Which sensory test assesses the ability to identify a number drawn on the hand with the eyes closed?

Which sensory test assesses the ability to identify a number drawn on the hand with the eyes closed?

• A. Stereognosis
• B. Two point discrimination
• C. Graphesthesia
• D. Astereognosis

Answer: (C)

Graphesthesia is the ability to recognize symbols, such as a number, traced on the skin (usually the palm) with the eyes closed. Successfully identifying the traced symbol requires the brain to interpret tactile input as a meaningful shape, which depends on cortical processing in the somatosensory association areas. This type of test specifically probes higher-order tactile perception and parietal lobe function. Two-point discrimination, by contrast, measures basic tactile acuity—how finely you can distinguish two separate touch points—without requiring symbol recognition. Stereognosis is about identifying objects by touch through manipulation, relying on recognizing shape and texture, not tracing a symbol. Astereognosis is the deficit in stereognosis, indicating trouble with object recognition by touch. So, tracing a number on the hand with the eyes closed directly assesses graphesthesia.

Graphesthesia is the ability to recognize symbols, such as a number, traced on the skin (usually the palm) with the eyes closed. Successfully identifying the traced symbol requires the brain to interpret tactile input as a meaningful shape, which depends on cortical processing in the somatosensory association areas. This type of test specifically probes higher-order tactile perception and parietal lobe function.

Two-point discrimination, by contrast, measures basic tactile acuity—how finely you can distinguish two separate touch points—without requiring symbol recognition. Stereognosis is about identifying objects by touch through manipulation, relying on recognizing shape and texture, not tracing a symbol. Astereognosis is the deficit in stereognosis, indicating trouble with object recognition by touch.

So, tracing a number on the hand with the eyes closed directly assesses graphesthesia.