Involuntary orienting and conflict resolution during auditory attention: The role of ventral and dorsal streams

Selective attention to sound object features such as pitch and location is associated with enhanced brain activity in ventral and dorsal streams, respectively. We examined the role of these pathways in involuntary orienting and conflict resolution using functional magnetic resonance imaging (fMRI). Participants were presented with two tones that may share, or not, the same non-spatial (frequency) or spatial (location) auditory features. In separate blocks of trials, participants were asked to attend to sound frequency or sound location and ignore the change in the task-irrelevant feature. In both attend-frequency and attend-location tasks, response times were slower when the task-irrelevant feature changed than when it stayed the same (involuntary orienting). This behavioural cost coincided with enhanced activity in the prefrontal cortex and superior temporal gyrus (STG). Conflict resolution was examined by comparing situations where the change in stimulus features was congruent (both features changed) and incongruent (only one feature changed). Participants were slower and less accurate for incongruent than congruent sound features. This congruency effect was associated with enhanced activity in the prefrontal cortex, and was greater in the right STG and medial frontal cortex during the attend-location than during the attend-frequency task. Together, these findings do not support a strict division of labour into ventral and dorsal streams, but rather suggest interactions between these pathways in situations involving changes in task-irrelevant sound feature and conflict resolution. These findings also validate the Test of Attention in Listening task by revealing distinct neural correlates for involuntary orienting and conflict resolution.