Speech perception
Agnosia is "the loss or diminution of the ability to recognize familiar objects or stimuli usually as a result of brain damage". There are several different kinds of agnosia that affect every one of our senses, but the two most common related to speech are speech agnosia and phonagnosia.
Anomic aphasia
The best way to see if anomic aphasia has developed is by using verbal as well as imaging tests. The combination of the two tests seem to be most effective, since either test done alone may give false positives or false negatives. For example, the verbal test is used to see if there is a speech disorder, and whether it is a problem in speech production or in comprehension. Patients with Alzheimer's disease have speech problems that are linked to dementia or progressive aphasias which can include anomia. The imaging test, mostly done using MRI scans, is ideal for lesion mapping or viewing deterioration in the brain. However, imaging cannot diagnose anomia on its own because the lesions may not be located deep enough to damage the white matter or damage the arcuate fasciculus. However, anomic aphasia is very difficult to associate with a specific lesion location in the brain. Therefore, the combination of speech tests and imaging tests has the highest sensitivity and specificity.