Agnosia
Agnosia is the inability to process sensory information. Often there is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss. It is usually associated with brain injury or neurological illness, particularly after damage to the occipitotemporal border, which is part of the ventral stream. Agnosia only affects a single modality, such as vision or hearing. More recently, a top-down interruption is considered to cause the disturbance of handling perceptual information.
Cognitive flexibility
Diminished cognitive flexibility has been noted in a variety of neuropsychiatric disorders such as anorexia nervosa, obsessive–compulsive disorder, schizophrenia, autism, and in a subset of people with ADHD. Each of these disorders exhibit varying aspects of cognitive inflexibility. For example, those with obsessive–compulsive disorder experience difficulty shifting their attentional focus as well as inhibiting motor responses. Children with autism show a slightly different profile with deficits in adjusting to changing task contingencies, while often maintaining the ability to respond in the face of competing responses. Potential treatments may lie in neurochemical modulation. Juveniles with Anorexia nervosa have marked decreases in set-shifting abilities, possibly associated with incomplete maturation of prefrontal cortices associated with malnutrition. One can also consider people with addictions to be limited in cognitive flexibility, in that they are unable to flexibly respond to stimuli previously associated with the drug.