The era centers on integrating physiological mechanisms with behavior to account for emotional experience and expression, bridging neuroscience and psychology. It shifts from simple, discrete-category models toward dimensional and network-based conceptions of affect, highlighting how bodily states shape perception, attention, and action. Methodological emphasis on quantitative measures, animal models, and early neuroanatomical theories laid the groundwork for later integrative approaches in affective science. Historical Significance: Foundational efforts introduced concrete neurobiological mechanisms, quantifiable emotionality, and dimensional structure that endured as core principles of affective theory. The focus on bodily states as drivers of emotion and the demonstration that emotion biases cue processing and behavior established a durable framework for subsequent research.