Early differences in auditory processing relate to Autism Spectrum Disorder traits in infants with Neurofibromatosis Type I

Abstract

Background: Sensory modulation difficulties are common in children with conditions such as Autism Spectrum Disorder (ASD) and could contribute to other social and non-social symptoms. Positing a causal role for sensory processing differences requires observing atypical sensory reactivity prior to the emergence of other symptoms, which can be achieved through prospective studies.

Methods: In this longitudinal study, we examined auditory repetition suppression and change detection at 5 and 10 months in infants with and without Neurofibromatosis Type 1 (NF1), a condition associated with higher likelihood of developing ASD.

Results: In typically developing infants, suppression to vowel repetition and enhanced responses to vowel/pitch change decreased with age over posterior regions, becoming more frontally specific; age-related change was diminished in the NF1 group. Whilst both groups detected changes in vowel and pitch, the NF1 group were largely slower to show a differentiated neural response. Auditory responses did not relate to later language, but were related to later ASD traits.

Conclusions: These findings represent the first demonstration of atypical brain responses to sounds in infants with NF1 and suggest they may relate to the likelihood of later ASD.

Keywords: Auditory processing; Autism spectrum disorder; Change detection; EEG; Habituation; Neurofibromatosis type 1.

Fig. 1

Auditory Task Methodology. (a) Participant numbers at each cohort, time point and task with attrition rates and reasons. Data was analysed using all infants with sufficient data at each time point; for information, the total number of infants who provided artefact-free EEG at both time points was NF1 n = 8; and TD n = 25. (b) ‘Train of vowels’ task design. Three (500 ms) auditory Standards were presented before a Deviant stimulus (500ms) followed by an ITI of ~ 2–3 s. (c) Electrodes chosen for analyses, with different colours depicting frontal left (dark green), frontal central (blue), frontal right (red), posterior left (purple), posterior central (maroon) and posterior right areas (turquoise)

Fig. 2

ERP waveforms for Standard 1; shading indicates the standard deviation. Topographic plots depict the absolute amplitude across the scalp in μV

Fig. 3

ERP difference waveforms for Standard 1-Standard 2; shading indicates the standard deviation. Topographic plots depict the difference in absolute amplitude between conditions across the scalp in μV. Solid horizontal bars indicate periods where the two conditions significantly differed from each other

Fig. 4

ERP difference waveforms for Standard 2-Deviant Pitch; shading indicates the standard deviation. Topographic plots depict the difference in absolute amplitude between conditions across the scalp in μV. Solid horizontal bars indicate periods where the two conditions significantly differed from each other

Fig. 5

ERP difference waveforms for Standard 2-Deviant Vowel; shading indicates the standard deviation. Topographic plots depict the difference in absolute amplitude between conditions across the scalp in μV. Solid horizontal bars indicate periods where the two conditions significantly differed from each other

Fig. 6

ERP difference waveforms for Deviant Pitch-Deviant Vowel; shading indicates the standard deviation. Topographic plots depict the difference in absolute amplitude between conditions across the scalp in μV. Solid horizontal bars indicate periods where the two conditions significantly differed from each other

Fig. 7

Scatter plots of Initial/Change response to Standard sounds at 10 months against IBQ-R Activity Level at 14 months in TL and NF1 cohorts (Panel a) and AOSI Total Scores in NF1 infants (Panel a)