The effects of attention on ear advantages in dichotic listening to words and affects

Auditory semantic priming and the dichotic right ear advantage

The current study presents two experiments that aimed to explore the effects of auditory semantic priming on the dichotic right ear advantage. In Experiment 1, a classic fused dichotic words task was modified with the addition of auditory associative primes with three levels of relatedness (right, left, or neither ear). In Experiment 2, a new dichotic listening task was developed based on a binaural task used in a published auditory priming study. In both experiments, we expected that priming would produce a large right ear advantage when related to the right ear target but that the magnitude of this advantage would decrease for left ear related targets. Although evidence of priming (faster responses for related than unrelated primes) was found in both experiments, only Experiment 2 confirmed our prediction of an ear by prime relatedness interaction. Results are interpreted in the context of models concerned with the role of each cerebral hemisphere in semantic processing as well as models of perceptual asymmetries.

Relationships between trait impulsivity and cognitive control: the effect of attention switching on response inhibition and conflict resolution

This study examined the relationship between trait impulsivity and cognitive control, as measured by the Barratt Impulsiveness Scale (BIS) and a focused attention dichotic listening to words task, respectively. In the task, attention was manipulated in two attention conditions differing in their cognitive control demands: one in which attention was directed to one ear at a time for a whole block of trials (blocked condition) and another in which attention was switched pseudo-randomly between the two ears from trial to trial (mixed condition). Results showed that high impulsivity participants exhibited more false alarm and intrusion errors as well as a lesser ability to distinguish between stimuli in the mixed condition, as compared to low impulsivity participants. In the blocked condition, the performance levels of the two groups were comparable with respect to these measures. In addition, total BIS scores were correlated with intrusions and laterality index in the mixed but not the blocked condition. The findings suggest that high impulsivity individuals may be less prone to attentional difficulties when cognitive load is relatively low. In contrast, when attention switching is involved, high impulsivity is associated with greater difficulty in inhibiting responses and resolving cognitive conflict than is low impulsivity, as reflected in error-prone information processing. The conclusion is that trait impulsivity in a non-clinical population is manifested more strongly when attention switching is required than during maintained attention. This may have important implications for the conceptualization and treatment of impulsivity in both non-clinical and clinical populations.