* Word selection<unk>  is caused by damage to the posterior inferior temporal area. This type of<unk>  occurs when the patient knows how to use an object and can correctly select the target object from a group of objects, and yet cannot name the object. Some patients with word selection<unk>  may exhibit selective impairment in naming particular types of objects, such as animals or colors. In the subtype known as color<unk> , the patient can distinguish between colors but cannot identify them by name or name the color of an object. The patients can separate colors into categories, but they cannot name them. * Semantic<unk>  is caused by damage to the angular gyrus. This is a disorder in which the meaning of words becomes lost. In patients with semantic<unk> , a naming deficit is accompanied by a recognition deficit. Thus, unlike patients with word selection<unk> , patients with semantic<unk>  are unable to select the correct object from a group of objects, even when provided with the name of the target object. * Disconnection<unk>  results from the severing of connections between sensory and language cortices. Patients with disconnection<unk>  may exhibit modality-specific<unk> , where the<unk>  is limited to a specific sensory modality, such as hearing. For example, a patient who is perfectly capable of naming a target object when it is presented via certain sensory modalities like audition or touch, may be unable to name the same object when the object is presented visually. Thus, in such a case, the patient's<unk>  arises as a consequence of a disconnect between their visual cortex and language cortices. * Patients with disconnection<unk>  may also exhibit callosal<unk> , in which damage to the corpus callosum prevents sensory information from being transmitted between the two hemispheres of the brain. Therefore, when sensory information is unable to reach the hemisphere that is language-dominant (typically the left hemisphere in most individuals), the result is<unk> . For instance, if patients with this type of disconnection<unk>  hold an object in their left hand, this somatosensory information about the object would be sent to the right hemisphere of the brain, but then would be unable to reach the left hemisphere due to callosal damage. Thus, this somatosensory information would fail to be transmitted to language areas in the left hemisphere, in turn resulting in the inability to name the object in the left hand. In this example, the patient would have no problem with naming, if the test object were to be held in the right hand. This type of<unk>  may also arise as a consequence of a disconnect between sensory and language cortices. * Articulatory initiation<unk>  results from damage to the frontal area. Characteristics of this<unk>  are non-fluent output, word-finding pauses, deficient word lists. Patients perform better at confrontation naming tasks, the selection of a label for a corresponding picture, than word list tasks. Patients are aided in word selection by prompting, unlike those with word selection<unk> . * Phonemic substitution<unk>  results from damage to the inferior parietal area. Patients maintain fluent output but exhibit literal and neologistic paraphasia. Literal paraphasia is the incorrect substitution of phonemes, and neologistic paraphasia is the use of non-real words in the place of real words. Patient’s naming ability is contaminated by paraphasia. * Modality-specific<unk>  is caused by damage to the sensory cortex, pathways to the dominant angular gyrus, or both. In these patients, word-finding is worst in one sensory modality, for example visual or tactile.
Anomic aphasia
Global aphasia
Receptive aphasia
Expressive aphasia
Jargon aphasia
Visuospatial dysgnosia
Integrative agnosia
Progressive nonfluent aphasia