Effects of auditory and visual interference on auditory-visual delayed matching to sample in monkeys (Macaca fascicularis)

Two monkeys were trained on an auditory-visual (AV) delayed matching-to- sample (DMS) task with auditory cues serving as sample stimuli and visual cues serving as comparison stimuli. To determine whether the monkeys were remembering auditory or visual information during the delay period, auditory and visual interference were presented following the sample stimulus. Auditory interference had little effect on AV DMS performance. In contrast, visual interference severely impaired AV DMS performance, indicating that the monkeys were remembering visual information during the delay period. This finding may reflect a predisposition of monkeys toward remembering information via their dominant visual modality.