A patient with a right-hemisphere stroke shows left neglect, failing to attend to stimuli on the left side. Which condition is most likely present?

• A. Agnosia
• B. Broca's aphasia
• C. Prosopagnosia
• D. Left neglect

Answer: (D)

Unilateral spatial neglect arises when attention to one side of space is impaired after damage to the opposite hemisphere, most often the right parietal lobes. The crucial idea is that the problem is not with sensing stimuli but with actively attending to or exploring the left side of space. So after a right-hemisphere stroke, neglect of the left side is a classic and expected outcome because the brain’s attention map for leftward space is disrupted.

Agnosia would involve trouble recognizing objects despite seeing them, prosopagnosia is difficulty recognizing faces, and Broca's aphasia is a language production deficit. None of these explain a failure to attend to stimuli on the left side. They reflect different brain networks and deficits, whereas left neglect specifically reflects disrupted spatial attention to the contralesional side. Therefore, the most likely present condition is left neglect.