Overview of "Babies got beat: Why rhythm might be innate" (Shortwave, NPR)
This episode of Shortwave (hosts Regina Barber and Rachel Carlson, with Juana Summers) presents a brief science-news roundup focused on three recent studies: (1) newborns’ ability to predict musical rhythm but not melody, (2) loss of the hunger hormone ghrelin in some reptiles and what that may mean for fasting, and (3) evidence that dreaming about specific problems (cued during sleep) improves problem-solving. Each story highlights study findings, expert commentary, and implications or caveats.
Key findings
Babies track rhythm at birth (PLOS Biology)
- Study: Newborns (sleeping) heard piano music by Bach while researchers recorded EEG to detect predictive brain signals for upcoming notes.
- Result: Babies’ brains predicted rhythmic patterns—even complex ones—but showed no evidence of predicting melody in the brain regions measured.
- Interpretation: Rhythm may be an ancient, innate capacity because biological systems (heartbeat, movement, prenatal exposure to parent’s walking/heartbeat) are inherently rhythmic. Melody perception likely develops later or in other brain areas.
- Caveat: The study focused on Western classical music; absence of melody-tracking in the measured signals doesn’t prove melody perception is entirely absent.
Some reptiles lack ghrelin, a hunger hormone (Royal Society publication)
- Study: Genomic survey of 100+ reptile species.
- Result: Certain snakes and chameleons appear to have lost the gene for ghrelin, a hormone that stimulates appetite in humans and many other animals.
- Implication: Loss of ghrelin might help explain extreme fasting behaviors in some reptiles (months-long fasts followed by large meals). Studying reptile metabolic pathways could inform human appetite and metabolic research.
- Interesting link: Modern GLP-1 drugs (e.g., inspired partly by Gila monster venom) show how animal biology can inform human therapies.
- Caveat: Gene loss is correlational; functional studies are needed to confirm causal links to feeding behavior.
Dreaming + targeted sound cues can boost problem solving (Neuroscience of Consciousness)
- Study: 20 lucid dreamers attempted short brain-teaser puzzles while each puzzle was paired with a unique soundtrack. During REM sleep, researchers replayed those sound cues to prompt dreams about specific puzzles.
- Result: Participants were more than twice as likely to solve puzzles they reported dreaming about (cue-triggered) compared with puzzles they didn’t dream about.
- Interpretation: Dreams can help process information and foster creative problem solving; targeted memory reactivation during REM may enhance that effect.
- Caveat: Small, special-population sample (lucid dreamers); more research needed to generalize.
Notable quotes / insights
- Laurel Trainor (developmental neuroscientist): “Babies crawl rhythmically, they flail their arms rhythmically, their heartbeats are rhythmic…predicting rhythm is an ancient trait.”
- Robert Stickgold (dream researcher): “Dreams aren’t just entertainment. They’re a catalyst for processing information and inducing creativity.”
- Fun puzzle example from the episode: G-E-S-G → “scrambled eggs” (illustrates how semantic creativity can arise from reinterpreting cues).
Limitations and caveats to keep in mind
- Small sample sizes or special participants (newborns in specific EEG paradigms; 20 lucid dreamers) limit broad generalization.
- Music study used Western classical stimuli — cross-cultural or non-Western music might yield different results for melody perception.
- Genomic correlations (loss of ghrelin) don’t prove causation for fasting behavior; functional and physiological follow-ups are required.
- Sleep-cueing techniques are experimental; practical application for the general public remains preliminary.
Practical takeaways and recommendations
- For parents/caregivers: Rhythm-rich environments (speech, movement, heartbeat-like patterns) may tap into an early-developing capacity in infants; variety of musical exposure is still important as melody perception develops.
- For researchers: Follow-ups should include diverse music types, broader participant samples, and functional tests linking ghrelin gene presence/absence to physiology.
- For learners/creatives: Targeted memory reactivation (pairing learning with unique cues, then replaying cues during sleep) is a promising strategy to explore—though current evidence is preliminary and mainly in controlled lab settings with lucid dreamers.
Sources & further reading
- PLOS Biology — study on newborns predicting rhythm vs. melody.
- Proceedings/Royal Society publications — reptile ghrelin gene loss study.
- Neuroscience of Consciousness — study on REM cueing and problem-solving.
- Commentaries quoted: Laurel Trainor (McMaster University), Ken Paller (Northwestern University), Robert Stickgold (sleep/dream researcher).
Produced as a concise guide to the episode’s main science stories, implications, and limits — useful for readers who want the core findings without listening to the full segment.