Behavioral and pharmacological variables affecting risky choice in rats.

The effects of manipulations of response requirement, intertrial interval (ITI), and psychoactive drugs (ethanol, phencyclidine, and d-amphetamine) on lever choice under concurrent fixed-ratio schedules were investigated in rats. Responding on the "certain' lever produced three 45-mg pellets, whereas responding on the "risky" lever produced either 15 pellets (p = .33) or no pellets (p .67). Rats earned all food during the session, which ended after 12 forced trials and 93 choice trials or 90 min, whichever occurred first. When the response requirement was increased from 1 to 16 and the ITI was 20 s, percentage of risky choice was inversely related to fixed-ratio value. When only a single response was required but the ITI was manipulated between 20 and 120 s (with maximum session duration held constant), percentage of risky choice was directly related to length of the ITI. The effects of the drugs were investigated first at an ITI of 20 s, when risky choice was low for most rats, and then at an ITI of 80 s, when risky choice was higher for most rats. Ethanol usually decreased risky choice. Phencyclidine did not usually affect risky choice when the ITI was 20 s but decreased it in half the rats when the ITI was 80 s. For d-amphetamine, the effects appeared to he related to baseline probability of risky choice; that is, low probabilities were increased and high probabilities were decreased. Although increase in risky choice as a function of the ITI is at variance with previous ITI data, it is consistent with foraging data showing that risk aversion decreases as food availability decreases. The pharmacological manipulations showed that drug effects on risky choice may be influenced by the baseline probability of risky choice, just as drug effects can be a function of baseline response rate.     

Pathways to Risk Among Inner-City African-American Adolescent Females: The Influence of Gang Membership

Differential rates of participation in three categories of risk behaviors (i.e., sexual activity, substance use, violence) were explored, comparing gang members to nonmembers, within a sample of 1,143 inner-city African American adolescent females. The relationship between gang membership and risk behavior also was examined, by exploring the association between a variety of microsystemic influences (e.g., gang, family, school) and participation in risk behaviors. MANOVA analyses indicated that gang members, relative to nonmembers, reported higher rates of participation in each of the three categories of risk behaviors. Stepwise linear regression analyses indicated that gang membership was the variable with the most consistent predictive ability, across all categories of risk, as it entered early in all equations and remained in all three final models after controlling for other statistically significant contextual variables. Findings suggest that intervention efforts aimed at reducing adolescent females' participation in sexual activity, substance use, and violence should consider the influence of gang membership on the participation in these behaviors.     

Family and Contextual Predictors of Depressive Symptoms in Inner-City African American Youth

Family and contextual predictors of depression in inner-city, African American youth have rarely been examined. In this study we explore the contribution of current and historical life events, family conflict, perceived social support from mother, maternal depression, and maternal explanatory style to the depressive symptoms of inner-city African American school-age (M = 10.7 years) children. Home interviews were conducted with 89 mother and child dyads living in moderate- to high-violent areas of a southeastern city. Regression analyses revealed that the children in this sample with higher levels of depressive symptoms had higher levels of child-reported everyday stress, were more likely to have been abused at some point in their past, came from homes with mothers who were less well educated, and had mothers who reported higher levels of depression, a past history of domestic abuse, as well as a less pessimistic explanatory style. Implications for interventions with inner-city African American families are discussed.     

Counter-stereotypical impulsivity and violence among African American college men

The study examined the relationship between impulse control and violence in terms of past feelings and acts among African American males enrolled in Historically Black Colleges and Universities. Data were gathered from a sample of 1,874 male undergraduates in eleven colleges and universities with predominantly African-American students. Less than six percent were classified as impulsive, and even less than half of the impulsive males had past feelings and acts of violence. The study offers strategies for impulse control which may help to further minimize incidents of violence on the college campus.     

A Bootstrapping Model of Frequency and Context Effects in Word Learning

Prior research has shown that people can learn many nouns (i.e., word–object mappings) from a short series of ambiguous situations containing multiple words and objects. For successful cross‐situational learning, people must approximately track which words and referents co‐occur most frequently. This study investigates the effects of allowing some word‐referent pairs to appear more frequently than others, as is true in real‐world learning environments. Surprisingly, high‐frequency pairs are not always learned better, but can also boost learning of other pairs. Using a recent associative model (Kachergis, Yu, & Shiffrin, 2012), we explain how mixing pairs of different frequencies can bootstrap late learning of the low‐frequency pairs based on early learning of higher frequency pairs. We also manipulate contextual diversity, the number of pairs a given pair appears with across training, since it is naturalistically confounded with frequency. The associative model has competing familiarity and uncertainty biases, and their interaction is able to capture the individual and combined effects of frequency and contextual diversity on human learning. Two other recent word‐learning models do not account for the behavioral findings.     

Identification With All Humanity: The role of self‐definition and self‐investment

Identification With All Humanity (IWAH) relates to higher levels of concern and supportive behavior toward the disadvantaged, stronger endorsement of human rights, and stronger responses in favor of global harmony. So far, IWAH has been conceptualized as a one‐dimensional construct describing the degree with which one identifies with all humans as a superordinate ingroup. However, recent group identification models suggest a multi‐dimensional model to provide a more differentiated approach toward the understanding of the highest level of social identification. Using principal axis (Study 1) and confirmatory (Study 2) factor analyses, we suggest that IWAH sub‐divides into two dimensions—global self‐definition and global self‐investment. Study 2 revealed that global self‐investment was a stronger predictor for both convergent measures (e.g., social dominance orientation and authoritarianism) and behavioral intentions than global self‐definition. Finally, in Study 3, we manipulated IWAH to test its causal effect on donation behavior. Participants in the experimental condition, compared with the control condition, showed higher global self‐investment, which in turn predicted greater giving to global charity. These findings suggest that two dimensions with different behavioral outcomes underlie IWAH.     

Laterality effects in the spinning dancer illusion: The viewing‐from‐above bias is only part of the story

The ‘silhouette illusion’, representing the silhouette of a female dancer pirouetting about her vertical axis, is a bistable stimulus created by Japanese web designer Nobuyuki Kayahara. Although the dancer can be perceived as spinning either clockwise or counterclockwise, the clockwise rotation is usually preferred. Troje and McAdam (i‐Perception, 2010, 1, 143) showed that this clockwise bias can be attributed to the tendency to assume a viewpoint from above rather than from below, given that the dancer is portrayed from a vantage point that is not perpendicular to the axis of rotation. Here, we tested whether another possible factor contributing to the observers’ interpretation of this bistable stimulus might be the tendency to perceive movements of the right rather than the left foot. We confirmed both the viewing‐from‐above bias and our hypothesis. The bias to perceive movements of the right leg might be a generalization to lower limbs of a perceptual frequency effect already observed for upper limbs. Such a perceptual and attentional bias towards the right hand/foot could account for the greater ability to predict the outcome of sport actions when observing right‐ rather than left‐limbed movements, and thus the left‐handers' and left‐footers' advantage observed in a variety of interactive sports.     

A Computational Evaluation of Sentence Processing Deficits in Aphasia

Individuals with agrammatic Broca's aphasia experience difficulty when processing reversible non‐canonical sentences. Different accounts have been proposed to explain this phenomenon. The Trace Deletion account (Grodzinsky, 1995, 2000, 2006) attributes this deficit to an impairment in syntactic representations, whereas others (e.g., Caplan, Waters, Dede, Michaud, & Reddy, 2007; Haarmann, Just, & Carpenter, 1997) propose that the underlying structural representations are unimpaired, but sentence comprehension is affected by processing deficits, such as slow lexical activation, reduction in memory resources, slowed processing and/or intermittent deficiency, among others. We test the claims of two processing accounts, slowed processing and intermittent deficiency, and two versions of the Trace Deletion Hypothesis (TDH), in a computational framework for sentence processing (Lewis & Vasishth, 2005) implemented in ACT‐R (Anderson, Byrne, Douglass, Lebiere, & Qin, 2004). The assumption of slowed processing is operationalized as slow procedural memory, so that each processing action is performed slower than normal, and intermittent deficiency as extra noise in the procedural memory, so that the parsing steps are more noisy than normal. We operationalize the TDH as an absence of trace information in the parse tree. To test the predictions of the models implementing these theories, we use the data from a German sentence—picture matching study reported in Hanne, Sekerina, Vasishth, Burchert, and De Bleser (2011). The data consist of offline (sentence‐picture matching accuracies and response times) and online (eye fixation proportions) measures. From among the models considered, the model assuming that both slowed processing and intermittent deficiency are present emerges as the best model of sentence processing difficulty in aphasia. The modeling of individual differences suggests that, if we assume that patients have both slowed processing and intermittent deficiency, they have them in differing degrees.     

Challenges in Developing a Cultural Evidence‐Based Psychotherapy in the USA: Suggestions for International Studies

In this article, we underscore some of the cultural challenges and limitations of the evidence‐based psychotherapy (EBP) utilised within the USA with the hope that these problems will be avoided or ameliorated in Australia and other countries. Although the EBP research is very diverse and complex, we categorise this fast‐growing literature using a threefold classification system that underscores culture. This classification system is proposed to examine the influence of culture on EBPs. The three categories used are (a) universal evidence‐based psychotherapies or universal psychotherapies, (b) race and ethnic minority evidence‐based psychotherapies or racial/ethnic psychotherapies, and (c) cultural evidence‐based psychotherapies or cultural psychotherapies. After each category is described, its benefits and limitations are discussed, emphasising implications for culturally diverse and international studies. We conclude with suggestions to promote the advancement of a more effective and inclusive cultural EBP in which researchers from different countries can collaborate and learn from each other.     

The learning benefits of teaching: A retrieval practice hypothesis

Teaching educational materials to others enhances the teacher's own learning of those to‐be‐taught materials, although the underlying mechanisms remain largely unknown. Here, we show that the learning‐by‐teaching benefit is possibly a retrieval benefit. Learners (a) solved arithmetic problems (i.e., they neither taught nor retrieved; control group), (b) taught without relying on teaching notes (i.e., they had to retrieve the materials while teaching; teaching group), (c) taught with teaching notes (i.e., they did not retrieve the materials while teaching; teaching without retrieval practice [TnRP] group), or (d) retrieved (i.e., they did not teach but only practised retrieving; retrieval practice group). In a final comprehension test 1 week later, learners in the teaching group, as did those in the retrieval practice group, outperformed learners in the TnRP and control groups. Retrieval practice possibly causes the learning benefits of teaching.