Electrophysiological evidence for an early processing of human voices
- Equal contributors
1 Centre for Cognitive NeuroImaging (CCNi) & Department of Psychology, University of Glasgow, Glasgow, UK
2 SFC Brain Imaging Research Centre, Division of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK
3 Cuban Neuroscience Centre, Department of Cognitive Neuroscience, Havana, Cuba
4 Département de Psychologie, Université de Montréal, Montréal, QC, Canada
5 International Laboratory for Brain, Music and Sound Research, Université de Montréal & McGill University, Montreal, Canada
BMC Neuroscience 2009, 10:127 doi:10.1186/1471-2202-10-127Published: 20 October 2009
Previous electrophysiological studies have identified a "voice specific response" (VSR) peaking around 320 ms after stimulus onset, a latency markedly longer than the 70 ms needed to discriminate living from non-living sound sources and the 150 ms to 200 ms needed for the processing of voice paralinguistic qualities. In the present study, we investigated whether an early electrophysiological difference between voice and non-voice stimuli could be observed.
ERPs were recorded from 32 healthy volunteers who listened to 200 ms long stimuli from three sound categories - voices, bird songs and environmental sounds - whilst performing a pure-tone detection task. ERP analyses revealed voice/non-voice amplitude differences emerging as early as 164 ms post stimulus onset and peaking around 200 ms on fronto-temporal (positivity) and occipital (negativity) electrodes.
Our electrophysiological results suggest a rapid brain discrimination of sounds of voice, termed the "fronto-temporal positivity to voices" (FTPV), at latencies comparable to the well-known face-preferential N170.