Some perceptual and cognitive factors in mirror tracing: their limits.

Three mirror tracing experiments were conducted to investigate the connection between perception and motor behavior. In the first experiment, some subjects traced a hex-maze, other subjects traced a hex-maze after observing a model trace, others traced a hex-maze after reading instructions on mirror images, and others traced a hex-maze after having observed a model and heard the instructions. There were no significant differences between the groups' error scores, but their time scores differed significantly, although not always in the predicted direction.

Illusion reversal rate as a function of subjective depth.

Undergraduate students (N = 48) served as subjects in a test of Gregory's theory of illusions. Twenty-four students made judgments about the subjective depth of three reversible illusions--Necker cube, Book, and Pyramid--under the conditions of complete versus incomplete illusions and illusions without depth cues versus with depth cues. An additional 24 subjects recorded the three illusion reversal rates under slightly altered conditions.

Identification reaction time as a function of target and field object orientation.

Four experiments were conducted investigating the effects of (a) target versus field object orientation, (b) target upside up versus target upside down and (c) inverting versus noninverting lenses on object identification reaction time. Inverting versus noninverting lenses had no significant effect. Target versus field orientation was significant when objects commonly found on a desk were used.

Autokinetic movement as a function of the amount of information in a target shape.

Amount of information was manipulated in four different target shapes; an additional target shape, a ring, was used as a control stimulus. Two levels of information were established, high and low. Information increased by simply adding detail and adding elements that suggested altered meaning.

Children's autokinetic movement as a function of inferred movement of target shape.

Four target shapes, a control stimulus (circle) and one each representing geometrical (arrow), representational (car), and symbolic (cross) implied movement were presented to 10 children in each of five age groups of boys and girls (4, 6, 8, 10, 12 yr.) in an autokinetic movement task. While there were no differences in direction of perceived movement with regard to the control stimulus (circle), all other target shapes showed a decrease in the effects of implied movement with increases in age.