Temporal dynamics of reflexive attention shifts: a dual-stream rapid serial visual presentation exploration.

We combined a prototypical exogenous cuing procedure with rapid serial visual presentation (RSVP) to provide a precise characterization of the temporal dynamics of reflexive attention shifts. The novel paradigm thus created has several useful properties, most notably that the physical presentation of the target is neither an onset nor a unique event and that temporal precision is provided without the requirement for a speeded response. A biphasic pattern was observed, with early benefits followed by later costs (inhibition of return) at the cued location relative to the uncued location. The finding of inhibition of return in this paradigm disproves the assertion that inhibition of return is merely a reluctance to respond in the target's direction. It may be partly that, but encoding mechanisms linked to attention must also be involved.