Slide Slam F9
Attentional Modulation of the Cortical Tracking of Acoustic Dimensions
Ashley Symons1, Fred Dick1,2, Adam Tierney1; 1Birkbeck, University of London, 2University College London
Many theoretical accounts of speech perception suggest that auditory dimensions that are strongly diagnostic for particular linguistic categories - for instance voice onset time or fundamental frequency in the case of some spoken consonants - attract attention. However, there has been relatively little research explicitly investigating whether this type of dimension-selective attention exists in the auditory domain. Here we investigate whether dimensional salience and dimension-selective attention modulate cortical tracking of acoustic dimension. In two experiments, participants listened to tone sequences varying in pitch and spectral peak frequency; these two dimensions changed at systematically different rates. Inter-trial phase coherence (ITPC) and EEG signal amplitude at the rates of pitch and spectral change allowed us to measure cortical tracking of these dimensions. In Experiment 1, tone sequences varied in the size of the pitch intervals, while the size of spectral peak intervals remained constant. Neural entrainment to pitch changes was greater for sequences with larger compared to smaller pitch intervals, with no difference in entrainment to the spectral dimension. In Experiment 2, participants selectively attended to either the pitch or spectral dimension. Neural entrainment was stronger in response to the attended compared to unattended dimension for both pitch and spectral dimensions. These findings demonstrate that bottom-up and top-down attentional mechanisms enhance the cortical tracking of different acoustic dimensions and provide the foundation for future research investigating the role of attention in speech perception.