Velocity-based motion categorization by pigeons

To examine if animals could learn action-like categorizations in a manner similar to noun-based categories, eight pigeons were trained to categorize rates of object motion. Testing 40 different objects in a go/no-go discrimination, pigeons were first trained to discriminate between fast and slow rates of object rotation around their central y-axis. They easily learned this velocity discrimination and transferred it to novel objects and rates. This discrimination also transferred to novel types of motions including the other two axes of rotation and two new translations around the display. Comparable tests with rapid and slow changes in the objects' size, color, and shape failed to support comparable transfer. This difference in discrimination transfer between motion-based and property-based changes suggests the pigeons had learned motion concept rather than one based on change per se. The results provide evidence that pigeons can acquire an understanding of motion-based actions, at least with regard to the property of object velocity. This may be similar to our use of verbs and adverbs to categorize different classes of behavior or motion (e.g., walking, jogging, or running slow vs. fast).     

Categorization and communication in the face of prejudice: when describing perceptions changes what is perceived

In the face of prejudice against an ingroup, common ground for communication exists when people use similar social categories to understand the situation. Three studies tested the hypothesis that describing perceptions of prejudice can fundamentally change those perceptions because communicators account for the common ground in line with conversational norms. When women (Study 1), African Americans (Study 2), and Americans (Study 3) simply thought about suspected prejudice against their ingroup, categorization guided their perceptions: Participants assimilated their views of the prejudiced event toward the perceptions of ingroup members but contrasted away from the perceptions of outgroup members. Conversely, when participants described their perceptions, they contrasted away from the given category information and actually arrived at the opposite perceptions as those who merely thought about the prejudiced event. Study 3 identified an important qualification of these effects by showing that they were obtained only when participants could assume their audience was familiar with the common ground. Implications are discussed for understanding the role of communication in facilitating and inhibiting collective action about prejudice.     

Executive control and the experience of regret

The experience of regret rests on a counterfactual analysis of events. Previous research indicates that regret emerges at around 6 years of age, marginally later than the age at which children begin to answer counterfactual questions correctly. We hypothesized that the late emergence of regret relative to early counterfactual thinking is a result of the executive demands of simultaneously holding in mind and comparing dual representations of reality (counterfactual and actual). To test this hypothesis, we administered two regret tasks along with four tests of executive function (two working memory tasks, a switch task, and an inhibition task) to a sample of 104 4- to 7-year-olds. Results indicated that switching, but not working memory or inhibition, was a significant predictor of whether or not children experienced regret. This finding corroborates and extends previous research showing that the development of counterfactual thinking in children is related to their developing executive competence.     

The hierarchical order of processes underlying the direction illusion and the direction aftereffect

Motion perception involves the processing of velocity signals through several hierarchical stages of the visual cortex. To better understand this process, a number of studies have sought to localise the neural substrates of two misperceptions of motion direction, the direction illusion (DI) and the direction aftereffect (DAE). These studies have produced contradictory evidence as to the hierarchical order of the processing stages from which the respective phenomena arise. We have used a simple stimulus configuration to further investigate the sequential order of processes giving rise to the DI and DAE. To this end, we measured the two phenomena invoked in combination, and also manually parsed this combined effect into its two constituents by measuring the two phenomena individually in both possible sequential orders. Comparing the predictions made from each order to the outcome from the combined effect allowed us to test the tenability of two models: the DAE-first model and the DI-first model. Our results indicate that DAE-invoking activity does not occur earlier in the motion processing hierarchy than DI-invoking activity. Although the DI-first model is not inconsistent with our data, the possible involvement of non-sequential processing may be better able to reconcile these results with those of previous studies.     

Do behavioral responses mediate or moderate the relation between cardiovascular reactivity to stress and parental history of hypertension?

To examine whether differences in behavioral responses to stress mediated or moderated the relation between cardiovascular response to stress and parental history of hypertension, 64 healthy undergraduates-16 men with hypertensive parents (PH+), 16 men without hypertensive parents (PH-), 16 PH+ women, and 16 PH- women-participated in a mental arithmetic task, mirror tracing task, and 2 interpersonal role plays. PH+ participants exhibited higher resting heart rates than PH- participants and higher resting systolic blood pressures (SBPs) than PH- women. PH+ participants exhibited greater SBP responses to tasks and engaged in more negative verbal and nonverbal behavior across tasks than PH- counterparts. Differences in behavioral responding neither mediated nor moderated the observed relation between parental history status and SBP response to stress.     

The influence of only on syntactic processing of long relative clause sentences

We report an eye movement experiment investigating the influence of the focus operator only on syntactic processing of long relative clause sentences. Paterson, Liversedge, and Underwood (1999) found that readers were garden pathed by short reduced relative clause sentences containing the focus operator only . They argued that due to thematic differences between short and long relative clause sentences, garden path effect might not occur when long reduced relative clause sentences are read. Eye-tracking data show that garden path effects found during initial processing of the disambiguating verb of long reduced sentences without only were absent or delayed in the case of counterparts with only . We discuss our results in terms of current theories of sentence processing.     

Natural born killers: The genetic origins of extreme violence

The current article examines the influence of genetics and evolution on acts of extreme and criminal violence among human primates. Moderate aggression can function to increase an organism's reproductive success; extreme violence can place the organism at unnecessary risk. Genetic polymorphisms that have been linked to extreme acts of violence are reviewed as is research elucidating how genetic risk and environmental stress may interact to increase risk of extreme violence. Extreme violence is viewed as high-end variance in an evolutionarily adaptive process in which the propensity for aggression and violent behavior, in moderate doses, has been adaptive for individual humans.     

Domestic Abuse as Terrorism

A number of philosophers and feminist authors have recently equated domestic abuse with the ubiquitous and ill‐defined concept of “terrorism.” Claudia Card, for instance, argues that domestic abuse is a frequently ignored form of terrorism that creates and maintains “heterosexual male dominance and female dependence and service” (Card 2003). Alison Jaggar, in a recent article, also concludes that an acceptable definition of terrorism will find rape and domestic violence to be terrorist acts (Jaggar 2005). Yet there seem to be several obstacles to any simple appropriation of the term “terrorism” for cases of domestic abuse. In this paper I will address what I take to be three significant problems that might be raised with regard to any attempt to identify domestic abuse as an act of terrorism. These problems include the fact that a) definitions of terrorism usually require clear political motivations, b) definitions of terrorism normally require that the terrorist intend to create a climate of terror, and c) adopting the term terrorism for cases of domestic abuse might appear simply inappropriate or unhelpful. I will argue, however, that each of these possible objections can be answered effectively and that domestic abuse rightly falls under the rubric of terrorism.     

Language Development and Assessment in the Preschool Period

Most young children make significant progress in learning language during the first 4?years of life. Delays or differences in patterns of language acquisition are sensitive indicators of developmental problems. The dynamic, complex nature of language and the variability in the timing of its acquisition poses a number of challenges for the assessment of young children. This paper summarises the key developmental milestones of language development in the preschool years, providing a backdrop for understanding difficulties with language learning. Children with specific language impairment (SLI) are characterised illustrating the types of language difficulties they exhibit. Genetic evidence for language impairment suggests complex interactions among multiple genes of small effect. There are few consistent neurobiological abnormalities and currently there is no identified neurobiological signature for language difficulties. The assessment of young children??s language skills thus focuses on the evaluation of their performances in comparison to typically developing peers. Assessment of language abilities in preschool children should involve an evaluation of both expressive and receptive skills and should include an evaluation of more than one dimension of language. The use of a single measure of a language component, such as vocabulary, is considered inadequate for determining whether preschool children have typical language or language impairment. Available evidence supports the inclusion of measures of phonological short-term memory in the assessment of the language abilities of preschool children. Further study of genetic, neurobiological and early behavioural correlates of language impairments in preschool children is needed.     

Divorce Stress,Stepfamily Stress,and Depression among Emerging Adult Stepchildren

Several decades of research have shown that parental divorce can be a stressful experience for children and may lead to depression and other negative outcomes. Similarly, research has highlighted the stressors often induced by stepfamily formation and their effects on children. Although singular family transitions can exert influence, few studies explore how the combined stress from two family transitions may interact to influence long-term outcomes. Our study addresses this gap by using national data from 1142 respondents who experienced parental divorce and a subsequent transition to stepfamily life. Congruent with prior research, we find that retrospective reports of divorce and stepfamily stress is associated with higher depressive symptoms in emerging adults (18–30 years of age). We also find that stress induced by parental divorce and subsequent stepfamily formation significantly interact to increase depressive symptoms in this population. The research and clinical implications of our findings are discussed.