Enhancement of Sander illusion in minimal form

This paper reports the effects of systematically reducing the number of component lines in the Sander parallelograms upon judgments of the relative lengths of the diagonal lines. The illusion was maximal when the parallelogram was reduced to its minimal form, viz., three parallel lines remained with all other lines, including the diagonals, omitted.     

The development of letter processing efficiency

The development of efficiency in letter processing skills was studied using a letter search task. In two experiments, subjects searched for a target letter displayed with items varying in their visual featural or conceptual categorical similarity to the target. Accuracy and reaction time of search were evaluated for evidence of the visual search “category effect.” In order to determine if subjects could efficiently use knowledge of stimulus differences to facilitate search, conditions tested search time as a function of the amount of information to be processed both within the visual display and in short-term memory. In the two experiments, subjects of ages 6 years through adulthood showed the category effect; however, efficiency of letter processing was found to be related to the amount of information that had to be processed in memory. While there were drastic changes in search speed with increasing grade level, patterns of processing were consistent, leading to the conclusion that the knowledge required to process the letter information accurately is acquired very early. Results were discussed in terms of the distinctions among accuracy, automaticity, and efficiency of skill development and the relationship of these to general reading and intellectual development.     

Induced motion of a fixated target: Influence of voluntary eye deviation

Induced motion (IM) was observed in a fixated target in the direction opposite to the real motion of a moving background. Relative to a fixation target located straight ahead, IM decreased when fixation was deviated 10° in the same direction as background motion and increased when fixation was deviated 10° opposite background motion. These results are consistent with a “nystagmus-suppression” hypothesis for subjective motion of fixated targets: the magnitude of illusory motion is correlated with the amount of voluntary efference required to oppose involuntary eye movements that would occur in the absence of fixation. In addition to the form of IM studied, this explanation applies to autokinesis, apparent concomitant motion, and the oculogyral illusion. Accounts of IM that stress visual capture of vection, afferent mechanisms, egocenter deviations, or phenomenological principles, although they may explain some forms of IM, do not account for the present results.     

Using word reading time in text processing research

A study that employed a moving-window task was designed to test the paradigm’s sensitivity to different levels of interclause integration. The program that controlled the task, implemented on a Terak 8510/a microcomputer in UCSD Pascal, is described. The results of the study indicate that word reading time is indicative of lower and “midlevel” types of integration, but not higher order domain knowledge considerations.     

The Effects of a PETTLEP Imagery Intervention on Learners' Coincident Anticipation Timing Performance

Little research has examined how imagery effects learners' acquisition of motor tasks requiring coincident anticipation timing (CAT). CAT is a fundamental component of hitting, passing, and receiving required in several sports. The purpose of the current study was to examine the effects of a PETTLEP imagery intervention on learners' CAT performance using a Bassin Anticipation Timer. Fifty-six participants (M = 20.61 years, SD = 2.48) were randomly assigned into one of four training groups: physical practice (PP), imagery practice (IP), imagery practice + physical practice (IP +PP), or a control (CON) group. The study consisted of three phases: pretest, intervention, and a posttest. Results revealed that the PP and IP+PP groups had significantly lower absolute timing error compared to the CON group on the posttest. The IP+PP group was the only group to have lower variable error compared to the CON group on the posttest. Results extend prior research by demonstrating that imagery combined with physical practice can benefit the learning of a CAT task and that imagery alone may not assist learners in acquiring tasks requiring CAT. Results are congruent with prior research demonstrating that imagery is most effective when combined with physical practice.     

Prompting a consumer behavior for pollution control

A field application of behavior modification studied the relative effectiveness of different prompting procedures for increasing the probability that customers entering a grocery store would select their soft drinks in returnable rather than nonreturnable containers. Six different 2-hr experimental conditions during which bottle purchases were recorded were (1) No Prompt (i.e., control), (2) one student gave incoming customers a handbill urging the purchase of soft drinks in returnable bottles, (3) distribution of the handbill by one student and public charting of each customer's bottle purchases by another student, (4) handbill distribution and charting by a five-member group, (5) handbills distributed and purchases charted by three females. The variant prompting techniques were equally effective, and in general increased the percentage of returnable-bottle customers by an average of 25%.