Name Description Akinetopsia Also known as cerebral akinetopsia, this is associated with the inability to perceive visual motion. One cause of cerebral akinetopsia is lesions outside the striate cortex. Allotopagnosia Patients cannot point at external targets located outside their own body, whether other persons' body parts or objects, but they perfectly point at their own body parts. Anosognosia This is the inability to gain feedback about one's own condition and can be confused with lack of insight but is caused by problems in the feedback mechanisms in the brain. It is caused by neurological damage and can occur in connection with a range of neurological impairments but is most commonly referred to in cases of paralysis following stroke. Those with anosognosia with multiple impairments may even be aware of some of their impairments but completely unable to perceive others. Apperceptive visual<unk>  Patients are unable to distinguish visual shapes and so have trouble recognizing, copying, or discriminating between different visual stimuli. Unlike patients suffering from associative<unk> , those with apperceptive<unk>  are unable to copy images. Associative visual<unk>  Patients can describe visual scenes and classes of objects but still fail to recognize them. They may, for example, know that a fork is something you eat with but may mistake it for a spoon. Patients suffering from associative<unk>  are still able to reproduce an image through copying. Astereognosis Also known as somatosensory<unk> , it is connected to tactile sense—that is, touch. Patient finds it difficult to recognize objects by touch based on its texture, size and weight. However, they may be able to describe it verbally or recognize same kind of objects from pictures or draw pictures of them. Thought to be connected to lesions or damage in somatosensory cortex. Auditory<unk>  Auditory<unk>  has been recognized since 1877. With auditory<unk> , there is difficulty distinguishing environmental and non-verbal auditory cues including difficulty distinguishing speech from non-speech sounds even though hearing is usually normal. There are two types of auditory<unk> : semantic associative and discriminative<unk> . Semantic associative<unk>  is associated with lesions to the left hemisphere, whereas discriminative<unk>  is associated with lesions to the right hemisphere. Auditory verbal<unk>  Also known as pure word deafness (PWD). This presents as a form of meaning 'deafness' in which hearing is intact but there is significant difficulty recognising spoken words as semantically meaningful. Autotopagnosia Is associated with the inability to orient parts of the body, and is often caused by a lesion in the parietal part of the posterior thalmic radiations. Cerebral achromatopsia A difficulty in perceiving colors in which the world may appear drab or in shades of gray. Cerebral achromatopsia is caused by neurological damage. There are two regions of the brain which specialize for color recognition, areas V4 and V8. If there is a unilateral lesion to area V4, a loss of color perception in only half of the visual field may result known as hemiachromatopsia. Similar, but distinct, is color<unk> , which involves having difficulty recognizing colors, while still being able to perceive them as measured by a color matching or categorizing task. Cortical deafness Refers to people who do not perceive any auditory information but whose hearing is intact. Environmental<unk>  It is the inability to locate a specific room or building that one is familiar with, as well as the inability to provide directions for how to arrive at a particular location. These individuals experience difficulty with learning routes. This form of<unk>  is often associated with lesions to the bilateral or right hemisphere posterior regions. It is also associated with prosopagnosia and Parkinson's disease. Finger<unk>  Is the inability to distinguish the fingers on the hand. It is present in lesions of the dominant parietal lobe, and is a component of Gerstmann syndrome. Form<unk>  Patients perceive only parts of details, not the whole object. Heterotopagnosia Patients cannot point at another person's body parts, but can point at their own body parts. Integrative<unk>  Usually a patient has a form of associative<unk>  or apperceptive<unk> . However, in the case of integrative<unk>  a patient falls in between a form of associative and apperceptive<unk> . This is where one has the ability to recognize elements of something but yet be unable to integrate these elements together into comprehensible perceptual wholes. Pain<unk>  Also referred to as congenital analgesia, this is the difficulty perceiving and processing pain; thought to underpin some forms of self injury. Phonagnosia Is the inability to recognize familiar voices, even though the hearer can understand the words used. Prosopagnosia Also known as faceblindness and facial<unk> : Patients cannot consciously recognize familiar faces, sometimes even including their own. This is often misperceived as an inability to remember names. Pure alexia Inability to recognize text. Patients with pure alexia often have damage to their corpus callosum, as well as damage to the left visual association areas. Pure alexia involves not being able to read printed material, but these individuals still have the ability to write. Individuals with pure alexia usually read words letter by letter. However, individuals with pure alexia show a frequency effect. They are able to read high frequency words better and faster than they can read low frequency words. Semantic<unk>  Those with this form of<unk>  are effectively 'object blind' until they use non-visual sensory systems to recognise the object. For example, feeling, tapping, smelling, rocking or flicking the object, may trigger realisation of its semantics (meaning). Social-emotional<unk>  Sometimes referred to as expressive<unk> , this is a form of<unk>  in which the person is unable to perceive facial expression, body language and intonation, rendering them unable to non-verbally perceive people's emotions and limiting that aspect of social interaction. Simultagnosia The inability to process visual input as a whole. The person instead processes faces, bodies, objects, rooms, places, pictures in a bit-by-bit fashion. When looking at a picture they can describe the parts of the picture but struggle to comprehend the picture as a whole. Simultagnosia occurs in Bálint syndrome but may also occur in brain injury. This condition can also be described by only seeing one object at a time. An example is having two cups in your visual field and only being able to see one at a time. Tactile<unk>  Impaired ability to recognize or identify objects by touch alone. Topographical disorientation Also known as topographical<unk>  or topographagnosia, this is a form of visual<unk>  in which a person cannot rely on visual cues to guide them directionally due to the inability to recognize objects. Nevertheless, they may still have an excellent capacity to describe the visual layout of the same place. Patients with topographical<unk>  have the ability to read maps, but become lost in familiar environments. Visuospatial dysgnosia This is a loss of the sense of "whereness" in the relation of oneself to one's environment and in the relation of objects to each other. It may include constructional apraxia, topographical disorientation, optic ataxia, ocular motor apraxia, dressing apraxia, and right-left confusion. Visual<unk>  Is associated with lesions of the left occipital lobe and temporal lobes. Many types of visual<unk>  involve the inability to recognize objects. Visual<unk>  Visual<unk>  is a broad category that refers to a deficiency in the ability to recognize visual objects. Visual<unk>  can be further subdivided into two different subtypes: apperceptive visual<unk>  and associative visual<unk> . Individuals with apperceptive visual<unk>  display the ability to see contours and outlines when shown an object, but they experience difficulty if asked to categorize objects. Apperceptive visual<unk>  is associated with damage to one hemisphere, specifically damage to the posterior sections of the right hemisphere. In contrast, individuals with associative visual<unk>  experience difficulty when asked to name objects. Associative<unk>  is associated with damage to both the right and left hemispheres at the occipitotemporal border. A specific form of associative visual<unk>  is known as prosopagnosia. Prosopagnosia is the inability to recognize faces. For example, these individuals have difficulty recognizing friends, family and coworkers. However, individuals with prosopagnosia can recognize all other types of visual stimuli. Speech<unk>  Speech<unk> , or auditory verbal<unk> , refers to "an inability to comprehend spoken words despite intact hearing, speech production and reading ability". Patients report that they do indeed hear sounds being produced, but that the sounds are fundamentally unrecognizable/untranslatable. # EXAMINER: What did you eat for breakfast? # PATIENT: Breakfast, breakfast, it sounds familiar but it doesn't speak to me. (Obler & Gjerlow 1999:45) Despite an inability to process what the speaker is saying, some patients have been reported to recognize certain characteristic information about the speaker's voice (such as being a man or woman).
Agnosia
Social-emotional agnosia
Musical anhedonia
Anosognosia
Apophlegmatism
Hypersexuality
Dysgraphia
Sexual anhedonia