The correlation analyses between fMRI and psychophysical results contribute to certify the activated area for motion-defined pattern perception

Abstract

Motion-defined pattern perception includes two perceptions: motion and pattern perception. The purpose of this study was to clarify the difference in activated areas between motion and pattern perception. Psychophysical experiments were carried out by employing a random dot kinematogram (RDK) to ask the direction of coherently moving dots in a core rectangle toward upper left or lower right (a direction discrimination task), and the shape of that rectangle oblong vertically or horizontally (a pattern discrimination task) by varying dot velocity in four levels (14.4, 28.8, 43.2 and 57.6 deg/s). The results of the psychophysical experiments revealed that the mean correct rate of 10 participants was significantly larger for motion discrimination than that for the pattern perception in three velocity levels (14.4, 28.8 and 43.2 deg/s). The functional MR measurements were carried out by employing the same RDK stimuli. Most of the activated areas located in the left occipital lobe. The correlation analyses were undertaken between the slopes of regression (sizes of effect) and correct rates of two tasks. The significant correlation was emerged at Brodmann's area (BA) 19. In contrast, the correlations between these slopes and those of direction discrimination were significant at BA9, BA39 and anterior parts of BA19. These results suggest that motion-defined pattern perception is processed at BA19. © 2011 Springer-Verlag.