Auditory processing abnormalities in schizotypal personality disorder: An fMRI experiment using tones of deviant pitch and duration

Abstract

Background-One of the cardinal features of schizotypal personality disorder (SPD) is language abnormalities. The focus of this study was to determine whether or not there are also processing abnormalities of pure tones differing in pitch and duration in SPD.Methods-Thirteen neuroleptic-naïve male subjects met full criteria for SPD and were groupmatched on age and parental socioeconomic status to 13 comparison subjects. Verbal learning was measured with the California Verbal Learning Test. Heschl's gyrus volumes were measured using structural MRI. Whole-brain fMRI activation patterns in an auditory task of listening to tones including pitch and duration deviants were compared between SPD and control subjects. In a Contributors Dickey: designed the study, collected the fMRI data, analyzed the clinical and fMRI data, and wrote the manuscript. Morocz: analyzed the fMRI data. Niznikiewicz: collected and analyzed the ERP data, and contributed to the manuscript. Voglmaier: collected and analyzed CVLT data, and performed SCID interview. Dreusicke: analyzed the fMRI data. Toner: aided in fMRI data collection. Yoo: aided in initial fMRI data collection. Khan: aided in final fMRI data presentation. Shenton: reviewed the manuscript. McCarley: reviewed the manuscript. Conflict of interestAll authors declare that they have no conflict of interest. Results-In the region of the STG, SPD subjects demonstrated more activation to pitch deviants bilaterally (p<0.001); and to duration deviants in the left hemisphere (p=0.005) (two-sample t). SPD subjects also showed more bilateral parietal cortex activation to duration deviants. In no region did comparison subjects activate more than SPD subjects in either experiment. Exploratory correlations for SPD subjects suggest a relationship between peak activation on the right for deviant tones in the pitch experiment with odd speech and impaired verbal learning. There was no difference between groups on Heschl's gyrus volume. NIH Public AccessConclusions-These data suggest that SPD subjects have inefficient or hyper-responsive processing of pure tones both in terms of pitch and duration deviance that is not attributable to smaller Heschl's gyrus volumes. Finally, these auditory processing abnormalities may have significance for the odd speech heard in some SPD subjects and downstream language and verbal learning deficits.

Abnormal pitch mismatch negativity in individuals with schizotypal personality disorder

“…For example, reduced left Heschl gyrus was found in male SPD (Dickey et al, 2002), and a volume of the left STG in female SPD was associated with odd speech (Dickey et al, 2003). Furthermore, in a recent fMRI study (Dickey et al, 2008) that used MMN-like paradigm (block design), more activation was found in the STG, bilaterally, to pitch deviants in the SPD relative to normal comparison individuals.…”

Neuroimaging findings in schizotypal personality disorder: A systematic review

“…There are also findings at various regions within the temporal lobe that initially pointed toward an abnormality, although a later study contradicted the initial findings (e.g. Heschl's gyrus (Dickey et al, 2002b(Dickey et al, , 2008). However, a finding of reduced left superior temporal gyrus volume was observed in males with SPD (Dickey et al, 1999) and females with SPD who also had a family history of schizophrenia (Dickey et al, 2003a).…”

“…A total of 54 studies described in 49 publications (2 included both MRI/fMRI (Dickey et al, 2008(Dickey et al, , 2010 and 3 included both MRI/PET (Hazlett et al, 1999;Haznedar et al, 2004;Shihabuddin et al, 2001)) met inclusion criteria. The studies include a total non-independent sample of 1181 SPD and 21,055 healthy control subjects.…”

“…Another study used an attention task and found increased activation in the dorsolateral prefrontal cortex, caudate, putamen and thalamus (Hazlett et al, 2008b). The other two studies employed a listening task and both found aberrant activity patterns within the superior temporal gyrus (Dickey et al, 2008(Dickey et al, , 2010. One study reported increased activation when listening to deviant tones versus standard tones in SPD (Dickey et al, 2008), and the other study found decreased activity across all conditions (Dickey et al, 2010).…”

Cingulate and temporal lobe fractional anisotropy in schizotypal personality disorder

“…For example, SPD-associated gray matter volume reduction has been found in the superior temporal gyrus 20, 28-32 , a region implicated in auditory processing 33 which is impaired in SPD 34 . Gray matter volume reductions have also been reported in other temporal cortex regions, such as Heschl’s gyrus 35 , middle temporal gyrus 20, 36 and inferior temporal gyrus 36 , but less consistently 37 .…”