The relationship between flash based illusory line motion and exogenous visual attention.

If a bar suddenly appears between 2 squares after 1 of the squares flashes the bar appears to shoot away from the flashed square toward the other. This occurs despite the bar actually having been presented all at once. This illusory motion is sufficiently strong to cancel real motion drawn in the opposite direction. One explanation for the illusion in these displays is based upon the prior entry benefits generated by exogenous attention at the flashed location. These prior entry benefits can be offset by real motion in the opposite direction, which enables 1 to quantify the illusion based upon the area between the response curves following left and right flashes. The influence of attention can be quantified as the costs plus benefits during an exogenous cuing study involving target discrimination. The current study required participants to complete motion direction discrimination trials and a set of target discrimination trials following noninformative peripheral cues. If attention is involved in the motion illusion during these displays then those who show large effects of attention during cuing should also show large illusions. Correlation analyses confirmed a positive relationship existed between the costs plus benefits of exogenous attention and the illusory motion. (PsycINFO Database Record