Particle.news
Download on the App Store

Dogs’ Brains Show Distinct Responses to Human Smiles and Negative Faces

Published Aug. 7, an fMRI study suggests domestication tuned dogs' brains to treat human smiles as rewarding, showing neural patterns that distinguish fearful faces from other negative expressions.

Overview

  • Researchers at the University of Vienna published the peer‑reviewed iScience paper on Aug. 7 reporting two fMRI experiments that probed how dogs’ brains respond to human facial expressions.
  • In scans of trained, awake pet dogs, a right temporal‑cortex cluster extending into the caudate nucleus lit up for happy faces, indicating smiles engage a visual‑to‑reward circuit.
  • Machine‑learning analyses restricted to that temporal‑caudate region reliably separated happiness from anger, fear and sadness, while whole‑brain pattern analyses separated fear from anger and sadness but did not separate anger from sadness.
  • The study used small samples of largely companion border collies (Experiment 1 n=8; Experiment 2 n=12) viewing static photos, and the authors warn these limits mean results may not generalize to other breeds or real‑world, multisensory cues.
  • Authors interpret the findings as consistent with domestication shaping dogs’ social tuning and say next steps will test moving and multisensory signals and compare dog and human brain responses to the same emotional cues.