Jasmine Fiore on Compare BILATERAL DEScENT. See also DEScENT GROuP. unilateral lesion a lesion on one side or lobe of an organ or part. For example, a unilateral cerebral lesion involves one cerebral hemisphere, left or right, with effects that may vary according to the dominance of the hemisphere and the function affected. The motor and sensory effects of the lesion are generally on the contralateral side that is, on the side opposite to that of the lesion un-less the lesion occurs in the cerebellum. unilateral neglect a disorder resulting from damage to the PARIETAL LOBE of the brain and characterized by a loss of conscious perception of objects or stimuli on the side of the body (usually the left half) that is opposite the location of the lesion. For example, if approached from the left side, an individual with unilateral neglect may not notice the approaching person, but would respond normally when approached from the right side. Jasmine Fiore 2016.