How Does the Brain Track Multiple Objects?
Date
2009-05
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Abstract
How does the brain allocate attention to a visual display? Do they pay attention more to the visual space or to the objects within the display? Questions like these can be answered by using the multiple object tracking (MOT) paradigm. This task requires observers to track target objects in an array as they move amongst identical distracter objects. In addition, we can use psychophysiological measures while participants complete this task, such as event related potentials (ERP). These
potentials represent brain activity in response to a particular stimulus (in this case, tracking). Drew & Vogel (2008) used this technique and found that as the participants tracked more targets, ERP activation increased. We replicated this experiment and added another variable - spacing; objects could either be spaced far apart or close together. We found that while left hemisphere activation is sensitive to increasing targets (as in Drew & Vogel, 2008), the right hemisphere activation is sensitive to the spacing manipulation. Therefore, our results support a dual-system hypothesis; observers use both spatial and object-based attention to complete the task.