Contiguity and contingency in the acquisition and maintenance of an operant

Three experiments compared the effects of nondifferential and differential reinforcement of response location on a circular dimension. Rats were required to operate a vertical joystick to produce food. When food was delivered immediately after responses, but independent of response location, the spatial concentration of responding was low and no progressive changes were observed. Traditional and percentile schedules of differential reinforcement for response location produced highly reliable acquisition of spatially concentrated responding. Once concentrated responding had been established, nondifferential reinforcement was sufficient to maintain it in some subjects. Since only the differential reinforcement schedules established a contingency with respect to response location, it was concluded that this relationship was necessary for acquisition, but that response-reinforcer contiguity may be sufficient for maintenance. This conclusion is consistent with the view that operant conditioning is a contiguity-based process, but that contingencies are required to produce reliable contiguity between reinforcers and particular responses.     

Silent reading: Insights from second-generation deaf readers

Previous studies indicate that hearing readers sometimes convert printed text into a phonological form during silent reading. The experiments reported here investigated whether second-generation congenitally deaf readers use any analogous recoding strategy. Fourteen congenitally and profoundly deaf adults who were native signers of American Sign Language (ASL) served as subjects. Fourteen hearing people of comparable reading levels were control subjects. These subjects participated in four experiments that tested for the possibilities of (a) recoding into articulation, (b) recoding into fingerspelling, (c) recoding into ASL, or (d) no recoding at all. The experiments employed paradigms analogous to those previously used to test for phonological recoding in hearing populations. Interviews with the deaf subjects provided supplementary information about their reading strategies. The results suggest that these deaf subjects as a group do not recode into articulation or fingerspelling, but do recode into sign.     

Audiences' reactions to self-enhancing,self-denigrating,and accurate self-presentations

Subjects in three experiments evaluated hypothetical actors whose claims about either an upcoming or past performance and whose performances were system-atically varied from very positive to very negative. Positive, self-enhancing claims were effective in generating favorable evaluations when either the claim was congruent with the performance or the subjects were unaware of how the actor performed. In general, accurate self-presentations were most favorably evaluated, especially when the claim occurred after the performance. The two exceptions to the preference for accurate self-presenters occurred when (a) the actor modestly underestimated a clearly superior prior performance by claiming to have done “only” well or all right, in which case he/she was evaluated more favorably than an accurate but seemingly boastful actor who claimed to have done extremely well, and (b) the actor self-deprecatingly predicted an inferior performance, in which case he/she was disliked even when accurate. Disclaimers about the importance of the performance (e.t., “I did well, but it's no big deal”) were seen as boastful rather than modest and decreased evaluations. The results mirror many of the tactics used by actor-subjects in past experiments, suggesting that people generally vary their self-presentations in optimal fashion to create the most favorable possible impression on the audience.     

A test of parallel versus serial processing applied to memory retrieval

Townsend has identified necessary and sufficient conditions that reaction time distributions meet if they are produced by two underlying processes that are parallel and within-stage independent. This paper describes an attempt to use one of these conditions to assess the assumption of independent parallel memory retrieval in Anderson's ACT theory. In the experimental test, subjects studied profession-location pairs, with each profession and location included in two pairs. One pair had a high frequency of presentation and the other had low. When cued with a profession (or location), subjects responded with the first of the two studied locations (or professions) that came to mind. The reaction times to these responses were used to test the ACT assumption of independent parallel search. The problems encountered in trying to apply Townsend's abstract test to a concrete situation included the need to consider mixtures and convolutions of distributions and empirical, rather than theoretical, distributions. These difficulties are discussed at length and some formal analyses concerning their effect on the test are given. Despite these problems, we were able to use Townsend's test and the results of the experiment support the within-stage independent parallel assumption of ACT.     

Activation of bipolar prototypes in attribute inferences

The present study examined how prototypes, as organizational principles of knowledge about persons, affect attribute inference judgments. A distinction is drawn between bipolar and unipolar categories. Two questions are addressed: First, whether only one or both prototypes of bipolar categories like extraversion-introversion are activated in making inference judgments, and second, whether information about the applicability of a stimulus item to a target is processed differently than information about the inapplicability of the stimulus item. The results support the hypothesis that only one prototype is activated and that this is the affirmative one, irrespective of whether the stimulus information is applicable or inapplicable to the target person. The implications of these findings are discussed.     

Ambiguity,cubist works of art,and preference

Number of one sec views and verbal judgements of interestingness and pleasingness of Cubist paintings were found to be a function of subjective ambiguity, defined in terms of the Shannon-Wiener average information measure, especially when an expectancy had been established regarding the identity of the main object or person in the paintings. Viewing behaviour was found to increase with subjective ambiguity; verbal judgements were found to decrease. Titles corresponding to varying degrees to the content of the paintings or instructions involving guessing were used to manipulate expectancy. An attempt was made to explain these findings and those involving recall of titles by making reference to Berlyne's point of view and the experimental literature.     

The limits of perceived magnitude: Comparison among individuals and among perceptual continua

Two models of perceived magnitude that focus on the concept of dynamic range (DR) for sensory systems are summarized and compared. The first asserts that, whereas the size of DR varies physically from one perceptual continuum to another, all are subjectively equal. The other asserts that, for any given continuum, whereas the size of DR varies over individual observers, the subjective range does not.A test of the second model is reported for perceived effort for a range of loads on a bicycle ergometer. Both DR and judgmental (magnitude estimation) range estimates were obtained for 30 subjects. The former exhibited the expected variability over subjects, but there was no support for the predicted invariance of the latter. However, it is concluded, first, that the finding constitutes disconfirming evidence for the second model only if it is assumed that magnitude estimates are proportional to perceived magnitude, an issue which itself remains in dispute, and second, that the testability of the second model is doubtful unless a measure can be identified that is a stateable function of perceived magnitude.