Eliminating inhibition of return by changing salient nonspatial attributes in a complex environment

Inhibition of return (IOR) occurs when a target is preceded by an irrelevant stimulus (cue) at the same location: Target detection is slowed, relative to uncued locations. In the present study, we used relatively complex displays to examine the effect of repetition of nonspatial attributes. For both color and shape, attribute repetition produced a robust inhibitory effect that followed a time course similar to that for location-based IOR. However, the effect only occurred when the target shared both the feature (i.e., color or shape) and location with the cue; this constraint implicates a primary role for location. The data are consistent with the idea that the system integrates consecutive stimuli into a single object file when attributes repeat, hindering detection of the second stimulus. The results are also consistent with an interpretation of IOR as a form of habituation, with greater habituation occurring with increasing featural overlap of a repeated stimulus. Critically, both of these interpretations bring the IOR effect within more general approaches to attention and perception, rather than requiring a specialized process with a limited function. In this view, there is no process specifically designed to inhibit return, suggesting that IOR may be the wrong framing of inhibitory repetition effects. Instead, we suggest that repetition of stimulus properties can interfere with the ability to focus attention on the aspects of a complex display that are needed to detect the occurrence of the target stimulus; this is a failure of activation, not an inhibition of processing.     

Rater Wealth Predicts Perceptions of Outgroup Competence

National income has a pervasive influence on the perception of ingroup stereotypes, with high status and wealthy targets perceived as more competent. In two studies we investigated the degree to which economic wealth of raters related to perceptions of outgroup competence. Raters’ economic wealth predicted trait ratings when (1) raters in 48 other cultures rated Americans’ competence and (2) Mexican Americans rated Anglo Americans’ competence. Rater wealth also predicted ratings of interpersonal warmth on the culture level. In conclusion, raters’ economic wealth, either nationally or individually, is significantly associated with perception of outgroup members, supporting the notion that ingroup conditions or stereotypes function as frames of reference in evaluating outgroup traits.     

Subjective Estimation of Task Time and Task Difficulty of Simple Movement Tasks

It has been demonstrated in previous work that the same neural structures are used for both imagined and real movements. To provide a strong test of the similarity of imagined and actual movement times, 4 simple movement tasks were used to determine the relationship between estimated task time and actual movement time. The tasks were single-component visually controlled movements, 2-component visually controlled, low index of difficulty (ID) moves and pin-to-hole transfer movements. For each task there was good correspondence between the mean estimated times and actual movement times. In all cases, the same factors determined the actual and estimated movement times: the amplitudes of movement and the IDs of the component movements, however the contribution of each of these variables differed for the imagined and real tasks. Generally, the standard deviations of the estimated times were linearly related to the estimated time values. Overall, the data provide strong evidence for the same neural structures being used for both imagined and actual movements.     

SAFE通路参与缺血后处理心肌保护作用机制的探讨

缺血后处理(ischemic postconditioning,IPost)是在心肌缺血后持续再灌注前给予多次短暂的再灌注/缺血处理的处理方法,对心肌缺血/再灌注损伤有着重要的保护作用.其心肌保护的具体机制十分复杂,尚未完全阐明.生存活化因子增强(survivor activating factor enhancement,SAFE)途径是IPost中新近发现的保护通路,阐明其在IPost心肌保护中的作用,将为寻找新的药物治疗靶点提供新思路.     

Directional learning,but no spatial mapping by rats performing a navigational task in an inverted orientation

Previous studies have identified neurons throughout the rat limbic system that fire as a function of the animal’s head direction (HD). This HD signal is particularly robust when rats locomote in the horizontal and vertical planes, but is severely attenuated when locomoting upside-down (Calton & Taube, 2005). Given the hypothesis that the HD signal represents an animal’s sense of directional heading, we evaluated whether rats could accurately navigate in an inverted (upside-down) orientation. The task required the animals to find an escape hole while locomoting inverted on a circular platform suspended from the ceiling. In Experiment 1, Long-Evans rats were trained to navigate to the escape hole by locomoting from either one or four start points. Interestingly, no animals from the 4-start point group reached criterion, even after 29 days of training. Animals in the 1-start point group reached criterion after about six training sessions. In Experiment 2, probe tests revealed that animals navigating from either 1- or 2-start points utilized distal visual landmarks for accurate orientation. However, subsequent probe tests revealed that their performance was markedly attenuated when navigating to the escape hole from a novel start point. This absence of flexibility while navigating upside-down was confirmed in Experiment 3 where we show that the rats do not learn to reach a place, but instead learn separate trajectories to the target hole(s). Based on these results we argue that inverted navigation primarily involves a simple directional strategy based on visual landmarks.     

An efficient computerized testing method for the capuchin monkey (<Emphasis Type="Italic">Cebus apella</Emphasis>): Adaptation of the LRC-CTS to a socially housed nonhuman primate species

Even with advances in automated testing techniques, the capuchin monkey (Cebus apella) can be a difficult species to test in the laboratory, given its social/behavioral tendencies and typical activity pattern. Laboratories that maintain social colonies of capuchin monkeys are able to separate and test individuals, but the process can be very effortful and time consuming, and the resulting data can be modest in quantity. The present article describes procedures and apparatuses that were used to train a colony of computer-naive capuchin monkeys to quickly and reliably isolate themselves from group members and interact with a computerized test system in order to produce a large volume of data. Several elements that were important in motivating the monkeys to participate are discussed.     

Precise instructions determine participants’ memory search strategy in judgments of relative order in short lists

Memory often requires knowledge of the order of events. Previous findings about immediate judgments of relative order in short, subspan lists are variable regarding whether participants’ strategy is to search memory in the forward direction, starting from the first list item and progressing toward the end item, or in the backward direction, starting from the end item and progressing toward the start. We asked whether wording of the instructions influences participants’ search direction. Participants studied sequences of three to six consonants, and for an immediate, two-item probe of each list, judged which probe was presented earlier (“earlier” instruction) or later (“later” instruction) on the list. Forward and backward searches were supported for “earlier” and “later” instructions, respectively. Our findings suggest that participants have more than one effective strategy for order judgments in short lists, and that subtle instructional differences can bias memory search in either the forward or backward direction.     

Human Nature and Moral Cultivation in the Guodian 郭店 Text of the Xing Zi Ming Chu 性自命出 (Nature Derives from Mandate)

The debate over whether human nature is good or bad and how this is related to self-cultivation was central in the minds of traditional Chinese thinkers. This essay analyzes the interrelationship between the key concepts of xing 性 (human nature), qing 情 (human emotions/feelings), and xin 心 (heart-mind) in the Guodian text of the Xing Zi Ming Chu 性自命出 (Nature Derives from Mandate) discovered in 1993 in Hubei province. The intellectual engagements evident in this Guodian text emerge as more syncretic and dynamic than those that can be found in the discourse of any single tradition, such as Gaozi, Mencius, or Xunzi. Its thesis on human nature and moral cultivation reveals the existence of a possibly more diverse intellectual discourse from which the different foci of philosophical debate represented by later thinkers developed.