Behavior analysis - the science of adaptive behavior - focuses on behavior as a subject matter in its own right, not as an index of cognitive events, and is thus, not dualistic. Behavior analysis incorporates several laws of learning discovered by researchers using single-subject experimental designs. I argue that behavior analysis can provide neuroscientists with an experimental and a theoretical framework within which to investigate the neural bases of behaviors including those that are usually described in cognitive terms. The importance of Behavior for Neuroscience Behavior includes anything an organism does whether it is observed or not. The emphasis on behavior should be appreciated within biopsychology given that behavior is a crucial evolutionary determinant of survival. It is what organisms do - for example, finding shelter. escaping predation, mating, or. caring for offspring - that is important. As a result, the nervous system has evolved to meet the demands of interacting with and adapting to the environment. As Engel and Schneiderman (1984) noted, "the raison d'etre of the CNS is to optimize the organism's ability to interact with its environment" Roughly speaking, the nervous system has evolved to carry out two functions related to an "organism's ability to interact with its environment": detecting energy changes and controlling movement, with specific. sensory and motor areas of the cortex devoted to each of these functions. Other cortical areas, however, are programmed largely by learning experiences (i.e.n Pavlovian and operant conditioning). Research using Positron Emission Tomography (PET) scans that compare brain activity in newborns to that in older children and adults (e.g., Chugani et al., 1987; Chugani, 1999) has shown the most activity in the neonate's brain occurs in the primary sensory and motor cortexes, thalamus, and brainstem, areas associated with the primitive reflexes seen in infants. Activity in the frontal association cortex and other areas associated with "higher cortical and cognitive function" is relatively nonexistent. As infants interact with their environments, more activity is seen in areas of the cortex that mediate these behaviors. Such research supports the suggestion that learning is. responsible for the significant. changes. in the brain related to complex behavior (Schlinger, 2004) and underscores the importance of behavioral plasticity. The physical basis of behavioral plasticity is neuroplasticity; that is, interactions between an organism's behavior and its environment cause. changes in the structure of the brain. There is a wealth of evidence of such changes in nonhumans (e.g., Turner and Greenough, 1985; .old and Whishaw, 1998; Rioult-Pedotti et al., 2000). Moreover, research shows that treatments based on operant conditioning can produce distinct changes in the human brain (e.g., Schwartz et al., 1996; Temple et al., 2003) To better investigate how the nervous system mediates adaptive behaviors, neuroscientists need to understand the functions of the behaviors themselves. Because organisms interact with their environment by behaving, then, "only when these organismic-environmental interactions are studied both behaviorally and physiologically, in a broad biological context, will it be possible to develop rational models of behavioral causation (Engel and Swhneiderman, 1984, p.199).