<prompt> The inability to perceive the texture shape an object occurs in a lesion ofLateral spino-thalamic tractNucleus gracilisSpino reticular tractNucleus cuneatus  <response>: Though both nucleus cuneatus nucleus gracilis are correct, since it is a single answer question, the best answer would be tractus cuneatus, as we commonly use hands to recognize size and shape of objects, more than the foot.Somatosensory cortex lesion- proprioception and tactile sensations are lost while pain and temperature sensations are preserved.Tractus cuneatus- formed by fasciculus cuneatus spinal cord and nucleus cuneatus medulla. Pass through the lateral portion of the dorsal column. Carries sensations of the dorsal column- proprioception and tactile sensations from upper part of the body.Tractus gracilis- formed by fasciculus gracilis spinal cord and nucleus gracilis medulla. Pass through the medial portion of the dorsal column. Carries sensations of the dorsal column- proprioception and tactile sensations from the lower part of the body. 