Limitations on flexible allocation of visual short-term memory resources with multiple levels of attentional prioritization.

Abstract

Although recent evidence suggests that visual short-term memory (VSTM) is a continuous resource, little is known about how flexibly this resource can be allocated. Previous studies using probabilistic cues to indicate two different levels of probe probability have found that response precision can be predicted according to a continuous allocation of resources that depends on attentional priority. The current study used a continuous report procedure and attentional prioritization via simultaneous probabilistic spatial cues to address whether participants can use up to three levels of attentional priority to allocate VSTM resources. Three experiments were performed with differing priority levels, different cues, and cue presentation time. Although group level analysis demonstrated flexible allocation, there was limited evidence that participants were using three priority levels. An individual differences approach revealed that a minority of participants were using three levels of attentional priority, demonstrating that, while possible, it is not the predominant pattern of behavior.