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Date Permissions Signed


Date of Award

Summer 2018

Document Type

Masters Thesis

Degree Name

Master of Science (MS)



First Advisor

Sampaio, Cristiana A.

Second Advisor

Symons, Larry

Third Advisor

Mana, Michael J.


The Category Adjustment (CA) model of spatial memory (Huttenlocher, Hedges, & Duncan, 1991) explains how bias towards the centers of spatial categories occurs when recalling locations for target objects. According to the model, this error is the product of Bayesian combination between the rapidly-deteriorating metric information of an object and its longer-lasting categorical information, a process which reduces error variance over time. This adjustment is robust, but previous testing has mainly relied upon remembering simple targets (e.g., dots) in geometric figures. Few studies have addressed whether objects’ real-world expectations are incorporated into this paradigm and, if so, how this information is used. In the present study, participants from a major public university completed a dot-localization task in an ecologically-valid “table” setting. Targets were pictures of everyday objects one might expect in one of two spatial regions: in the center of a table and towards the edge of a table (e.g., a candle or a cup, respectively). I expected participants’ responses would rely on and bias towards long-term prototypes as opposed to the default. On average, responses biased away from the center, with Central objects exhibiting greater magnitudes of bias. A significant portion of responses were replaced on or beyond the default prototype, suggesting participants used their imagined positions as landmarks. Differences between groups suggest possible ways in which long-term prototypes are used. The data will help us understand the contribution of experience-based, long-term prototypical locations for real-world objects in the combinatory processes of spatial memory.




Category adjustment, spatial memory, prototypes



Western Washington University

OCLC Number


Subject – LCSH

Memory; Short-term memory; Space perception; Spatial ability; Bayesian statistical decision theory




masters theses




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