Module 12: Brain Stories of Visual Perception and Communication Disorders

Literal translation of agnosia

without knowledge

What modalities does agnosia exist in?

visual, auditory or tactile

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is a lack of recognition NOT due to intellectual or sensory impairment; it is an inability to identify what is otherwise sensed through the affected modality

agnosia

Hermann Munk

Destroyed the occipital lobes of dogs and then observed their behavior. He noticed that they appeared to remain able to “see” objects, in that they didn’t walk into them or trip over them, but they also appeared to no longer react appropriately when seeing familiar objects (e.g., they attempted to eat stones, ignored other dogs, etc.). Munk called this condition mind-blindness

Mind-blindness

A syndrome of visual imperception first described in the 1870s by the physiologist Hermann Munk. Not being able to “see” objects (not walking into them or tripping over them but also appearing to no longer react appropriately when seeing familiar objects like attempting to eat stones and ignore others)

H.Lissauer

The neurologist who distinguished two general types of mind-blindness in 1885. These are visual apperception and associative.

How many general t

Visual apperception

The first type of mind-blindness. The person has difficulty taking all of the elements of what is seen (e.g., the individual lines, light, shadow, edges, proportions) and combining them to form a whole percept (or Gestalt, you might say). Thus, lack of recognition

Gestalt

Whole percept

Associative