NLN NEX Science Practice Test

The key idea is that ticklish and protective sensations come from gentle skin contact that prompts a quick withdrawal from something potentially dangerous. This is the kind of light touch that alerts you to contact without deep pressure, so your body can react fast to move away. Light pressure fits this idea because it describes that gentle skin stimulation which triggers that protective, reflexive response.

Discriminative touch is about identifying texture and fine details, which isn’t mainly about a rapid protective withdrawal. Olfaction is smell, not touch. Touch pressure describes stronger, deeper contact, which wouldn’t be as closely linked to the light, ticklish sensation that signals a quick protective reaction.