PP1304 - Trading Relationships Among Frequency Discrimination Ability and Task Demands

Rationale: Auditory temporal processing and patterning (ATPP) is a fundamental auditory process, where sounds a listener hears are encoded, maintained, and recalled. There is limited information about how individual factors (e.g., memory capacity, domain-specific knowledge) impact ATPP capacity. Prior use of an adaptive ATPP task indicated that the Pspan is sensitive to those with a musical background (Weaver et al., 2019). The contributions of other individual differences and the refinement of the task for clinical use, however, have not been reported.  

Objective: The aim of this study was to investigate the effects of working memory demands on an individual’s frequency difference limen (DL). To do so the Pspan was modified to collect an individual’s DL relative to an ATPP task. Based on prior work (Weaver, 2015), the authors hypothesized that pitch discrimination resolution will be negatively impacted as the task demands exceed the Pspan capacity of the listener. A participant’s DL is expected to be smaller when around or below their individual Pspan score.  

Design: Participants completed a measure of non-verbal intelligence (TONI), pitch discrimination (DL at 1000k Hz), short-term memory capacity (STMC; forward digit span), working memory capacity (reverse digit span), as well as measures of musical background (intake form) and sophistication (Gold-MSI) prior to completing several runs in a spectral-temporal sequencing task (i.e., PspanDL). The PspanDL was programmed in MATLAB, using Tucker-Davis-Technologies psychoacoustic workstation.  

Data collection/Analysis: Each PspanDL took approximately 5-minutes and altogether behavioral testing took about 1 hour to complete. 100 young adults (30 musicians and 70 non-musicians), ages 19-32 years old, were included in formal data analysis if they met the inclusion criterion of hearing within normal limits, no diagnosed or suspected attention disorders, and completion of all experimental measures. Results were analyzed in SPSS statistical software.  The PspanDL was collected for three pattern lengths (relative to Pspan) and evaluated using a general linear mixed model (GLMM) with repeated measures to determine the effects of the music group and pattern length. 

Results:   The GLMM showed a significant main effect for pattern length F(2,282) = 133.34; p < 0.001, but no significant effect for music group F(1,86) = 1.42; p = 0.236. The interaction between the music group and pattern length was significant when using a Helmert contrast F(3,282) = 9.92; p < 0.001*(*Geisser Greenhouse correction). Results indicated that a participant’s DL proved to have smaller values for pattern lengths below their span limit and increasingly larger values for pattern lengths exceeding their span limit, with musicians producing smaller DLs than non-musicians at and below capacity.   

Conclusions: These findings provide further evidence that the Pspan and PspanDL are reliable measures for ATPP and pitch discrimination abilities in adults. Those with higher musical sophistication had a discrimination advantage at or below their capacity, which disappeared with higher capacity demands. Outcomes suggest the potential utility of an adaptive spectral-temporal task for both auditory processing assessment and outcome measurements for auditory training protocols aimed at enhancing spectral-temporal processing.