Conceptually, bottom-up processes are stimulus-driven. Raw information from sensory organs is organized as it passes through sensory-specific brain networks to multi-modal association areas that bind manifold information streams into unitary percepts of bodily and environmental conditions within an organism’s sensorium. In the development and maintenance of addiction, bottom-up processes are thought to bias attention towards drug-associated stimuli which, in turn, elicit top-down processes that promote drug-seeking behavior (Nestor et al., 2011; Rauss & Pourtois, 2013).
