Spontaneous generalization of abstract multimodal patterns in young domestic chicks

From the early stages of life, learning the regularities associated with specific objects is crucial for making sense of experiences. Through filial imprinting, young precocial birds quickly learn the features of their social partners by mere exposure. It is not clear though to what extent chicks can extract abstract patterns of the visual and acoustic stimuli present in the imprinting object, and how they combine them. To investigate this issue, we exposed chicks (Gallus gallus) to three days of visual and acoustic imprinting, using either patterns with two identical items or patterns with two different items, presented visually, acoustically or in both modalities. Next, chicks were given a choice between the familiar and the unfamiliar pattern, present in either the multimodal, visual or acoustic modality. The responses to the novel stimuli were affected by their imprinting experience, and the effect was stronger for chicks imprinted with multimodal patterns than for the other groups. Interestingly, males and females adopted a different strategy, with males more attracted by unfamiliar patterns and females more attracted by familiar patterns. Our data show that chicks can generalize abstract patterns by mere exposure through filial imprinting and that multimodal stimulation is more effective than unimodal stimulation for pattern learning.     

Selective auditory grouping by zebra finches: testing the iambic–trochaic law

Humans have a strong tendency to spontaneously group visual or auditory stimuli together in larger patterns. One of these perceptual grouping biases is formulated as the iambic/trochaic law, where humans group successive tones alternating in pitch and intensity as trochees (high–low and loud–soft) and alternating in duration as iambs (short–long). The grouping of alternations in pitch and intensity into trochees is a human universal and is also present in one non-human animal species, rats. The perceptual grouping of sounds alternating in duration seems to be affected by native language in humans and has so far not been found among animals. In the current study, we explore to which extent these perceptual biases are present in a songbird, the zebra finch. Zebra finches were trained to discriminate between short strings of pure tones organized as iambs and as trochees. One group received tones that alternated in pitch, a second group heard tones alternating in duration, and for a third group, tones alternated in intensity. Those zebra finches that showed sustained correct discrimination were next tested with longer, ambiguous strings of alternating sounds. The zebra finches in the pitch condition categorized ambiguous strings of alternating tones as trochees, similar to humans. However, most of the zebra finches in the duration and intensity condition did not learn to discriminate between training stimuli organized as iambs and trochees. This study shows that the perceptual bias to group tones alternating in pitch as trochees is not specific to humans and rats, but may be more widespread among animals.     

Past Trauma and Current Stress and Coping: Toward a General Model

Studies find trauma to both sensitize and steel its victims to subsequent stress, but results are specific to certain populations, traumas, or indices of stress and coping. Here, a general population sample (N = 255) completed comprehensive measures of trauma, stress, and coping to suggest a general model of their relationships. Regressions showed childhood—but not lifetime—trauma linked to avoidant coping and greater stress, indicating a partial mediation model. Structural equation modeling (SEM) verified that childhood trauma predicted adult stress both directly and through avoidance. Limitations of present methods, and suggestions for continuing the development of a general trauma-coping-stress model, are discussed.     

An Examination of Biodata Theory‐Based Constructs in a Field Context

This study examined whether items from a biodata inventory were consistent with theory‐based constructs as suggested by the ecology model. The model posits five constructs explain biodata predictive ability. Items were sorted using the theory‐based construct domains. The resulting scale scores were assessed for evidence of content, criterion‐related, and construct validity in a sample of 6032 automated systems controllers. Results suggested moderate support for the theory‐based constructs. A notable finding was that items capturing a theoretical construct were impacted by the life stage in which they were anchored. Results further suggest the need to examine if certain life stages are more predictive than others or perhaps if certain constructs are more predictive when related to a particular life stage.     

Psychological Control Associated with Youth Adjustment and Risky Behavior in African American Single Mother Families

A distinction between parental behavioral control and psychological control has been elucidated in the literature, yet far less is known about the role of psychological control in youth adjustment broadly or risky behavior in particular. We examined the interrelationship of maternal psychological control, youth psychosocial adjustment, and youth risk behaviors among African American single mother-youth (11–16-year old) dyads (n = 194), families in which youth are more vulnerable to adjustment problems and risky behavior than Caucasian youth or youth from intact homes. Higher levels of maternal psychological control were associated with increased youth psychosocial adjustment problems as well as increased youth risk behavior, after statistically controlling for one domain of behavioral control, parental knowledge about a child’s whereabouts and activities. Furthermore, youth externalizing problems mediated the relation between psychological control and risk behavior. The findings suggest that parenting programs targeting risk behavior among African American youth may benefit from including psychological control among the parenting dimensions that are targeted.     

Complicity and Criminal Liability in Rwanda: A Situationist Critique

In Complicity and the Rwandan Genocide (2010b), Larry May argues that complicity can be the basis for criminal liability if two conditions are met: First, the person’s actions or inactions must contribute to the harm in question, and secondly, the person must know that his actions or inactions risk contributing to this harm. May also states that the threshold for guilt for criminal liability is higher than for moral responsibility. I agree with this latter claim, but I think that it casts doubt on May’s account of criminal liability, particular in so-called performance cases in which low-level participants merely fail to help. This is because it is far from clear that passive non-helpers are morally responsible for their participation in widespread harms. Situationism purports to show that passive bystanders typically are not morally responsible for their role in such harms, because they were behaving reasonably subject to the constraints they faced. In this paper, I assess this claim, and defend it on the basis of O. W. Holmes’ standard of the reasonable person as a guide to judging criminal complicity. Finally, I provide a situationist account of the Rwandan genocide, which focuses on the systemic causes and primary perpetrators of the genocide, rather than low-level participants.     

Performance on a measure of category fluency in cognitively impaired elderly

Measures of verbal fluency are widely used in the assessment of cognitive functioning of the elderly. However, limited research has evaluated patterns (across specific timed intervals) of performance on tasks of language fluency in different forms of dementia. The current study investigated semantic fluency in 488 elderly individuals (249 with Alzheimer's dementia, 97 Vascular dementia, 97 Mild Cognitive Impairment and 45 cognitively intact) across 15-second intervals in an animal naming task using retrospective chart review. Normal controls produced significantly more exemplars and AD patients produced fewer animal names than the other groups. After the first 15- second time interval, the demented groups produced significantly fewer exemplars than the non-demented. At the end of 30 seconds it was possible to differentiate normal aging from MCI who no longer differed from the VaD group. Overall, it appears that the greatest and most clinically meaningful differences between the diagnostic groups were detected in the first three 15-second intervals. The present findings support the use of time intervals and total scores on tasks of verbal fluency in clinical settings and for research purposes.     

Developmental changes in children's inductive inferences for biological concepts: implications for the development of essentialist beliefs

We examined developmental changes in children's inductive inferences about biological concepts as a function of knowledge of properties and concepts. Specifically, 4‐ to 5‐year‐olds and 9‐ to 10‐year‐olds were taught either familiar or unfamiliar internal, external, or functional properties about known and unknown target animals. Children were asked to infer whether each of four probes, varying in categorical and perceptual similarity to the target, also shared that property. Overall, children made more inferences for known concepts and familiar properties. Older children were more likely to use categorical than perceptual information when making inferences about internal and functional properties of known concepts; however, younger children, in general, made no distinction for property type, and they weighted categorical and perceptual information similarly. Both age groups utilized appearance when making inferences about external properties. Results are discussed in terms of developmental changes in children's appreciation of essentialism. Copyright © 2010 John Wiley & Sons, Ltd.     

Increasing following headway with prompts, goal setting, and feedback in a driving simulator

We evaluated the effects of prompting, goal setting, and feedback on following headway of young drivers in a simulated driving environment and assessed whether changes produced in following headway were associated with reductions in hard braking when drivers were and were not using cell phones. Participants were 4 university students. During baseline, drivers spent half of the time talking on cell phones while driving. At the start of the intervention, drivers were prompted to increase following headway while on the cell phones and were provided a specific target for following headway. Drivers were given feedback on increasing following headway when on cell phones at the end of each session. The intervention package was associated with an increase in following headway and a decrease in hard braking when participants were on and off the cell phones. Cell phone use did not affect any of the measures.