Reciprocal organization of the cerebral hemispheres.

The cerebral hemispheres are anatomically and neurophysiologically asymmetrical. The evolutionary basis for these differences remains uncertain. There are, however, highly consistent differences between the hemispheres, evident in reptiles, birds, and mammals, as well as in humans, in the nature of the attention each applies to the environment.

Planum temporale asymmetry reversal in schizophrenia: replication and relationship to gray matter abnormalities.

Objective: The planum temporale, the posterior superior surface of the superior temporal gyrus, is a highly lateralized brain structure involved with language. In schizophrenic patients the authors previously found consistent reversal of the normal left-larger-than-right asymmetry of planum temporale surface area. The original subjects plus new patients and comparison subjects participated in this effort to replicate and extend the prior study.

Exploratory factor analysis of MRI brain structure measures in schizophrenia.

Much of the literature shows various regional structural brain abnormalities in schizophrenia, but the complexity and variability of brain makes it difficult to determine how these regions are related. Statistical methods which estimate factors underlying patterns of covariance have not been widely used, but could be useful for analyzing such complex data. We applied exploratory and confirmatory factor analysis procedures to specific cortical and subcortical regional brain volume measures from MRI data in 60 normal and 44 schizophrenic subjects.

Asymmetry of the planum temporale: methodological considerations and clinical associations.

Asymmetry of the planum temporale, a region on the posterosuperior surface of the temporal lobe involved in the production and comprehension of language, is a notable feature of the normal human brain. Several attempts have been made to measure it using both post-mortem and magnetic resonance imaging (MRI) methods, but previous approaches made inadequate allowance for the convoluted nature of the structure. The current study used rigorous criteria to define the planum and examined three separate approaches for its measurement on MRI scans.

Somatic delusions in schizophrenia and the affective psychoses.

Background: Delusions relating to the body, a ready source of information about the immediate experiences of psychotic patients, have not been systematically studied. We attempted an account of the phenomena, looking for differences between diagnostic groupings in the type and lateralisation of such phenomena, and for evidence of localisation.

Method: Somatic delusions elicited at interview with 550 Research Diagnostic Criteria-diagnosed psychotic patients were categorised according to content, and the results were compared across diagnostic groupings.

Reversal of asymmetry of the planum temporale in schizophrenia.

Objective: The planum temporale is intimately involved in the generation and understanding of language and has been suggested to be a key area affected in schizophrenia. To explore temporal lobe abnormalities in schizophrenia, the authors measured the planum temporale, a normally asymmetric area lying on the superior part of the temporal lobe, in schizophrenic patients.

Method: High-resolution magnetic resonance imaging (MRI) scans were obtained for 14 right-handed schizophrenic patients and 14 healthy comparison subjects individually matched for age, sex, handedness, race, and parental socioeconomic status.

'Dyschronia' in a patient with Tourette's syndrome presenting as maternal neglect.

We report an unusual and unsuspected cause of maternal neglect in a patient with Tourette's syndrome. An important cause of the behaviour appears to have been a form of dyscalculia characterised by a complete inability to appreciate the passage of time. To our knowledge this is the first case of its kind to be reported.

Thalamo-frontal psychosis.

A 43-year-old man presented with an 18-month history of acute-onset cyclical behavioural change affecting mood, appetite, sleep, and energy levels. This had followed an initial episode of transient drowsiness which lasted 24 hours. On examination, there was some evidence of visual memory and frontal lobe deficits.