Comparison of neural responses to cat meows and human vowels in the anterior and posterior auditory field of awake cats

PLoS One. 2013;8(1):e52942. doi: 10.1371/journal.pone.0052942. Epub 2013 Jan 2.

Abstract

For humans and animals, the ability to discriminate speech and conspecific vocalizations is an important physiological assignment of the auditory system. To reveal the underlying neural mechanism, many electrophysiological studies have investigated the neural responses of the auditory cortex to conspecific vocalizations in monkeys. The data suggest that vocalizations may be hierarchically processed along an anterior/ventral stream from the primary auditory cortex (A1) to the ventral prefrontal cortex. To date, the organization of vocalization processing has not been well investigated in the auditory cortex of other mammals. In this study, we examined the spike activities of single neurons in two early auditory cortical regions with different anteroposterior locations: anterior auditory field (AAF) and posterior auditory field (PAF) in awake cats, as the animals were passively listening to forward and backward conspecific calls (meows) and human vowels. We found that the neural response patterns in PAF were more complex and had longer latency than those in AAF. The selectivity for different vocalizations based on the mean firing rate was low in both AAF and PAF, and not significantly different between them; however, more vocalization information was transmitted when the temporal response profiles were considered, and the maximum transmitted information by PAF neurons was higher than that by AAF neurons. Discrimination accuracy based on the activities of an ensemble of PAF neurons was also better than that of AAF neurons. Our results suggest that AAF and PAF are similar with regard to which vocalizations they represent but differ in the way they represent these vocalizations, and there may be a complex processing stream between them.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Acoustics
  • Animals
  • Auditory Cortex / physiology
  • Auditory Pathways / physiology
  • Auditory Perception / physiology*
  • Cats
  • Discrimination, Psychological
  • Electrophysiology
  • Humans
  • Language*
  • Models, Neurological
  • Models, Statistical
  • Neurons / metabolism*
  • Reproducibility of Results
  • Sound Localization / physiology
  • Vocalization, Animal*

Grants and funding

This study was supported by the Strategic Research Program for Brain Sciences 08038015 and No. 23700377 from the Japan Ministry of Education, Culture, Sports, Science and Technology (YS and LQ), and the National Nature Science Foundation of China under Grant No. 30970979 and 31171057 (LQ). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.