Introduction

1. 806.15 Introduction Experiment 1:Place training and matching-to-place testing in the bead maze Experiment 2:Place training and evaluation of response strategy after 20 trials in the bead maze Experiment 3:Place training and evaluation of response strategy after 10 trials in the bead maze Figure 2: Path topography is plotted for a representative participant during place training. Figure 3: Path topography is plotted for representative participant during matching-to-place testing. Figure 7: Average latency (left panel), distance traveled (middle panel), and path circuity (right panel) are plotted for the blindfolded and sighted groups during place training. Figure 10: Average latency (left panel), distance traveled (middle panel), and path circuity (right panel) are plotted for the sighted group during place training. The water maze is a ubiquitous task for investigating the neural basis of rat spatial orientation. Virtual reality versions of this task have been developed for humans, and the similarity in performance has suggested that processes involved in spatial orientation are conserved across species. The nature of the representation that mediates performance in these tasks remains debated. Although both species have been shown to use environmental cues to guide performance in this task, relatively few studies have examined the contribution of self-movement cues to performance. Observations from the current set of experiments are consistent with results obtained from humans in the virtual water maze and rats in the standard water maze. These parallels provide further evidence that processes involved in spatial orientation are conserved across species and scales of movement. The bead maze: Adapting the water maze task to the human manipulatory scaleE.L. Loda, A.B. Thoennes, J.R. Köppen, S.S. Winter, D.A. Hamilton, D.G. Wallace1Dept Psychology, Northern Illinois Univ., DeKalb, IL, USA2Dept Psychology, Univ. of New Mexico, Albuquerque, NM, USA Figure 8: The diagram represents the apparatus position for the first 20 trials and the shift in apparatus position that occurred on the 21st trial (top left). Representative paths taken by blindfolded (black circles) and sighted (white circles) participants are plotted for trial 20 (top right). The initial paths are plotted for both participants on the 21st trial and the subsequent path is plotted for the blindfolded (bottom left) and sighted (bottom right) participants. Figure 4: Average latency to reach the Velcro tape is plotted for females and males during initial place training (left panel) and matching-to-place testing (right panel). Figure 11: The average absolute heading direction is plotted for the first 10 place training trials (left panel). The average signed heading direction is plotted for the 10th and 11th trials (right panel). Methods Blindfolded (Experiments 1 and 2) or sighted (Experiments 2 and 3) participants were seated at the edge of a small table with a circular arena (0.483 m in diameter) within reaching distance. During training trials (Experiments 1, 2, and 3), participants started from random locations around the perimeter of the circle and were instructed to search for a piece of Velcro tape that remained in a fixed location. During matching-to-place testing (Experiment 1), location of the Velcro tape shifted after the participant searched for for two trials and continued until three positions were sampled. Recordings of each trial were analyzed using Peak Performance motion capture system such that topographic and kinematic profiles associated with finger movements could be quantified. Several measures were used to characterize performance: latency to find the Velcro tape, distance traveled to reach the Velcro tape, path circuity of the path to reach the Velcro tape, and initial heading direction. Figure 5: Average distance traveled prior to locating the Velcro tape is plotted for each trial for females and males during initial place training (left panel) and matching-to-place testing (right panel). Conclusions • Performance of the participants in the bead maze parallels the performance of rats tested in the standard water maze task. • Performance improved across place training trials. • Performance improved across matching-to-place testing. • Manipulating access to environmental cues influenced the nature of the representation mediating performance. • Limiting access to self-movement cues biased an absolute response in participants. • Providing access to environmental and self-movement cues biased a relative response in participants. • This effect was not due to over training. • The bead maze is a novel technique that assesses spatial orientation at the manipulatory scale. The bead maze could be used to characterize the spatial deficits mediating wandering behavior observed during the progression of neurodegenerative disorders like Alzheimer’s Disease. • Contact: Douglas G. Wallace • dwallace@niu.edu or wallacelab.weebly.com Figure 9: The average absolute heading direction is plotted for the first 20 place training trials (left panel). The average signed heading direction is plotted for the 20th and 21st trials (right panel). Figure 1: A photograph of a blindfolded participant seated at the testing apparatus is provided along with topographic (middle panel) and kinematic (right panel) characteristics of a single searching trial. Figure 6: Average path circuity is plotted for each trial for females and males during initial place training (left panel) and matching-to-place testing (right panel).