Studies on the Cerebral Cortex

THE POSTURAL ABNORMALITIES OF DECORTICATE CATS One of the most striking abnormalities exhibited by four cats without cerebral cortex throughout periods of survival ranging from six weeks to twenty-eight months was a tendency to assume peculiar attitudes of the legs while standing, sitting or crouching. The most prominent defects of attitude were crossing, abduction or retroposition of the forelegs and abduction or forward displacement of the hindlegs. These static abnormalities contrasted conspicuously with the relative normality of locomotion seen in the decorticate cat. They commonly developed after the animal had remained for some time in a standing, crouching or sitting position, and then the peculiar attitude of the leg was often the result of an uncorrected sliding of the foot away from its normal position. Another event favoring their appearance was the premature cessation of some movement; for example, a normally executed act of scratching might cease without withdrawal of