Effects of clausal structure and word frequency in sentence processing

A phoneme-monitoring task was employed to test the effects of clausal structure and lexical ambiguity on sentence processing. Results supported the hypothesis that the clause serves as a psychologically real unit of sentence processing, with the semantic interpretation of each clause being assigned at the clause boundary. The frequency of the ambiguous or control word preceding the critical item in the phoneme-monitoring task was also found to affect the results obtained, with higher frequency words leading to longer mean reaction times.This research is based on a thesis submitted by the first author as partial fulfillment of the M.A. degree at The University of Iowa. Portions of this paper were presented at the meeting of the Psychonomic Society, San Antonio, Texas, 1978.     

A biased random walk model for two choice reaction times

This paper generalizes Stone's (1960, Psychometrika 25, 251–260) random walk model of two choice response times (RTs) that is based on the sequential probability ratio test (SPRT) and that predicts equal correct and incorrect RTs to the same response. The generalized version allows a bias of the type found in signal detection theory to enter directly into the accumulation process so that ambivalent evidence may be seen as slightly favoring one alternative. The resulting biased SPRT model can predict any relation between correct and incorrect mean RTs. In particular, unlike the special symmetric case of Link and Heath's (1975, Psychometrika 40, 77–105) relative judgment theory (RJT), the biased SPRT model can predict that correct mean RTs are faster for one response but slower for the other. The biased SPRT model, the classical SPRT model, and the symmetric RJT model are all fit to the data of an RT deadline experiment reported by Green and Luce (1973, Attention and performance, New York: Academic Press) and it is shown that, of the three, the biased SPRT model provides the best account. Finally, a method for incorporating the same sort of bias into RJT models is sketched out.     

Young children's understanding of displaced aggression

According to previous research, young children do not understand displaced aggression. The present study examines the early phases of the understanding of the causes of moderately and extremely displaced aggression. Preschool and kindergarten children (3 to 5 years of age) viewed eight videotaped episodes of displaced aggression. Their comprehension of this aggression was assessed by means of open ended questions and forced choice picture selections. By age 5 most children had some understanding of displaced aggression, but this understanding was not complete. The early understanding revealed in the present study may be due to the use of short, simple realistic videotaped episodes appropriate for the limited processing abilities of young children. Extreme displacement was not more difficult to understand than moderate displacement.     

Accommodation fatigue and dark focus: The effects of accommodation-free visual work as assessed by two psychophysical methods

Past studies of accommodation fatigue have yielded inconsistent results, partly because they have not used direct measures of accommodation, and partly because they may have been based on a misleading conception of the nature of accommodation. The dual-innervation theory of accommodation suggests that the resting position of accommodation may be neuromuscular rather than just muscular, and that it lies not at optical infinity, as assumed by older conceptions, but at some intermediate position (dark focus). Among the predictions that may be deduced from this theory is that long-term visual work not requiring active accommodation will not induce fatigue. The present study involved continuous measurements of dark focus for 10 young adults over a 3-h period, using the laser optometer with two psychophysical procedures Ibracketing and staircase. Consistent with the prediction, no changes in dark focus were found, in spite of the demanding visual task. Furthermore, it was found that both psychophysical methods yielded essentially identical results. The practical and theoretical implications of these results are discussed, and recommendations are given regarding situations in which each of the psychophysical methods is likely to be most useful.     

Social intimacy: An important moderator of stressful life events

Two studies were conducted to explore the role of social intimacy in predicting the individual's response to stress. In the first study the experimenter reinforced the experimental subjects' verbalizations during an interview on a fixed schedule for the first 3 minutes, withdrawing reinforcement for the final 4 minutes. The control group received reinforcement on a fixed schedule for the total 7 minutes. Subjects scoring low on a measure of intimacy disclosed less personal material during the withdrawal period in the experimental condition than in the control condition in contrast to high scoring subjects who maintained their level of disclosure for both parts of the interview. In the second study, previously experienced life change events were assessed. Individuals lacking a current intimacy were found to be prone to higher levels of emotional disturbance especially when many previous negative or few positive life change events had occurred.     

A Social Learning Approach to Increasing Blood Donations1

A field experiment conducted in high schools throughout the country was aimed at increasing the number of high school students who donate blood. Special interventions that emphasized psychological or educational approaches to heightening motivation to donate, as well as a combined intervention, were compared with the usual approach taken at blood drives. Psychological interventions in which social learning principles (modeling, perceptions of social norms) played important roles either alone or in combination with an educational (informational) approach were more successful in stimulating blood donations than either an educational approach alone or the approaches traditionally followed by the participating local blood centers. The results demonstrated that use of social learning principles in designing interventions to strengthen socially relevant altruistic behavior could be valuable both practically and theoretically.     

The Predictors of Post-Sterilization Regret in Married Women1

We interviewed a sample of 317 married women prior to a tubal sterilization (195) or a husband's vasectomy (122) and then reinterviewed them yearly for 5 years. Using these women's responses to six questions about their feelings and desires following sterilization, we fitted a latent-variable model of post-sterilization regret to the data by means of a linear structural equation analysis. The results confirmed our view that post-sterilization regret was not a simple psychological state but rather was a complex process with different, causally linked manifestations. This process began with a renewed interest in having a baby, proceeded to the development of negative feeling about the three decisions that lead to sterilization, and concluded with a desire to reverse the surgery. This sequence was affected by the negative, post-sterilization effects of the sterilization and by the Occurrence of divorce. Next, we identified the pre-sterilization predictors of six regret variables from our model by means of a series of linear regression analyses. The major pre-sterilization predictors of the regret process included being relatively young, ambivalence about future childbearing, negative attitudes toward sterilization, dominance of the decision making by the woman's husband, and conflict with her husband during decision making. Finally, we divided the sample into quintiles on the basis of their scores on a Pre-Sterilization Predictor Scale and assessed the performance of our predictor variables as indicators of risk of regret by determining the level of negative feelings toward sterilization in each quintile. The results confirm the discriminatory power of our predictors. The overall findings indicate a number of psychological and marital issues, the exploration of which might help counselors provide anticipatory and preventative services to couples seeking sterilization.     

Parent-Offspring and Sibling Adoption Analyses of Parental Ratings of Temperament in Infancy and Childhood

A first step toward understanding the etiology of personality is to investigate the relative impact of genetic and environmental factors using twin and adoption designs. Twin studies of infants and young children indicate substantial genetic influence for parental ratings of temperament in the preschool years. Adoption studies, however, have not previously been reported during the early years of life. We present parent-offspring comparisons for temperament (emotionality, activity, sociability, and impulsivity) for adopted and nonadopted children yearly from 1 to 7 years of age and their biological, adoptive, and nonadoptive parents. Also presented are correlations for adoptive and nonadoptive siblings when each child was 1, 2, 3, and 4 years of age. In contrast with twin results, little evidence is found for genetic influence. The average correlation between biological parents and their adopted-away children for data averaged over the 7 years is only .03. Similarly, the average parent-offspring correlation in nonadoptive families (.08) is no greater than in adoptive families (.12). Results for nonadoptive and adoptive siblings also indicate little genetic influence. The difference between the twin and adoption results may be due to environmental effects or to nonadditive genetic variance.     

The flanker compatibility effect as a function of visual angle, attentional focus, visual transients, and perceptual load: a search for boundary conditions

When subjects must respond to a relevant center letter and ignore irrelevant flanking letters, the identities of the flankers produce a response compatibility effect, indicating that they are processed semantically at least to some extent. Because this effect decreases as the separation between target and flankers increases, the effect appears to result from imperfect early selection (attenuation). In the present experiments, several features of the focused attention paradigm were examined, in order to determine whether they might produce the flanker compatibility effect by interfering with the operation of an early selective mechanism. Specifically, the effect might be produced because the paradigm requires subjects to (1) attend exclusively to stimuli within a very small visual angle, (2) maintain a long-term attentional focus on a constant display location, (3) focus attention on an empty display location, (4) exclude onset-transient flankers from semantic processing, or (5) ignore some of the few stimuli in an impoverished visual field. The results indicate that none of these task features is required for semantic processing of unattended stimuli to occur. In fact, visual angle is the only one of the task features that clearly has a strong influence on the size of the flanker compatibility effect. The invariance of the flanker compatibility effect across these conditions suggests that the mechanism for early selection rarely, if ever, completely excludes unattended stimuli from semantic analysis. In addition, it shows that selective mechanisms are relatively insensitive to several factors that might be expected to influence them, thereby supporting the view that spatial separation has a special status for visual selective attention.