Superior temporal gyrus volume abnormalities and thought disorder in left-handed schizophrenic men.

OBJECTIVE: Studies of schizophrenia have not clearly defined handedness as a differentiating variable. Moreover, the relationship between thought disorder and anatomical anomalies has not been studied extensively in left-handed schizophrenic men. The twofold purpose of this study was to investigate gray matter volumes in the superior temporal gyrus of the temporal lobe (left and right hemispheres) in left-handed schizophrenic men and left-handed comparison men, in order to determine whether thought disorder in the left-handed schizophrenic men correlated with tissue volume abnormalities. METHOD: Left-handed male patients (N = 8) with DSM-III-R diagnoses of schizophrenia were compared with left-handed comparison men (N = 10) matched for age, socioeconomic status, and IQ. Magnetic resonance imaging (MRI) with a 1.5-T magnet was used to obtain scans, which consisted of contiguous 1.5-mm slices of the whole brain. MRI analyses (as previously defined by the authors) included the anterior, posterior, and total superior temporal gyrus in both the left and right hemispheres. RESULTS: There were three significant findings regarding the left-handed schizophrenic men: 1) bilaterally smaller gray matter volumes in the posterior superior temporal gyrus (16% smaller on the right, 15% smaller on the left); 2) a smaller volume on the right side of the total superior temporal gyrus; and 3) a positive correlation between thought disorder and tissue volume in the right anterior superior temporal gyrus. CONCLUSIONS: These results suggest that expression of brain pathology differs between left-handed and right-handed schizophrenic men and that the pathology is related to cognitive disturbance.

Reappraisal of filter effects on P300 voltage and latency.

The selection of which high-pass filter cutoff to use in P300 studies continues to be a serious methodological consideration. To determine whether there was an optimal range of bandpass widths-a range in which P300 voltage and latency would not show statistically significant differences-the authors recorded P300 responses to the auditory "oddball" paradigm from Cz and Pz electrodes in a group of eight healthy males. The authors used high-pass filter cutoffs of 0.01, 0.1, 0.3, and 1.0 Hz with low-pass filter cutoffs of 30 and 100 Hz and measured both P300 peak voltages and P300 integrated mean voltages at 12 bandpass settings. There were statistically significant differences in 7 out of 12 bandpass comparisons for P300 peak voltages and in 7 out of 12 bandwidth comparisons for P300 integrated mean voltages. For P300 latencies, there were statistically significant differences in 9 out of 12 bandwidth comparisons. Based on these results, the best recommendation, therefore, is that the high-pass filter be set no higher than 0.3 Hz.

Violent deaths among children in the United States, 1900-1980. An epidemiologic study of suicide, homicide and accidental deaths among 5- to 14-year-olds.

The authors examined the violent death rates among children aged 5-14 years in the United States from 1900 to 1980. For homicides and non-motor-vehicle accident deaths, 5- to 14-year-olds are at a lower risk than any other age group; for suicides and motor-vehicle accident mortality, only 0- to 4-year-olds have lower rates. Males tend to have higher rates than females for all forms of violent deaths for 5- to 14-years-olds. Nonwhites are at greater risk of dying by homicide and non-motor-vehicle accidents than whites; for suicide, whites are at greater risk; and for motor-vehicle accidents, nonwhites are currently at greater risk, with white children having been at greater risk earlier in the century. The epidemiologic time trends throughout the 20th century for 5- to 14-year-olds are quite similar to other ages for non-motor-vehicle accidents, but show some differences from other age groups in homicide, motor-vehicle accident mortality and, especially, suicide patterns. Various psychobiological perspectives as well as socioenvironmental issues are discussed as possible means of enhancing an understanding of the low violent death rates among 5- to 14-year-olds.

Reversed temporal region asymmetries of P300 topography in left- and right-handed schizophrenic subjects.

The auditory P300 evoked potential was recorded in 36 subjects: left- (LH) and right-handed (RH) schizophrenic males and LH and RH normal controls. LH and RH normals showed no asymmetry in P300 scalp topography. LH and RH schizophrenics, however, showed lateralized asymmetries in temporal scalp regions: left < right P300 voltage asymmetry in RH schizophrenics and left > right P300 voltage asymmetry in LH schizophrenics. These data suggest that the schizophrenic pathology of P300 neural generators is lateralized according to handedness and provide the first evidence that LH and RH schizophrenics can be dissociated based on left-right voltage asymmetries in P300 topography. These findings further emphasize the need for control of handedness in P300 studies of schizophrenia.