Apperceptive agnosia
Each patient that suffers from apperceptive agnosia does not have brain damage in exactly the same area. However, brain damage in proximity to the occipital lobe is largely correlated with the patterns of deficit seen in apperceptive agnosics. For example, patient JB suffered extensive damage to the parietal-occipital areas to the left cerebral hemisphere leading to his deficit in the ability to name distinguish between structurally similar object.
Tip of the tongue
Anomic aphasia is the inability to recall words and names and is a common symptom of patients with Aphasia and Alzheimer's disease (AD). Research has been conducted to find out how these particular diseases affect TOTs in these individuals. In a study by Beeson, Holland, and Murray (1997), participants with Alzheimer's disease and three classic aphasic syndromes (Broca’s, anomic, and conduction aphasia) were instructed to name famous people. Those with anomic aphasia showed to be superior to the other groups in their ability to naming famous people that were presented. This finding was expected as the group has relatively mild aphasia. However, the Broca’s conduction and AD groups did not differ in immediate or delayed naming of famous faces. All of the groups provided some basic identifying semantic information for at least half of the items presented, suggesting a fair number of items potentially in TOT. Conduction and Broca’s groups showed strongest evidence of TOT, performing better than the other groups in identification of initial letters.