Biomedical subjects

L Knuf

Publications and source records attributed to L Knuf.

2 recordsLinked to original sources

PubMed2001

An analysis of ideomotor action.

This article presents a framework based on the work of R. H. Lotze (1852), W. James (1890), and A. G. Greenwald (1970) for understanding ideomotor actions that tend to arise when individuals watch others perform certain actions. Two principles of ideomotor action induction are distinguished: perceptual induction, in which people tend to perform the movements they see, and intentional induction, in which people tend to perform movements suited to achieve what they would like to see. In 3 experiments, ideomotor hand, head, and foot movements were studied while participants watched a ball traveling toward a target. Results showed strong support for intentional induction, weaker support for perceptual induction, and a strong impact of the effector studied. The representational basis of action induction (stimulus vs. goal representations) and the automaticity of the underlying processing (task-dependent vs. task-independent induction) were considered.

Adult↗

PubMed2000

Hierarchical coding in the perception and memory of spatial layouts.

Two experiments were performed to investigate the organization of spatial information in perception and memory. Participants were confronted with map-like configurations of objects which were grouped by color (Experiment 1) or shape (Experiment 2) so as to induce cognitive clustering. Two tasks were administered: speeded verification of spatial relations between objects and unspeeded estimation of the Euclidean distance between object pairs. In both experiments, verification times, but not distance estimations, were affected by group membership. Spatial relations of objects belonging to the same color or shape group were verified faster than those of objects from different groups, even if the spatial distance was identical. These results did not depend on whether judgments were based on perceptually available or memorized information, suggesting that perceptual, not memory processes were responsible for the formation of cognitive clusters.

Adult↗