Direct Viewing of Dyslexics' Compensatory Strategies in Speech in Noise Using Auditory Classification Images

PLoS One. 2016 Apr 21;11(4):e0153781. doi: 10.1371/journal.pone.0153781. eCollection 2016.

Abstract

A vast majority of dyslexic children exhibit a phonological deficit, particularly noticeable in phonemic identification or discrimination tasks. The gap in performance between dyslexic and normotypical listeners appears to decrease into adulthood, suggesting that some individuals with dyslexia develop compensatory strategies. Some dyslexic adults however remain impaired in more challenging listening situations such as in the presence of background noise. This paper addresses the question of the compensatory strategies employed, using the recently developed Auditory Classification Image (ACI) methodology. The results of 18 dyslexics taking part in a phoneme categorization task in noise were compared with those of 18 normotypical age-matched controls. By fitting a penalized Generalized Linear Model on the data of each participant, we obtained his/her ACI, a map of the time-frequency regions he/she relied on to perform the task. Even though dyslexics performed significantly less well than controls, we were unable to detect a robust difference between the mean ACIs of the two groups. This is partly due to the considerable heterogeneity in listening strategies among a subgroup of 7 low-performing dyslexics, as confirmed by a complementary analysis. When excluding these participants to restrict our comparison to the 11 dyslexics performing as well as their average-reading peers, we found a significant difference in the F3 onset of the first syllable, and a tendency of difference on the F4 onset, suggesting that these listeners can compensate for their deficit by relying upon additional allophonic cues.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Case-Control Studies
  • Cognition / physiology
  • Dyslexia / physiopathology*
  • Evoked Potentials, Auditory / physiology*
  • Female
  • Hearing / physiology*
  • Humans
  • Male
  • Noise*
  • Phonetics*
  • Reading
  • Speech Perception / physiology*
  • Young Adult

Grants and funding

LV is funded by a PhD grant from the Ecole Doctorale Neurosciences et Cognition (http://nsco.universite-lyon.fr/), Lyon-1 University, France. This research was partially supported by a European Research Council (http://erc.europa.eu/) grant for the SpiN project (No. 209234) attributed to FM and by a public grant overseen by the French National Research Agency (ANR) as part of the “Investissements d’Avenir” program (reference: ANR-10-LABX-0083).