Human trace fear conditioning: right-lateralized cortical activity supports trace-interval processes

Pavlovian conditioning requires the convergence and simultaneous activation of neural circuitry that supports conditioned stimulus (CS) and unconditioned stimulus (US) processes. However, in trace conditioning, the CS and US are separated by a period of time called the trace interval, and thus do not overlap. Therefore, determining brain regions that support associative learning by maintaining a CS representation during the trace interval is an important issue for conditioning research. Prior functional magnetic resonance imaging (fMRI) research has identified brain regions that support trace-conditioning processes. However, relatively little is known about whether this activity is specific to the trace CS, the trace interval, or both periods of time. The present study was designed to disentangle the hemodynamic response produced by the trace CS from that associated with the trace interval, in order to identify learning-related activation during these distinct components of a trace-conditioning trial. Trace-conditioned activity was observed within dorsomedial prefrontal cortex (PFC), dorsolateral PFC, insula, inferior parietal lobule (IPL), and posterior cingulate (PCC). Each of these regions showed learning-related activity during the trace CS, while trace-interval activity was only observed within a subset of these areas (i.e., dorsomedial PFC, PCC, right dorsolateral PFC, right IPL, right superior/middle temporal gyrus, and bilateral insula). Trace-interval activity was greater in right than in left dorsolateral PFC, IPL, and superior/middle temporal gyrus. These findings indicate that components of the prefrontal, cingulate, insular, and parietal cortices support trace-interval processes, as well as suggesting that a right-lateralized fronto-parietal circuit may play a unique role in trace conditioning.     

Bicultural identity, bilingualism, and psychological adjustment in multicultural societies: immigration-based and globalization-based acculturation

ABSTRACT The present investigation examined the impact of bicultural identity, bilingualism, and social context on the psychological adjustment of multicultural individuals. Our studies targeted three distinct types of biculturals: Mainland Chinese immigrants in Hong Kong, Filipino domestic workers (i.e., sojourners) in Hong Kong, and Hong Kong and Mainland Chinese college students. Individual differences in Bicultural Identity Integration (BII; Benet-Martínez, Leu, Lee, & Morris, 2002 ) positively predicted psychological adjustment for all the samples except sojourners even after controlling for the personality traits of neuroticism and self-efficacy. Cultural identification and language abilities also predicted adjustment, although these associations varied across the samples in meaningful ways. We concluded that, in the process of managing multiple cultural environments and group loyalties, bilingual competence, and perceiving one's two cultural identities as integrated are important antecedents of beneficial psychological outcomes.     

Tuning in to another person's action capabilities: perceiving maximal jumping-reach height from walking kinematics

Three experiments investigated the ability to perceive the maximum height to which another actor could jump to reach an object. Experiment 1 determined the accuracy of estimates for another actor's maximal reach-with-jump height and compared these estimates to estimates of the actor's standing maximal reaching height and to estimates of the perceiver's own maximal reaching and reach-with-jump height. Perception of another actor's maximum reach-with-jump height was less accurate than the other estimates, but still accurate to within 8% error. The actor's reach-with-jump height was modified in Experiment 2 by attaching weights around the actor's ankles. Perceivers, who were explicitly aware of the manipulation, adjusted their maximum reach-with-jump estimates for the actor accordingly. In Experiment 3, perceivers were not explicitly aware of the weight manipulation, but provided significantly lower maximum reach-with-jump estimates after watching the actor walk while wearing the weights compared to estimates obtained after watching the actor walk while not wearing the weights. The results suggest that the actor's walking pattern was informative about the actor's capacity to produce a different action, jumping to reach an object.     

Children's preference for mixed‐ versus fixed‐ratio schedules of reinforcement: A translational study of risky choice

Laboratory research has shown that when subjects are given a choice between fixed‐ratio and bi‐valued mixed‐ratio schedules of reinforcement, preference typically emerges for the mixed‐ratio schedule even with a larger ratio requirement. The current study sought to replicate and extend these findings to children's math problem completion. Using an ABCBC reversal design, four fourth‐grade students were given the choice of completing addition problems reinforced on either a fixed‐ratio 5 schedule or one of three mixed‐ratio schedules; an equivalent mixed‐ratio (1, 9) schedule, a mixed‐ratio (1, 11) schedule with a 20% larger ratio requirement, and an equally lean mixed‐ratio (5, 7) schedule without the small fixed‐ratio 1 component. This was followed by a reversal back to the preceding phase in which preference for the mixed‐ratio schedule had been observed, and a final reversal back to the mixed‐ratio (5, 7) phase. Findings were consistent with previous research in that all children preferred the mixed‐ratio (1, 9) schedule over the equivalent fixed‐ratio 5 schedule. Preference persisted for the leaner mixed‐ratio (1, 11) schedule for three of the four children. Indifference or preference for the fixed‐ratio 5 alternative was observed in phases containing the mixed‐ratio (5, 7) schedule. These results extend previous research on risky choice to children's math problem completion and highlight the importance of a small ratio component in the emergence of preference for bi‐valued mixed‐ratio schedules. Implications of these results for arranging reinforcement to increase children's academic responding are discussed.     

Agmatine facilitates memory of an inhibitory avoidance task in adult rats

Agmatine is a new putative neurotransmitter; however, the physiological role(s) of this endogenous released polyamine is still to be determined. We investigated its cognitive effect in an inhibitory avoidance task in adult rats. Agmatine (0.1, 1, 10, and 20 mg/kg) or saline was administered ip immediately after training or 1 h before testing. Posttraining injection of agmatine facilitated (p < 0.05) memory consolidation in this task; however pretest treatment showed no effect on retrieval (p > 0.05). We suggest that the facilitatory effect of agmatine on memory consolidation in inhibitory avoidance task might be mediated through the activation of the locus coeruleus.     

Underlying dimensions of ecocentric and anthropocentric environmental beliefs

This study focuses on the cognitive components of general environmental attitudes. Taking as a starting point the scale of Thompson and Barton (1994) to identify ecocentric and anthropocentric motives in environmental conservation, the beliefs that guide attitudes in the person-environment relationship are analyzed. Confirmatory factor analysis was used to contrast the tripartite structure of these beliefs--based on egoistic, socioaltruistic, and biospheric aspects-with a two-dimensional structure that confronts ecocentric and anthropocentric orientations. The results obtained from two samples, a student sample (n = 212) and a sample from the general population of Madrid (n = 205), indicate the existence of a three-dimensional structure of environmental beliefs: an anthropocentric dimension based on the instrumental value of the environment for human beings, a biospheric dimension that values the environment for its own sake, and, lastly, an egobiocentric dimension that values the human being within nature as a whole.     

Terrorists and victims. Infrahumanization of Moroccans after 11-M

Infrahumanization studies have verified that most people attribute more secondary emotions to the ingroup than to the outgroup. However, these results may vary with changing contexts. The main objective of this study was to investigate the infrahumanization of Moroccans, depending on the context, after the 11-M attacks and seven years later. For this purpose, variations that occur in the allocation of essential human qualities--secondary emotions--were analyzed by activating images of outgroup members in two opposite contexts: Guilty of the terrorist attack or its victim. The results show that the infrahumanization of the Moroccans in the perpetrator context does not change significantly with regard to the control group. However, infrahumanization does not take place when Moroccans are associated with a victim context, though only immediately after the terrorist attack, because seven years later, this effect disappears.