RT Journal Article
SR Electronic
T1 Cortical Mechanisms of Prioritizing Selection for Rejection in Visual Search
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4738
OP 4748
DO 10.1523/JNEUROSCI.2407-17.2018
VO 38
IS 20
A1 Sarah E. Donohue
A1 Mandy V. Bartsch
A1 Hans-Jochen Heinze
A1 Mircea A. Schoenfeld
A1 Jens-Max Hopf
YR 2018
UL http://www.jneurosci.org/content/38/20/4738.abstract
AB In visual search, the more one knows about a target, the faster one can find it. Surprisingly, target identification is also faster with knowledge about distractor-features. The latter is paradoxical, as it implies that to avoid the selection of an item, the item must somehow be selected to some degree. This conundrum has been termed the “ignoring paradox”, and, to date, little is known about how the brain resolves it. Here, in data from four experiments using neuromagnetic brain recordings in male and female humans, we provide evidence that this paradox is resolved by giving distracting information priority in cortical processing. This attentional priority to distractors manifests as an enhanced early neuromagnetic index, which occurs before target-related processing, and regardless of distractor predictability. It is most pronounced on trials for which a response rapidly occurred, and is followed by a suppression of the distracting information. These observations together suggest that in visual search items cannot be ignored without first being selected.SIGNIFICANCE STATEMENT How can we ignore distracting stimuli in our environment? To do this successfully, a logical hypothesis is that as few neural resources as possible should be devoted to distractor processing. Yet, to avoid devoting resources to a distractor, the brain must somehow mark what to avoid; this is a philosophical problem, which has been termed the “ignoring paradox” or “white bear phenomenon”. Here, we use MEG recordings to determine how the human brain resolves this paradox. Our data show that distractors are not only processed, they are given temporal priority, with the brain building a robust representation of the to-be-ignored items. Thus, successful suppression of distractors can only be achieved if distractors are first strongly neurally represented.