David Bourget (Western Ontario)
David Chalmers (ANU, NYU)
Rafael De Clercq
Jack Alan Reynolds
Learn more about PhilPapers
In Multiple Object Tracking (MOT), an observer is able to track 4 – 5 objects in a group of otherwise indistinguishable objects that move independently and unpredictably about a display. According to the Visual Indexing Theory (Pylyshyn, 1989), successful tracking requires that target objects be indexed while they are distinct -- before tracking begins. In the typical MOT task, the target objects are briefly flashed resulting in the automatic assignment of indexes. The question arises whether indexes are only assigned automatically or whether they can be assigned voluntarily in a top-down manner. This study compares several ways of specifying which of 8 items are the targets to be tracked. In the Flash condition the target items were flashed, in the Nonflash condition the targets were the items not flashed, and in the Number condition the targets were specified by number (e.g., items numbered 1-4). The results showed no difference between the three conditions, suggesting that tracking was possible with either voluntary or involuntary indexing. The second experiment tested the hypothesis that voluntary indexing is possible only if the target items are visited serially. The conditions were the same as experiment 1 except that the time available for index assignment was too short to allow targets to be visited serially. In this experiment, targets flashed only once (or, in the Numbers condition, remained visible for about 400 ms). The results showed a decrease in tracking performance for the Number condition, but the Flash and the Nonflash conditions did not differ, suggesting that as long as the designation of targets was done rapidly, the observer did not have to visit each target serially in order to index it. These results suggest that indexing can occur both automatically and voluntarily, and without serially visiting them, so long as the items are successfully specified.
|Keywords||No keywords specified (fix it)|
|Categories||categorize this paper)|
Setup an account with your affiliations in order to access resources via your University's proxy server
Configure custom proxy (use this if your affiliation does not provide a proxy)
|Through your library||
References found in this work BETA
No references found.
Citations of this work BETA
No citations found.
Similar books and articles
Brian J. Scholl & Zenon W. Pylyshyn, Tracking Multiple Items Through Occlusion: Clues to Visual Objecthood.
Zenon Pylyshyn, Some Puzzling Findings in Multiple Object Tracking (MOT): II. Inhibition of Moving Nontargets.
Brian J. Scholla (2001). What is a Visual Object? Evidence From Target Merging in Multiple Object Tracking. Cognition 80 (1-2):159-177.
Zenon W. Pylyshyn, Charles E. King & James E. Reilly, Selective Nontarget Inhibition in Multiple Object Tracking (MOT).
Zenon W. Pylyshynb, Jacob Feldmanb & Brian J. Scholla (2001). What is a Visual Object? Evidence From Target Merging in Multiple Object Tracking. Cognition 80 (1-2):159-177.
Added to index2009-01-28
Total downloads4 ( #288,602 of 1,410,002 )
Recent downloads (6 months)1 ( #176,758 of 1,410,002 )
How can I increase my downloads?