Differential effects of beta-adrenergic receptor blockade in basolateral amygdala or insular cortex on incidental and associative taste learning

The importance of central β-adrenergic system has been essentially investigated in aversive/emotional learning tasks. However, recent data suggest that the β-adrenergic system is also required for incidental taste learning. In the present study we evaluated in rats whether β-adrenergic receptor activity is required for taste habituation, an incidental taste learning, and also for conditioned taste aversion (CTA) learning, an associative learning. To address this issue, a low dose of the β-adrenergic antagonist propranolol was infused before learning in either the basolateral amygdala (BLA) or the insular cortex (IC), two forebrain areas reported to play a key role in taste memory formation. Incidental taste learning was assessed using a single presentation of the sweet taste saccharin 0.1%, which is sufficient to increase saccharin consumption (relative to water baseline) during a second presentation. CTA was assessed by pairing the first saccharin 0.1% presentation with a delayed gastric malaise, thus causing a decrease in saccharin consumption (relative to water baseline) during a second presentation. Propranolol infusion in BLA (1 μg/0.2μl) or IC (2.5 μg/0.5 μl) before the first taste exposure impaired incidental taste learning but did not affect CTA. These results highlight the important role played by the β-adrenergic receptor activation in cortical and amygdaloid structures during taste learning. Moreover, they are the first to suggest that incidental learning is more sensitive to blockade of noradrenergic system than associative learning.     

No Plaything: Ethical Issues Concerning Child-pornography

Academic discussion of pornography is generally restricted to issues arising from the depiction of adults. I argue that child-pornography is a more complex matter, and that generally accepted moral judgements concerning pornography in general have to be revised when children are involved. I look at the question of harm to the children involved, the consumers, and society in general, at the question of blame, and at the possibility of a morally acceptable form of child-pornography. My approach involves an objectivist meta-ethics and a utilitarian view of practical ethics, and I bring out the advantages of these theories to the consideration of moral issues such as this one.

Asymmetrical retention functions for sequences of light flashes or tone bursts in the rat

In Experiment 1, rats were trained in a symbolic delayed matching-to-sample task to discriminate sample stimuli that consisted of sequences of magazine light flashes. The intertrial interval was illuminated by the houselight for Group Light, and it was dark for Group Dark. Retention functions exhibited a choose-many response bias when the delay interval was illuminated by the houselight in both groups, and no consistent response bias when the delay interval was dark. In Experiment 2, rats were trained to discriminate sample stimuli that consisted of sequences of tone bursts. During delay testing, a different tone (i.e., different frequency and location than the sample tone) was present or absent during the delay interval. The retention functions exhibited a significant choose-many bias when tone was present during the delay and a choose-few bias when tone was absent. Asymmetrical retention functions for tone burst and light flash sequences are due to the similarity between the stimulus conditions of the delay interval and the modality of the sequential event being discriminated. These results are consistent with an instructional ambiguity explanation of response biases in memory for number.     

The Confucian Self and Experiential Spirituality

Since the publication of his book on Zhongyong (Tu 1976), Tu Weiming has worked for more than 30 years on an anthropocosmic reconstruction of the Confucian universe, in which self-transformation is defined both as the starting point and as the necessary vehicle for one’s spiritual journey. This article is primarily intended to examine Tu’s attempts to reconstruct Confucian spirituality but further to take a step forward to argue that in the spiritual world as construed by Confucius and Mencius, the experiential functions as transcendental by which the self initiates and empowers the transformative process. Through exploring the spiritual significance of Confucian experiences, this essay will conclude that although “transcendental experience” is only one of many dimensions in other religious or intellectual traditions, it is the most important path for Confucians by which the self is enabled to become fully integrated with ultimate reality.     

记忆中"曾经"的承诺

该文关注“曾经”与“承诺”—“复仇”与“拯救”如何相关特别是如何转换的“记忆的政治”。问题的背景是苦难:作为存在论或现象着的生活世界的基本事实,它是人类唯一可以普遍面对神、面对政治的“救赎地”,而不是“弥撒”中可以流逝的将来时,或在“复仇”中永远走不出的过去时。这里重要的是记忆形式的时间结构发生了根本的变化。因而“曾经”不是无生命力的过去压力(如尼采所批判的和本雅明所清理的);也不是简单转化为复仇的有生命力的权力意志即强权政治(如尼采所一厢情愿的);而是走出复仇的拯救———即走出过去时的———“记忆”中的“曾经”的“承诺”。但事实上,它已不能由西方文化的特质独立承担了。     

Differences in Fear of Isolation as an explanation of Cultural Differences: Evidence from memory and reasoning

Previous research suggests that members of East Asian cultures show a greater preference for dialectical thinking and sensitivity to context information than do Westerners. We suggest this difference is rooted in a greater chronic Fear of Isolation (FOI) in East Asians than in Westerners. To support this hypothesis, we manipulated FOI in a group of Westerners and assessed their relative preference for dialectical proverbs and sensitivity to context. For cross-cultural validation of our hypothesis, we assessed the relationship between chronic levels of FOI and dialectical reasoning in Koreans. Consistent with our proposal, both experimentally primed FOI (Experiment 1A and 2) and chronic levels of FOI (Experiment 1B) were positively related to relative preference for dialectical proverbs. This effect was independent of participants’ level of negative mood (Experiment 2). A third experiment showed that sensitivity to context was affected by FOI in a manner consistent with previous studies of cultural differences (Experiment 3).     

Individual differences in information order effects: The importance of right-hemisphere access in belief updating

The order in which information is received alters the evaluation of causal hypotheses. Specifically, research suggests that the last piece of information oftentimes has the greatest impact on the evaluation and that the difference in subjective value between two pieces of information is an important factor influencing the magnitude of this recency effect. The present paper extends this line of work by exploring individual differences in this phenomenon via one's degree of handedness. Two hundred and five participants were given two hypothetical scenarios and related causal hypotheses accompanied by two pieces of additional information and asked to revise their belief in each hypothesis as information accumulated. Results confirmed predictions that 1) inconsistent/mixed-handers (those who use their non-dominant hand for at least some activities) show a larger effect with two pieces of inconsistent weak or strong information, and 2) neither mixed-handers nor consistent/strong-handers (those who use their dominant hand for almost all activities) show an effect with strong and weak pieces of consistent information. Mixed-handers' susceptibility to persuasive arguments and Ramachandran’s (1995; Ramachandran and Blakeslee, 1998) belief-updating theory centered around communication between the two halves of the brain and functional access to the right hemisphere are used to account for these data.     

The effects of stress and stress hormones on human cognition: Implications for the field of brain and cognition

In this review, we report on studies that have assessed the effects of exogenous and endogenous increases in stress hormones on human cognitive performance. We first describe the history of the studies on the effects of using exogenous stress hormones such as glucocorticoids as anti-inflammatory medications on human cognition and mental health. Here, we summarize the cases that led to the diagnosis of glucocorticoid-induced 'steroid psychosis' in human populations and which demonstrated that these stress hormones could thus cross the blood-brain barrier and access the brain where they could influence cognition and mental health. We then summarize studies that assessed the effects of the exogenous administration of glucocorticoids on cognitive performance supported by the hippocampus, the frontal lobes and amygdala. In the second section of the paper, we summarize the effects of the endogenous release of glucocorticoids induced by exposure to a stressful situation on human cognition and we further dissociate the effects of emotion from those of stress on human learning and memory. Finally, in the last section of the paper, we discuss the potential impact that the environmental context to which we expose participants when assessing their memory could have on their reactivity to stress and subsequent cognitive performance. In order to make our point, we discuss the field of memory and aging and we suggest that some of the 'age-related memory impairments' observed in the literature could be partly due to increased stress reactivity in older adults to the environmental context of testing. We also discuss the inverse negative correlations reported between hippocampal volume and memory for young and older adults and suggest that these inverse correlations could be partly due to the effects of contextual stress in young and older adults, as a function of age-related differences in hippocampal volume.     

Aging and strategic retrieval in a cued-recall test: the role of executive functions and fluid intelligence

Cued-recall in episodic memory was investigated in relation to low and high cognitive support at retrieval, executive function level and fluid intelligence level in 81 healthy adults divided first into two age groups (young and elderly adults). The first analyses showed that age-related differences were greater when a low cognitive support was provided to recall the words. An individual index of loss of performance when the number of cues was decreased was then calculated. Hierarchical regression analysis revealed that the executive functions measure (perseverative errors on the Wisconsin Card Sorting Test) was a better candidate than the fluid intelligence measure (Cattell's culture fair test) to account for the age-related variance of the size of performance loss. These findings suggest that age differences in implementing strategic retrieval may be mainly due to a decline in executive functions.     

Intrahippocampal insulin improves memory in a passive-avoidance task in male wistar rats

The main impacts of insulin favor the peripheral organs. Although it functions as a neuropeptide, insulin possesses also some central effects. The aim of this study was to determine the effect of intrahippocampal infusion of insulin on passive avoidance learning in healthy male rats. Thirty male wistar rats were divided into three groups (n=10 each). The experimental group had posttraining insulin infusion into the CA1 region of dorsal hippocampus, after which they were compared with sham (saline) and control (intact) groups. Insulin treated animals had greater latency to enter the dark compartment in compare with saline treated (p=0.023) or control groups (p=0.017). Upon our results, we concluded that intrahippocampal injections of insulin may enhance memory for a simple learning task which supports the concept that insulin possibly plays an endogenous role in memory formation.