Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

Perceptual simulation in developing language comprehension

We tested an embodied account of language proposing that comprehenders create perceptual simulations of the events they hear and read about. In Experiment 1, children (ages 7–13 years) performed a picture verification task. Each picture was preceded by a prerecorded spoken sentence describing an entity whose shape or orientation matched or mismatched the depicted object. Responses were faster for matching pictures, suggesting that participants had formed perceptual-like situation models of the sentences. The advantage for matching pictures did not increase with age. Experiment 2 extended these findings to the domain of written language. Participants (ages 7–10 years) of high and low word reading ability verified pictures after reading sentences aloud. The results suggest that even when reading is effortful, children construct a perceptual simulation of the described events. We propose that perceptual simulation plays a more central role in developing language comprehension than was previously thought.     

大学二年级学生人际宽恕与报复心理及其与抑郁的关系研究

采用沉思量表、报复动机量表、宽恕倾向量表、宽恕态度量表和流调中心用抑郁量表对236名大二学生进行问卷调查,综合探讨大学生人际宽恕和报复心理及其与抑郁的关系。研究发现:(1)男大学生的报复倾向显著高于女大学生。(2)宽恕倾向与报复倾向及对侵犯的沉思程度显著负相关。沉思程度和抑郁显著正相关。(3)沉思程度和宽恕倾向对抑郁分别具有显著的正向和负向的预测作用。(4)大学生的宽恕倾向和宽恕态度的相互作用以及宽恕倾向和报复倾向之间的交互作用对抑郁均没有显著预测作用。     

Speech disruption under delayed auditory feedback in multilingual speakers

The present study investigated the language familiarity hypothesis formulated by Mackay [(1970). How does language familiarity influence stuttering under delayed auditory feedback? Perceptual and Motor Skills, 30, 655-669] that bilinguals speak faster and stutter less under delayed auditory feedback (DAF) when speaking their more familiar language than a less familiar language. Thirty normally fluent native speakers of Dutch (17 males and 13 females, aged between 18;1 and 26;4 years) who were also proficient in French and English read meaningful and nonsense text under DAF in their mother tongue and in the two later acquired languages. The existence of a language familiarity effect was confirmed. The participants required significantly more time and showed significantly more speech disruptions under DAF in the later acquired languages than in the mother tongue, and reading time and number of speech disruptions was significantly higher for the nonsense texts than for the meaningful text for each of the three languages. An additional question addressed was whether or not there were any gender differences in the susceptibility to DAF. Results did not reveal a clear gender difference. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) summarize the importance of language familiarity for the degree of speech disruption experienced by normally fluent multilingual speakers under delayed auditory feedback; and (2) describe gender differences in the susceptibility to delayed auditory feedback.     

Information processing bias against emotional facial expressions in social anxiety

The present study examined whether information processing bias against emotional facial expressions is present among individuals with social anxiety. College students with high (high social anxiety group; n  = 26) and low social anxiety (low social anxiety group; n  = 26) performed three different types of working memory tasks: (a) ordering positive and negative facial expressions according to the intensity of emotion; (b) ordering pictures of faces according to age; and (c) ordering geometric shapes according to size. The high social anxiety group performed significantly more poorly than the low social anxiety group on the facial expression task, but not on the other two tasks with the nonemotional stimuli. These results suggest that high social anxiety interferes with processing of emotionally charged facial expressions.     

Cognitive confidence in obsessive-compulsive disorder: distrusting perception, attention and memory

Previous studies have established that obsessive-compulsive disorder (OCD) is characterised by significant levels of distrust in memory (e.g. for actions). Ironically, this lowered confidence is at least in part due to repeated checking, which is assumed to lower perceptual processing and thereby reduces vividness and detail of the recollections. In a previous study, Hermans, D., Martens, K., De Cort, K., Pieters, G., and Eelen, P. [(2003). Reality monitoring and metacognitive beliefs related to cognitive confidence in OCD. Behaviour Research and Therapy, 41, 383-401] observed that OCD is not only characterised by reduced confidence in memory, but also by a similar distrust in attention (Hermans et al., 2003). The present study aimed at replicating and extending this finding. It was observed (a) that patients suffering from OCD showed less confidence in attention and memory than a clinical and a nonclinical control group; (b) that confidence in attention was uniquely related to checking behaviour, and (c) that repeated checking caused increased levels of distrust in attention. In addition, it was observed that cognitive distrust while performing OCD-related actions not only extends to attention, but also to perception. It is argued that research on metacognition in OCD should move beyond the study of memory.     

Implied motion language can influence visual spatial memory

How do language and vision interact? Specifically, what impact can language have on visual processing, especially related to spatial memory? What are typically considered errors in visual processing, such as remembering the location of an object to be farther along its motion trajectory than it actually is, can be explained as perceptual achievements that are driven by our ability to anticipate future events. In two experiments, we tested whether the prior presentation of motion language influences visual spatial memory in ways that afford greater perceptual prediction. Experiment 1 showed that motion language influenced judgments for the spatial memory of an object beyond the known effects of implied motion present in the image itself. Experiment 2 replicated this finding. Our findings support a theory of perception as prediction.     

Effective Vote Markets and the Tyranny of Wealth

Res Publica - What limits should there be on the areas of life that are governed by market forces? For many years, no one seriously defended the buying and selling votes for political elections. In...