| dc.description.abstract | Responses in covert orienting of visual attention tasks (COVAT) produce a
biphasic pattern of results. When the stimulus onset asynchrony (SOA) is less than 300
ms, reaction times (RTs) to cued targets are faster than uncued targets, whereas when the
SOA is greater than 300 ms RTs to uncued targets are faster than cued targets. This latter
phenomenon is termed inhibition of return (lOR). lOR is believed to be a mechanism
that promotes efficient search by biasing attention to new locations or objects. To date,
most research on lOR has been restricted to situations in which participants are seated
while viewing stimuli presented on a monitor; however, many real life searches take
place while the searcher is in motion. One way to look at the effect of motion on the
orienting of attention is to stimulate the otoliths of the vestibular system by having people
lie prone with their neck in a flexed position (known as head down neck flexion or
HDNF). We had participants complete a COVAT (with SO As of 100 and 800 ms) while
in three different positions: seated, lying prone, and in HDNF. When in HDNF there
was a significant decrease in the magnitude of responses compared to the other two
positions; both less facilitation and less inhibition were observed. The results are
discussed in terms of the relationship between vestibular activation (i.e., HDNF) and the
orienting of visual attention. | |
