Contextual conditional discriminations

Three experiments used a discriminated operant procedure to study conditional discrimination learning in rats. The first experiment showed that rats were capable of learning a biconditional discrimination in which two contexts served as conditional cues signalling the reinforcement contingencies associated with two discriminative stimuli. The discrimination was learned equally well when one discriminative stimulus signalled food, the other its absence, and when one stimulus signalled food, the other extinction plus mild footshock.

In Experiment 2 it was shown that prior training on such a conditional discrimination enhanced the subsequent context specificity of simple conditioning relative to control groups of animals for whom the prior training had not been conditional. Experiment 3 showed that a reversal of the significance of one pair of discriminative stimuli produced no spontaneous reversal in performance to a second, target, pair.

The pattern of results is best accounted for by an analysis of contextual conditional discrimination learning in terms of stimulus configurations and offers no support for the notion that rats may learn a general conditional rule or set.     

Neurological soft signs and school achievement: The mediating effects of sustained attention

A group of 115 black male adolescents drawn from a clinically unselected birth cohort, half of whom were known to have had neurological soft signs at age 7, were examined at age 17 to determine the relation between soft signs and performance on standard tests of school achievement and sustained attention. Three signs measured at age 17-dysgraphesthesia, difficulties with rapid alternating movements (dysdiadochokinesis), and motor slowness—were related to lower concurrent and past IQ and to impaired performance on laboratory and paper-and-pencil measures of sustained attention. The relation between signs and the attentional measures remained significant after IQ was statistically controlled. The three age 17 soft signs as well as age 7 signs were related to impaired performance on standardized tests (age 17) of school achievement. Most of the relation between signs and school achievement could be accounted for by the variance signs shared with sustained attention. One sign, mirror movements, was unrelated to all other attentional and cognitive measures.The study was supported by center grant MH 306906 and research training grant 5 T32 MH 13043-13 from the National Institute of Mental Health, as well as by the City College and the City University Computing Centers. We thank Lillian Belmont and two reviewers for their critical comments on an earlier version of the paper. We dedicate this paper to the memory of Joseph Barmack.     

Continuities in the development of the physical and social sciences: Principles of a new social physics

The original concept of “social physics” was built on positivist philosophy and scientific method. Evidence from quantum physics suggests that a postpositivist “social physics” may yet be viable, not because social science should emulate physics, but because physics is more like social science. The five principles of complementarty, uncertainty, the measurement problem, nonlocal causation, and participatory collusion are presented in this article to demonstrate the contemporary convergence of the physical and social sciences into a new social physics. E. Sam Overman is associate professor of public affairs at the Graduate School of Public Affairs, University of Colorado at Denver, Denver CO 80204. He recently editedMethodology and Epistemology for Social Science, selected papers by Donald T. Campbell (University of Chicago Press, 1988). He has published other articles on policy physics and social science philosophy, and has conducted research and published extensively in the area of information resource policy and management.     

Metaphors do not use associations between concepts,they are used to create them

Does the interpretability and aptness of a metaphor depend on prior existing associative relations between the metaphor topic and vehicle? Lexical decision latencies for pairs of words drawn from apt, comprehensible metaphors were no faster than latencies for randomly paired words. In contrast, lexical decision latencies for associatively related word pairs were faster than latencies for randomly paired words. These data suggest that good metaphors do not use preexisting associations to achieve their effects. Instead, we argue tht people use metaphors to create new relations between concepts. Implications for a theory of metaphor comprehension are discussed.     

“Put a Little Love in Your Heart”: Acceptance of Paternalistic and Ally Political Discourses Both Predict Pro-Roma Solidarity Intentions Through Moral Inclusion

The way politicians talk about minorities institutes the normative context of intergroup relations. We investigated how endorsement of different political discourses predicts donation and collective action intentions by majority members toward the Roma in five European countries. The survey was conducted online using samples demographically similar to the populations of Hungary, Slovakia, Romania, France, and Ireland (N = 5,054). First, results showed that accepting paternalistic discourse versus discourse promoting allyship were not distinguishable; both promoted higher moral inclusion which in turn predicted higher prosocial intentions. Second, donations (i.e., immediate relief) and collective action (i.e., social change action) were driven by identical factors. Third, acceptance of openly hostile political discourse neither predicted moral exclusion, nor lower prosocial intentions. In summary, our research provides important evidence that when it comes to Roma—non-Roma relations, the previously established distinction between solidarity intentions that aim to solidify status relations versus bring about social change is completely blurred, presumably because of the social context in which any positive message communicates moral inclusion challenging the hostile status quo.     

Redistributing control between the elements of a compound stimulus

Twenty-eight pigeons were given discrimination training. Four groups were run in which for 0, 2, 4 and 9 sessions of training colour was an irrelevant cue and tone was relevant. Generalization tests were given in extinction; the training colour (C₁) and another colour (C₂) were presented with tone (T) and noise (N). Responding to these four stimulus combinations, TC₁, TC₂, NC₁ and NC₂, allowed the assessment of control by colour and tone. A reduction of control by colour and an increase in control by tone were found to be positively related to the amount of training with colour irrelevant. Tests showed a strong inverse relationship between control by colour and tone.     

Combination of drive and incentive

This experiment was designed to investigate the combination of drive and incentive as determinants of performance. Nine groups of rats were trained to press a bar under three levels of food deprivation (12, 24 and 36 hr.) and three incentive conditions (1,2 and 3 pellets). Response strength was estimated by counting the number of responses with a latency of 1 sec. or less during five 20 trial sessions. The results indicated that response strength increased with hours of deprivation and with amount of food reward. Significant interactions between sessions and drive, and sessions and incentive provided additional support for the multiplicative combination of H (habit) and D (drive) and H and K (incentive). The lack of significant interaction between D and K was interpreted as supporting the hypothesis that D and K combine additively rather than multiplicatively.     

Overtraining, transfer to proprioceptive control and position reversal

If rats are overtrained on a visual discrimination they generally learn the reversal of the discrimination faster than non-overtrained rats. In position discriminations, however, this effect does not generally hold—indeed several investigators have found overtraining to retard position reversal. One of the important differences between the two types of problem seems to be the presence of irrelevant cues in visual discriminations, and their absence in position discriminations. It is suggested that a second important feature of position discriminations is that overtraining usually causes control of the maze running habit to be transferred from external to proprioceptive stimuli, and that successful reversal cannot normally occur until external control is re-established. In two experiments a study by Krechevsky and Honzik (1932) is repeated with certain modifications, with results that support this hypothesis; and a third experiment provides direct evidence of transfer to proprioceptive control in a T-maze. It is shown that this analysis will explain the apparently conflicting results of all recent position reversal experiments.     

Role of intertrial interval following an escape or avoidance response in bar-press avoidance

In three experiments, rats learned bar-press avoidance as a function of the intertrial interval following an escape or an avoidance. The general hypothesis is that the length of these intervals affects bar-press avoidance differentially, depending on whether an avoidance follows an escape (avoidance/escape) or an avoidance (avoidance/avoidance) on the previous trial. Specifically, it is proposed that short escape ITIs will facilitate avoidance/escape and avoidance/avoidance, while avoidance ITIs will have no effect on avoidance responding. The results tend to support this hypothesis. The shorter the intertrial interval following an escape, the higher the probability of both measures: avoidance/escape and avoidance/avoidance. No effect of avoidance interval was found on avoidance/avoidance. Unpredictedly, however, it was found that in comparison to a very short intertrial interval following an avoidance (0.5 sec), relatively long intervals (5 and 45 sec) facilitate avoidance/escape. These results were interpreted as mainly reflecting nonassociative factors such as shock-produced activity.