Fitting and testing carroll's weighted unfolding model for preferences

A quadratic programming algorithm is presented for fitting Carroll's weighted unfolding model for preferences to known multidimensional scale values. The algorithm can be applied directly to pairwise preferences; it permits nonnegativity constraints on subject weights; and it provides a means of testing various preference model hypotheses. While basically metric, it can be combined with Kruskal's monotone regression to fit ordinal data. Monte Carlo results show that (a) adequacy of true preference recovery depends on the number of data points and the amount of error, and (b) the proportion of data variance accounted for by the model sometimes only approximately reflects true recovery.This study is based on a doctoral dissertation submitted to the University of Illinois at Urbana-Champaign. The author wishes to thank the members of his dissertation committee—Lawrence E. Jones, Chairman, Charles Lewis, Stephen Golding, Ledyard Tucker, and Nancy Wiggins—for their helpful comments.     

Priming and property dominance effects in semantic memory

Retrieval from semantic memory was examined by means of reaction times to property statements (e.g., sparrow has beak). The variables of interest were normatively defined property dominance (frequency), type of priming between related sentences (sparrow-sparrow vs. sparrow-robin), and separation or lag between related sentences. Statements asserting a high-dominant property (1) were verified more quickly than those containing low-dominant properties, (2) were primed by a preceding related sentence of either high or low dominance, and (3) revealed decay of priming from Lag 1 to 4. The differences between priming with and without stimulus repetition were nonsignificant when stimuli were treated as a random effect. In support of the Collins and Quillian (1972) model of semantic memory, the priming and property dominance factors interacted.     

A perspective on the recognition of other-race faces

The purpose of the present study is to provide a perspective on the recognition of other-race faces, i.e., black faces by white subjects. Past research has indicated that individuals have greater difficulty recognizing other-race faces than they do same-race faces. On the basis of previous findings, we chose to investigate the recognition of black faces by white subjects as a function of the quantity and quality of previous experience with blacks, racial attitudes, field dependence/independence, and recognition training. Forty-two white subjects participated in pre-, post-, and delayed recognition tests. Subject data were also collected to explore individual differences in recognition performance. Using multiple regression techniques, it was found that field dependence/independence accounted for the largest proportion of variance in recognition performances; a feature-discrimination training task and past experience with blacks were also found to significantly relate to recognition performance. The applied aspects of these results are discussed.     

Lump detection in simulated human breasts

Sixteen observers palpated silicone models of human breasts containing lumps 1.6-12.1 mm in diameter. Detectability depended on the size of the lump, producing a systematic psychometric function. In eight observers who participated in three or more sessions, performance improved with practice, with most improvement occurring within one or two 26-trial sessions. Three-week retention measures disclosed no appreciable decrease in performance, but a significant correlation was found between the number of lumps detected and duration of trial (p < .01). There was no difference in performance between four observers who used their preferred hands and four observers who used their nonpreferred hands. These data establish that examination of breast models for the detection of lumps simulating cancer is a task amenable to experimental analysis.     

The role of surface order and surface deletion in sentence perception

The perceptual complexity of intransitive adverbials, truncated passives and full passives was investigated in two experiments using rapid visual processing tasks. Both forms of passive were found to be more complex than the intransitive adverbials, presumably because of the lack of correspondence of surface and base orders. However, deletion of the logical subject in truncated passives did not increase their complexity relative to full passives.     

Constraints on Analogical Mapping: A Comparison of Three Models

Three theories of analogy have been proposed that are supported by computational models and data from experiments on human analogical abilities. In this article we show how these theories can be unified within a common metatheoretical framework that distinguishes among levels of informational, behavioral, and hardware constraints. This framework clarifies the distinctions among three computational models in the literature: the Analogical Constraint Mapping Engine (ACME), the Structure-Mapping Engine (SME), and the Incremental Analogy Machine (IAM). We then go on to develop a methodology for the comparative testing of these models. In two different manipulations of an analogical mapping task we compare the results of computational experiments with these models against the results of psychological experiments. In the first experiment we show that increasing the number of similar elements in two analogical domains decreases the response time taken to reach the correct mapping for an analogy problem. In the second psychological experiment we find that the order in which the elements of the two domains are presented has significant facilitative effects on the ease of analogical mapping. Of the three models, only IAM embodies behavioral constraints and predicts both of these results. Finally, the immediate implications of these results for analogy research are discussed, along with the wider implications the research has for cognitive science methodology.     

Do parents reinforce somatic complaints in their children?

OBJECTIVE: To examine the influence of parental solicitousness on self-reported somatic complaints in school-age children. DESIGN AND MAIN OUTCOME MEASURES: Participants were 564 children (mean age 10 years) and their parents. Children completed self-report measures of somatic complaints, parental solicitousness, depressiveness, fear, and sense of coherence. Somatic complaints were assessed again 6 months later. Parents also completed a questionnaire about solicitousness. RESULTS: Parental solicitousness as reported by children or parents was unrelated to the frequency of self-reported somatic complaints. Symptoms of depression, fear, and lower sense of coherence were associated with more somatic complaints, but did not interact with parental solicitousness. CONCLUSION: Parental solicitousness seems unrelated to more frequent somatic complaints in schoolchildren.