Internal models—computational representations supposedly stored in the nervous system—dominate current theories of how animals control movement. This perspective argues that such representational approaches fundamentally mischaracterize biological systems for six reasons: they require an infinite regress of internal interpreters; decades of research have failed to find neural evidence for them; biological movement is nonlinear and multiscale, not reducible to conventional computations; they implicitly rely on Cartesian dualism by separating a controller from what is controlled; the framework is circular and unfalsifiable; and alternative ecological dynamics and self-organization explain adaptive behavior without representations. Sensorimotor control instead emerges from dynamic coupling between organism and environment across multiple scales.
Cardiorespiratory synchronization is high during Zen and Kinhin meditation even in people with no meditation experience, while it is low during spontaneous breathing and only slightly higher during a mental task. The effect is driven by the low breathing frequencies that meditation induces, which produce pronounced in-phase respiratory sinus arrhythmia. Low breathing frequencies during meditation decrease high-frequency heart rate variability but increase low-frequency variability and the extent of respiratory sinus arrhythmia. Heart rate primarily reflects physical effort. The findings suggest that the physiological effects of meditation do not require prior experience.