A recent study by Fuminori Ono and Katsumi Watanabe has shown that these attentional effects are even more complicated than this theory suggests. Their experimental design perfectly mirrored that of Suzuki & Cavanagh, except that sometimes the attention-tracking cue could occur after the presentation of the vertical lines. Surprisingly, this post-attentional cue still distorted the perceived location of the upper line, causing it to be perceptually shifted toward the region where attention had been cued— an attentional attraction effect. In other words, attention can distort the perceived location of objects even after they are no longer physically present.
In fact, it turns out that attention seems to dramatically reorganize the spatial relationships between objects throughout our visual field. One of us (Brandon Liverence) conducted a study together with Brian Scholl at Yale University in which participants had to pay attention to two particular circles (the targets) on a computer screen, while also selectively ignoring two other identical-looking circles (the distractors). During what is called a multiple-object tracking (MOT) task, participants had to keep track of the targets as they moved haphazardly among the distractors, and then re-identify them many seconds later.
At the end of the trial, the objects all disappeared and participants used the mouse to indicate the objects’ last perceived locations. Their responses revealed two striking effects: they misperceived the targets as being closer together than they really were, and the distractors as further apart than they really were. That is, attention simultaneously compresses perceived space between targets (as if they are attracting each other) and expands perceived space between distractors (as if they are repelling each other). Given that everything in the visual world ultimately consists of objects and space, these findings have far-reaching implications for how we perceive just about anything we can see. Since we are almost constantly paying attention to space and objects, this means that space and objects are almost constantly being distorted perceptually.
Another (perhaps disturbing) implication of this research is that we can’t completely trust our eyes to give us a true reflection of the world. This realization creates quite a philosophical conundrum, if not a practical one. It’s a bit like finding out that all along you’ve been seeing the world through a pair of “distorting glasses.”
These studies suggest a fundamental revision to our naïve concept of attention: even though we experience attention as a spotlight that enables perception, it may be more accurately described as a distorting zoom lens — both sharpening and warping our perception of the visual world.
Are you a scientist who specializes in neuroscience, cognitive science, or psychology? And have you read a recent peer-reviewed paper that you would like to write about? Please send suggestions to Mind Matters editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe. He can be reached at garethideas AT gmail.com or Twitter @garethideas.