Emotional Stroop Dilution: The boundary conditions of attentional capture by threat words.

It is widely believed that threatening stimuli in our environment capture attention. Much of the core evidence for attentional capture by threatening stimuli comes from the Emotional Stroop task. Yet recent evidence suggests that the Emotional Stroop task does not measure attentional capture (e.g., Algom et al., 2004). The present paper assesses whether threat words can capture attention using a modified Stroop Dilution procedure (e.g., Kahneman & Chajczyk, 1983), where attentional capture by a threat word is inferred from a reduction in color-word interference for threat words compared to non-threat words (emotional Stroop Dilution). The outcome of the present experiments indicates that threat words can capture attention, but only when task demands do not require that a word be attended. It is suggested that threat words produce (1) cognitive slowing, and influence two processes of selective attention (2) attentional capture and (3) the ability to filter irrelevant dimensions of an attended stimulus.

Global and local processing near the left and right hands.

Visual targets can be processed more quickly and reliably when a hand is placed near the target. Both unimodal and bimodal representations of hands are largely lateralized to the contralateral hemisphere, and since each hemisphere demonstrates specialized cognitive processing, it is possible that targets appearing near the left hand may be processed differently than targets appearing near the right hand. The purpose of this study was to determine whether visual processing near the left and right hands interacts with hemispheric specialization. We presented hierarchical-letter stimuli (e.g., small characters used as local elements to compose large characters at the global level) near the left or right hands separately and instructed participants to discriminate the presence of target letters (X and O) from non-target letters (T and U) at either the global or local levels as quickly as possible. Targets appeared at either the global or local level of the display, at both levels, or were absent from the display; participants made foot-press responses. When discriminating target presence at the global level, participants responded more quickly to stimuli presented near the left hand than near either the right hand or in the no-hand condition. Hand presence did not influence target discrimination at the local level. Our interpretation is that left-hand presence may help participants discriminate global information, a right hemisphere (RH) process, and that the left hand may influence visual processing in a way that is distinct from the right hand.