The Effect of an Irrelevant Premise on Temporal and Spatial Reasoning

The mental model theory of reasoning postulates that individuals reason by constructing models of the situation described by premises. The more models reasoners have to build, the harder a problem will be. Byrne and Johnson-Laird (1989) confirmed this prediction with spatial problems and Schaeken et al. (1996 a, b) with temporal ones. There is, however, a problem with these studies. All the multiple-model problems and some of the one-model problems contained an irrelevant premise. As Rips (1994) argues, it is possible that an irrelevant premise would complicate the search for a derivation. The present paper reports an experiment which explicitly manipulated the presence of such an irrelevant premise in both one-model and multiple-model problems. The results corroborate the predictions of the mental model theory.     

Measures of perceived linear size, sagittal motion, and visual angle from optical expansions and contractions

Using monocular observation, open-loop measurements were obtained of the perceptions of linear size, angular size, and sagittal motion associated with the terminal (largest or smallest) stimuli of repetitive optical expansions and contractions using 1-D or 2-D displays produced on a video monitor at a constant distance from the observer. The perceptions from these dynamic conditions were compared with those from static conditions in which the stimuli were of the same physical size and at the same physical distance as the terminal dynamic stimuli, but that were not part of the optical expansions or contractions. One result, as expected, was that the measures of perceived linear and angular size differed, but also, unexpectedly, some substantial errors were associated with the measures of perceived angular size. Another result was that the amount of size constancy was considerably less than was expected from the obtained amount of perceived motion in depth. Consistent with the latter result, it was found that the size-distance invariance hypothesis (SDIH), using the physical visual angles of the terminal stimuli, predicted only about half of the perceived motion in depth obtained with the dynamic changes. Using the obtained measures of perceived visual angles in the SDIH increased rather than decreased the error in predicting the amount of motion in depth as perceived. An additional experiment suggests that at least some of the error in the measurement of the perceived visual angle is a consequence of error in the perceived origin of the visual angles. The absence of the expected relation between size constancy and perceived motion in depth in the dynamic conditions is hypothesized to be due to cognitive processes associated with off-sized perceptions of the stimuli.     

Effects of Alprazolam on Complex Human Functioning1

Benzodiazepines can reduce anxiety, can have favorable effects upon sleep, and may diminish problems that interfere with patients' quality of life. On the other hand, these drugs can generate transient anterograde amnesia and may diminish aspects of task performance. Research on the impact of alprazolam and other “tranquilizing” drugs has generally focused on tasks that remain below the complex efforts of managerial or professional personnel. Alprazolam-induced reduction of anxiety under challenging conditions might aid complex task performance, yet anterograde amnesia might interfere. In the present research, managers participated in validated complex simulation tasks. In a double-blind, dual crossover design, placebo, 0.5 mg, or 1.0 mg alprazolam was administered on 2 occasions during the task day. Drug treatment diminished performance on measures that require sequential actions but improved performance on measures less subject to short term memory but more determined by long-term style of functioning. Thus, depending on task requirements, positive or negative alteration of performance might occur.     

The development of a measure of enculturation for Native American youth

Enculturation is the process by which individuals learn about and identify with their ethnic minority culture. It is distinguished from acculturation which refers to the process by which an ethnic minority individual is assimilated into the majority culture. Three studies with Native American youths are reported that describe the development of a measure of enculturation for Native American youths. Development of a measure of enculturation provides a foundation upon which to build a body of literature that focuses on strengths in a youth's life rather than on deficits. Results of the first study (n=120), a confirmatory factor analysis, indicated that cultural affinity, Native American identity, and family involvement in traditional activities adequately represent the construct of enculturation. The study also provides some convergent validity for this interpretation. The second study examines factor invariance for enculturation among youths with data from over 2 years (n=69). The factor structure was similar across time. The third study replicates the factor structure and validity analyses with a new sample (n=42). Usefulness of the measure for assessing protective factors and stressing ethnicity over simple assessment of race categories is discussed. We would like to thank the Tribe that participated in this study and especially the youth and their parents who agreed to participate. We would also like to thank the Tribal staff youth workers who helped us on many aspects of the study. This research was supported by the Center for Substance Abuse Prevention, Grant No. 1 H86 SPO1835-01A1 to the Grand Traverse Band of Ottawa/Chippewa Indians. Benjamin Walter and Kathleen Washienko were research assistants on the project during data collection at Time 1. Sandra Dyer was the Director for the project upon which this study is based at the time of data collection.     

Women who tell and men who ask: Perceptions of men and women departing from gender stereotypes during initial interaction

An experiment was conducted to determine if behavior that deviated from gender stereotypes during initial interaction produced less positive perceptions of a target than did behavior conforming to stereotype. Thirty-seven males and 38 females (targets) were randomly assigned to conditions where they either enacted a behavior stereotypical to their gender or engaged in a behavior departing from the stereotype during initial interaction with a randomly assigned different-gender stranger (perceiver). All of the participants were raised in the United States. The majority of participants were Caucasian, approximately 30% of the participants were Hispanic. The participants were predominantly middle class. The gender stereotypical condition required the female target to ask questions and the male target to talk about himself during the interaction. A second condition required male and female targets to do the reverse (female tell and male ask). Following the interaction perceivers completed measures of positive affect and social attractiveness. The results indicated that perceptions of targets engaging in behavior opposite of gender stereotypes depend on the perceiver's level of gender-schematicity. The level of gender schematicity indicates a person's tendency to depend on traditional gender stereotypes. While schematics tended to feel less positively or no differently during interactions with gender opposite versus gender norm targets, they tended to evaluate the gender opposite target as more or no differently socially attractive than gender norm targets. Results also suggest that men may have more latitude to engage in gender opposite behaviors than do women.     

Reading rate and retention as a function of the number of propositions in the base structure of sentences

English texts were constructed from propositional bases. One set of 16-word sentences was obtained from semantic bases containing from 4 to 9 propositions. For another set of sentences and paragraphs, number of words and number of propositions covaried. Subjects read the texts at their own rate and recalled them immediately. For the 16-word sentences, subjects needed 1.5 sec additional reading time to process each proposition. For longer texts, this value increased. In another experimental condition reading time was controlled by the experimenter. The analysis of both the text and the recall protocols in terms of number of propositions lent support to the notion that propositions are a basic unit of memory for text. However, evidence was also obtained that while the total number of propositions upon which a text was based proved to be an effective psychological variable, all propositions were not equally difficult to remember: superordinate propositions were recalled better than propositions which were stucturally subordinate.     

Absolute motion parallax and the specific distance tendency

In the absence of definitive cues’to distance, the perceived distance of an object will be in error in the direction of the object appearing at a distance of about 2 m from O. This tendency to perceive an object at a relatively near distance is termed the specific distance tendency (Gogel. 1969). Also, it has been found that an error in perceiving the distance of an object will result in an apparent movement of the object when the head is moved (Hay & Sawyer. 1969; Wallach, Yablick. & Smith. 1972). From these two results, it was expected that the direction of trie apparent movement of a stationary point of light resulting from head movement would vary predictably as a function of the physical distance of the point of light from O. This expectation was confirmed in an experiment in which both the perceived motion and perceived distance of the point of light were measured. The consequences of the study for the role of motion parallax in the perception of distance and for the reafference principle in the perception of object motion with head motion are discussed