Mismatch field latency, but not power, may mark a shared autistic and schizotypal trait phenotype

Increased glutamate/GABA+ ratio in a shared autistic and schizotypal trait phenotype termed Social Disorganisation

“…Following rotation, two factors yielded eigenvalues > 1; these factors were consistent with Ford and Crewther's Social Disorganisation and Perceptual Oddities factors ( Ford and Crewther, 2014 ), respectively, and with the two principal components reported by Dinsdale et al (2013) . The full factor structure is presented in the Supplementary Information (SI) of Ford et al (2017a) . Normalised regression z -scores for each participant on Social Disorganisation and Perceptual Oddities were calculated, with a mean value of zero.…”

“…Furthermore, psychosocial dysfunction – the central feature of the Social Disorganisation phenotype – has been associated with an increased excitation/inhibition ratio ( Yizhar et al, 2011 ). Finally, auditory processing deficits are reported across the autism and schizophrenia spectra ( Kompus et al, 2015 , Gandal et al, 2012 , Rossignol, 2011 , Ford et al, 2017a , Ford et al, 2017b ), and these deficits have been related to glutamate and GABA concentrations ( Kompus et al, 2015 ), and social and interpersonal impairment ( Fulham et al, 2014 , Rasser et al, 2011 ).…”

Spatio-temporal source cluster analysis reveals fronto-temporal auditory change processing differences within a shared autistic and schizotypal trait phenotype

“…Psychosocial functioning is a core deficit of both autism spectrum disorders and Social Disorganisation, thus the relationship with the MMN/F may translate. In fact, recent evidence from our lab suggests a delay in MMF peak latency for those with more of the Social Disorganisation phenotype ( Ford et al, 2017 ). This study utilises the cortical source analysis capacity of MEG to investigate source processing differences across the Social Disorganisation spectrum phenotype in the non-clinical population.…”

“…MMF data were acquired within a larger experimental battery; only the MMF-related methodology is reported below. Participant recruitment and data collection methods have been detailed elsewhere ( Ford et al, 2017 ).…”

“…Principal axis factor analysis of the AQ and SPQ subscales with a promax (oblimin) rotation revealed the Social Disorganisation factor as reported in Ford and Crewther (2014) . The Social Disorganisation factor comprised the AQ subscales Social Skills, Communication and Attention Switching, and SPQ subscales No Close Friends, Constricted Affect, Social Anxiety and Odd Behaviour (see Ford et al, 2017 , for full factor structure), as well as weaker contributions from Suspiciousness, Ideas of Reference and Imagination. For each participant, the standardised regression score (z-score) for Social Disorganisation was calculated, with those in the top (high group) and bottom (low group) quintile of z-scores recruited to participate in the MEG study.…”