Anomia is a disorder that results in the inability to recall words or names. Individuals with anomia have difficulty naming an object if it was presented visually, by touch, or by sound. Anomia is differentiated from agnosia in that agnosia is often limited to a singe modality. Hence, an individual may not be able to name an object visually but if allowed to tactually explore it with their hands, then he or she would be able to identify and name the object without difficulty.
Amnesia is a general umbrella term for the breakdown of memory. With agnosia, however, there is no deficit in memory. Rather there is a disruption in the pathway that connects specific stimuli and memories of a perceived stimuli.
Aphasia is an acquired disorder that affects an individual's ability to communicate. An individual with aphasia may have difficulties with expressing themselves through speech, difficulty understanding speech of others, and difficulty reading and writing (Aphasia Institute, n.d.). An individual with agnosia is unable to perceptually analyze a stimulus or give meaning to it, which can be mistaken for an inability to express oneself through speech.
Apraxia of speech is an inability to initiate and execute voluntary movement patterns necessary to produce speech when there is no paralysis or weakness of speech muscles (American Stroke Association, n.d.). Similar to aphasia, the inability to recognize a stimulus and provide an answer can be mistaken for agnosia.
Wernicke-Korsafoff syndrome is a rare alcohol-induced persisting amnestic disorder, in which there is a severe impairment to the ability to encode new memory (American Psychological Association, 2014). As mentioned before, agnosia does not cause deficits to an individual's memory but rather the there is a disruption in the pathway that connects specific stimuli and memories of a perceived stimuli.