Why are artificial polymorphous concepts so hard for birds to learn?

Stimulus sets defined in terms of artificial polymorphous concepts have frequently been used in experiments to investigate the mechanisms of discrimination of natural concepts, both in humans and in other animals. However, such stimulus sets are frequently difficult for either animals or humans to discriminate. Properties of artificial polymorphous stimulus sets that might explain this difficulty include the complexity of the individual stimuli, the unreliable reinforcement of individual positive features, attentional load, difficulties in discriminating some stimulus dimensions, memory load, and a lack of the correlation between features that characterizes natural concepts. An experiment using chickens as subjects and complex artificial visual stimulus sets investigated these hypotheses by training the birds in discriminations that were not polymorphous but did have some of the properties listed above. Discriminations that involved unreliable reinforcement or high attentional load were found to approach the difficulty of polymorphous concept discriminations, and these two factors together were sufficient to account for the entire difficulty. The usual kind of artificial polymorphous concept may not be a good model for natural concepts as they are perceived and discriminated by birds. A RULEX account of natural concept learning may be preferable.     

Self-enhancement by social comparison: a prospective analysis

A longitudinal investigation showed that self-enhancement by social comparison (assessing whether people perceive themselves more positively than they perceive others) was prospectively related to an increase in self-reported adjustment, controlling for the effects of narcissism. Better adjustment, including higher self-esteem, was not prospectively related to an increase in self-enhancement. The investigation also included a diary period, allowing the assessment of intrasubject covariation between daily reports of self-esteem and daily reports of perceived challenge and daily events (positive or negative). High (compared to low) self-enhancers were less likely to report lower self-esteem under higher challenge and less likely to report higher self-esteem under positive events.     

Executive control in a modified antisaccade task: Effects of aging and bilingualism

Two studies are reported that assess differences associated with aging and bilingualism in an executive control task. Previous work has suggested that bilinguals have an advantage over monolinguals in nonlinguistic tasks involving executive control; the major purpose of the present article is to ascertain which aspects of control are sensitive to the bilingual experience. Study 1 used an antisaccade task and found no effects of aging or bilingualism. Study 2 used the identical visual display but coupled to keypress responses. The results showed that bilinguals resolved various types of response conflict faster than monolinguals and that this bilingual advantage generally increased with age. A speculative interpretation of this pattern of results is offered in conclusion.     

Demographic variables and microCog performance: relationships for VA patients under treatment for substance abuse

The associations of demographic variables with cognitive performance, as measured by the MicroCog ability domain scores, were assessed with 222 substance abusers who were patients in a VA medical center. Analysis indicated that age was negatively related to all five outcomes scores, and education was positively related to measures assessing Attention/Mental Control and Reasoning/Calculation. These findings are consistent with past theoretical and applied research. The demographic variables, as a group, accounted for a total of 17% to 37% of the variance in the five domain scores.     

Narrative representations of caregivers and emotion dysregulation as predictors of maltreated children's rejection by peers

This study examined whether maltreated children were more likely than nonmaltreated children to develop poor-quality representations of caregivers and whether these representations predicted children's rejection by peers. A narrative task assessing representations of mothers and fathers was administered to 76 maltreated and 45 nonmaltreated boys and girls (8-12 years old). Maltreated children's representations were more negative/constricted and less positive/coherent than those of nonmaltreated children. Maladaptive representations were associated with emotion dysregulation, aggression, and peer rejection, whereas positive/coherent representations were related to prosocial behavior and peer preference. Representations mediated maltreatment's effects on peer rejection in part by undermining emotion regulation. Findings suggest that representations of caregivers serve an important regulatory function in the peer relationships of at-risk children.     

Learning and performance effects of accurate and erroneous knowledge of results on time perception

Performance feedback (also known as knowledge of results or KR) has both performance and learning effects on many tasks. Earlier studies have demonstrated performance but not learning effects on time perception tasks. In this experiment, we dissociate and identify these two phenomena on two different time perception tasks. Participants were presented with either accurate (100%) or erroneous (80% or 120% of actual performance) KR on either a reproduction or a numerical estimation time perception task. Accurate (100%) KR reduced the group variability and increased the accuracy of response magnitude but left individual variability unchanged. Erroneous (80% or 120%) KR also reduced the group variability while leaving individual variation unchanged, but decreased the true accuracy of the response, with response magnitudes increasing for the 80% KR group and decreasing for the 120% group. Thus external KR that is in conflict with internal time cues overrides these internal cues and dictates response magnitude on these two tasks. Thus KR provides guidance for these behaviors. KR did not reduce the variability (dispersion) of participants' responses, but centered each participant's responses closer to the targeted performance. This decreased group response variability reflected a performance enhancing effect of KR because group response variability increased after KR was withdrawn. In contrast, response magnitudes remained changed for the duration of the post-KR period, indicating that KR also induced a learned response. Thus individual response variability, group response variability and response magnitude represent dissociable features of performance on these time perception tasks.     

The antecedents and correlates of agreeableness in adulthood

Data from a 25-year prospective study of 194 individuals indicated that teacher and peer reports of aggression, compliance, and self-control at age 8 distinguished high-agreeable from low-agreeable adults at age 33. Profile analyses revealed two behavioral types in childhood and two personality types in adulthood, with considerable continuity in the composition of these high- and low-agreeable types over time. High-agreeable childhood types had fewer disobedience and concentration problems than low-agreeable childhood types, and among boys, high-agreeable childhood types had better school grades and fewer behavior problems than their low-agreeable counterparts. High-agreeable adulthood types reported less alcoholism and depression, fewer arrests, and more career stability than did low-agreeable adulthood types.     

Neural correlates of spatial term use

The current research used event-related brain potentials (ERPs) to assess the processes underlying online apprehension of the spatial term above. Constituent steps defined within G. D. Logan and D. D. Sadler's (1996) computational theory of apprehension were associated with distinct modulations of ERPs. Specifically, finding the relevant objects was associated with an amplitude modulation of P3; competition in assigning directions to space was associated with modulation of a frontal slow wave; and computing and comparing the spatial relation was associated with modulation of a parietal slow wave. These modulations were differentially influenced by the type of reference frame used to define the spatial term and by the participant's response. The current study supports this decompositional approach to apprehension and provides a means of assessing each step independently.