Learning on a response continuum: Comparison of a linear change and a functional learning model

Two reinforcement schedules were used to compare the predictive validity of a linear change model with a functional learning model. In one schedule, termed “convergent,” the linear change model predicts convergence to the optimum response, while in the other, termed “divergent,” this model predicts that a subject's response will not converge. The functional learning model predicts convergence in both cases. Another factor that was varied was presence or absence of random error or “noise” in the relationship between response and outcome. In the “noiseless” condition, in which no noise is added, a subject could discover the optimum response by chance, so that some subjects could appear to have converged fortuitously. In the “noisy” conditions such chance apparent convergence could not occur.The results did not unequivocally favor either model. While the linear change model's prediction of nonconvergence in the divergent conditions (particularly the “noisy” divergent condition) was not sustained, there was a clear difference in speed of convergence, counter to the prediction inferred from the functional learning model. Evidence that at least some subjects were utilizing a functional learning strategy was adduced from the fact that subjects were able to “map out” the relation between response and outcome quite accurately in a follow-up task. Almost all subjects in the “noisy” conditions had evidently “learned” a strong linear relation, with slope closely matching the veridical one.The data were consistent with a hybrid model assuming a “hierarchy of cognitive strategies” in which more complex strategies (e.g., functional learning) are utilized only when the simpler ones (e.g., a linear change strategy) fail to solve the problem.     

Spatial,non-spatial and hybrid models for scaling

In this paper, hierarchical and non-hierarchical tree structures are proposed as models of similarity data. Trees are viewed as intermediate between multidimensional scaling and simple clustering. Procedures are discussed for fitting both types of trees to data. The concept of multiple tree structures shows great promise for analyzing more complex data. Hybrid models in which multiple trees and other discrete structures are combined with continuous dimensions are discussed. Examples of the use of multiple tree structures and hybrid models are given. Extensions to the analysis of individual differences are suggested.1976 Psychometric Society Presidential Address.While people too numerous to list here have contributed ideas, inspiration, and other help, I particularly wish to acknowledge the contributions of Sandra Pruzansky, without whom this paper could not have been written. I would also like to acknowledge the past contributions of my long-time colleague Jih-Jie Chang, without whose help I probably would not have beenasked to write it.     

Sentence perception units and levels of syntactic structure

Subjects listened to recorded sentences which were followed by probe words. They performed a next-word naming task—uttering the word that followed the probe word in the original sentence as quickly as possible. Other things being equal, naming latencies are longer when the juncture between the probe word and the response word in the original sentence sequence terminates a “functionally complete” unit than when this position corresponds to the boundary of a “functionally incomplete” unit. These results are not predicted by existent “syntactic” theories of sentence perception units, and these theories are to that extent shown to be inadequate. A “functional” program for the study of sentence perception is suggested.     

The assessment of empathy in early childhood

In much of the literature on empathy in young children, researchers have assessed empathy with the FASTE (Feshbach and Roe Affective Situations Test for Empathy). Consequently, much of the literature on early affective responsiveness and the role of empathy in prosocial development is dependent on the validity of the FASTE. However, examination of the literature on gender differences in young children's empathy has suggested a methodological flaw in picture/story techniques such as the FASTE; children's responses to these instruments appear to vary as a function of the interaction of sex of experimenter with sex of subject. In the present study, we empirically examined the effects of sex of experimenter on children's responses to the FASTE. Eighty preschool children were randomly assigned by sex to four male and four female experimenters and were administered the FASTE. Children scored higher when interviewed by a same-sex experimenter, especially if only the stories that the children comprehended (the happy/sad episodes, not the anger or fear episodes) were examined. The implications of the findings for interpreting the literature on children's empathy (especially gender differences in empathy) are discussed.     

Risk Factors for Infant Abuse and Neglect in Group-Living Rhesus Monkeys

This study investigated maternal abuse and neglect of offspring in a large population of rhesus monkeys over a period of 29 years. Abuse and neglect did not occur together and were associated with different risk factors. Infant abuse was concentrated in 8 of 57 families and among closely related females. Abuse was also repeated with successive offspring. In contrast, infant neglect was not affected by genealogical factors, was not repeated with successive offspring, and was displayed mostly by primiparous mothers. These results suggest that abuse and neglect may be different phenomena and that infant abuse in group-living monkeys could represent a good animal model for investigating the mechanisms underlying the intergenerational transmission of child maltreatment.     

The dependency of schema formation on type of verbal material: Linear orderings and set inclusions

Two paragraph structures, linear orderings (Potts, 1972) and set inclusions (Frase, 1969), were equated on relevant independent variables to examine recognition memory for relationships between pairs of terms. Experiment 1 replicated Potts' findings: Proportion correct was greater on remote than on adjacent linear pairs. For set pairs, however, there was an interaction between remoteness and truth, giving better performance on remote false and adjacent true pairs. It was suggested that the memory representation (schema) for linear structure was predicted by Potts' end-term anchoring and rating-scale strategies, while set structure performance reflected logical errors in processing. Experiment 2, an "open book" test, confirmed this view: In the nonmemory task, there was no evidence of schema formation for linear structure, whereas set performance still merely reflected logical errors in processing.     

Binocular summation in the evoked cortical potential

Computer-averaged evoked potentials were recorded from six subjects presented with flashes under conditions of binocular and monocular viewing, with a device fitted over each eye to produce ganzfeld conditions. Tests were run with red light and with blue. Analysis of the evoked potentials indicates a substantially larger amplitude with binocular stimulation.