TitleEffect of recent auditory environment on neural response in zebra finch auditory cortex
NameYang, Lillian (author), Vicario, David (chair), McGann, John (internal member), Stromswold, Karin (internal member), Rutgers University, Graduate School - New Brunswick,
Auditory perception--Testing ,
DescriptionSongbirds provide a model for studying human vocal learning due to many similarities between the two systems, e.g. a critical period for vocal learning, hemispheric lateralization, and sensory-motor integration for vocal imitation. One area of study relevant to human communication is short term plasticity in auditory cortex as a function of recent auditory experience. Changes in auditory processing in adulthood have been observed in the caudo-medial nidopallium (NCM), a higher auditory area that is known to respond selectively to conspecific vocalizations. To test how recent auditory experience with sounds of another species affects selectivity, adult male zebra finches were housed for 9d in different auditory environments. Two groups of birds were isolated as individuals and received playback of either recorded zebra finch (CONENV; n=9) or canary (HETENV; n=11) aviary. A third group remained in the general zebra finch aviary (Aviary; n=8). On day 9, electrodes placed bilaterally in NCM of these awake restrained birds recorded extracellular multi-unit activity in response to presentation of novel conspecific(ZFStim) and heterospecific (CANStim) songs,and pure tones. We assessed differences in absolute response magnitude, stimulus-specific adaptation, and tuning between exposure groups, stimulus types, hemispheres, and at different depths in NCM. Both CONENV and HETENV had higher responses overall compared to Aviary. Absolute responses were stronger to ZFStim than to CANStim across all exposure conditions. Preferential responding to conspecific song was greater in the right hemisphere than the left and greater in dorsal than ventral regions of NCM overall. CONENV birds showed higher absolute responses and higher rates of stimulus-specific adaptation in the right hemisphere for both ZFStim and CANStim. HETENV birds had higher absolute responses in the left hemisphere and showed no hemispheric difference in adaptation rates. Exposure to a completely novel auditory environment alters auditory processing of natural stimuli in a lateralized, but not stimulus-specific, manner. The reversal in lateralized processing suggests that the two hemispheres exhibit plasticity in different ways when confronted with the challenge of a new acoustic feature space and are likely to play different roles in the maintenance or revision of perceptual filters and stimulus categories.
NoteIncludes bibliographical references
Noteby Lillian Yang
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.