Behavioral and event-related potentials (ERPs) study of Cantonese tone merging : the role of cognitive abilities in speech processing

Abstract

Although the speech processing mechanism is so complex that it is still being actively researched, increasing evidence has suggested that cognitive abilities play a role in this complex process. The present study took advantage offered by tone merging phenomenon to study the role of cognitive abilities in speech processing among native Cantonese speakers in Hong Kong. Three groups of participants were recruited, including participants of good perception of all tones but with (i) good production of all tone pairs (control), (ii) poor production of T2/T5 pairs (both groups from Ou et al. (2015), and (iii) poor production of T3/T6 pairs (from current study). Tone production and perception (both behavioral and ERP experiment) tasks and a battery of published cognitive tests were conducted to examine the participants’ speech processing and cognitive abilities. Results indicated that tone discrimination efficiency and production accuracy were correlated to one’s visual and auditory attentional switching. Our findings have complemented the studies of Law et al. (2013) and Ou et al. (2015). We have demonstrated that impact of attention can be extended to other types of mergers, which are T3/T6 in this case, and reinforced the role of amplitude rise time in discriminating the Cantonese rising tones.