People often perform routine actions without consciously thinking about them, such as moving objects or driving a car. In the late 19th century, psychologists William James and Wilhelm Wundt proposed opposing theories about how we become aware of our actions. James believed awareness occurs after a movement through sensory feedback, while Wundt argued that it begins before movement during brain planning.
For more than 130 years, scientists could not test these ideas. Recently, researchers Hal Blumenfeld and David S. Jin from Yale University solved the debate. They tested 67 participants who played a puzzle game while researchers measured their brain activity using electroencephalography (EEG). The results showed that both early scientists were correct.
Awareness requires two signals: a motor-planning signal before the action and a sensory signal after it. The study also found that tired or distracted participants had smaller pupils and lower awareness. Knowing how these brain signals work is important because they are often disrupted in conditions like Parkinson's disease, stroke, or schizophrenia.
Difficult words
- routine — Done regularly as part of a normal habit.
- aware — Knowing or noticing that something exists or is happening.
- debate — A discussion or argument about a specific topic.
- participant — A person who takes part in an activity.participants
- distracted — Unable to concentrate because attention is elsewhere.
- disrupt — To interrupt something and prevent it from continuing normally.disrupted
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Why do you think it is helpful that our brains can perform routine actions without conscious thought?
- How might this research help doctors care for patients with brain conditions in the future?
Related articles
Light tool measures activity inside living brain cells
Researchers developed a bioluminescent calcium sensor called CaBLAM to record activity inside living brain cells without external light. The tool works in mice and zebrafish and enables long recordings that avoid damage from bright light.
Targeting a brain circuit to reduce opioid relapse
Researchers at Washington State University found that lowering activity in a specific brain connection cut heroin-seeking in a preclinical model. The study identifies a pathway between the prelimbic cortex and the paraventricular thalamus and tests two ways to reduce its activity.