To press or not to press? Differential receptor expression and response to novelty in rats learning an operant response for reward

Learning to perform instrumental tasks is an ability of all animals. In a population of rats, not all individuals will acquire an operant response for reward. We hypothesized that there could be a genetic explanation for differences between High Consumers (those that acquired the lever press response) and Low Consumers (lever press response is low). Additionally, we proposed that this genetic difference could produce measurable changes in response to novelty. Wistar rats were trained to lever press for a 0.2% saccharin reward and on the 10th day they were placed in a novel open field for 30 min to record locomotor activity. The prefrontal cortex and hippocampus were dissected and qPCR was used to measure mRNA expression. A significant difference (p=.048; 2-way ANOVA) in gene expression was observed between Low and High Consumers. A principal component analysis (PCA), to cluster which genes represent this difference, identified 4 genes; 5-HT2A and mGlu1 in the hippocampus and AMPA GluR1 and adrenergic alpha2A in the prefrontal cortex. Response to a novel open field also differed since Low Consumers displayed a higher Total Distance in comparison to High Consumers. Additionally, Low Consumers could be subdivided into Low-Lever (with lever press response only when water deprived) and Low-Non-Lever (lever press response is low throughout training). PCA with this subdivision identified an additional nine genes differing within the divisions; NMDA NR2B and GABAAalpha3 in the prefrontal cortex and adrenergic alpha2B and alpha2A, AMPA GluR1, GluR2 and GluR3, 5-HT1B and GABAAalpha5 in the hippocampus.     

The neural correlates of social attention: automatic orienting to social and nonsocial cues

Previous evidence suggests that directional social cues (e.g., eye gaze) cause automatic shifts in attention toward gaze direction. It has been proposed that automatic attentional orienting driven by social cues (social orienting) involves a different neural network from automatic orienting driven by nonsocial cues. However, previous neuroimaging studies on social orienting have only compared gaze cues to symbolic cues, which typically engage top-down mechanisms. Therefore, we directly compared the neural activity involved in social orienting to that involved in purely automatic nonsocial orienting. Twenty participants performed a spatial cueing task consisting of social (gaze) cues and automatic nonsocial (peripheral squares) cues presented at short and long stimulus (cue-to-target) onset asynchronies (SOA), while undergoing fMRI. Behaviorally, a facilitation effect was found for both cue types at the short SOA, while an inhibitory effect (inhibition of return: IOR) was found only for nonsocial cues at the long SOA. Imaging results demonstrated that social and nonsocial cues recruited a largely overlapping fronto-parietal network. In addition, social cueing evoked greater activity in occipito-temporal regions at both SOAs, while nonsocial cueing recruited greater subcortical activity, but only for the long SOA (when IOR was found). A control experiment, including central arrow cues, confirmed that the occipito-temporal activity was at least in part due to the social nature of the cue and not simply to the location of presentation (central vs. peripheral). These results suggest an evolutionary trajectory for automatic orienting, from predominantly subcortical mechanisms for nonsocial orienting to predominantly cortical mechanisms for social orienting.     

工作记忆的保持与操控：腹侧和背侧额叶皮层的特异性功能磁共振成像活动

为了进行大样本的老化与记忆的功能磁共振成像(fMRI)研究, 研究者设计了言语工作记忆的方案, 并且对一组健康青年人进行了施测。字母的呈现方式主要为两种条件: (i) 保持, 要求被试记住呈现的字母并且能够在4秒的间隔后保持; (ii) 操控, 被试需要将呈现的字母按字母表的顺序进行转换, 并且记住新的顺序。不管是用全脑分析, 还是用预先定义的感兴趣区域的分析方法, 对fMRI数据的分析表明本方案诱发了可靠的额叶皮层的激活, 且操控条件则引发了更为广泛的激活。背外侧和腹内侧前额叶的激活也表现出了不同特点, 操控引发了更多的背外侧前额叶激活。一些皮下区域也得到了激活, 特别是以前发现与工作记忆任务相关的一些区域。这说明该工作记忆研究方案适合探索额叶功能的与年龄相关的改变。     

The role of motivation and volition in economic decisions: Evidence from eye movements and pupillometry

Economic decisions usually involve high stakes, real consequences, and some degree of personal risk. This article explores the impact of motivational and volitional states on economic decision processes in an incentivized lottery choice task. We investigated the patterns of decision time, choice, information search, and pupil dilation dependent on an experimental manipulation of motivation and volition, that is, the deliberative and the implemental mindset. The results indicated that choice preferences in economic decisions were robust and remained unaffected by motivational and volitional states, but decision processes were notably impacted. Decision makers in a deliberative state of mind searched for information more extensively and made slower decisions than the baseline. The implemental mindset was associated with more attention paid to the probability attributes of the gambles relative to the deliberative mindset. Furthermore, we observed that gamble outcomes that entailed no win at all (i.e., zero outcomes) played an important role for information search. These outcomes were largely disregarded in terms of predecisional information search but elicited pupillary responses similar to very high outcome lotteries. These results inform the current debate about the zero effect in risky choice. We also discuss the potential of eye-tracking studies of risky choice to dissolve ambiguities concerning the contributions of effort and arousal to modulating pupillary response. Implications for theoretical advances in decision research are discussed.     

Comparative Mental Development

To reconstruct the evolution of human cognitive development we are studying its comparative ontogeny in primate phylogeny (i.e., two monkey species, two chimpanzee species, and humans). The research has discovered primate conceptual universals including logical (e.g., classifying), arithmetic (e.g., quantitative substituting), and physical (e.g., causal) cognitions. But the ontogenetic covariation between these conceptual universals is progressively displaced or heterochronic in primate phylogeny. Heterochronic evolution produced the most synchronic and widest ontogenetic window for progressive cognitive development in humans.     

Finite Cardinals in Quasi-set Theory

Quasi-set theory is a ZFU-like axiomatic set theory, which deals with two kinds of ur-elements: M-atoms, objects like the atoms of ZFU, and m-atoms, items for which the usual identity relation is not defined. One of the motivations to advance such a theory is to deal properly with collections of items like particles in non-relativistic quantum mechanics when these are understood as being non-individuals in the sense that they may be indistinguishable although identity does not apply to them. According to some authors, this is the best way to understand quantum objects. The fact that identity is not defined for m-atoms raises a technical difficulty: it seems impossible to follow the usual procedures to define the cardinal of collections involving these items. In this paper we propose a definition of finite cardinals in quasi-set theory which works for collections involving m-atoms.     

Reactance,the self,and its group: When threats to freedom come from the ingroup versus the outgroup

We investigated the assumption that independent versus interdependent self‐construals yield different manifestations of psychological reactance in different group contexts. We expected collectivists (interdependent) to value the collective freedom of an ingroup more in face of an outgroup threat than individualists (independent) who should be protective of their individual freedom especially within an ingroup. In Study 1, we showed that collectivists (Taiwanese students) did not show reactance when a threat to their freedom of choice originated in the ingroup, but they did show reactance when it originated in an outgroup. In Study 2, Austrian students showed more reactance the more interdependent their self‐construal was when confronted with an outgroup restriction. However, the more independent Austrian students' self‐construal was, the more reactance they showed when the threat came from the ingroup. Priming an independent (versus interdependent) self‐construal in Study 3, we again observed more reactance when freedom was restricted by the ingroup. The findings underline the importance of understanding psychological reactance as a socially situated phenomenon. Copyright © 2011 John Wiley & Sons, Ltd.