Training requirements and retention characteristics of serial list organization by macaque monkeys

This work evaluated the prospect that organizational accounts of the retention of list information by monkeys might be an artifact of familiarity with conditional relationships. Seven sophisticated macaques were trained on four five-item lists. Each acquisition selectively excluded one of the internal conditional pairs of the typical four-problem sequence (AB,BC,CD,DE) that defines a five-item serially ordered list. Then, all possible novel pairings and the trained pairs appeared together in a test. After this, the previously omitted pair was trained and animals were retested. On all tasks, initial tests revealed little organization and much intersubject variability of characteristic choice strategies, but subsequent inclusion of all four conditional pairs always yielded organized serial choice. On both the four-problem tests and in a later retention, errors were directly related to interitem distance between the objects paired on test trials. These results helped to specify the conditions required for demonstration of non-human primate analogs of transitivity, and showed that even sophisticated monkeys organize information in retention only if they know all interitem relationships. Received: 7 October 1998 / Accepted after revision: 10 October 1999     

Connectionist and diffusion models of reaction time.

Two connectionist frameworks, GRAIN (J. L. McClelland, 1993) and brain-state-in-a-box (J. A. Anderson, 1991), and R. Ratcliff's (1978) diffusion model were evaluated using data from a signal detection task. Dependent variables included response probabilities, reaction times for correct and error responses, and shapes of reaction-time distributions. The diffusion model accounted for all aspects of the data, including error reaction times that had previously been a problem for all response-time models. The connectionist models accounted for many aspects of the data adequately, but each failed to a greater or lesser degree in important ways except for one model that was similar to the diffusion model. The findings advance the development of the diffusion model and show that the long tradition of reaction-time research and theory is a fertile domain for development and testing of connectionist assumptions about how decisions are generated over time.     

Milestones in the development of infant numeracy

This article deals with the development of numeracy among young children of the four to seven year age group. The research investigation described had two aims: to see how early numeracy develops in children of different ages; and to see whether there are fixed points which might serve as milestones in the development of infant numeracy. The results of this investigation involving 96 children indicate a strong development of numeracy skills during this period. With reference to the literature, it is also shown that certain items of a test previously developed for this purpose may be taken as core items that do indeed represent milestones in the development of infant numeracy.     

Time course of word identification and semantic integration in spoken language

The minimum duration signal necessary to identify a set of spoken words was established by the gating technique; most words could be identified before their acoustic offset. Gated words were used as congruous and incongruous sentence completions, and isolation points established in the gating experiment were compared with the time course of semantic integration evident in event-related brain potentials. Differential N400 responses to contextually appropriate and inappropriate words were observed about 200 ms before the isolation point. Semantic processing was evident before the acoustic signal was sufficient to identify the words uniquely. Results indicate that semantic integration can begin to operate with only partial, incomplete information about word identity. Influences of semantic constraint, word frequency, and rate of presentation are described.     

Effects of reinforcement magnitude on spontaneous recovery.

Extinction of operant behavior has been associated with a number of undesirable effects. One such effect is the temporary reappearance of behavior after responding appears to be completely extinguished, known as spontaneous recovery. In this report, the occurrence of spontaneous recovery and its attenuation with large amounts of reinforcement were examined during the treatment of disruption.     

Are Conservatives Less Likely to be Prosocial Than Liberals? From Games to Ideology,Political Preferences and Voting

Do political preferences reflect individual differences in interpersonal orientations? Are conservatives less other‐regarding than liberals? On the basis of past theorising, we hypothesised that, relative to individuals with prosocial orientations, those with individualistic and competitive orientations should be more likely to endorse conservative political preferences and vote for conservative parties. This hypothesis was supported in three independent studies conducted in Italy (Studies 1 and 2) and the Netherlands (Study 3). Consistent with hypotheses, a cross‐sectional study revealed that individualists and competitors endorsed stronger conservative political preferences than did prosocials; moreover, this effect was independent of the association between need for structure and conservative political preferences (Study 1). The predicted association of social value orientation and voting was observed in both a four‐week (Study 2) and an eight‐month (Study 3) longitudinal study. Taken together, the findings provide novel support for the claim that interpersonal orientations, as measured with experimental games rooted in game theory, are important to understanding differences in ideology at the societal level. Copyright © 2011 John Wiley & Sons, Ltd.     

Capturing the Structure of Distinct Types of Individual Differences in the Situation‐specific Experience of Emotions: The Case of Anger

The aim of this paper was to understand why some people experience certain emotions in a specific situation, whereas others do not. We postulate that these individual differences arise from individual differences in two underlying processes of emotion elicitation: (i) individual differences in the emotion components (appraisals and action tendencies) that situations activate in a person and (ii) individual differences in how these emotion components are related to subjective emotional experience. In this paper, we re‐analysed data from two studies on anger to capture the structure of these two types of individual differences by using clustering modelling techniques. Consistent results across the two studies demonstrated that individuals differ in anger because they (i) differ in how easy they experience anger‐relevant appraisals (Studies 1 and 2) and action tendencies (Study 2) in increasingly negative situations and (ii) differ in which of these components are necessary to experience anger. Copyright © 2011 John Wiley & Sons, Ltd.     

Avoiding negative vs. achieving positive outcomes in hard and prosperous economic times

Three studies suggest that business cycle fluctuations trigger distinct motivational orientations that selectively affect economic judgment and decision making. Economic contractions induce avoidance motivation and affect negative economic sentiment, but leave approach motivation and positive economic sentiment unaffected. In contrast, economic expansions induce approach motivation and positive economic sentiment, but do not affect avoidance motivation or negative economic sentiment (study 1). Moreover, economic contractions induce risk aversion for negative outcomes, but not for positive outcomes, while economic expansions instigate risk seeking for positive outcomes, but not for negative outcomes (study 2). A time-series study based on consumer spending over eight decades mirrors the findings of the experimental studies: The consumption of products associated with avoiding negative outcomes increases during economic contractions, but not during expansions. In contrast, the consumption of products associated with achieving positive outcomes increases in expansions, but is unaffected by contractions (study 3).