Research Article Bottom-Up and Top-Down Processes in Emotion Generation Common and Distinct Neural Mechanisms

ABSTRACT—Emotions are generally thought to arise through the interaction of bottom-up and top-down processes. How-ever, prior work has not delineated their relative contribu-tions. In a sample of 20 females, we used functionalmagnetic resonance imaging to compare the neural correlates of negative emotions generated by the bottom-up perception of aversive images and by the top-down interpretation of neutral images as aversive. We found that (a) both types of responses activated the amygdala, although bottom-up responses did so more strongly; (b) bottom-up responses activated systems for attending to and encoding perceptual and affective stimulus properties, whereas top-down re-sponses activated prefrontal regions that represent high-level cognitive interpretations; and (c) self-reported affect correlated with activity in the amygdala during bottom-up responding and with activity in the medial prefrontal cortex during top-down responding. These findings provide a neu-ral foundation for emotion theories that posit multiple kinds of appraisal processes and help to clarify mechanisms un-derlying clinically relevant forms of emotion dysregulation. How do emotions arise? Do they arise via low-level processes that provide quick, bottom-up affective analyses of stimuli? Or do they arise via high-level, top-down cognitive appraisal processes that draw upon stored knowledge? This has long been one of the most contentious issues in the field (Lazarus, 1982; Zajonc, 1984), and these opposing viewpoints have only grad-ually yielded to a synthetic perspective holding that both types of processes are important for emotion generation (Scherer