Effects of ipsilateral and contralateral counterirritation on experimentally produced itch in human beings.

The experimental study of itch was reviewed, and an experiment performed to test the effects of ipsilateral and contralateral counterirritation distal to the itching wrist. Each of the 18 subjects served in all experimental conditions, receiving cowage as the itch stimulus and a placebo. Counterirritation consisted of a 10-sec immersion of the fingers into a 2 degrees C water bath. Lateral differences both in response to cowage and to counterirritation were obtained. In general, counterirritation reduced itch significantly more than the control procedure during the treatment period and the first three intervals following treatment. The results of the present experiment suggest a central mechanism attenuating the sensation of itch.     

Tactile short-term memory in relation to the two-point threshold

The purpose of the present work was to discover whether there was a relationship between the sensitivity of a body site as measured by the two-point threshold and the degree or rate of forgetting of a location stimulated at that body site. In Experiment I, it was found that the higher the two-point threshold, the greater the distance between two successive points of stimulation erroneonously thought to be identical (12 body sites). In Experiment II, it was found that forgetting over time was greater when the retention interval was filled with movement or other tactile stimulation than when the retention interval was unfilled (six body sites). It was concluded that highly sensitive areas also show the least degree of forgetting as compared with less sensitive sites, but this statement should be qualified in various ways.     

A constituent comparison model of a picture-first verification task

In a recent critique of Carpenter and Just’s (1975) verification model, Tanenhaus, Carroll, and Bever (1976) pointed out that the estimates of the comparison parameter of the model varied considerably among tasks. In particular, estimates of this parameter were higher for picture-first than for sentence-first sentence-picture verification tasks. The picture-first estimates, however, were based upon an analysis of only a subset of the trials: namely, those in which the preposition “above” was embedded in the sentence. When a more comprehensive model is applied to the data of picture-first experiments, the estimates of the comparison operation are comparable to those based on sentence-first tasks.     

Equilibration as cognitive conflict

The suitability of taking cognitive conflict as an operational definition of equilibration is examined along with the implications for conservation training. Exceptions are taken to the B. J. Zimmerman and D. E. Blom (Developmental Review, 1983, 3, 18–38) analysis of conservation and some qualifying empirical results presented. It is concluded that cognitive conflict is sufficient, but not necessary, to bring about cognitive change.     

A family‐therapy approach to child abuse: countering resistance

Abusing and high-risk families have been seen over three years at a new treatment resource with a family therapy orientation. The families present with established resistance to any treatment intervention and many have defeated a succession of previous helping agencies. Initial typology and treatment strategies are described with the aim of more systematic selection of therapeutic techniques.     

Marginal maximum likelihood estimation of item parameters: Application of an EM algorithm

Maximum likelihood estimation of item parameters in the marginal distribution, integrating over the distribution of ability, becomes practical when computing procedures based on an EM algorithm are used. By characterizing the ability distribution empirically, arbitrary assumptions about its form are avoided. The Em procedure is shown to apply to general item-response models lacking simple sufficient statistics for ability. This includes models with more than one latent dimension.Supported in part by NSF grant BNS 7912417 to the University of Chicago and by SSRC (UK) grant HR6132 to the University of Lancaster.We are indebted to Mark Reiser and Robert Gibbons for computer programming. David Thissen clarified a number of points in an earlier draft.     

A bird is a bird is a bird: Making reference within and without superordinate categories

Adults with localized cerebral insult often err in their use of a word to refer to an object or an idea. It is important to assess, then, the patients' appreciation of what a word can refer to, and the way in which they may violate the borders around a referential field. Nonfluent aphasics, fluent aphasics, and nonaphasic patients with insult to the right hemisphere were asked to provide names of items which could be referred to by familiar superordinate terms like “bird.” The principal results revealed that the nonfluent aphasics are anchored to the central portions of a superordinate's referential field (naming items like “robin” and “sparrow,” for instance). While fluent aphasics often violate the borders around a referential field (e.g., providing “beaver” in response to “birds”), it was nevertheless possible to characterize some limits to their choice of a superordinate's referents. These findings were independent both of the absolute number of responses provided and the frequency of occurrence of the response. Further, the patients with insult to the left hemisphere produce few consecutive items whose referents hold attributes in common. When these clusters are produced by aphasics, they consist primarily of subordinates whose referents exhibit many overlapping features (e.g., “bald eagle, black eagle, golden eagle” in response to “bird”). The right-hemisphere-damaged subjects, in contrast, produce many clusters of related items. These consist of less central, basic object level words whose referents hold less obvious features in common (e.g., “albatross, crane, gull” in response to “bird”). Aphasics, then, may be limited in their ability to analyze referents for critical features. Taken together, these data contribute to a more precise characterization of the nonfluent aphasics' and the fluent aphasics' referential deficits, and lend support specifically to the notion that neither group of aphasics relies on definition-like features to determine what a word can refer to.     

Does Knowledge that a Crime Was Staged Affect Eyewitness Performance?1

The Staged crime has generally been considered a valid paradigm for assessing eyewitness identification accuracy. Yet the typical procedure informs the witness before the lineup task that the event was staged. The current study manipulated whether or not witnesses were informed that the witnessed crime was staged (information variable). Two other variables, the presence or absence of the perpetrator in the photo-lineup and the physical similarity of lineup members, were manipulated to asses any possible interactions with the information variable. A theft was staged individually for 184 unsuspecting witnesses who were then randomly assigned to be either informed that the theft was staged or not informed. Next, all witnesses were met by a uniformed security officer who showed them a photo-lineup of six individuals. Half of the witnesses viewed a perpetrator-present lineup with either high or low physical similarity between the foils and the perpatrator and half viewed a perpetrator-absent lineup with either high or low physical similarity. Three confidence measures, one cooperation measure, and an Embedded Figures Test score were obtained. The results showed that (a) the information variable did not affect the likelihood that a witness would attempt an identification; (b) the information variable did not have a main effect on the particular choices made by the witnesses nor did it interact with lineup similarity, but it did interact with the presence-absence variable; and (c) the information variable did not affect witness confidence either as a main effect or interaction effect, but, was relatively consistent in affecting the correlation between confidence and accuracy such that the correlation was lower for witnesses who were not informed. The interaction between the information variable and the presence-absence variable on accuracy was due to the uninformed witnesses being less accurate than the informcd witnesses in the perpetrator-present condition. The results suggest that accuracy among actual eyewitnesses may be lower than obtained in the typical staged crime procedure and that accuracy-confidence correlations may be overestimated by the typical staged crime.     

Therapists and Psychotherapy

The Grit and Grist of Psychotherapy: The Inspirations of John Warkentin. Voices: The Art and Science of Psychotherapy, 1981, 17.