AMPHETAMINE AND HALOPERIDOL MAY ALTER TEMPORAL PROCESSING DURING A NATURALLY OCCURRING BEHAVIOR P.S.Wallace 1* ; E.F.Field 2 ; I.Q.Whishaw 2 ; D.G.Wallace 1 1. Dept Psychology, Northern Illinois University, De Kalb, IL, USA 2. CCBN, University of Lethbridge, Lethbridge, AB, Canada Introduction Animals rely on their ability to process the passage of time while engaging in behaviors. Previous research has focused on operant and classical conditioning paradigms to measure an animal’s perception of time. These techniques are useful in examining certain processes; however, recent studies have demonstrated that temporal processing can be investigated while an animal engages in naturally occurring behaviors. Dodging behavior is observed when two rats compete for a limited amount of food. A typical dodge involves a rat displacing its body to prevent a second rat from robbing the food item. Previous data have shown that rats will adjust their dodges as a food item becomes smaller and eating is nearly complete. This suggests that the rat uses the time left to eat the food item to modulate dodging behavior. The current study examined pharmacological manipulations that are known to change a rat’s temporal processing in predictable ways. Both amphetamine and haloperidol have been identified as drugs that alter an animal’s time perception. Methods Following administration of saline, amphetamine, or haloperidol, female Long-Evans rats were videotaped while consuming individual food items in the presence of a robber. Both the dodger’s and robber’s behaviors were analyzed using kinematic analysis software. Results Figure 2: Topographic and kinematic representation of a dodge. Top panel: changes in head, torso, and tail positions for the dodger and robber during a dodge. Bottom panel: moment- to-moment speeds of the dodger and robber during a dodge. Figure 1: Apparatus used during dodging task. Plexiglas cylinder (20 cm diameter) resting on a Plexiglas shelf with mirror at an angle below. Video camera records from mirror image. Figure 3: Topographic and kinematic representation of a brace. Top panel: changes in head, torso, and tail positions for the dodger and robber during a brace. Bottom panel: moment-to-moment speeds of the dodger and robber during a brace. Figure 5: Dodger’s and robber’s mean speeds during each of the five samples across drug conditions. Figure 4: Mean percent of sample duration spent engaging in dodges, braces, and other behaviors across drug conditions. Figure 7: Mean distance between the heads of the dodger and robber at the start of dodges and braces combined for each of the five samples across drug conditions. Figure 8: Mean distance between the heads of the dodger and robber during the dodges and braces combined for each of the five samples across drug conditions. Figure 6: Dodger’s mean distance traveled when dodging and bracing combined for each of the five samples across drug conditions. Conclusions A dodger’s movement strategies change during the consumption of a hazel nut. Amphetamine and Haloperidol influence a dodger’s ability to modify movement strategies. Kinematic analysis of dodger and robber movements do not support hyper- or hypokinetic explanations of drug effects. Modification of temporal or attentional mechanisms may account for the effects of Amphetamine and Haloperidol on dodge efficiency. Dodger head Robber head