"Itch happens in your brain, not your skin"
somatosensory signals are modulated as they are transmitted along sensory pathways (see complex processing), and the perception of the signal may differ significantly from the receptor sensation
- as in all sensory systems, somatosensory processing is geared toward encoding contrast, which can lead to perceptual illusions
for a somatosensory example, perform the experiment you probably tried in elementary school:
- Prepare 3 cups of water: one with ice cubes, one at room temperature and one as hot as you can stand it.
- Put one finger of your left hand into the cold water, and one finger of your right hand into the hot water.
- After ~30 s, move both fingers into the warm water at the same time. The right somatosensory cortex perceives the warm water as hot, but the left somatosensory cortex as cold.
Can you explain your results in terms of thermoreceptor responses and somatosensory pathways? Click here for an explanation.