UC Berkeley

Even the simplest human behavior is likely governed by the complex integration of cognitive, sensory, affective and motor factors. Yet, researchers have typically studied these factors in isolation with limited attention to the link between them. The goal of this dissertation was to investigate this link through a mixture of behavioral and neural measures. The focus was on the selection and planning of actions, as well as the subsequent monitoring and evaluation of the outcome and the consequences of the actions. These planning and evaluation processes are perhaps where the link between cognitive, sensory, affective and motor systems is most evident. Chapter 1 provides a general introduction to the topic. Chapter 2 reviews studies that emphasize multiple levels of constraints in motor control, specifically in bimanual coordination, suggesting a link between two systems (i.e., motor and cognitive) that have been generally studied separately by researchers. Chapter 3 describes two experiments on action selection showing that decision-making, which has traditionally been seen as a purely cognitive task, is directly influenced by, and in fact emerges from, the activation of the motor system. Chapter 4 provides experimental evidence that the medial prefrontal cortex (MPFC) acts to signal the need of increased resources to other brain centers and establish action-outcome contingencies that can be used to regulate future behavior. This finding, along with the anatomical connections of the MPFC, suggests that the MPFC is in a unique position to interface cognition and action and to translate intentions into behavior by modulating effort and arousal levels. Chapter 5 focuses on action observation and the role of empathy in the function of the mirror neuron system and the MPFC performance monitoring system during the observation of actions. The findings of Chapter 5 suggest that empathy plays a role in the function of the MPFC performance monitoring system but not in the activation of the mirror neuron system during action observation. These findings provide insight into how cognitive, sensory, motor and affective systems might interact to regulate behavior. Taken together the chapters of this dissertation highlight the strong link between cognitive, affective and motor systems in producing behavior. Through this work, we provide new insight into how humans plan and regulate movements and suggest that the study of the integration between cognitive, sensory, affective and motor systems is critical for our understanding of human cognition and behavior.