Making the skew positive turns the brightest points of the image into specular highlights, so the surface looks glossy; making the skew negative sharpens the depths of shaded regions but, more importantly, strips away the highlights so the surface looks matte.
Attention, Perception, & Psychophysics 2009, 71 (8), 1679-1681 doi:10.3758/APP.71.8.1679 News From the Field COGNITIVE CONTROL ers, and similar results occurred for bumpy, materially homogeneous sur- other cognitive tasks. For example, in faces and showed that if one fixes the “One Moment, Let Me Just both a visual memory task and a con- mean luminance of such an image, the Get This Text . . .” tinuous performance task, the number perceived albedo of the surface is sen- Ophir et al. (2009). Cognitive control in of task-irrelevant distractors produced sitively controlled by the skew of the media multitaskers. PNAS, 106, 15583. a greater memory decrement in heavy image’s gray-level histogram. Positive Recent technologies allow users to than in light media multitaskers. Inter- skew makes the surface look glossy; be online at all times through moni- estingly, there were few, if any, differ- negative skew makes it look matte. toring their phones, text messages, ences in results for the latter two tasks The spatial pattern of light reflected e-mails, and Web sites, often simulta- when distractors were absent. by the surface is irrelevant to this sta- neously. Ophir et al. investigated the Ophir et al.’s results are provocative tistic: You can scramble the pixels in consequences of this “media multi- in suggesting that directing limited the image without altering the skew tasking” on the control of basic cog- processes to multiple sources does not of the histogram, so if skew really nitive processes. Media multitasking improve such multitasking behavior does control our visual judgments of has two potential effects: On the one as task switching. Although the find- surface albedo, this is a serious short- hand, directing attention and other ings are correlational, one straight- cut indeed. Anderson and Kim have limited cognitive resources from forward and testable explanation of mounted a concerted assault on this one environmental source to another them is that various technologies claim. In essence, they argue that Mo- might reduce the typical limitations may emphasize the bottom-up con- toyoshi et al.’s results are an artifact of human cognition through mere trol of attention and cognition. Heavy of the restricted set of surfaces they practice, allowing cognition to be media multitaskers may relinquish used. When you fix the mean of an more flexible and reducing the costs top-down control, thereby becoming image of a materially homogeneous of performing several tasks simulta- more susceptible to the effects of dis- surface and massage the histogram neously. On the other, media multi- tractors and becoming hindered when to alter its skew, the only possible ef- tasking might make cognitive control top-down control must be exercised, fects, Anderson and Kim argue, are more difficult. as in task switching. —S.P.V. the following: Making the skew posi- To investigate these issues, Ophir
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