Psychophysiological Correlates of Developmental Changes in Healthy and Autistic Boys

Abstract

This study investigated neurodevelopmental changes in sound processing by recording mismatch negativity (MMN) in response to various degrees of sound complexity in 18 mildly to moderately autistic versus 15 healthy boys aged between 6 and 15 years. Autistic boys presented with lower IQ and poor performance on a range of executive and social function measures when compared to their healthy counterparts. We found that MMN in response to duration deviants was less lateralized in the clinical group whereas larger amplitudes correlated with advanced age, thus capturing neurodevelopmental changes. Larger MMN in response to speech-like sound deviants was associated with better verbal fluency and executive function performance, respectively, but did not reliably discriminate the two groups.

Sensory processing in autism spectrum disorders and Fragile X syndrome—From the clinic to animal models

“…There is some evidence indicating that MMN to complex speech-like deviants or vowel/word change is reduced in children with ASD compared to typically developing children (Kuhl et al, 2005; Kujala et al, 2010; Ludlow et al, 2014). However, other studies have not reported such diagnostic differences (Ceponiene et al, 2003; Kasai et al, 2005; Oram Cardy et al, 2005; Weismuller et al, 2015), or have reported enhanced MMN amplitude to frequency deviants or affective prosody in ASD or Asperger’s syndrome compared to typically developing children (Korpilahti et al, 2007; Lepisto et al, 2005, 2006). In the studies of Lepisto and colleagues, increased MMN in ASD and Asperger’s syndrome was not found at the usual frontal electrodes (Fz) but rather only at parietal electrodes, possibly reflecting the MMN in primary auditory cortex and reinforcing that differences in the locations of recording electrodes may impact the ability to detect MMN abnormalities in ASD.…”

“…Reports on MMN in ASD are highly inconsistent. Some studies report larger MMN amplitude in children with ASD (Ferri et al, 2003; Kujala, 2007; Lepisto et al, 2005, 2006), whereas others report smaller (Abdeltawwab and Baz, 2015; Ludlow et al, 2014) or equal amplitudes compared to typically developing children (Dunn et al, 2008; Jansson-Verkasalo et al, 2003; Roberts et al, 2011; Seri et al, 1999; Weismuller et al, 2015). Given the scope of this review, only MMN amplitude data are considered here.…”

“…In pure tone MMN paradigms, children with ASD have been reported to show either less (Abdeltawwab and Baz, 2015; Dunn et al, 2008), more (Ferri et al, 2003) or normal MMN to frequency deviants (Jansson-Verkasalo et al, 2003; Weismuller et al, 2015). Attention may impact consistency of findings with pure tone frequency deviants, given that one study reported reduced MMN amplitude to changes in frequency of pure tones in children with ASD in unattended conditions, but equal amplitudes in attended conditions (Dunn et al, 2008).…”

“…Electrode placement may also play a role, given that in some work, MMN amplitude deficits to pure tone frequency deviants could only be detected in children with ASD when the topography of the electrodes was taken into account, since maximal MMN amplitude was observed at the frontal Fz electrode in controls and more posterior C3/4 electrodes in individuals with ASD (Gomot et al, 2002). While some studies only record at Fz (Abdeltawwab and Baz, 2015; Seri et al, 1999), others use the International 10–20 System to record at multiple sites (Weismuller et al, 2015). Inconsistent results found with pure tone paradigms may also have been caused by differences in composition of ASD cohorts.…”

“…Firstly, studies employing a range of paradigms have reported that normal lateralization of MMN is diminished or absent in ASD subjects compared to healthy controls (Jansson-Verkasalo et al, 2003; Korpilahti et al, 2007; Kuhl et al, 2005; Lepisto et al, 2006; Weismuller et al, 2015). Unfortunately, due to the placement of electrodes, many studies are not designed to compare MMN in both hemispheres.…”