Brain chemical abnormalities are present in ASD at 3 to 4 years of age. However, the direction and widespread distribution of these abnormalities do not support hypothesis of diffuse increased neuronal packing density in ASD.

Objective. This study was conducted 1) to determine the feasibility of using computer programs to measure radiographic joint space width and estimate erosion volume in the hands of patients with rheumatoid arthritis (RA), and 2) to compare the new computer-based methods with established scoring methods. Methods. To measure the joint space width in the finger and wrist joints of RA patients, hand and wrist radiographic films were scanned using a tabletop scanner and analyzed with programs written using the "macro" capabilities of NIH Image software. Estimation of erosion volume was determined by utilizing gray-scale intensity to calibrate bone density units per mm 3 , which made possible comparisons between the erosions and noneroded, anatomically similar sites. Results. In 3 sets of duplicate measurements of joint space width on 79, 48, and 48 finger and wrist joints, the mean absolute deviation from the mean of the 2 measurements was 0.036 mm (SD 0.034), 0.032 mm (SD 0.049), and 0.021 mm (SD 0.016), respectively. Joint space measurements and scoring of joint space narrowing both demonstrated a difference between active treatment and placebo in an old trial set on gold therapy (P 0.03 and P 0.01, respectively). Two repeated measurements of bone density units in the bones of 3 different hands differed from the mean of the measurement by 2.29-4.04%. In 2 experiments, estimates of erosion volume showed a greater difference between gold therapy and placebo than did erosion scores in the trial set (P 0.049 and P 0.016 versus P 0.27). Conclusion. Computer-based methods for measuring finger and wrist joint spaces and estimating erosion volume in patients with RA agree with the results of radiographic scoring of erosions and joint space narrowing.

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Responses to binocular visual stimulation were compared in cortical area 18 of normal cats and in cats in which one eye was exodeviated by surgery early in postnatal life. In contrast to normal cats where most units (58%) were binocularly activated, relatively few units (10%) in strabismic cats were activated well by stimulation of either eye. Rather individual units were driven mainly via one eye or the other but not both. In addition, there was a tendency for more units to be driven well via the unoperated eye than via the exodeviated eye. Fewer cells preferring vertically oriented than horizontally oriented stimuli were found in area 18 of strabismic cats. This trend was observed for cells driven by either the normal or deviated eye and was especially marked among the small number of binocularly activated cells. Generally binocular responses and binocular interactions were found with stimulation at corresponding retinal points. In a few striking instances, however, the receptive fields of binocular neurons were located on noncorresponding retinal points at loci which would enable the cat to correlate the two images of an external object despite the large divergent strabismus. Quantitative responses to binocular stimuli presented at varied disparities and to stimuli with varied directions of motion in depth were compared in normal and strabismic cats. Despite the large strabismus, a reduced fraction of cortical neurons displayed substantial binocular interactions. In fact, binocular facilitation was as marked in the population of cells studied in strabismic cats as it was in normal animals. The major effect of strabismus was a reduction in the strength of binocular inhibition when units were tested with sideways motion. Disparity-specific responses to motion toward or away from the organism were little affected by strabismus. The degree of binocular facilitation and binocular inhibition among the cell population was similar in normal and strabismic cats. A subpopulation of units encountered in strabismic cats showed strong disparity-specific interactions for motion toward or away from the animal without equivalent modulation for sideways moving stimuli. Units with these properties were not found in normal animals and may, therefore, represent a special adaptation of the strabismic animals.