Redundant visual signals boost saccade execution

The redundant signal effect (RSE) refers to the fact that human beings react more quickly to a pair of stimuli than to only one stimulus. In previous studies of the RSE in the oculomotor system, bimodal signals have been used as the goal of the saccade. In consistency with studies using manual response times (RTs), saccadic RTs have been shown to be shorter for redundant multimodal stimuli than for single unimodal stimuli. In the present experiments, we extended these findings by demonstrating an RSE in the saccadic system elicited only by unimodal visual stimuli. In addition, we found that shorter saccadic RTs were accompanied by an increased saccadic peak velocity. The present results are of relevance for neurophysiological models of saccade execution, since the boost of saccades was elicited by two visual transients (acting as a “go” signal) that were presented not at the goal of the saccade but at various other locations.     

Fornix, medial prefrontal cortex, nucleus accumbens, and mediodorsal thalamic nucleus: roles in a fear-based context discrimination task

The goal of the present study was to evaluate the contributions of various brain structures anatomically and functionally linked to the hippocampus and amygdala in a fear-based context discrimination task. The brain areas of interest included the fornix, medial prefrontal cortex, mediodorsal (MD) thalamic nucleus, and nucleus accumbens. Damage to the MD thalamic nucleus and medial prefrontal cortex produced the largest impairment in context-specific fear responses. Damage to the fornix impaired some fear responses (freezing, ultrasonic vocalizations, defecation, and approach/avoidance) while leaving conditioned fear expression of heart rate and urination unaltered. Damage to the nucleus accumbens was also coupled with deficits in the discriminative expression of some (heart rate, urination, and ultrasonic vocalizations) but sparing of context-appropriate freezing, defecation, and approach/avoidance behaviors.     

An immunochemical approach to model and long-term suppression of depressive and anxiety behavior

The inhibitor of monoaminooxydase isatin and the ligand of B-receptors cholecystokinin-4 play a significant role in the suppression and induction of depressive and anxiety states. We induced the formation of auto-antibodies to these compounds against their conjugates with antigen-carrier by immunization of white rats. The result was long-term (more than 2 months) stimulation of depressive and anxiety behavior after immunization to isatin and, in contrast, the suppression of such behavior after immunization to cholecystokinin. The perspective of immunochemical approach to long-term correction of behavior is discussed.     

Is the Chinese number-naming system transparent? Evidence from Chinese-English bilingual children.

Chinese-speaking children have been shown to have an advantage over English-speaking children in a variety of mathematical areas, including counting. One possible explanation for the advantage in counting is that the Chinese number-naming system is relatively transparent, compared to English, in that number names typically are directly indicative of base-10 structure (e.g., 12 is named "ten-two" rather than "twelve"). To determine whether the transparency of the Chinese number-naming system influences counting in bilingual children, we tested 25 Chinese-English bilingual children between the ages of 3 and 5 years, both in English and in Chinese. Children were asked to count as high as they could (abstract counting) and also to count objects in small, medium, and large arrays (object counting). No evidence was found for transparency or for transfer from one language to the other. Instead, relative proficiency in the two languages influenced counting skill. These results are discussed in terms of linguistic and cultural variables that might account for cross-linguistic differences in counting.     

How we interact with objects: learning from brain lesions

Motor deficits are the most common outcome of brain damage. Although a large part of such disturbances arises from loss of elementary sensorimotor functions, several syndromes cannot be explained purely on these bases. In this article, we briefly describe higher-order motor impairments, with specific attention to the characteristic ability of the human hand to interact with objects and tools. Disruption of this motor skill at several independent levels is used to outline a comprehensive model, in which various current proposals for a modular organization of hand-object interactions can be integrated. In this model, cortical mechanisms related to object interaction are independent from representations of the semantic features of objects.     

Transference occurs across group boundaries

Transference occurs when a perceiver's representation of a significant other is activated and applied to a new target person (Andersen & Chen, 2002). Extending past research, it was hypothesized that transference occurs even when a target person possesses a core feature—namely, group membership status—that is inapplicable to the relevant significant-other representation. Supporting this, transference led perceivers to make representation-consistent memory and evaluation judgments about a target—regardless of whether the target's political (experiment 1) or ethnic (experiment 2) group membership was the same or different from that of the relevant significant other. Moreover, in experiment 2, perceivers undergoing transference involving a positively evaluated significant other behaved more positively toward the target even when the target was from an ethnic out-group. The results represent initial evidence of transference processes occurring across group boundaries. Implications for transference and the reduction of out-group bias are discussed.     

Relations of proactive and reactive dimensions of aggression to overt and covert narcissism in nonclinical adolescents

In recent years, there has been increasing acknowledgment of the multidimensionality of narcissism and that different types of narcissism may relate differently to other domains of functioning. Similarly, aggression—a frequently discussed correlate of narcissism—is a heterogeneous construct. In this study, the relations of proactive and reactive aggression with overt and covert manifestations of narcissism were examined in a sample of 674 Italian high school students (mean age=15.5 years, SD=2.1 years). Overt narcissism was positively related to both proactive and reactive subtypes of aggression, whereas covert narcissism related only to reactive aggression. Vanity, Authority, Exhibitionism, and Exploitativeness were the components of overt narcissism related to Proactive Aggression (all remained unique correlates when controlling for Reactive Aggression), whereas Reactive Aggression was associated with the Exhibitionism, Superiority, and Entitlement subscales (only the latter was uniquely related when controlling for Proactive Aggression). Aggr. Behav. 36:21–27, 2010. © 2009 Wiley‐Liss, Inc.