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.     

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.     

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.     

Testing the assumptions of exponential,additive reaction time models

Two assumptions commonly made by choice reaction time (RT) models are (1) that certain experimental tasks can be found that cause an extra processing stage to be inserted into the cognitive process and (2) that the duration of one or more processing stages is random with an exponential distribution. Few rigorous tests of either assumption exist. This paper reviews existing tests and presents several new results that can be used to test these assumptions. First, in the case in which the duration of an inserted stage is exponentially distributed, it is shown that the observable RT density functions must always intersect at the mode of the density requiring the extra processing stage. Second, when only the first assumption (Assumption 1) is made, it is shown that the cumulative RT distribution functions and, in many cases, the hazard functions must be ordered. Finally, when only Assumption 2 is assumed, it is shown that, under fairly weak conditions, the taft of the RT density function must be exponential. The first two results are applied to data from a memory scanning experiment, and the two assumptions are found to receive tentative support     

An experimental psychology laboratory system for the Apple II microcomputer

A system for on-line control of experiments is described that uses the Apple II microcomputer and requires no knowledge of programming. This system, APT, is used to construct test files, randomize stimulus order, and conduct experiments. Construction of an experiment is very easy through use of an interactive program. APT provides powerful options for controlling stimulus duration, feedback, and response type. Programs are available to conduct either a sequence of tests without any experimenter present or a single experiment. Over 200 subjects, ranging from 18 to 86 years of age, have completed a battery of cognitive and abilities tests using the system.     

Manipulating the word frequency effect in free recall

A recall advantage for common words was not evidenced when subjects generated or rated the list words on the basis of commonness and on a semantic, phonological, or orthographic basis prior to recall. Recall of the same set of words following only structural judgments of the words resulted in the usual recall advantage for common words. Results were not consistent with interpretations based only on the associative strengths of the recalled items. A process based on categorization of the words to be recalled was suggested as an alternative explanation.     

The effects of alcohol and extreme provocation on the use of a highly noxious electric shock

Intoxicated and nonintoxicated subjects were given the opportunity to administer a potentially injurious level of shock to an opponent who behaved in either a provocative or an extremely provocative manner. The provocative opponent attempted to administer high-intensity shocks to the subject. The extremely provocative opponent attempted to administer high-intensity shocks and the potentially injurious level of shock. The intoxicated subjects in the extreme provocation condition evidenced the greatest increase in the use of the potentially injurious shock. It was concluded that aggression is a function of the interaction of alcohol consumption and level of provocation.