Cognitive Load and the Equality Heuristic: A Two-Stage Model of Resource Overconsumption in Small Groups

Two studies were conducted to test a two-stage model of the psychological mechanisms underlying the overconsumption of scarce resources in small groups. The model proposes that members of groups sharing resources first anchor their consumption choices on an “equal-division” heuristic and then, given sufficient cognitive capacity, adjust their choices in a self-serving direction. The results from both studies support the model. The first study found that when faced with a common resource pool almost all group members expressed thoughts regarding equality; however, individuals with sufficient cognitive capacity requested more from the pool and expressed more task-relevant thoughts than individuals lacking the necessary cognitive resources. The second study provided additional support for the two-stage model by demonstrating that group members' cognitions occur in the order predicted by the model and by demonstrating that an individual difference, social value orientation, affects thought processes only when individuals are not experiencing high cognitive loads. Implications are discussed.     

Discrete and contextual cue alterations eliminate the instrumental appetitive-to-aversive transfer impairment in phenytoin-treated rats

We have shown previously that the antiepileptic phenytoin impairs transfer in an instrumental learning task (Banks et al., 1999). The present study examined the effects of contextual alterations on appetitive-to-aversive transfer performance of rats treated with either phenytoin or tang. Adult rats were tested in tone-signaled appetitive and aversive instrumental tasks, where the animal bar-pressed to obtain a food reward (sugar pellet) or to avoid shock. Rats were trained on the appetitive task for 31 days. Beginning on the twenty-first day, rats were gavaged with either phenytoin or tang twice daily. Animals were then transferred to aversive training, with the phenytoin or tang treatment continuing throughout the 25 testing days. For some animals, contextual changes were introduced as they shifted from appetitive to aversive training, while for other animals these changes were not made. Phenytoin-treated rats that were presented with changes in context as they transferred from the appetitive to the aversive task learned the avoidance response to levels substantially higher than drug-treated rats not presented with the contextual changes. These results indicate that phenytoin impairs avoidance learning following transfer from the appetitive task, and that this impairment can be eliminated by introducing changes in context at the point of transfer. In the tang-treated control subjects, on the other hand, there was no improvement in transfer learning performance associated with the changes in contextual cues. This pattern of results suggests that contextual encoding processes in rats being trained in an instrumental appetitive-to-aversive paradigm are dramatically affected by phenytoin.     

They call it like they see it: spontaneous naming and attention to shape

Two experiments explore children's spontaneous labeling of novel objects as a method to study early lexical access. The experiments also provide new evidence on children's attention to object shape when labeling objects. In Experiment 1, the spontaneous productions of 21 23- to 28-month-olds (mean 26;28) shown a set of novel, unnamed objects were analyzed both in terms of the specific words said and, via adult judgments, their likely perceptual basis. We found that children's spontaneous names were cued by the perceptual feature of shape. Experiment 2 examines the relation between spontaneous productions, name generalizations in a structured task, and vocabulary development in a group of children between 17 and 24 months of age (mean 21;6). Results indicate that object shape plays an important role in both spontaneous productions and novel noun generalization, but contrary to current hypotheses, children may name objects by shape from the earliest points of productive vocabulary development and this tendency may not be lexically specific.     

Maternal Trauma and Children’s Functioning: The Role of Kinship Social Support

Although research has documented the detrimental effects of maternal trauma on child behavior (Lambert, Holzer, & Hasbun, 2014), the role of extended family support in potentially mitigating the effects of intergenerational transmission of trauma is not clearly understood. With a diverse community sample of 52 trauma-exposed mothers and their children between the ages of 7 and 12, we investigated relationships between kinship social support, maternal trauma exposure severity, maternal posttraumatic stress disorder (PTSD) symptom severity, and child behavioral problems. Results showed that kinship social support was negatively related to maternal trauma exposure severity, maternal PTSD symptom severity, child internalizing behaviors, and child externalizing behaviors. Additionally, kinship social support moderated the relationship between maternal trauma exposure severity and child internalizing behaviors. These results have implications in the implementation of interventions aimed at supporting diverse families facing trauma that incorporate extended family networks.     

Children's Pets and Adults' Self-Concepts

Self-concepts of adults were related to the age when they had their first pet. The Tennessee Self Concept Scale (TSCS) (Fitts, 1965) Total Positive self-concept scores were higher if subjects were under 6 years or over 10 years old than if they were between 6 and 10 years old when they had their first pet. Similar results were found for the TSCS Physical and Social subscales. Whereas gender effects were also found, no significant pet ownership or other childhood Companion Animal Bonding Scale (Poresky, Hendrix, Mosier, & Samuelson, 1987) effects were found.     

Two-sample models with monotonic likelihood ratios for ordinal regression

Signal detection experiments with human observers frequently generate ordinal data which are evaluated using receiver operating characteristic (ROC) methods. These methods may include regressing a continuous two-distribution model to the data set. Because we assume that human observers will not systematically select observations absent the signal, this model should have a monotonic likelihood ratio between the distributions. This paper gives a general method for constructing pairs of distributions that have monotonic likelihood ratios and a possibly large number flexible parameters. It suggests two specific simple parametric forms of monotonic likelihood ratios, constructs new distributions with those likelihood ratios using other standard distributions, and performs ordinal regression with those new distributions to model some example data from the literature.     

The Effects of Phenytoin on the Performance of Rats in a Delayed Match-to-Place Task

We have shown previously that phenytoin impairs learning in rats in several different behavioral paradigms (Churchill et al., 1998, 2003; Banks et al., 1999). The present study has examined this drug's effects on performance in a delayed match-to-place water maze paradigm developed by Steele and Morris (1999). We find that phenytoin retards performance, but only when the inter-trial interval (ITI) is short (i.e., 15-sec). With longer ITIs (i.e., 20-min, 2-hr), the performance of the phenytoin-treated rats was quite comparable to the controls. We suggest that this pattern of results stems from a disruption of spatial working memory, perhaps due to the effects of the drug on hippocampal function (cf., Churchill et al., 1998, 2003). This disruption is, however, not so profound that consolidation is prevented.     

An attentional learning account of the shape bias: reply to Cimpian and Markman (2005) and Booth, Waxman, and Huang (2005)

Recently, Developmental Psychology published 2 articles on the shape bias; both rejected the authors' previous proposals about the role of attentional learning in the development of a shape bias in object name learning. A. Cimpian and E. Markman (2005) did so by arguing that the shape bias does not exist but is an experimental artifact. A. E. Booth, S. R. Waxman, and Y. T. Huang (2005), in contrast, concluded that the shape bias (and its contextual link to artifact categories) does exist but that the mechanisms that underlie it are conceptual knowledge and not attentional learning. In response, in this article the authors clarify the claims of the Attentional Learning Account (ALA) and interpretations of the data under question. The authors also seek to make explicit the deeper theoretical divide: cognition as sequestered from processes of perceiving and acting versus as embedded in, and inseparable from, those very processes.     

Students’ Reasoning About Whether to Report When Others Cheat: Conflict,Confusion, and Consequences

Journal of Academic Ethics - Nearly all students believe academic cheating is wrong, yet few students say they would report witnessed acts of cheating. To explain this apparent tension, the present...     

Learning words in space and time: probing the mechanisms behind the suspicious-coincidence effect

A major debate in the study of word learning centers on the extension of categories to new items. The rational approach assumes that learners make structured inferences about category membership, whereas the mechanistic approach emphasizes the attentional and memory processes that form the basis of generalization behaviors. Recent support for the rational view comes from observations of the suspicious-coincidence effect: People generalize category membership narrowly when presented with three subordinate-level exemplars that share the same label and generalize category membership broadly when presented with one exemplar. Across three experiments, we examined the mechanistic basis of this effect. Results showed that the presentation of multiple subordinate-level exemplars led to narrow generalization only when the exemplars were presented simultaneously, even when the number of exemplars was increased from three to six. These data demonstrate that the suspicious-coincidence effect is firmly grounded in the general cognitive processes of attention, memory, and visual comparison.