In 1980, we showed that visual search with displays containing two abrupt onsets (two brief flashes) was not better than visual search with displays containing one abrupt onset lone long flash). These results showed that saccade-like stimulus transients (abrupt onsets) do not aid visual information processing. This paper extends our previous work by showing that abrupt and gradual onsets are equally effective for visual search. Subjects searched sequences of displays of alphanumeric characters for a single numeral. Display waveforms were: (1) ramp onset and abrupt offset; (2) abrupt onset and ramp offset; (3) abrupt onset and abrupt offset with duration equal to and (4) half that of the ramp displays. Time between onsets of successive displays was 150 or 250 msec. Performance did not depend on waveform or duration. It was, however, better when the time between onsets of successive displays was 250 msec. The results show that visual information processing is unaffected by eaccade-like image perturbations. This outcome means that: (1) saccades need be made only to improve the location of the retinal image and not to produce transients, and (2) previously described contributions of abrupt onsets to detection of sinusoidal gratings do not apply to complex information processing tasks.
All Science Journal Classification (ASJC) codes
- Experimental and Cognitive Psychology
- Sensory Systems