Neglect and extinction differ in that neglect is failure to attend to contralesional space, while extinction is failure to notice contralesional stimuli only when competing ipsilesional stimuli are present.

• A. Neglect is failure to attend to contralesional space; extinction is failure to notice contralesional stimuli only when there are competing ipsilesional stimuli.
• B. Neglect and extinction are the same phenomenon.
• C. Extinction is a complete neglect of contralesional space.
• D. Neglect occurs only with auditory stimuli.

Answer: (A)

The important distinction is how attention to space operates in these two conditions. Unilateral spatial neglect is a broad failure to attend to the side opposite the brain injury, and this can affect responses across senses and in many tasks even when stimuli are presented alone. Extinction is a related but different phenomenon: the contralesional stimulus is noticed when it stands alone, but it fails to be perceived when there are competing stimuli on the ipsilesional side. In other words, extinction depends on simultaneous bilateral stimulation and a competitive process for attention, whereas neglect is a more general, persistent deficit of attending to the contralesional space. So the statement accurately captures that neglect is about failure to attend contralesional space, while extinction is specifically about failing to notice contralesional stimuli only when competing ipsilesional stimuli are present.