Role of sensory prediction on perceptual and motor mechanisms

The ability to interact with the environment through action is an essential aspect of human existence. Predication of sensory action outcome allows us to optimally influence and manipulate the environment for a meaningful interaction. Four studies were performed to investigate the role of predication on limb state estimation, sense of agency, attentional selection, and perceptual decision mechanisms. In study 1, prediction was updated by both relevant and irrelevant predication error in a visuomotor adaptation tack. Results showed the altered perceptual estimate of limb position after adaptation. Results suggest that somatosensory mechanisms use the predictions about the sensory consequences of movement commands and do not rely solely on the information provided by the sensory systems. Study 2 manipulated the feedback about the action performed and found that error monitoring mechanisms evoked through feedback recalibrate the prediction in real time and optimize the sense of self- agency. Study 3 investigated the role of predication on attentional selection mechanisms by employing irrelevant feature singleton paradigm of visual search. Feature singleton was either presented as results of an action or it appeared automatically. Results suggest that singleton captures attention when preceded by action. It suggests that predication could be considered as a third factor apart from top-down goals and bottom-up features of the stimulus which determines how attention is allocated to the environment. Study 4 investigated how updating sensory predictions through motor adaptation influences perceptual processing and subsequent decisions based on the outcome of those perceptual processes in a visual search task. Results demonstrate the strong influence of adaptation and updating of predictive mechanism that adaptation entails on perception and decisions based on perceptual processing. Perceptual decisions can be clearly modified by manipulating the relationship between movement commands and their sensory consequences, and the degree of the odification may depend on how strongly the adapted state is reinforced. This thesis provides a holistic perspective about the contribution of prediction in various cognitive processes. It also provides conclusive and novel evidence to supports the hypothesis that cognition emerges out of out interaction with the world.by Neeraj KumarPh.D