The Magical Number One-on-Square-Root-Two: The Double-Target Detection Deficit in Brief Visual Displays

Abstract

How limited representational capacity is divided when multiple items need to be processed simultaneously is a fundamental question in cognitive psychology. The double-target deficit is the finding that, when monitoring multiple locations or information streams for targets, identification of 2 simultaneous targets is substantially worse than is predicted from the cost of divided attention alone. This finding suggests that targets and nontargets are treated differently by the cognitive system. We investigated the double-target deficit in 4 different visual decision tasks using noisy, backwardly masked targets presented for a range of exposure durations to test the theory that the deficit refle..