Abstract
Perceptual decision making has been extensively studied. It has been reported that past occurrence of weak signals significantly biases perceptual decision-making (Nishina et al., 2009; Kim et al., 2011). How can such biases be terminated? Here we investigated the effects of meditative states on decision biases induced by weak past stimulus signals. We examined whether this bias effect could be reduced or overcome by meditation. Participants were instructed to engage in either meditation or relaxation for 15 minutes before the test. The signal to noise ratio of the stimulus varied from trial to trial: four levels of signal were used. When the signal is zero, perceptual decision is solely based upon past sensory signals. We manipulated the probability of two stimulus alternatives of the weak signals. The results show that the magnitude of the effect of past occurrence on perceptual decision making was significantly smaller in the meditation condition than in the relaxation condition. These results suggest that meditative states reduce decision bias induced by weak signals.
Meeting abstract presented at VSS 2013