Article Review: How Many Object Can You Track?: Evidence for a Resource Limited Attentive Tracking Mechanism

Article Review: How Many Object Can You Track?: Evidence for a Resource Limited Attentive Tracking Mechanism Before the paper by Alvarez & Franconeri (2007), the general consensus was that people are able to track about 4 moving objects at any given time. However to some, it was clear that this issue is more complicated than the original view; which is the most likely inspiration for this further research. In the paper by Alvarez & Franconeri (2007), it is found that it is not as simple as the previous approach; for example they looked at how speed affected the ability to track objects and found that speed did have an affect whereby the higher the speed; the participants ability to track all objects would decrease. Alvarez & Franconeri (2007) also found an effect where, if the objects were allowed to move closer together the participant would find it harder to track, but more so in the faster condition. Alvarez & Franconeri (2007) did 2 experiments. The first looks at how increasing the speed in which the stimulus moves, affects how many stimuli that the eye can track. This is done by first presenting a number of identicle black circles on a white computer screen, identical distractor circles will then appear. The circles then start moving. It is the participant’s task to follow these circles and identify the target stimuli (not distractors) at the end of the task. It is found that the more stimuli presented on screen, the less chance there is of identifying the correct stimuli at the end. Alvarez & Franconeri (2007) point out that participant’s should be able to identify less stimulus as the speed increases. It is found that when 1 stimulus is presented, participants can track it a high speed. The speed in which the participant can identify the correct stimuli decreases with every stimulus added. There was also an accuracy check to made sure the each participant’s results was a true representation of what was being observed. The second

References: Alvarez, G. A. & Franconeri, S. L. (2007). How Many Objects Can you Track?: Evidence For a Resource-Limited Attentive Tracing Mechanism. Journal of Vision, 7(13), 1-10. Feria, C. S. (2012). The Effects of Distractors in Multiple Object Tracking are Modulated by the Similarity of Distractor and Target Features. Perception, 41, 287-304. Franconeri, S. L., Alvarez, G. A. & Enns, J. T. (2007). How Many Locations Can Be Selected At Once? Journal of Experimental Psychology: Human Perception and Performance, 33(5), 1003-1012. Franconeri, S. L., Jonathan, S. V. & Scimeca, J. M. (2010). Tracking Multiple Objects Is Limited Only by Object Spacing, Not by Speed, Time, or Capacity. Psychological Science, 21(7), 920-925. Francorneri, S. L., Lin, J. Y., Pylyshyn, Z. W., Fisher, B. & Enns, J. T. (2008). Evidence Against a Speed Limit in Multiple-Object Tracking. Psychonomic Bulletin & Review, 15(4), 802-808. Google Inc Green, C. S. & Bavelier, D. (2006). Enumeration Versus Multiple Object Tracking: The Case of Action Video Game Players. Cognition. 101, 217-245. Horowitz, T. S., Klieger, S. B., Fencsik. D. E., Yang, K. K., Alvarez, G. A. & Wolfe, J. M. (2007). Tracking Unique Object. Perception & Psychophysics, 69(2), 172-184. Howard, C Pylyshyn, Z. (1989). The role of location indexes in spatial perception sketch of the FINST spatial index-model, Cognition, 32. 65-97. Trick, L. M., Audet, D. & Dales, L. (2003) Age Differences in enumerating things that Move: Implications for the Development of Multiple-Object Tracking. Memory & Cognition, 31, 1229-1237. Trick, L. M., Jaspers-Fayer, F. & Sethi, N. (2005). Multiple Object Tracking in Children: The ‘Catch the Spies’ task. Cognitive Development, 20, 373-387. Xu, Y & Chun, M. (2009). Selecting and Perceiving Multiple Visual Objects. National Institute of Health, 13(4). 167-174.