Psychophysical estimates of frequency discrimination: more than just limitations of auditory processing.

Johanna Barry,Benjamin Weiss,Beate Sabisch

doi:10.3390/brainsci3031023

Abstract

Efficient auditory processing is hypothesized to support language and literacy development. However, behavioral tasks used to assess this hypothesis need to be robust to non-auditory specific individual differences. This study compared frequency discrimination abilities in a heterogeneous sample of adults using two different psychoacoustic task designs, referred to here as: 2I_6A_X and 3I_2AFC designs. The role of individual differences in nonverbal IQ (NVIQ), socioeconomic status (SES) and musical experience in predicting frequency discrimination thresholds on each task were assessed using multiple regression analyses. The 2I_6A_X task was more cognitively demanding and hence more susceptible to differences specifically in SES and musical training. Performance on this task did not, however, relate to nonword repetition ability (a measure of language learning capacity). The 3I_2AFC task, by contrast, was only susceptible to musical training. Moreover, thresholds measured using it predicted some variance in nonword repetition performance. This design thus seems suitable for use in studies addressing questions regarding the role of auditory processing in supporting language and literacy development.

Highlights

Many children and adults with impairments in language or literacy often perform poorly on tasks assessing auditory processing abilities [1,2,3,4]
In the case of behavioural measures of auditory processing where the minimum difference between two stimuli is estimated (i.e., JND: just noticeable difference), task performance reflects auditory abilities, and factors associated with the design of the task and its susceptibility to a broad range of other differences specific to the individuals doing it
We have focused entirely on issues to do with task design, it is possible that differences in the stimuli may have contributed to the variations in individual differences apparent between the two tasks

Summary

Introduction

Many children and adults with impairments in language or literacy often perform poorly on tasks assessing auditory processing abilities [1,2,3,4]. There is debate about whether auditory processing deficits are causal to delayed language or literacy development The relationship between these different abilities may reflect the presence of a third underlying factor which is important for both [7]. In the case of behavioural measures of auditory processing where the minimum difference between two stimuli is estimated (i.e., JND: just noticeable difference), task performance reflects auditory abilities, and factors associated with the design of the task and its susceptibility to a broad range of other differences specific to the individuals doing it. Understanding how these individual differences interact with task design to predict thresholds measured is important for interpreting findings from studies addressing questions of clinical or developmental interest

Results

Discussion

Conclusion