Final answer:
Patients with posterior parietal lesions may have difficulties with praxis, gnosis, stereognosis, and graphesthesia, which are related to the conscious perception and understanding of sensory information and motor functions.
Step-by-step explanation:
Patients with posterior parietal lesions may struggle with tasks that involve the conscious perception and cortical processing of sensory information. These tasks include not only motor skills like praxis—the ability to execute voluntary movements—but also cognitive functions such as gnosis, which involves the recognition and association of sensory input with conceptual knowledge. For example, if an individual is unable to perceive stimuli on one side when a double simultaneous stimulation test is performed, this can indicate damage to the contralateral posterior parietal lobe and suggest a deficit in cortical processing rather than in the spinal pathways. Cognitive function tests like the mental status exam assess for deficits related to the parietal lobe such as stereognosis (the ability to perceive the form of solid objects by touch) and graphesthesia (the ability to recognize writing on the skin purely by the sensation of touch).