A multilevel and cross-modal approach towards neuronal mechanisms of auditory streaming

Reaction times reflect subjective auditory perception of tone sequences in macaque monkeys

“…This was termed the AV2 sequence. Although for this type of AV coupling, RTs were not found to reflect the temporal organization for the small set of sequence parameters tested in the pilot study (Rahne et al, 2008), we nevertheless tested AV2 sequences with other sequence parameters to get insights into the interactions between the auditory and the visual stimuli that underlie RT changes. Conditions in which every flash was synchronized with a tone were not included into the study design because human subjects report feeling uncomfortable with the resulting high flash rates.…”

“…Our pilot study (Rahne et al, 2008) showed that RTs depended on the frequency separation, and reflected the perceptual organization of the tone sequence, only if the tone sequence terminated shortly before the flash sequence. Hence, we also used sequences with asynchronous terminations in which the tone sequence ended before the flash sequence.…”

“…Experiments were performed on two adult male macaque monkeys (Macaca fascicularis), both 6 years old at the beginning of the experiments. Monkey W participated in the pilot study (Rahne et al, 2008), whilst monkey E had previously participated in an auditory detection task. Throughout the experiments, the two monkeys were housed together in a cage in which they had free access to dry food including pellets, bread, corn flakes, and nuts.…”

“…To this end, we again used AV sequences in which a flash sequence was synchronized to a tone sequence and measured RTs, but we performed more comprehensive behavioral testing on monkeys than in the previous experiment (Rahne et al, 2008). This included the use of sequences with more rates and with more refined frequency separations as well as AV sequences in which either every second or third tone was synchronized with a flash.…”

“…Based on a pilot experiment on monkeys (see Rahne et al, 2008), some of the authors have recently proposed a new method for assessing the perceptual organization of tone sequences that utilizes response times (RT) to an audio-visual (AV) sequence (see Fig. 1).…”