Laughter isn't just laughter. According to a new study published June 23 in Trends in Neurosciences, your brain uses two completely separate networks to produce genuine, helpless giggles versus polite, conversational chuckles. This discovery helps explain why some laughter feels uncontrollable and why we can laugh on command without finding anything funny.
The Research: Mapping Laughter in Real Time
An international team led by Sophie Scott at University College London analyzed data from pre-surgical brain stimulation in awake epilepsy patients. During these procedures, doctors electrically probe brain tissue to locate seizure origins. Inadvertently, these probes sometimes trigger involuntary laughter, and patients can describe exactly what they feel. The researchers aggregated hundreds of such reports, along with animal studies, to identify two distinct neurological pathways.
The first, the spontaneous network, includes the pregenual anterior cingulate cortex, nucleus accumbens, and temporal pole. Stimulating these areas produces genuine, euphoric laughter — the kind that's hard to stop and feels emotionally rich. This network is evolutionarily ancient, emerging from rough-and-tumble play in mammals to signal safety and defuse aggression.
The second, the volitional network, involves the rolandic operculum, globus pallidus, and presupplementary motor area. Stimulation here produces laughing and smiling movements but zero positive emotion — it's purely mechanical. This network overlaps with speech-motor regions, allowing you to insert perfectly timed chuckles at the end of sentences during conversation.
Why It Matters for Your Brain
This dual system explains why genuine laughter can relieve pain: the spontaneous pathway runs through the anterior cingulate cortex, a key node in the brain's natural pain-dampening system. It also clarifies why certain neurological conditions — like gelastic epilepsy or pathological laughter in Alzheimer's — can trigger uncontrollable mirth. For healthy brains, the volitional network shows how social laughter is a learned, controlled skill, much like language. The next time you laugh at a joke you don't really find funny, you're exercising a highly sophisticated cognitive-motor circuit.
What You Can Do
You can strengthen your volitional laughter skills just by socializing. Engaging in lively conversations that require back-and-forth timing — like storytelling or banter — exercises the same prefrontal and motor networks. Want to tap into genuine laughter? Seek out playful, low-stakes interactions. The more you laugh spontaneously, the more you activate your brain's analgesic system, potentially lowering stress.
Source: Neuroscience News
Curious about your own brain? Take our free adaptive IQ test or try 306 brain training levels.
