Autobiographically recalled emotional states impact forward gait initiation as a function of motivational direction.

The impact of self-generated affective states on self-initiated motor behavior remains unspecified. The purpose of the current study was to determine how self-generated emotional states impact forward gait initiation. Participants recalled past emotional experiences (anger, fear, happy, sad, and neutral), "relived" those emotional memories before gait initiation (GI), and then walked ∼4 m across the laboratory floor. Kinetic and kinematic data revealed GI characteristics consistent with a motivational direction hypothesis. Specifically, participants produced greater posterior-lateral displacement and velocity of their center of pressure (COP) during the initial phase of GI after self-generation of happy and anger emotional states relative to sad ones. During the second phase of GI, greater medial displacement of COP was found during the happy condition compared with sad, greater velocity was occasioned during happy and angry trials compared with sad, and greater velocity was exhibited after happy compared with fear memories. Finally, greater anterior velocity was produced by participants during the final phase of GI for happy and angry memories compared with sad ones. Steady state kinetic and kinematic data when recalling happy and angry memories (longer, faster, and more forceful stepping behavior) followed the anticipatory postural adjustments noted during GI. Together the results from GI and steady state gait provide robust evidence that self-generated emotional states impact forward gait behavior based on motivational direction. Endogenous manipulations of emotional states hold promise for clinical and performance interventions aimed at improving self-initiated movement.