Symposium: Deviance detection along the auditory pathway
Friday, Sep 11, 2015
Stimulus-specific adaptation: can it be a neural correlate of habituation?
Neurobiology, The Technion, Haifa, Israel
The optic tectum (OT) is a multisensory midbrain structure (also called the superior colliculus in mammals) which is believed to be linked with the control of spatial attention to salient stimuli. It is therefore of interest to characterize stimulus-specific adaptation (SSA) in the OT. In this presentation I will present our recent studies on SSA in the barn owl's OT. Most Neurons in the OT of barn owls are robustly sensitive to auditory stimuli simplifying the study of auditory SSA in this species. Using Oddball and constant-order paradigms we exposed robust SSA in the OT. However, SSA in the OT differed in several aspects from SSA types that were reported in the inferior colliculus, thalamus and A1. First, SSA was recorded to multiple auditory features. In addition to SSA to frequency we identified in the same neurons SSA to binaural cues, to amplitude modulations and to the intensity of the sound. Second, significant SSA was still recorded even if the inter-stimulus-intervals were increases up to 60 sec. This relatively long memory trace is correlated with the time scale of behavioral habituation. We suggest that the SSA in the OT represents a higher level of deviance processing compare to most other SSA types. These results point to the superior colliculus as a possible new target for focusing research on SSA and deviance detection in mammals.