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Biomedical subjects

M D Hazelrigg

Publications and source records attributed to M D Hazelrigg.

5 recordsLinked to original sources

Evidence that therapy works in clinically representative conditions.

This article reports a secondary analysis of past therapy outcome meta-analysis. Fifteen meta-analysis provided effect sizes from 56 studies in previous reviews that met 1 of 3 increasingly stringent levels of criteria for clinical representativeness. The effect sizes were synthesized and compared with results from the original meta-analyses. Effect sizes from more clinically representative studies are the same size at all 3 criteria levels as in past meta-analyses. Almost no studies exist that meet the most stringent level of criteria. Results are interpreted cautiously because of controversy about what criteria best capture the notion of clinical representativeness, because so few experiments have tested therapy in clinical conditions, and because other models for exploring the generalizability of therapy outcome research to clinical conditions might yield different results.

Humans

Orientation specificity in spatial memory: what makes a path different from a map of the path?

Three studies investigated the factors that lead spatial information to be stored in an orientation-specific versus orientation-free manner. In Experiment 1, we replicated the findings of Presson and Hazelrigg (1984) that learning paths from a small map versus learning the paths directly from viewing a world leads to different functional characteristics of spatial memory. Whether the route display was presented as the path itself or as a large map of the path did not affect how the information was stored. In Experiment 2, we examined the effects of size of stimulus display, size of world, and scale transformations on how spatial information in maps is stored and available for use in later judgments. In Experiment 3, we examined the effect of size on the orientation specificity of the spatial coding of paths that are viewed directly. The major determinant of whether spatial information was stored and used in an orientation-specific or an orientation-free manner was the size of the display. Small displays were coded in an orientation-specific way, whereas very large displays were coded in a more orientation-free manner. These data support the view that there are distinct spatial representations, one more perceptual and episodic and one more integrated and model-like, that have developed to meet different demands faced by mobile organisms.

Adult

Building spatial representations through primary and secondary learning.

The current study examined the conditions under which cognitive representations of spatial information are stored in orientation-specific ways (like pictures) versus orientation-free ways. College students learned simple paths by viewing a map of them (map condition), by walking them while blindfolded (walk condition), or by directly viewing the route from a single vantage point (look condition). Blindfolded subjects then stood on the route in various orientations and made directional judgments to other locations on the route. When subjects learned the route by indirect, symbolic means (map), judgments were quite easy when aligned with the learned map orientation and were difficult if the judgment was not aligned with the learned map orientation. However, when subjects learned the route by more direct, primary spatial learning (walk or look), there were no alignment effects. Thus, subjects treat information from primary (direct) and secondary (symbolic) spatial learning in distinct ways. Learning from a map results in a figural representation that has great precision but a specific orientation. Learning the route more directly results in a representation that is less precise but one that can be used in more flexible ways.

Cognition