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.     

Choice in a variable environment: effects of blackout duration and extinction between components

Pigeons were trained in a procedure in which sessions included seven four- or 10-reinforcer components, each providing a different reinforcer ratio that ranged from 27:1 to 1:27. The components were arranged in random order, and no signals differentiated the component reinforcer ratios. Each condition lasted 50 sessions, and the data from the last 35 sessions were analyzed. Previous results using 10-s blackouts between components showed some carryover of preference from one component to the next, and this effect was investigated in Experiment 1 by varying blackout duration from 1 s to 120 s. The amount of carryover decreased monotonically as the blackout duration was lengthened. Preference also decreased between reinforcers within components, suggesting that preference change during blackout might follow the same function as preference change between reinforcers. Experiment 2 was designed to measure preference change between components more directly and to relate this to preference change during blackout. In two conditions a 60-s blackout occurred between components, and in two other conditions a 60-s period of unsignaled extinction occurred between components. Preference during the extinction period progressively fell toward indifference, and the level of preference following extinction was much the same as that following blackout. Although these results are consistent with Davison and Baum's (2000) theory of the effects of reinforcers on local preference, other findings suggest that theory is incomplete: After a sequence of reinforcers from one alternative, some residual preference remained after 60 s of extinction or blackout, indicating the possibility of an additional longer term accumulation of reinforcer effects than originally suggested.     

Social science as dialogue: narcissism,individualist and collectivist values,and religious interest in iran and the united states

This investigation most importantly sought to illustrate the use of social science to promote cross-cultural dialogue. Fukuyama (1992) explained contemporary cultural trends in terms of a triumphant individualism that would overcome all other forms of social life, including what he described as the “fundamentalist resentment” of Iran. Lasch (1979) more pessimistically diagnosed Western social arrangements in terms of an emerging “culture of narcissism.” In this study, Iranian and American university students responded to measures of narcissism, individualist and collectivist values, religious interest, and psychological adjustment (identity, self-actualization, and self-consciousness). Variables related to a sense of community (collectivist values, religious interest, and identity) correlated negatively with narcissism in both societies, as did self-actualization. These data supported a moderate position between the polarized extremes of Fukuyama and Lasch and more importantly demonstrated how social scientific methods might be useful in creating a “space” for conducting a “dialogue between civilizations.”     

Conditions affecting the revelation effect for autobiographical memory

In four experiments involving 184 participants, people rated their confidence that particular events had happened in their childhood (e.g., "Broke a window playing ball"). If participants had to unscramble a key word in a phrase just before rating it (e.g., "Broke a nwidwo [window] playing ball"), confidence ratings increased-the revelation effect. However, the pattern of revelation effects depended on the particular way in which participants processed key words (e.g., visualizing vs. counting vowels in the word window) approximately 10 min prior to rating life events that contained those words. Prior exposure to key words never in itself directly affected confidence ratings. These results demonstrate that one can manipulate the revelation effect by altering the processing that participants perform on words prior to unscrambling them. These results also pose difficulties for many accounts of the revelation effect. The major puzzle posed by our present findings is that unscrambling key words increases confidence that an event has happened in childhood, whereas prior exposure to these words does not.     

Extraordinary moral commitment: young adults involved in social organizations

The personality of exemplary young adults was studied in an effort to paint a portrait of moral excellence that expanded upon the traditional emphasis on moral reasoning maturity. These young adults were nominated based on their extraordinary moral commitment towards various social organizations. The sample included 40 moral exemplars and 40 matched comparison individuals who responded to a battery of questionnaires and participated in a semistructured interview. It was found that moral exemplars, in contrast to comparison individuals, were more agreeable, more advanced in their faith and moral reasoning development, further along in forming an adult identity, and more willing to enter into close relationships. These findings are discussed in the context of describing moral excellence from a multifaceted, personality perspective.     

Concurrent therapies: a model for collaboration between psychoanalysts and other therapists

Many psychoanalysts treat individuals who are simultaneously in couples therapy or whose partners are in individual therapy. If such cases stall, some analysts may seek consultation from a colleague, though most have accepted the tacit historical prohibition against communication between therapists treating members of the same family. Experience, however, suggests that a certain form of communication between such therapists can have a powerfully enhancing effect on the concurrent therapies. After a review of the literature, the advantages, disadvantages, and impediments to collaborative cross-communication are examined. A model is then presented for use in ongoing discussion between therapists, and is illustrated with two clinical examples. The proposed model centers on the transference-countertransference configurations within the therapeutic field, and serves as an organizer highlighting areas for discussion.     

Top-down and bottom-up attentional control: On the nature of interference from a salient distractor

In two experiments using spatial probes, we measured the temporal and spatial interactions between top-down control of attention and bottom-up interference from a salient distractor in visual search. The subjects searched for a square among circles, ignoring color. Probe response times showed that a color singleton distractor could draw attention to its location in the early stage of visual processing (before a 100-msec stimulus onset asynchrony [SOA]), but only when the color singleton distractor was located far from the target. Apparently the bottom-up activation of the singleton distractor’s location is affected early on by local interactions with nearby stimulus locations. Moreover, probe results showed that a singleton distractor did not receive attention after extended practice. These results suggest that top-down control of attention is possible at an early stage of visual processing. In the long-SOA condition (150-msec SOA), spatial attention selected the target location over distractor locations, and this tendency occurred with or without extended practice.     

Visual selection mediated by location: Feature-based selection of noncontiguous locations

Experiments using two different methods and three types of stimuli tested whether stimuli at nonadjacent locations could be selected simultaneously. In one set of experiments, subjects attended to red digits presented in multiple frames with green digits. Accuracy was no better when red digits appeared successively than when pairs of red digits occurred simultaneously, implying allocation of attention to the two locations simultaneously. Different tasks involving oriented grating stimuli produced the same result. The final experiment demonstrated split attention with an array of spatial probes. When the probe at one of two target locations was correctly reported, the probe at the other target location was more often reported correctly than were any of the probes at distractor locations, including those between the targets. Together, these experiments provide strong converging evidence that when two targets are easily discriminated from distractors by a basic property, spatial attention can be split across both locations.