TY - JOUR
T1 - Left hemisphere lateralisation of auditory hallucinations in schizophrenia
T2 - A dichotic listening study
AU - Hugdahl, Kenneth
AU - Løberg, Else Marie
AU - Jørgensen, Hugo A.
AU - Lundervold, Arvid
AU - Lund, Anders
AU - Green, Michael F.
AU - Rund, Bjørn
PY - 2008/3
Y1 - 2008/3
N2 - Introduction. We propose that auditory hallucinations are internally generated speech misrepresentations that are lateralised to the left temporal lobe. If hallucinations are misrepresentations involving the speech perception area of the left temporal lobe, then hallucinating patients should have problems identifying a simultaneously presented external speech sound, especially when the sound is lateralised to the left hemisphere. Lateralisation of speech perception can be experimentally studied with the dichotic listening task with consonant-vowel syllables. We predicted a negative relation between frequency of auditory hallucinations and performance on the dichotic listening task. Method. We studied 87 right-handed patients with schizophrenia. Hallucination scores were taken from the BPRS symptom scale. Right and left ear scores in the dichotic listening task were recorded. A right ear advantage is expected in healthy individuals, indicating left temporal lobe processing superiority. The patients were compared with 36 right-handed healthy reference subjects. Results. A gradual decrease in the ability to process and report the right ear stimulus with increasing frequency of hallucinations was seen in the schizophrenia patients. No such relationship was found for processing and reporting of the left ear stimulus. There were no significant correlations with negative symptoms. Thus, the results were not the consequence of illness severity. There was however a significant correlation with unusual thought content symptom, pointing to a relationship also between delusions and auditory hallucinations. Conclusion. The results support that auditory hallucinations may be internally generated speech misrepresentations, originating in the left temporal lobe.
AB - Introduction. We propose that auditory hallucinations are internally generated speech misrepresentations that are lateralised to the left temporal lobe. If hallucinations are misrepresentations involving the speech perception area of the left temporal lobe, then hallucinating patients should have problems identifying a simultaneously presented external speech sound, especially when the sound is lateralised to the left hemisphere. Lateralisation of speech perception can be experimentally studied with the dichotic listening task with consonant-vowel syllables. We predicted a negative relation between frequency of auditory hallucinations and performance on the dichotic listening task. Method. We studied 87 right-handed patients with schizophrenia. Hallucination scores were taken from the BPRS symptom scale. Right and left ear scores in the dichotic listening task were recorded. A right ear advantage is expected in healthy individuals, indicating left temporal lobe processing superiority. The patients were compared with 36 right-handed healthy reference subjects. Results. A gradual decrease in the ability to process and report the right ear stimulus with increasing frequency of hallucinations was seen in the schizophrenia patients. No such relationship was found for processing and reporting of the left ear stimulus. There were no significant correlations with negative symptoms. Thus, the results were not the consequence of illness severity. There was however a significant correlation with unusual thought content symptom, pointing to a relationship also between delusions and auditory hallucinations. Conclusion. The results support that auditory hallucinations may be internally generated speech misrepresentations, originating in the left temporal lobe.
KW - Dichotic listening
KW - Functional impairment
KW - Hallucinations
KW - Lateralisation
KW - Temporal lobe
UR - http://www.scopus.com/inward/record.url?scp=39849110874&partnerID=8YFLogxK
U2 - 10.1080/13546800801906808
DO - 10.1080/13546800801906808
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C2 - 18302028
AN - SCOPUS:39849110874
SN - 1354-6805
VL - 13
SP - 166
EP - 179
JO - Cognitive Neuropsychiatry
JF - Cognitive Neuropsychiatry
IS - 2
ER -