A small new study suggests that your morning coffee could be slowly changing how the brain responds to touch and body movements. Millions worldwide consume a cup of coffee daily to boost wakefulness and concentration, but exactly how higher doses affect the brain's perception of touch has remained less studied.
Researchers assessed 20 healthy adults who received either 200mg of caffeine or a placebo. Using a method called short-latency afferent inhibition (SAI), they sent a mild electrical shock to the wrist shortly before a magnetic pulse to the brain. The brain typically filters this signal to keep movements smooth, but caffeine enhanced this filtering process, increasing the brain's ability to restrict muscle response after a touch.
The scientists suspect caffeine acts by blocking adenosine receptor proteins, leading to an increase in acetylcholine, a chemical messenger that helps coordinate senses and muscle movement. This effect aligns with known cholinergic-enhancing drugs like donepezil, which also enhance SAI. The findings offer insights into caffeine's physiological action and its potential links to disorders such as Alzheimer's and Parkinson's.
The researchers hope to conduct further studies with more participants and higher doses of caffeine. They concluded that, for now, subjects should continue to abstain from caffeine before SAI examinations to avoid influencing results.
