractor trials in the distractor-salient condition. This suggests that the salient distractor produced automatic oculomotor capture.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3046127&req=5

pone-0016243-g002: The latency of saccades.First saccade latencies in each experimental condition in A) group and B) individuals. Error bars on group data are standard error of the mean. First saccade latencies were significantly faster for fs-distractor trials in the distractor-salient condition. This suggests that the salient distractor produced automatic oculomotor capture.
Mentions: Fs-target trials were more efficient and this suggests that fs-distractor trials were due to a failure of top-down attentional control to direct the first saccade away from the salient item, which was known to be a non-target. Consistent with the notion that fs-distractor trials were due to involuntary oculomotor capture, saccades to the salient distractor had shorter latencies than any other trial type, including target-alone trials (all t(10)>10, p<.0001; Figure 2AB). This pattern was seen in all individuals (Figure 2B). Thus, despite individual differences in the likelihood of executing a saccade to the target versus the salient distractor first, fs-distractor trials represented instances where automatic bottom-up selection of the salient item won the competition for attention despite prior knowledge of its task-irrelevance. These results are similar to previous findings where behavioral and oculomotor responses from a similar paradigm are more fully explicated [13].

Bottom Line: Our ability to process visual information is fundamentally limited.This leads to competition between sensory information that is relevant for top-down goals and sensory information that is perceptually salient, but task-irrelevant.We propose that the high frontal alpha reflects a disengagement of attentional control whereas the transient posterior alpha time-locked to the saccade indicates sensory inhibition of the salient distractor and suppression of bottom-up oculomotor capture.

View Article: PubMed Central - PubMed

Affiliation: Center for Mind and Brain, University of California Davis, Davis, California, United States of America. a.mazaheri@donders.ru.nl

ABSTRACT
Our ability to process visual information is fundamentally limited. This leads to competition between sensory information that is relevant for top-down goals and sensory information that is perceptually salient, but task-irrelevant. The aim of the present study was to identify, from EEG recordings, pre-stimulus and pre-saccadic neural activity that could predict whether top-down or bottom-up processes would win the competition for attention on a trial-by-trial basis. We employed a visual search paradigm in which a lateralized low contrast target appeared alone, or with a low (i.e., non-salient) or high contrast (i.e., salient) distractor. Trials with a salient distractor were of primary interest due to the strong competition between top-down knowledge and bottom-up attentional capture. Our results demonstrated that 1) in the 1-sec pre-stimulus interval, frontal alpha (8-12 Hz) activity was higher on trials where the salient distractor captured attention and the first saccade (bottom-up win); and 2) there was a transient pre-saccadic increase in posterior-parietal alpha (7-8 Hz) activity on trials where the first saccade went to the target (top-down win). We propose that the high frontal alpha reflects a disengagement of attentional control whereas the transient posterior alpha time-locked to the saccade indicates sensory inhibition of the salient distractor and suppression of bottom-up oculomotor capture.

Show MeSH
Related in: MedlinePlus