Cue usage in memory for location when orientation is fixed

Context effects on reproduced magnitudes from short-term and long-term memory

Extant research has demonstrated strong contextual dependencies in reproducing magnitudes of perceptual stimuli from short-term memory. Two experiments examined how context as defined by (a) the mean of the distribution, (b) stimulus ranks, (c) values of anchor stimuli used in the reproduction task, and (d) values from the most recent trial operate on estimates of square size. Experiment 1 demonstrated distributional contrast effects on ratings of squares and distributional assimilation effects on reproduction of squares from short-term memory for the same participants. The fit of a modified version of the category adjustment model demonstrated reliable effects of the running mean, start anchors, and previous stimulus on reproduction bias. In Experiment 2, participants first learned to associate labels with squares, then reproduced square sizes based on the label cues, a long-term memory task, followed by a reproduction from short-term memory task as in Experiment 1. Results for the short-term memory task were largely consistent with Experiment 1. Results for the long-term memory task showed a very different pattern of effects, with larger reproduced sizes when squares were drawn from positively skewed rather than negatively skewed distributions. This contrast effect was explained by a modified range-frequency model as the result of rank encoding of square values along with displacement away from the running mean and shifts towards the prior response and start anchors. The combined results identify multiple sources of context effects in estimation that depend critically on memory retrieval factors and show how they can be incorporated into existing models.

Sex differences in the weighting of metric and categorical information in spatial location memory

According to the Category Adjustment model, remembering a spatial location involves the Bayesian combination of fine-grained and categorical information about that location, with each cue weighted by its relative certainty. However, individuals may differ in terms of their certainty about each cue, resulting in estimates that rely more or less on metric or categorical representations. To date, though, very little research has examined individual differences in the relative weighting of these cues in spatial location memory. Here, we address this gap in the literature. Participants were asked to recall point locations in uniform geometric shapes and in photographs of complex, natural scenes. Error patterns were analyzed for evidence of a sex difference in the relative use of metric and categorical information. As predicted, women placed relatively more emphasis on categorical cues, while men relied more heavily on metric information. Location reproduction tasks showed a similar effect, implying that the sex difference arises early in spatial processing, possibly during encoding.

From maps to navigation: the role of cues in finding locations in a virtual environment

In two experiments, participants navigated through a large arena within a virtual environment (VE) to a location encoded in memory from a map. In both experiments, participants recalled locations by navigating through the VE, but in Experiment 2, they additionally recalled the locations on the original map. Two cues were located outside and above the walls of the arena at either north-south locations or east-west locations. The pattern of angular bias was used to infer how the cues affected the creation of spatial categories influencing memory for location in the two tasks. When participants navigated to remembered locations in the VE, two cue-based spatial categories were inferred, with cues serving to demarcate the boundaries of the categories. When participants remembered locations on the original map, two cue-based categories were again formed, but with cues serving as category prototypes. The pattern of results implies that cue-based spatial categorization schemes may be formulated differently at the memory retrieval stage depending on task constraints.

Cue effects on memory for location when navigating spatial displays

Participants maneuvered a rat image through a circular region on the computer screen to find a hidden target platform, blending aspects of two well-known spatial tasks. Like the Morris water maze task, participants first experienced a series of learning trials before having to navigate to the hidden target platform from different locations and orientations. Like the dot-location task, they determined the location of a position within a two-dimensional circular region. This procedure provided a way to examine how the number of surrounding cues (1, 2, or 3) affects the memory for spatial location in navigation. Memory performance was better when there were more cues and when targets were close to cues, consistent with the idea that cues bolster fine-grain memory, especially in proximal regions. Early and late measures of bias in memory reflected biases in a direction toward the nearest cue, implicating a cue-based category structure of the navigational space. Collectively, results suggest cue-based spatial memory representations that have been inferred from the dot-location task generalize to a navigation task within a simple, computer-based environment, as demonstrated by the good fits of the spatial model developed for the dot-location task (Fitting, Wedell, & Allen, 2005, 2007).