Abstract
Previous research has examined our ability to attend selectively to particular features of perceptual objects, as well as our ability to switch from attending to one type of feature to another. This is usually done in the context of anticipatory attentional-set control, comparing the neural mechanisms involved as participants prepare to attend to the same stimulus feature as on the previous trial (“task-stay” trials) with those required as participants prepare to attend to a different stimulus feature to that previously attended (“task-switch” trials). We wanted to establish how participants maintain or switch attentional set retrospectively, as they attend to features of objects held in visual short-term memory (VSTM). We found that switching, relative to maintaining attentional set retrospectively, was associated with a performance cost, which can be reduced over time. This control process was mirrored by a large parietal and frontal amplitude difference in the event-related brain potentials (ERPs) and significant differences in global field power (GFP) between switch and stay trials. However, when taking into account the switch/stay GFP differences, thereby controlling for this difference in amplitude, we could not distinguish these trial types topographically. By contrast, we found clear topographic differences between preparing an anticipatory feature-based attentional set versus applying it retrospectively within VSTM. These complementary topographical and amplitude analyses suggested that anticipatory and retrospective set control recruited a qualitatively different configuration of underlying neural generators. In contrast, switch/stay differences were largely quantitative, with them differing primarily in terms of amplitude rather than topography.
Highlights
When we process perceptual input we do so in the context of an attentional set
Event-related brain potentials (ERPs) have been used to chart the temporal dynamics of these processes. To date these studies have primarily looked at the biasing of a particular spatial location within a visual short term memory (VSTM) representation: for example, Griffin and Nobre [3] found both similarities and differences in the way spatial attentional biases are applied to incoming perceptual input and representations held in VSTM; lateralised components locked to the onset of spatially informative attention cues were similar for prospective and retrospective spatial attentional orienting
We presented cues either prior to the onset of the memory-array, in which case participants could prepare an attentional set in anticipation of incoming perceptual input, or after the memory-array, in which case participants would initially have to remember all features in the memory-array, and apply an attentional set retrospectively to that stored representation
Summary
When we process perceptual input we do so in the context of an attentional set. For example, when shopping for red apples we might distinguish them from other fruit on the basis of their color or shape. More recently studies have explored the mechanisms by which we create internal representations in VSTM, and selectively modulate them via attentional mechanisms after the offset of perceptual information, according to our task goals [e.g., 2–9] This implies that VSTM is not a passive store of information, but rather that information held in this way can be manipulated according to top-down biases directly related to task-relevant goals, just as has been proposed for incoming perceptual input [10]. Event-related brain potentials (ERPs) have been used to chart the temporal dynamics of these processes To date these studies have primarily looked at the biasing of a particular spatial location within a VSTM representation: for example, Griffin and Nobre [3] found both similarities and differences in the way spatial attentional biases are applied to incoming perceptual input and representations held in VSTM; lateralised components locked to the onset of spatially informative attention cues were similar for prospective and retrospective spatial attentional orienting. By contrast to studies that provide participants with retrospective spatial cues (such as Sperling’s cueing of a line of letters), the current study explores the biasing of task-relevant features (i.e. colors and shapes) within perceived and stored representations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
