Summary statistic encoding plus limits on decision complexity underlie the richness of visual perception as well as its quirky failures

摘要

Visual perception is full of puzzles. Human observers effortlessly perform many visual tasks, and have the sense of a rich percept of the visual world. Yet when probed for details they are at a loss. How does one explain this combination of marvelous successes and puzzling failures? Numerous researchers have explained the failures in terms of severe limits on resources of attention and memory. But if so, how can one explain the successes? My lab has argued that many experimental results pointing to apparent attentional limits instead derived at least in part from losses in peripheral vision. Furthermore, we demonstrated that those losses could arise from peripheral vision encoding its inputs in terms of a rich set of local image statistics. This scheme is theoretically distinct from encoding ensemble statistics of a set of similar items. I propose that many of the remaining attention/memory limits can be unified in terms of a limit on decision complexity. This decision complexity is difficult to reason about, because the complexity of a given task depends upon the underlying encoding. A complex, general-purpose encoding likely evolved to make certain tasks easy at the expense of others. Recent advances in understanding this encoding -- including in peripheral vision -- may help us finally make sense of the puzzling strengths and limitations of visual perception.