Human short-term spatial memory: Precision predicts capacity

Abstract

Here, we aimed to determine the capacity of human short-term memory for allocentric spatial information in a real-world setting. Young adults were tested on their ability to learn, on a trial-unique basis, and remember over a 1-min interval the location(s) of 1, 3, 5, or 7 illuminating pads, among 23 pads distributed in a 4 m  4 m arena surrounded by curtains on three sides. Participants had to walk to and touch the pads with their foot to illuminate the goal locations. In contrast to the predictions from classical slot models of working memory capacity limited to a fixed number of items, i.e., Miller's magical number 7 or Cowan's magical number 4, we found that the number of visited locations to find the goals was consistently about 1.6 times the number of goals, whereas the number of correct choices before erring and the number of errorless trials varied with memory load even when memory load was below the hypothetical memory capacity. In contrast to resource models of visual working memory, we found no evidence that memory resources were evenly distributed among unlimited numbers of items to be remembered. Instead, we found that memory E-mail address: pamela.bantalavenex@unil.ch (P. Banta Lavenex).for even one individual location was imprecise, and that memory performance for one location could be used to predict memory performance for multiple locations. Our findings are consistent with a theoretical model suggesting that the precision of the memory for individual locations might determine the capacity of human shortterm memory for spatial information.

Spatial working memory capacity predicts bias in estimates of location.

“…Previous studies that have examined how age or cognitive constructs relate to spatial memory have usually examined error in responses, calculated as the distance from stimulus to response (e.g., Lavenex et al, 2015; Olson et al, 2004; Siedlecki & Salthouse, 2014). The present study takes a different approach in that it conceptualizes responses as the product of an assembly of information sources, including a noisy memory trace, a spatial organization, and an additional fixed bias.…”

“…According to the optimal Bayesian weighting embedded in CAM, categories are weighted more heavily, and thus estimates are more biased, when memory is less precise. As noted in the introduction, a relation between precision and storage capacity is predicted by many models of SWMC, such as resource models (e.g., Bays & Hussain, 2008; Bays et al, 2011; Fougnie et al, 2010), updated slot models (Zhang & Luck, 2008), the map-architecture account from Franconeri and colleagues (e.g., Franconeri et al, 2013) and a recent model from Lavenex and colleagues (Lavenex et al, 2015). The literatures on spatial working memory capacity limits and on bias in location memory have been largely separate even though both invoke the same theoretical construct of memory precision, and the connection between these invocations of precision has been unexamined.…”

“…Resource models (Bays & Hussain, 2008; Bays, Wu, & Hussain, 2011; Fougnie, Asplund, & Marois, 2010) and Dynamic Field Theory (Johnson, Simmering, & Buss, 2014; Simmering & Perone, 2013; Spencer, Perone & Johnson, 2009), hold that the resource of working memory can be flexibly allocated to remember fewer objects with greater precision or more objects with less precision: individuals who have more of this resource will perform better on measures of capacity and on measures of precision. The map-architecture account of spatial working memory capacity from Franconeri and colleagues (e.g., Franconeri, Alvarez & Cavanagh, 2013), suggests that being able to maintain more precise location information in memory produces the ability to store more simultaneous object locations in memory, i.e., that precision gives rise to greater capacity, specifically in the spatial domain (see also Lavenex, Boujon, Ndarugendamwo, & Lavenex, 2015). Thus, with the exception of the classic slot models, several models of visual working memory capacity predict that people who are able to hold more items in memory simultaneously will also be able to remember a single location more precisely.…”

The “when” and the “where” of single‐trial allocentric spatial memory performance in young children: Insights into the development of episodic memory

“…All adult participants gave informed written consent. Adult participants’ data have been previously published elsewhere (Banta Lavenex et al, ).…”

Improvement of allocentric spatial memory resolution in children from 2 to 4 years of age

“…For each stage, we first analysed the number of correct choices made before erring (CBE), as a proxy to estimate memory capacity (Banta Lavenex, Boujon, Ndarugendamwo, & Lavenex, 2015;Banta Lavenex et al, 2014), and calculated an average value per child for the last 8 trials in the AS condition (omitting the first 2 trials). We also determined the average of the total number of locations visited (TNV) in order to find the reward for the last 8 trials in the AS condition.…”