| |
Abstract:
Abstract: The correlation between pre-attentive processes
(e.g., pop-out) and the amplitude of the P300 component was
demonstrated with visually evoked potentials (VEPs). Observers were
presented randomly with either one of two stimuli (an open diamond
and a diamond with an X in its center) imbedded in a 3x3 array of
right pointing arrows. Five experiments compared the P300 for each
stimulus configuration. Experiment 1 recorded observers' reaction
time for only those arrays with all right arrows (control
condition). Experiment 2 compared reaction times between the
diamond and diamond-x stimulus patterns. Experiments 3, 4, and 5
required the observer to mentally count the number of times each
stimulus pattern was presented. Both experiments that required the
observers to attend to the array containing the diamond (2 and 4)
demonstrated significantly greater P300 amplitudes for the diamond
compared to the diamond-x and control conditions. With Experiments
1, 3, and 5 no significant differences in P300 amplitude were
obtained. Analysis of reaction times in experiments 1and 2 showed
significant differences between all stimulus patterns with the
control condition being reliably shorter than either the diamond or
the diamond-x and the diamond being significantly shorter than the
diamond-x. These results show that a stimulus configuration that
readily "pops-out" correlates with an increased amplitude of the
P300 component of the VEP.
|
