Force Measurements of TCR/pMHC Recognition at T Cell Surface

The rupture forces and adhesion frequencies of single recognition complexes between an affinity selected peptide/MHC complex and a TCR at a murine hybridoma surface were measured using Atomic Force Microscopy. When the CD8 coreceptor is absent, the adhesion frequency depends on the nature of the peptide but the rupture force does not. When CD8 is present, no effect of the nature of the peptide is observed. CD8 is proposed to act as a time and distance lock, enabling the shorter TCR molecule to bridge the pMHC and have time to finely read the peptide. Ultimately, such experiments could help the dissection of the sequential steps by which the TCR reads the peptide/MHC complex in order to control T cell activation

Self-acceptance, discrepancy between parents' perceptions of their children, and goal-seeking effectiveness

Delineates the interrelationship of self-acceptance, differences between parents' perceptions of their children, and goal-seeking effectiveness within an academic setting. Measures were obtained on about 350 male and 400 female college students of their self-perceptions and self-acceptance, their parents' perceptions and acceptance of them, and parental attitudes toward academic pursuits. Self-acceptance and parental acceptance related to academic effectiveness in males but not in females. The discrepancy between parents' perceptions of their children related negatively to self-acceptance in females and in general to academic effectiveness in both males and females. Males whose parent either agreed that a college education was primarily for intellectual broadening or agreed that it was primarily for social broadening were more effective than those whose parents disagreed on this matter. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1965 American Psychological Association

Changes in meaning and halo effects in personality impression formation

Explored the reason why evaluations of a personality adjective increase with the favorableness of the adjectives accompanying it. In Exp I, involving 137 undergraduates, context effects increased with the ambiguity of the (test) adjective being rated, as inferred from an information measure of uncertainty about the evaluative implications of the adjective. Exp II, with 48 Ss, showed that the average of the evaluative implications of the meanings assigned to test adjectives in different contexts was highly correlated with the actual evaluations of the adjectives in these contexts. Changes in the meanings assigned to test adjectives in different contexts appeared to account for context effects when the adjectives in each collective described a single person but underestimated the magnitude of these effects when each adjective described a different member of a group of persons. While results of the experiments are more consistent with a change-of-meaning interpretation of context effects than with the generalized halo effect interpretation proposed by N. H. Anderson (See PA, Vol 46:2989, 4805), they suggested that both changes in meaning and halo effects may contribute to these effects to different degrees, depending on the type of judgment. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1974 American Psychological Association

Effects of outcome matrix and partner's behavior in two-person games

Wyer's (1969) formulation of behavior in two-person games, which predicts responses as a function of three descriptive parameters of the payoff matrix and the expectancy for how the other (O) will respond, was tested by systematically manipulating payoff values in the matrices to which subjects were exposed, and by using a simulated O who responded in a predetermined random sequence. The effects of these manipulations on subjects' responses over a series of 50 trials were generally consistent with predictions. However, quantitative predictions of individual subjects' behavior were fairly inaccurate. Additional data indicated that, at least in Prisoner's Dilemma games, quantitative predictions of behavior were substantially more accurate when subjects interacted with real O's that when they interacted with simulated O's whose overall probabilities of responding were similar. Moreover, the tendency for subjects to reciprocate cooperative behavior appeared to be less when O was simulated rather than real. These differences occurred despite the fact that between-group comparisons showed no differences between the effects of playing with real and simulated Os. These differences were tentatively attributed to a decreased utility attached by subjects to the points received by O under simulated conditions. © 1971

Behavioral correlates of academic achievement: Conformity under achievement-and affiliation-incentive conditions

61 FRESHMAN MALES AND 64 FRESHMAN FEMALES, REPRESENTING 4 COMBINATIONS OF ACADEMIC APTITUDE (COLLEGE ENTRANCE EXAMINATION SCORE) AND PERFORMANCE (1ST-TERM GRADE-POINT AVERAGE), WERE ASKED TO ESTIMATE THE NUMBER OF DOTS ON SLIDES BEFORE AND AFTER EXPOSURE TO FICTITIOUS GROUP JUDGMENTS. CONFORMITY WAS MEASURED UNDER ACHIEVEMENT-INCENTIVE CONDITIONS, IN WHICH SS WERE TOLD THAT THEIR PERFORMANCE ON THE TASK WOULD REFLECT THEIR ACHIEVEMENT POTENTIAL, AND AFFILIATION-INCENTIVE CONDITIONS, IN WHICH THE IMPORTANCE OF THE TASK WAS DEEMPHASIZED AND GROUP ATTRACTIVENESS WAS INCREASED. RESULTS PROVIDED INSIGHT INTO THE MOTIVATIONAL CORRELATES OF ACADEMIC PERFORMANCE AND APTITUDE AMONG MALE AND FEMALE COLLEGE STUDENTS, AND INTO THE BEHAVIOR TYPICAL OF THESE STUDENTS IN ACHIEVEMENT AND SOCIAL SITUATIONS. (18 REF.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1967 American Psychological Association

Functional measurement methodology applied to a subjective probability model of cognitive functioning

Used functional measurement procedures to test R. S. Wyer and L. Goldberg's subjective probability model of cognitive organization. 54 undergraduates estimated the likelihood that a hypothetical person had an attribute (PB) on the basis of information that directly affected their beliefs that persons in general have a particular gene (Pa) and that persons who do not have this gene possess the attribute (Pb/a and Pb/a'). Pa interacted significantly with both Pb/a and Pb/a'; each of these interactions was concentrated in the bilinear component, supporting the assumption that each pair of beliefs has multiplicative effects upon Pb. A small but significant interaction of Pb/a and Pb/a' was also detected, contrary to implications of the model. Although the model provided a good quantitative description of the relations among the beliefs involved without the necessity of introducing ad hoc curve-fitting parameters, small but significant discrepancies from prediction were detected. These discrepancies suggested that Pa and Pb/a were weighted appropriately, but that Pb/a' should receive a weight inversely proportional to its magnitude. In sum, results support the general formulation proposed. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1975 American Psychological Association

Quantitative prediction of belief and opinion change: A further test of a subjective probability model

Tested implications of the hypothesis that relations among beliefs, if defined in terms of subjective probabilities, are predictable by applying the laws of objective probability. Of particular interest was the extent to which change in 1 belief would predictably affect other beliefs which were related to it. 9 hypothetical situations were constructed, each of which pertained to an event (A) and its relation to a 2nd event (B). Descriptions of each situation were presented to 49 undergraduates in 2 parts: the 1st to produce a low estimate of the likelihood of occurrence of A, and the 2nd to increase this estimate. Ss estimated various probabilities associated with occurrence of A and B after reading each part of the communication. Estimates of the probability of B and the change in these estimates after reading the 2nd part of the communication were both predicted accurately by applying the laws of objective probability. These predictions were more accurate than those generated by the 1960 model proposed by W. J. McGuire. Obtained and predicted estimates of the conjunctive and disjunctive probabilities of A and B were also compared. In general, the hypothesis appeared to be of substantial value in generating accurate quantitative descriptions of the relations among beliefs. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1970 American Psychological Association

The effects of information redundancy on evaluations of social stimuli

Subjects were asked to estimate their liking for persons described by pairs of adjectives. These estimates were analyzed as a function of the favorableness of the adjectives in each pair and the redundancy of these adjectives. The degree of redundancy of an adjective B with a second adjective A was defined as the conditional probability of occurrence of B given A; these probabilities were estimated from normative data. Results supported the hypothesis that if adjectives are redundant with others presented, they have less effect upon evaluations. This study, which led to conclusions similar to those made by Dus tin & Baldwin (1966), eliminated several methodological difficulties in the earlier research