追求快乐还是追求意义?青少年幸福倾向及其对学习行为的影响

研究使用问卷调查法,以2828名中学生为对象,考察了幸福倾向对其学习目标、学习毅力、学习策略、学习投入等学习行为的影响。结果表明:(1)青少年的意义倾向对其成就目标中的掌握目标和表现趋近维度、学习毅力、学习策略和学习投入都有显著的正向预测作用,对成就目标中的表现回避维度具有显著的负向预测作用;(2)青少年的快乐倾向对掌握目标、学习毅力、学习策略和学习投入都有显著的负向预测作用,对表现趋近和表现回避有显著的正向预测作用;(3)通过意义倾向和快乐倾向两个维度可以将青少年分为四类,双高组和单高意义组的青少年在学习行为表现上最积极,双低组的青少年学习行为表现最为消极。总体来说,追求快乐还是意义会影响到青少年学习行为这一重要的发展指标,意义比快乐更能促进青少年的积极健康发展。     

中国远程学习者学习风格理论模型与验证

为帮助中国远程学习者了解自身的学习风格,选择相应的学习策略,进而提高远程学习质量,根据学习风格的信息加工理论、Kolb的经验学习理论以及荣格的人格特征类型理论,从生理、社会、心理三个维度,构建了我国远程学习者学习风格的理论模型,通过编制量表和实际测量,对该模型进行验证分析和修订完善.结果表明,最初提出的理论模型假设得到验证,修订后的量表具有良好的效度和信度,可以用来测量我国远程学习者的学习风格.     

Influence of chronic corticosterone and glucocorticoid receptor antagonism in the amygdala on fear conditioning

Glucocorticoid receptor activation within the basolateral amygdala (BLA) during fear conditioning may mediate enhancement in rats chronically exposed to stress levels of corticosterone. Male Sprague-Dawley rats received corticosterone (400 microg/ml) in their drinking water (days 1-21), a manipulation that was previously shown to cause hippocampal CA3 dendritic retraction. Subsequently, rats were adapted to the fear conditioning chamber (day 22), then trained (day 23), and tested for conditioned fear to context and tone (day 25). Training consisted of two tone (20s) and footshock (500 ms, 0.25 mA) pairings. In Experiment 1, muscimol (4.4 nmol/0.5 microl/side), a GABAergic agonist, was microinfused to temporarily inactivate the BLA during training. Rats given chronic corticosterone showed enhanced freezing to context, but not tone, compared to vehicle-supplemented rats. Moreover, BLA inactivation impaired contextual and tone conditioning, regardless of corticosterone treatment. In Experiment 2, RU486 (0, 0.3, and 3.0 ng/0.2 microl/side) was infused on training day to antagonize glucocorticoid receptors in the BLA. Corticosterone treatment enhanced fear conditioning to context and tone when analyzed together, but not separately. Moreover, RU486 (3.0 ng/side) selectively exacerbated freezing to context in chronic corticosterone-exposed rats only, but failed to alter tone conditioning. Serum corticosterone levels were negatively correlated with contextual, not tone, conditioning. Altogether, these suggest that chronic corticosterone influences fear conditioning differently than chronic stress as shown previously. Moreover, chronic exposure to corticosteroids alters BLA functioning in a non-linear fashion and that contextual conditioning is influenced more than tone conditioning by chronic corticosterone and BLA glucocorticoid receptor stimulation.     

Role of estrogen in balancing contributions from multiple memory systems

In addition to modulating memory per se, estrogen alters the learning strategy used to solve a task, thereby regulating the quality of information processed by the brain. This review discusses estrogen's actions on cognition within a memory systems framework, highlighting our work with a variety of paradigms showing that learning strategy is sensitive to estrogen even when learning rate is not. Specifically, high levels of gonadal steroids, in particular, elevations in estrogen, bias female rats toward using hippocampal-sensitive approaches while low levels of gonadal steroids promote the use of non-hippocampal sensitive strategies. In light of findings from a variety of approaches involving the hippocampus in allocentric and the striatum in egocentric response patterns, it is likely that estrogen alters the relative participation of these, and most undoubtedly other, neural systems during cognition. Changes in neuromodulators such as acetylcholine that regulate other processes such as inhibitory tone and excitability reflect one mechanism by which estrogen may orchestrate learning and memory.     

Technological aids to promote basic developmental achievements by children with multiple disabilities: evaluation of two cases

Technological aids such as microswitches may be critical to foster learning and development in children with multiple disabilities. In study I, a child with minimal motor behavior was provided with a microswitch for chin movements to assess whether he could learn to use these movements to activate environmental stimuli. In study II, a child with dystonic (difficult-to-control) behavior was provided with microswitches for two motor responses and two vocal utterances. We wanted to assess whether he could use both types of responses effectively (varying within each pair, consistent with choice performance). The results were highly encouraging with both children. In study I, there was a significant increase in the childs responding, suggesting learning and contingency awareness. In study II, there was a significant increase in responding as well as response variation that suggested choice behavior. The importance of microswitch devices in promoting new learning/developmental objectives and improving quality of life is discussed.     

Do I get what you get? Learning about the effects of self-performed and observed actions in infancy

The present study investigated whether infants learn the effects of other persons' actions like they do for their own actions, and whether infants transfer observed action-effect relations to their own actions. Nine-, 12-, 15- and 18-month-olds explored an object that allowed two actions, and that produced a certain salient effect after each action. In a self-exploration group, infants explored the object directly, whereas in two observation groups, infants first watched an adult model acting on the object and obtaining a certain effect with each action before exploring the objects by themselves. In one observation group, the infants' actions were followed by the same effects as the model's actions, but in the other group, the action-effect mapping for the infant was reversed to that of the model. The results showed that the observation of the model had an impact on the infants' exploration behavior from 12 months, but not earlier, and that the specific relations between observed actions and effects were acquired by 15 months. Thus, around their first birthday infants learn the effects of other persons' actions by observation, and they transfer the observed action-effect relations to their own actions in the second year of life.     

Cholinergic modulation of learning and memory in the human brain as detected with functional neuroimaging

The advent of neuroimaging methods such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) has provided investigators with a tool to study neuronal processes involved in cognitive functions in humans. Recent years have seen an increasing amount of studies which mapped higher cognitive functions to specific brain regions. These studies have had a great impact on our understanding of neuroanatomical correlates of learning and memory in the living human brain. Recently, advances were made to go beyond the use of fMRI as a pure cognitive brain mapping device. One of these advances includes the use of psychopharmacological approaches in conjunction with neuroimaging. The paper will introduce the combination of neuroimaging and psychopharmacology as a tool to study neurochemical modulation of human brain function. A review of imaging studies using cholinergic challenges in the context of explicit and implicit learning and memory paradigms is provided which show that cholinergic neurotransmission modulates task-related activity in sensory and frontal cortical brain areas.     

Metacognitive control and optimal learning

The notion of optimality is often invoked informally in the literature on metacognitive control. We provide a precise formulation of the optimization problem and show that optimal time allocation strategies depend critically on certain characteristics of the learning environment, such as the extent of time pressure, and the nature of the uptake function. When the learning curve is concave, optimality requires that items at lower levels of initial competence be allocated greater time. On the other hand, with logistic learning curves, optimal allocations vary with time availability in complex and surprising ways. Hence there are conditions under which optimal strategies will be relatively easy to uncover, and others in which suboptimal time allocation might be expected. The model can therefore be used to address the question of whether and when learners should be able to exercise good metacognitive control in practice.     

Estrogen modulates place learning through estrogen receptors in the hippocampus

Moderate elevations in circulating estradiol enhance learning in tasks that tap place learning strategies such as those requiring the use of extramaze cues. Use of place learning strategies is particularly impaired by damage to the hippocampus, a structure shown to be sensitive to estrogen treatments. We have shown that direct estrogen infusions into the dorsal hippocampus, and not the dorsolateral striatum, enhance place learning, suggesting that the hippocampus may be an important modulatory site for the effects of estrogen on place learning. The current experiment tested whether the hippocampus is indeed a critical site of estrogen modulation through classical estrogen receptors. Young adult female Sprague-Dawley rats were ovariectomized for 21 days and given systemic injections (0.1 ml) of sesame oil (OIL) or 10 microg of 17beta-estradiol-benzoate (E2), 48 and 24 h before being trained on a place task. Twenty-four hours prior to the first systemic injection, separate groups of rats received bilateral hippocampal implants of either the antiestrogen ICI 182,780 (ICI) or cholesterol vehicle. Implants were maintained until and throughout training. Intrahippocampal ICI reversed the enhancement in place learning seen with systemic E2 treatment. Unexpectedly, intrahippocampal ICI in OIL-treated rats also enhanced place learning. These data suggest that ICI may have some mixed agonist and antagonist effects in the hippocampus and that estrogen enhances place learning through activation of estrogen receptors located in the hippocampus.