Attentional switches and dual-task interference

Attentional switches and dual-task interference

Ettwig, J.F.
Bronkhorst, A.W.

2015

In four experiments, we studied the time course of interference between detection of an oddball orientation target (OT) in an 8-item circular search display, and identification of a letter target (LT) in a central stream of distractor letters. Dual-task performance for different temporal lags between targets was compared to single-task performance. When the LT preceded the OT, dual-task performance levels were reduced at short inter-target intervals of 0 and 166 ms; when the OT preceded the LT, the dual-task interference was unexpectedly stronger and lasted for up to 500 ms. Resource competition due to temporally overlapping target processing cannot account for this result, because the feature search task is easier than the letter identification task, and therefore would have generated less interference when presented first. Two alternative explanations were explored. First, by manipulating the spatial inter-target distance, we investigated to what degree there is a penalty associated with directing the attentional window from a large object (the search display) to a smaller object (the central letter stream). Second, by varying the duration of the OT and subsequent mask, we studied whether the interference was caused by the difficulty of disengaging attention from the search display. Results support this second explanation and thus indicate that switching attention to the letter stream is hampered by the continuing presence of (masked) search display items. This result shows that attentional effects may play a major role in dual-task execution and can easily obscure interference due to other factors such as resource competition. © 2015 Ettwig, Bronkhorst.

Human & Operational Modelling
PCS - Perceptual and Cognitive Systems
ELSS - Earth, Life and Social Sciences
adult
attention
controlled study
distractibility
female
human experiment
male
normal human
spatial discrimination
task performance
visual masking
visual orientation
visual stimulation
word recognition
young adult

http://resolver.tudelft.nl/uuid:60e5dbee-1557-4c59-bb34-df2645c6529f

https://doi.org/10.1371/journal.pone.0118216

524135

Public Library of Science

1932-6203

PLoS ONE, 10 (3)

e0118216

article