Perceptual Asymmetries in Schizophrenia: Subtype Differences in Left Hemisphere Dominance for Dichotic Fused Words

Friedman, Michelle; Bruder, Gerard E.; Nestor, Paul G.; Stuart, Barbara; Amador, Xavier; Gorman, Jack M.

doi:10.1176/appi.ajp.158.9.1437

Cited by 15 publications

(12 citation statements)

References 18 publications

(18 reference statements)

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“…These findings are suggestive of disturbances of early stage auditory processing, consistent with findings of reduced mismatch negativity (Alain et al, 2002;Javitt et al, 2000) and reduced P50 amplitude and impaired auditory sensory gating in schizophrenia (McCarley et al, 1997;Adler et al, 1998). Behavioral studies have also suggested disturbed auditory processing in schizophrenia (Friedman et al, 2001). In contrast, neither of these early ERP components was affected in bipolar disorder.…”

Section: Discussionsupporting

confidence: 82%

Auditory event-related potential abnormalities in bipolar disorder and schizophrenia

O’Donnell

Vohs

Hetrick

et al. 2004

International Journal of Psychophysiology

171

115

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Section: Discussionsupporting

confidence: 82%

Auditory event-related potential abnormalities in bipolar disorder and schizophrenia

O’Donnell

Vohs

Hetrick

et al. 2004

International Journal of Psychophysiology

171

115

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“…Using either fused rhymed words or consonant-vowel paired syllables, studies have found reduced REA in patients with schizophrenia 2–7. Conversely, other studies have reported enhanced REA in patients with paranoid but not undifferentiated schizophrenia,8 enhanced REA in male patients,9 and enhanced REA in both paranoid and nonparanoid patients 10. Two other studies have found no differences in REA between patients and controls 11,12…”

Section: Introductionmentioning

confidence: 99%

“…However, a key factor that may explain some of this variability may be the use of word versus nonword stimuli, given that syllable-based studies consistently show reduced REA in patients,3–7 whereas the results of word-based studies are more variable,2,8–12 often finding a relative preservation or even enhancement of REA in patients. The possibility of word/nonword effects is supported by studies of semantic priming, which suggest a facilitation of automatic semantic processing in schizophrenia 13,14.…”

Section: Introductionmentioning

confidence: 99%

Stimulus-dependent effects on right ear advantage in schizophrenia

Smucny¹,

Wylie²,

Tregellas³

2012

NDT

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BackgroundWhen presented with different sounds in each ear (dichotic listening), healthy subjects typically show a preference for stimuli heard in the right ear, an effect termed “right ear advantage”. Previous studies examining right ear advantage in schizophrenia have been inconsistent, showing either decreased or increased advantage relative to comparison subjects. Given evidence for enhanced semantic processing in schizophrenia, some of this inconsistency may be due to the type of stimuli presented (words or syllables). The present study examined right ear advantage in patients and controls using both words and syllables as stimuli.MethodsRight ear advantage was compared between 20 patients with schizophrenia and 17 healthy controls. Two versions of the task were used, ie, a consonant-vowel pairing task and a fused rhymed words task.ResultsA significant group × task interaction was observed. Relative to healthy controls, patients showed a greater difference on the syllable-based task compared with the word-based task. The number of distractors marked during the syllable-based task was inversely correlated with score on the Global Assessment of Function Scale.ConclusionThe findings are consistent with a left hemisphere dysfunction in schizophrenia, but also suggest that differences may be stimulus-specific, with a relative sparing of the deficit in the context of word stimuli. Performance may be related to measures of social, occupational, and psychological function.

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“…While all subgroups show abnormalities in limbic function, patients with nonparanoid SZ, such as those subjects with chronic undifferentiated SZ (SZU) or disorganized SZ, display a broader and/or more severe spectrum of signs and symptoms, including more severe deficits in cognition and working memory, than do SZP. Previous imaging and neuropsychological testing has shown that there are abnormalities specific to the SZU subtype of SZ, which are absent or greatly diminished in paranoid patients (Auslander et al,2002; Bruder et al,2001; Fenton and McGlashan,1991; Friedman et al,2001; Fukuzako et al,1999; Goldstein et al,2005; Hagh‐Shenas et al,2002; Nasrallah et al,1982; Rosse et al,1991; Seltzer et al,1997; Turetsky et al,1995). The general conclusions are that subjects with the SZP subtype show fewer abnormalities and perform better on many tasks than the subjects with nonparanoid SZ.…”

Section: Introductionmentioning

confidence: 99%

Striatal mitochondria in subjects with chronic undifferentiated vs. chronic paranoid schizophrenia

Somerville

Conley

Roberts

2011

Synapse

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Schizophrenia (SZ) is a heterogeneous disease with a spectrum of symptoms, risk factors, and etiology. Abnormalities in mitochondria, the energy-producing organelles of the cell, have been observed in mixed cohorts of subjects with SZ. The purpose of the present study was to determine if striatal mitochondria were differentially affected in two different DSM-IV subgroups of SZ. Postmortem striatal tissue was examined from normal controls (NC), chronic paranoid SZs (SZP), and chronic undifferentiated SZs (SZU). Tissue was processed for calbindin immunohistochemistry to identify striosomal compartments, prepared for electron microscopy and analyzed using stereological methods. In both caudate and putamen, the density of mitochondria in the neuropil was decreased in SZP compared to both NCs and SZU. In the putamen, both the SZP and the SZU subgroups had fewer mitochondria per synapse than did NCs. When examining patch matrix compartments, striatal compartments associated with different circuitry and function, only the matrix exhibited changes. In the caudate matrix, the SZP subgroup had fewer mitochondria in the neuropil than did the SZU and NCs. In the putamen matrix, the SZP had fewer mitochondria in the neuropil as compared to NCs, but not the SZU. The numbers of mitochondria per synapse in both the SZP and the SZU groups were similar to each other and fewer than that of NCs. A decrease in mitochondrial density in the neuropil distinguishes the SZP from the SZU subgroup, which could be associated with the symptoms of paranoia and/or could represent a protective mechanism against some of the symptoms that are less pronounced in this subtype than in the SZU subgroup such as cognitive and emotional deficits.

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Perceptual Asymmetries in Schizophrenia: Subtype Differences in Left Hemisphere Dominance for Dichotic Fused Words

Abstract: The findings support the hypotheses that undifferentiated schizophrenia is associated with underactivation of left hemisphere resources for verbal processing and that paranoid schizophrenia is characterized by preserved left hemisphere processing.

Cited by 15 publications

References 18 publications

Auditory event-related potential abnormalities in bipolar disorder and schizophrenia

Auditory event-related potential abnormalities in bipolar disorder and schizophrenia

Stimulus-dependent effects on right ear advantage in schizophrenia

Striatal mitochondria in subjects with chronic undifferentiated vs. chronic paranoid schizophrenia

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