Prioritizing new elements with a brief preview period: evidence against visual marking

Area of Science:

• Cognitive Psychology
• Visual Perception
• Attention Research

Background:

• Theories on prioritizing new visual elements over old ones include Watson and Humphreys' (1997) visual marking, a time-consuming inhibition process (≥400 ms).
• Donk and Theeuwes (2001) proposed an instantaneous process linked to luminance changes of new elements.

Purpose of the Study:

• To empirically test the visual marking versus luminance-based theories of prioritized selection.
• To investigate if prioritized selection of new elements over old elements occurs with a brief preview (50 ms).

Main Methods:

• Experimental manipulation of element onset timing and luminance changes.
• Participants performed a task requiring selection of new visual elements presented after a short preview of old elements.
• Comparison of selection performance when new elements appeared with luminance onset versus simultaneous onset with old elements.

Main Results:

• Prioritized selection of new elements was successful when they had luminance onset and old elements did not.
• Prioritization failed if both old and new elements appeared with luminance onset.
• Participants could prioritize new elements even with a very short (50 ms) preview of old elements.

Conclusions:

• The findings support an instantaneous process for prioritizing new visual elements over old ones.
• Luminance onset of new elements is a critical factor in this rapid selection mechanism.
• The results challenge the necessity of a time-consuming active inhibition process (visual marking).