Douglas A. Hardwick

The content and manipulation of cognitive maps in children and adults.

Comparison of cognitive maps generated by first graders, fifth graders, and college students using a triangulation task revealed that the first graders possessed very accurate, coherent cognitive maps. However, analyses of the cognitive maps generated when Ss were asked to imagine either the room rotating (mental rotation) or themselves moving within the room (perspective-taking) revealed that the accuracy and completeness of the mental manipulation increased dramatically with age. Only the cognitive maps of the college students were coherent and accurate during mental rotation than during perspective-taking. Careful attention was given to the types of errors made, and several systematic error patterns were identified which reflected qualitative differences. These qualitative differences indicated mental manipulation was a two-stage process. In the first stage, a strategy of transformation was applied to the ordinal spatial relationships contained within the cognitive map. First graders evidenced difficulty here. In the second stage, more specific relationships between self and spatial layout were reconstructed. Fifth graders evidenced difficulty here. In contrast, college students were able to complete both stages of the process.

An Assessment of Visibility at the Entrance of a Long Vehicular Tunnel

A field study is described which employs a multi-faceted approach to assess the nature and impact of the visibility problems encountered when entering long vehicular tunnels. The methods employed were photometric and performance studies of visibility, a survey of tunnel users, examination of available accident records, and an analysis of traffic flow. Analysis of the northern entrance of the Hampton Roads Bridge-Tunnel in Virginia revealed that a reduction in speed of vehicles entering the tunnel was attributable in part to reduced visibility into the tunnel and in part to factors relating to the geometry of the approach. It is suggested that the procedures used could be profitably employed at other tunnel facilities.

Summation of transfer of adaptation gradients

Transfer of adaptation resulting from a 90-deg rotation of the visual field was examined when movement during exposure was limited to either one or two dimensions. Positive transfer of adaptation was found for all conditions; however, the curvilinear pattern of adaptation for the one-dimension exposure condition was different from that found for the two-dimension exposure condition. Subsequent analyses revealed the pattern of adaptation obtained for the two-dimension exposure condition was similar to that predicted by an algebraic summation of the patterns associated with the one-dimension exposure conditions. These results indicated that the dimensions of perceptual-motor space are not organized as either an integrated system or as an independent set.

Non-Uniformities in Transient Adaptation I: Unrestricted Background Fields

While the four experiments reported here followed this general procedure, there was one important difference. In the earlier studies, the background field was a uniform surface, which simply increased or decreased in luminance as the change from B1 to B2 was made. In the current research, the change in luminance was effected by presenting or removing one or more bright non-uniformities on an other wise uniform, dimmer background.

Cognitive Development and the Utilization of Memorization Strategies in Middle Childhood

Summary The relationship between cognitive development and the use of memorization strategies in a free recall task was assessed in first, third, and fifth grade children. The results indicated a prerequisite relationship in which changes in underlying cognitions proceed in advance of the spontaneous and deliberate use of memorization strategies. In addition, the results indicated that multiple mnemonic activities do not emerge concurrently at the same rate of development. The results are discussed in terms of the issue of homogeneity in cognitive development. Conclusions are drawn with respect to the Soviet position on the subordination of cognitive activities to the goal of memorization.