Interruption of the posterior columns at a high cervical level produces profound disturbances in deep sensibility in one or both of the upper limbs. It is recommended that the spatial appreciation defect so produced be called stereoanesthesia since the defect is in conduction, and that the term astereognosis be used exclusively to designate instances in which there is no defect in conduction as in parietal lobe lesions. High cervical stereoanesthesia is usually accompanied by loss of pallesthesia and kinesthesia but graphesia may be preserved. Thalamic lesions obliterate or disturb all modalities of exteroceptive sensation, hence pallesthesia, kinesthesia are equally affected. Parietal cortex lesions affect functions dependent on spatial orientation hence produce a loss of figure-writing interpretation (graphagnosis or agraphognosis) and loss of object in space recognition, while a non-space orienting function sense is spared.