During this period the field coalesced around standardizing sleep-stage definitions and scoring to enable cross-laboratory comparability, providing a stable framework for studying sleep-disordered breathing. Researchers increasingly integrated respiratory physiology with sleep research, examining how breathing pauses, arousals, and sleep stage dynamics interact. Attention also turned to autonomic and cardiovascular responses during sleep, and early pediatric observations linked prolonged apnea with infant sleep disturbances, hinting at broader lifespan implications for sleep-disordered breathing.