Abstract: People cannot maintain his/her orientation or specify a spatial location without using, at least basically, a frame of reference.. Egocentric reference frame and allocentric/exocentric reference frame are used most coordinately and frequently for the purpose of successful navigation. Many recent studies have focused on how and why misalignment and target position relative to reference object affect cardinal direction judgments. In these studies, participants see a north-up map indicating one observer’s heading relative to a ground target, which was presented as camera scene with corresponding forward view. A typical task is to determine the cardinal direction between two objects in the scene. They have reported 0o (up) and 180o (bottom) advantage effect and mismatch effect. However these studies have little consideration about information processing and many of them only use cardinal direction task. In the current study, we defined three types of navigation components: specifying paths from reference object to target object (route specifying), identifying one’s own heading (heading identifying), and determining the direction of the target object in the scene (direction determining). We aimed to investigate whether different component’s processing could influence the aforementioned effects on absolute direction judgment. Different information presenting orders were used in corresponding experiments.
Two within-subject experiments were conducted. Participants were asked to use a map/direction-word to determine the absolute direction (i.e., North, Northeast) between two objects in a visual scene. Information processing in Exp.1 contained all three components with heading presented in a map in Exp. 1a and direction-word (i.e., Southeast) in Exp. 1b. Exp. 2 contained two kinds of task with one route specifying component (Task-R) and the other heading identifying component (Task-H). Each task was presented on a computer screen and had 8 target position (0o/up, 45o (R45o), 90o (R90o), 135o (R135o), 180o, 225o (R135o), 270o (R 90o), and 315o/left-up (R45o)) and 8 heading (North(N), Northeast(NE), East(E), Southeast(SE), South(S), Southwest(SW), West(W), Northwest(NW)). Participants used the number pad on the keyboard to show directions, for example pressing 8 for N and 9 for NE. Accuracy and response time were collected by E-prime as judgment performance. A total of 64 college students participated in this study to complete three trials (64 problems per trial). Repeated measures statistical analysis was used.
The main finding could be summarized as follows: (1) the North direction advantage effect was found for all tasks and the pattern could be described as N < E / S / W < Non-canonical direction (< means shorter response time, and / means no significant difference); (2) the response time was shortest at the 0o/up position (except for Exp. 1a and 1b where no significant difference was found between 0o and 180o/bottom position) and the advantage effect at 180o/bottom position was more evident for Task-H and Task-R (i.e., R180o < R45o, R90o and R135o) than for Exp. 1a and 1b (i.e., R180o < R90o and R135o); (3) the Canonical direction-R90o advantage effect, which means the left/right position advantage effect depends on the canonical direction, was found for Exp 1a and 1b and Task-H. This effect was first reported in our studies.
In absolute direction judgment, the traditional effect patterns have not changed by different ways to present information components. However the current findings, especially the discovery of Canonical direction-R90o advantage effect, would help shed light on the understanding of cognitive structure for absolute direction judgments. Future work should pay more attention to cognitive strategies for this new effect. Our work could be applied to personnel selection and training, and designing interface display for navigation assistance.

Key words: absolute direction judgment, egocentric reference frame, allocentric reference frame, information presentation