3.16 : 視覚失認

Visual agnosia is a condition where individuals can describe the shape and color of an object but cannot identify or recognize it despite having normal vision.

For example, at a family dinner, an individual might say, "Please pass that silver thing with a rounded end," instead of "Please pass the spoon."

Visual agnosia has two types: apperceptive visual agnosia and associative visual agnosia.

Individuals with apperceptive visual agnosia may find it difficult to recognize or draw objects from memory or copy figures. For instance, a person may have difficulty in recognizing or drawing a cat, seeing only disconnected lines and shapes. However, if told it's a cat, he can accurately describe its appearance and characteristics.

In contrast, individuals with associative visual agnosia can draw or copy objects but do not recognize what they have drawn. For instance, a person can accurately draw or copy a picture of a bicycle but cannot identify the drawing as a bicycle afterward.