Abstract
Selective attention can be directed to locations, objects, or features. A large and growing literature – drawing on results from psychophysics and electrophysiology – suggests that the benefits of attention wax and wane over short time scales (e.g., several cycles per second). However, it is unclear whether different modes of attentional selection share similar temporal profiles. The work presented here was designed to address this question. In Experiment 1, participants performed a data-limited variant of the classic Egly, Driver, and Rafal (1994) object-based attention paradigm. Briefly, participants were shown two horizontally or vertically arranged rectangles and cued to the likely position of a peri-threshold target at one end of one rectangle. During invalid trials, the target could appear at the wrong end of the cued rectangle (same-object condition) or at the same end of the non-cued rectangle (different-object condition). To measure the temporal dynamics of object-based attention benefits, we systematically varied the stimulus onset asynchrony (SOA) between the cue and target, then plotted participants’ target detection performance as a function of SOA. Experiment 2 was identical to Experiment 1, with the exception that the two rectangles were replaced with four squares to mimic classic spatial attention paradigms (e.g., Posner, 1980) while eliminating object-based attention effects. In both experiments, we found that the benefits of selective attention varied over short time scales in the theta band (3-5 Hz). These results imply that different modes of selective attention rely on a common rhythmic mechanism.