Validating the Directional Command Flanker Task: An Auditory Analog of the Arrows Flanker.

Executive function, notably the capacity to resolve conflict, is commonly studied using the arrows flanker task, which is a particularly intuitive variation of the classic Eriksen flanker task. To date, no study has translated this task to the auditory modality. A possible reason for this omission is the risk of perceptual masking. The present study used the strategy of introducing spectral differences between voices to induce a release from such masking with co-located voices (two talkers heard in the center of the head via diotic, headphone-based presentation). In a series of three studies with 142 healthy young participants (ages 18-24), we explored the potential for masking in this task with three different vocal configurations. Masking was measured via neutral, masking flankers that consisted of competing speech that had no task relevance. The task-relevant directional commands were the words ‘left’ and ‘right.’ Each trial consisted of a warning cue, then concurrent speech from the target and flanker talkers. Participants were instructed to ignore the flanker and indicate the direction spoken by the target talker. This task yielded classic conflict effects in the form of response slowing during incongruent trials. This slowing was not matched by the interference imposed by the masking flankers, indicating that RTs under the incongruent condition did indeed reflect conflict resolution. This conflict, as well as masking, were both influenced by spectral separation. Same-day test-retest reliability for this task and a visual arrows flanker task were measured in a fourth experiment that included 62 health adult participants (ages 18-59). The two tasks showed similar test-retest reliability and distributional properties, suggesting that the Directional Command Flanker Task measures inhibitory control similarly to the arrows flanker task.