TARGET PROXIMAL DISTAL RT (ms) 380 400 420 440 460 480 PROXIMAL RESPONSE DISTAL RESPONSE TARGET PROXIMAL DISTAL MT Std Dev (ms) 40 60 80 100 120 PROXIMAL RESPONSE DISTALE RESPONSE Aurélien RICHEZ 1 , Yann COELLO 1 & Gérard OLIVIER 2 1: laboratoire URECA EA 1059, Université Lille-Nord de France, France 2: Laboratoire Bases Corpus Langage, UMR 6039 Université Nice sophia Antipolis aurelien.richez@univ-lille3.fr Objects afford kinematic properties of potential actions RESPONSE RT / MT / Error 500 ms 500-1500 ms PROTOCOL INTRODUCTION A coupling between perception and action is a common idea in cognitive psychology and a way to implement it is trough the study of stimulus-response compatibility effect (for a review see 1). This refers to the potential influence of the presentation of visual stimulus on the planning and the execution of a later motor response. Indeed a growing body of evidence has indicated that the perception of a stimulus can functionally potentiate an action allowing interaction with that stimulus (2;3). These compatibility effect are observed when target an response share intrinsic properties, such as size and shape to potentiate a certain type of grasping movement (power vs precision grip as 3) and are often interpreted as a visuo-motor priming effect between a simulated action prime by the perception of the stimulus and the executed action (4) or as a facilitation of visual perception trough a motor-visual attentional effect (5). In the present study we varied extrinsic properties shared by the stimulus and the motor response with variation of the reaching distance within peripersonal space of both the presented target and the switch used by the participants to give their responses. We thus expect a motor compatibility effect between the simulated and the executed reaching movement. We hypothesized that this effect will be observed in the preparation as well as the execution part of the response. METHOD Thirty-two right handed adults participants with normal or corrected to normal vision. 8 colored pictured representing a chessboard with a bishop was used as stimuli: 4 positions (2 proximal and 2 distal positions) * 2 color (black and white). One additional picture represented an empty chessboard. In starting position the participant’s right hand was placed on the table, with the index resting on the first switch. From this starting position, the participant could perform 2 manual response: a proximal response (grasping the nearest switch) and a distal response (grasping the farthest switch). The participant pressed the start button and held it down to make the picture of the empty board appear. 500 ms after a fixation cross appear on the board at the same position as the starting position on the response device. After a random period (500 to 1500 ms) the stimulus was presented. The participant was informed that he will be doing a perceptual decision task and instructed to answered according to the color of the stimulus as quickly as possible. Two experimental groups were created: the first group was instructed to respond to white stimuli grasping the proximal switch and the second to respond white stimuli grasping the distal switch. All stimuli were repeated 4 time and presented in a random order (for a total of 40 trial). The experimental plan was as follows P 16 *I 2 <T 2 *R 2 >, with P for participants, I for instruction, T for target’s position and R for manual response. RESULTS The ANOVA on the mean Reaction Time revealed no effect of neither instruction, target’s position nor manual response alone, but revealed a significant interaction of target’s position and manual response (F(1,30)=56.26, p<.001, ηp 2 =.66). DISCUSSION The purpose of the present experiment was to show that during a perceptual decision task, the mere presentation of a visual target activate representation of the manual movement that would allow to reach the visual object. Indeed the results confirm that visual objects primed the reaching movement they afford (6). Without any effect of manual response on the reaction time, it suggest that the reaching amplitude of the movement did not influence the duration of its preparation. In the present study, contrary to what have been previously done(3, 4, 5), the activation of motor representation functionally linked to the visual object did not influence the decision process. Indeed, mentally simulate reaching an object does not help to judge its color. Consequently the motor activation probably influence the preparation of the participant’s manual response: the preparation of the response was faster when the participant first activate a reaching response whose amplitude is compatible with the actual response he had to give. The presence of a “late effect” on the movement time and their variation also reveal that this visuo-motor priming effect affect both the preparation and the execution of the reaching movement. In conclusion this study demonstrate that the visuo-motor priming effect of a hand movement by a the visual perception of an object is not limited to the grasping component but also concern its reaching component, and thus permit us to anticipate the kinematic properties of hand transportation in the peripersonal space. It also confirm the importance of the perception-action coupling(6). REFERENCES 1. Proctor, R. W., & Vu, K.-P. L. (2001). TEC: Integrated view of perception and action or framework for response selection? Behavioral and Brain Sciences, 24(5), 899-900. 2. Hommel, B., Müsseler, J., Aschersleben, G., Prinz, W., 2001. The theory of event coding (TEC): a framework for perception and action planning. Behavioral and Brain Sciences. 24( 5), 849–937. 3. Tucker, M., Ellis, R., 2001. The potentiation of grasp types during visual object categorization. Visual Cognition. 8, 769–800. 4. Tucker, M., Ellis, R., 1998. On the relations between seen objects and components of actions. Journal of Experimental Psychology: Human Perception and Performance. 24, 830–846. 5. Craighero, L., Fadiga, L., Umilta, C., Rizzolatti, G., 1999. Action for perception: a motor-visual attentional effect. Journal of Experimental Psychology: Human Perception and Performance. 25, 1673–1692. 6. Olivier, G. (2006). Visuomotor priming of a manual reaching movement during a perceptual decision task. Brain Research, 1124, 81-85. RESPONSE PROXIMAL DISTAL MT (ms) 300 350 400 450 500 550 PROXIMAL TARGET DISTAL TARGET This work was supported by the University Lille 3 and grants from Maison Européenne des Sciences de l’Homme et de la Société (MESHS) - Nord Pas de Calais and European Science Foundation, Eurocores CNCC CRP. The ANOVA on the mean Movement Time revealed no effect of neither instruction nor target’s position alone, but revealed a significant effect of manual response (F(1,29)=272.48, p<.001, ηp 2 =.91) and a significant interaction of target’s position and manual response (F(1,29)=28.72, p<.001, ηp 2 =.51). The ANOVA on the variation of Movement Time revealed no effect of neither instruction, target’s position nor manual response alone, but revealed a significant interaction of target’s position and manual response (F(1,29)=12.65, p=.0014, ηp 2 =.31).