Neural and Psychological Mechanisms of Pain Perception

Objective

Pain is one of the most important signals for an organism s survival. The pathways that transfer noxious input from the periphery to the central nervous system are highly conserved across human and animal models. In humans, the ultimate experience of pain is also highly influenced by psychological factors. For example, the placebo effect leads to robust pain relief and can influence responses to noxious stimuli in the human brain. However, the psychological and neurobiological mechanisms by which psychological factors influence pain remain largely unknown.

Pain can be modulated by explicit beliefs about treatments, prior experience and learning, interpersonal processes that support the patient-provider relationship, and contextual factors related to the treatment environment. In the proposed series of experiments, we will systematically investigate the neural and psychological mechanisms that mediate the effects of these factors on acute pain. We will focus on expectations, attention, emotion, conditioning/associative learning, and social factors. These experiments will principally use functional magnetic resonance imaging (fMRI) and psychophysiological measurements, as well as behavioral assays and self-reports. We will examine the effects of different types of pain-related expectations on decisions about pain as well as responses in the brain and periphery. We will also compare acute pain with other hedonic and perceptual processes. This will allow us to distinguish processes that are unique to pain perception from those that are not specific to pain, such as processes involved in perception and decision-making across domains.

Together, the proposed series of experiments aim to elucidate the psychological, neurobiological, and physiological mechanisms that modulate pain. This, in turn, can identify targets for pain treatment and inform mechanistic studies of altered pain processing in clinical populations.

Study Population