Attention and Perceptual Decision Making

Selective attention has a direct influence on perceptual decision making. This chapter reviews how attention biases or facilitates judgments of sensory stimuli by examining decision-theoretic models, such as the signal detection model and sequential sampling models. These models assume that the processing order of multiple signals is invariant to attentional influence. By contrast, the relative saliency hypothesis suggests that attention affects how multiple signals are accumulated for perceptual decision making. To support this suggestion, studies using Systems Factorial Technology (SFT, Townsend & Nozawa, 1995) are reviewed to examine the impact of attentional manipulations (e.g., spatial cueing, contingency, attentional instruction, payoff) on perceptual decisions in a redundant-target detection task. Results highlight the flexibility of the perceptual decision mechanism, the role of top-down attentional control, and conscious awareness in selecting a decision strategy to optimize detection performance. Finally, the concept of processing capacity is discussed in relation to attentional capacity.