Role of optical flow field asymmetry in the perception of heading during linear motion

During linear translation through a stationary environment, the pattern of optical flow generated on each retina is symmetrical when the head is aligned with the heading, but during lateral gaze the optical flow is asymmetric. We assessed whether human subjects could use the magnitude of this asymmetry to determine the direction of heading during passive translation through a 3-D environment. When allowed to move their heads in order to look in the direction of self-motion, subjects indicated their heading precisely and accurately. When the head was locked in alignment with the misaligned body, and gaze adjustments were not allowed, responses were quite precise, but showed a large bias which increased with increasing heading angle.     

A critical review of theS/L reliability index

The meaning and properties of a commonly used index of reliability, S/L,were examined critically. It was found that the index does not reflect any conventional concept of reliability. When used for an identical behavioral observation session, it is not statistically correlated with other reliability indices. Within an observation session, the standardizing measure of Lis beyond the control of the investigator. Furthermore, the reason for the choice of Las the standard is unclear. The role of chance agreement in S/Lis not known. The exact interpretation of the index depends on which observer reports L.Overall the conceptual and mathematical meaning of S/Lis dubious. It is suggested that the S/Lindex should not be used until its nature is shown to be a measure of reliability. Other approaches such as the intraclass correlations and generalizability coefficients should be used instead.The authors are indebted to Johnny Matson for his critique of an earlier version of this paper.     

The effect of serving as a model of self-control on subsequent resistance to deviation in children

The effect of having a child serve as a rule-following model for other children on the model's own subsequent rule-following was investigated in a resistance to deviation situation. First- and second-grade boys (age range 73 to 94 months) who were told they would serve as self-controlling models for others and who actually served in this capacity touched prohibited toys less than did boys who were not told they would serve as models. Boys told they were to serve as models but who were prevented from performing deviated at a level between the models and boys given no responsibility. Having children serve as rule-following models for others is suggested as an effective, non-punitive technique to increase their self-control.     

The extinction of within-compound flavor associations

Three experiments studied extinction of the associations which are formed between two flavors presented in a simultaneous compound. In Experiment 1 those associations were identified by a sensory preconditioning procedure in which the poisoning of one element of the compound led to the rejection of the other element. Separate presentation of either element between their joint occurence and the poisoning of one element sharply attenuated the rejection of the other element. That attenuation was interpreted in terms of the extinction of within-compound associations. Experiment 2 obtained similar results with an alternative extinction procedure in which the elements of the original compound were presented in other compounds. Experiment 3 obtained similar results when the existence of the within-compound associations was determined by an alternative assessment procedure in which one element of the compound was made more attractive by the induction of a specific hunger. These experiments suggest that within-compound associations can be extinguished when the elements are separately presented outside of the compound. Experiments 2 and 3 make less plausible an alternative interpretation of the effects of separate element presentation in terms of reduction of the novelty of the element. The findings may be taken as implying that the elements of a simultaneously presented compound are joined by a single symmetrical association which acts at various points during a sensory preconditioning experiment.     

Children's responses to stories with male and female characters

The sex of the main character was varied in six children's stories which were then read by fourth, sixth and eighth graders. The children answered four questions about the stories. Both boys and girls responded more positively to the questions “Would you like to be (character's name?)” and “Would you like to do the things (character's name) did?” when the main character was a male. Boys preferred stories about males, and this preference increased with grade level. A preference for stories about females was marginally significant only for the older girls. Theoretical and practical implications are discussed.     

Extending Holland's theory to the later years

Sixty-five men and women, aged 50 to 88 years, completed Holland's Vocational Preference Inventory (VPI) and a work history questionnaire. Each participant was assigned one-letter Holland personality type codes for his or her first full-time job, longest full-time job, last job (if retired) or present job (if employed), and hobbies. In general, VPI scale scores and high point codes were consistent with the occupational codes but less consistent with the hobby code. The usefulness of Holland's vocational theory to the aged population is discussed.     

A comparison of techniques to affect sociometric status: A small step toward primary prevention in the classroom?

Interdependent tasks and role play were implemented as treatment conditions in three elementary classrooms (n=142) to affect the peer nominations of the subjects. Third to fifth grade subjects, 68 female and 74 male, received $\text{1}\text{2}$ hour per day of treatment or a control condition for two weeks. Sociometric measurements were obtained prior to the treatment, one week after, and six weeks after. Analysis of covariance was used to test the effectiveness of the treatments. One week following treatment, intersependent tasks was effective (p<.05) in causing subjects in all grades to pick formerly low status children. On the six weeks followup only fifth grade subjects showed the effects of interdependent tasks (p<.01). Several post hoc analyses were performed to investigate the mechanisms behind the change. The results suggest that interdependent tasks may be an effective strategy in raising the popularity of low status children if the treatment becomes an ongoing part of classroom routine. The implications for primary prevention are discussed.     

Instantiation in skilled and less skilled comprehenders

Previous research has shown that adults tend to infer particular meanings of words, according to their context, a process that has been termed instantiation. An experiment was carried out to investigate the relation between 7 to 8 year olds' skill at reading comprehension and their ability to instantiate. A cued recall paradigm was used: the subjects were presented with a series of short sentences, and either the general noun that had appeared in the original sentence, or a particular noun that fitted the context, was given as a cue. The results showed that both skilled and less skilled comprehenders recalled the original sentences equally well, given the original nouns, but that the performance of the skilled group was superior when they were given the particular word cues, indicating that the skilled comprehenders were instantiating more readily. An independent test showed that their superior performance was not attributable to their better general knowledge.