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1.
Zebra finches (Taeniopygia guttata) are able to learn the position of food by orienting on spatial cues in a ‘dry water maze’. In the course of spatial learning, the hippocampus shows high expression of the immediate early genes (IEGs) Zenk and c-Fos, indicating high activation of this area during learning. In contrast, the IEG activity is nearly absent if the birds do not have to rely on spatial cues. In the present experiment it was investigated whether hippocampal activation can also be observed if the learned spatial task is recalled. For this purpose, the hippocampal Zenk and c-Fos activation of birds in an early learning stage was compared with that of others having well reached their maximal performance. The results show that the avian hippocampus is also active during recall of a learned spatial task, but the activation is significantly lower than in animals learning actually. As in previous experiments, hippocampal IEG expression showed strong variation not only in the position of the active patches of neurons, but also in size and cell density. The observed difference contributes to the view that immediate early genes may not be indicators of activation alone, but may be due to a combination of activation and plastic changes.  相似文献   

2.
Two studies examined the effects of quantitative (“complexity”) differences in a visual reinforcer and subsequent reward shifts, on operant response rates. Footkicks and visual attention of 3-month-old infants were measured across daily sessions with conjugate reinforcement provided by an overhead mobile containing either two, six or ten identical components. In Experiment 1, initial rates to the three mobiles differed. The relation between components and kicking was not linear, but was an inverted U-shaped function of component numerosity. The infant responses as a function of numerosity from Experiment 1 were used to define “complexity” in Experiment 2, and all subjects were switched to an intermediate complexity level (two components) after achieving a criterion of stable responding. Although the number of mobile components did not differentially affect acquisition rates, infants who received a shift from six to two components exhibited a reliable and immediate response increase whereas those experiencing a ten- to two-component shift exhibited negative behaviors. These results imply that infants respond relationally, actively manipulating their visual environments as a function of their previous contextual experiences.  相似文献   

3.
Homer1 belongs to a family of scaffolding proteins that interact with various post-synaptic density proteins including group I metabotropic glutamate receptors (mGluR1/5). Previous research in our laboratory implicates the Homer1c isoform in spatial learning. Homer1 knockout mice (H1-KO) display cognitive impairments, but their synaptic plasticity properties have not been described. Here, we investigated the role of Homer1 in long-term potentiation (LTP) in the hippocampal CA1 region of H1-KO mice in vitro. We found that late-phase LTP elicited by high frequency stimulation (HFS) was impaired, and that the induction and maintenance of theta burst stimulation (TBS) LTP were reduced in H1-KO. To test the hypothesis that Homer1c was sufficient to rescue these LTP deficits, we delivered Homer1c to the hippocampus of H1-KO using recombinant adeno-associated virus (rAAV). We found that rAAV-Homer1c rescued HFS and TBS-LTP in H1-KO animals. Next, we tested whether the LTP rescue by Homer1c was occurring via mGluR1/5. A selective mGluR5 antagonist, but not an mGluR1 antagonist, blocked the Homer1c-induced recovery of late-LTP, suggesting that Homer1c mediates functional effects on plasticity via mGluR5. To investigate the role of Homer1c in spatial learning, we injected rAAV-Homer1c to the hippocampus of H1-KO. We found that rAAV-Homer1c significantly improved H1-KO performance in the Radial Arm Water Maze. These results point to a significant role for Homer1c in synaptic plasticity and learning.  相似文献   

4.
Expression of the immediate-early genes (IEGs) has been shown to be induced by activity-dependent synaptic plasticity or behavioral training and is thought to play an important role in long-term memory. In the present study, we examined the induction and expression of the IEG-encoded protein Egr-1 during an in vitro neural correlate of eyeblink classical conditioning. The results showed that Egr-1 protein expression as determined by immunocytochemistry and Western blot analysis rapidly increased during the early stages of conditioning and remained elevated during the later stages. Further, expression of Egr-1 protein required NMDA receptor activation as it was blocked by bath application of AP-5. These findings suggest that the IEG-encoded proteins such as Egr-1 are activated during relatively simple forms of learning in vertebrates. In this case, Egr-1 may have a functional role in the acquisition phase of conditioning as well as in maintaining expression of conditioned responses.  相似文献   

5.
Differences in attraction to same- and other-sex peers as a function of sex, age, individual characteristics (i.e., aggression), and context were examined in a longitudinal study of early adolescent boys and girls (N = 217) that covered the transition from elementary school (Time 1) to middle school (Times 2 and 3). Consistent with T. Moffitt's (1993) concept of the "maturity gap," attraction to aggressive peers, especially attraction to aggressive boys among girls, increased with age and upon entry to middle school, as did attraction to peers who stood out in the peer group in easily observable ways. Attraction to peers who presented features associated with good classroom-based behavior decreased. These patterns are discussed in terms of the developmental needs served by associating with particular peers.  相似文献   

6.
7.
This study has discussed two distinct relational patterns which can occur between parents suffering from a narcissistic disturbance and their children: the instrumental and the focal child syndromes. Individual and intergenerational dynamics were examined. The typical outcomes for the child were outlined.  相似文献   

8.
Letters are more difficult to detect in function words than in content words, presumably because function words serve to cue sentential structure but recede to the background as meaning unfolds. This function disadvantage was found for the definite article in German for all three genders and all four cases, but it was more pronounced when the article appeared in a nominative noun phrase than in an object noun phrase. It was also more pronounced for the typical subject-predicate-object sentential format than for the object-predicate-subject sentential format and also when the definite article unequivocally specified the case of a phrase than when it was ambiguous. The results suggest that the structural frames established on line in reading are finely tuned to both phrase-level and sentence-level organization.  相似文献   

9.
Garatti M  Rudnitski RA 《Adolescence》2007,42(167):501-523
Adolescents' views of war and peace were assessed among 209 children aged 10-14 who attended a parochial school or its after-school religious program located in a predominantly middle-class, suburban area within commuting distance of New York City. Findings were compared to those of youth surveyed during other armed conflicts, specifically the Vietnam War, the first Persian Gulf War, and the U.S. military involvement in Latin America. The study took place in early fall 2003, and results were interpreted in light of the social climate and complex realities of post 9/11 in New York State, the Catholic Church's initial opposition to the Iraq conflict, and popular opinion. In spite of differences between the Iraq War and other conflicts, findings are remarkably similar. Although the present group is highly preoccupied with terrorism and nuclear war, even in a time of war, participants show concern for what they perceived as affecting their lives directly, rather than with conventional war. While they believe that President Bush was honest about the war in Iraq and right in sending troops, they do not glorify war. On a theoretical level, they overwhelmingly believe that wars are bad and the majority is optimistic that world peace is possible, though they realize that wars are difficult to prevent, believe that they are sometimes needed, and will occur in the future. Unlike the Catholic group surveyed by Tolley during the Vietnam War, however, participants are not as ready to die for their country, although findings show that, overall, like past groups, more boys tend to be pro-war than are girls and participants' views tend to reflect contemporary public opinions.  相似文献   

10.
Young infants are capable of integrating auditory and visual information and their speech perception can be influenced by visual cues, while 5-month-olds detect mismatch between mouth articulations and speech sounds. From 6 months of age, infants gradually shift their attention away from eyes and towards the mouth in articulating faces, potentially to benefit from intersensory redundancy of audiovisual (AV) cues. Using eye tracking, we investigated whether 6- to 9-month-olds showed a similar age-related increase of looking to the mouth, while observing congruent and/or redundant versus mismatched and non-redundant speech cues. Participants distinguished between congruent and incongruent AV cues as reflected by the amount of looking to the mouth. They showed an age-related increase in attention to the mouth, but only for non-redundant, mismatched AV speech cues. Our results highlight the role of intersensory redundancy and audiovisual mismatch mechanisms in facilitating the development of speech processing in infants under 12 months of age.  相似文献   

11.
The age-correlated gains and losses in visual identification under backward pattern masking were studied in a representative sample of 226 individuals ranging from 6 to 88 years of age. Participants identified masked symbols at leisure under high and low stimulus quality and at varying Stimulus Onset Asynchronies. Performance increased from childhood to early adulthood and then decreased, describing the common inverted U-shaped function. However, measures of general processing speed accounted for the gains in childhood and adolescence but not for losses in older age. This asymmetry between child development and aging is inconsistent with general-factor lifespan theories of cognitive development and suggests that specific mechanisms underlying visual identification during child development and aging are different.  相似文献   

12.
This study documented significant changes in prejudice toward gay and lesbian individuals among adolescents from the ages of 12 to 18 years. Moreover, in line with developmental theories of prejudice, there was substantial variability in these patterns, partially predicted by the gender and ideological beliefs (reflected by social dominance orientation [SDO]) of individuals. Boys reported higher prejudice at age 12 than girls. SDO also accounted for initial differences in levels of prejudice. Further, although prejudice toward gay men did decrease among girls over time, it did not decrease among boys. Prejudice toward lesbians decreased at similar rates for boys and girls. These different trajectories are explained within the context of gender socialization processes during adolescence. In addition, fluctuations in adolescents' own SDO corresponded with fluctuations in their level of prejudice, over and above those tied to age-related changes. This association was even stronger among those with overall higher SDO tendencies than others. However, SDO, when treated as a stable invariant factor, did not predict different patterns of progressive age-related change in prejudice. These results extend the research on sexual prejudice by examining it within a broader and more dynamic developmental framework, in greater alignment with developmental theories of prejudice.  相似文献   

13.
The conversion of Scotland, in the fifth, sixth and seventh centuries, was carried out largely by Gaelic-speaking missionaries from Ireland. When Scotland was largely Gaelic-speaking it was freely acknowledged that the conversion had come mainly from Ireland. But in the later Middle Ages, as Gaelic retreated from the Lowlands and became increasingly seen there as barbaric and uncivilised, new historical models were developed in Scottish hagiography which portrayed missionaries as civilised Lowlanders penetrating and pacifying the barbaric Highlands. In the course of this process the ancient Picts disappeared from view. This rewriting of history could not overcome the known facts about St Columba, however, and on the eve of the Reformation Roderick MacLean, a Gaelic-speaking bishop (with Lutheran sympathies), wrote elaborate and sophisticated Latin poems proclaiming the achievements of Columba and Iona.  相似文献   

14.
Maltreated youths in foster care often experience negative developmental and psychological outcomes, which have been linked with poor response inhibition. Recent evidence suggests that childhood maltreatment is also associated with alterations in the neural circuitry underlying response inhibition. However, a burgeoning line of research has begun to explore the mitigating effects of preventive interventions on neural functioning. The current study used event‐related functional magnetic resonance imaging to explore the impact of early childhood maltreatment and a preventive intervention on response inhibition in early adolescence. Thirty‐six demographically similar adolescents (ages 9–14 years) completed a Go/NoGo task. The sample included nonmaltreated adolescents (= 14) and maltreated adolescents who were in foster care as preschoolers and randomly assigned to receive services as usual (= 11) or a preventive intervention, Multidimensional Treatment Foster Care for Preschoolers (= 11). The groups demonstrated similar behavioral performance but significantly different neural patterns. The maltreated adolescents who received services as usual demonstrated subcortical hypoactivity during successful response inhibition and subcortical hyperactivity during unsuccessful response inhibition. In contrast, the nonmaltreated adolescents and maltreated adolescents who received the intervention exhibited strikingly similar neural patterns during successful response inhibition, but the maltreated adolescents who received the intervention demonstrated prefrontal hypoactivity during unsuccessful response inhibition. These findings offer preliminary evidence that early childhood maltreatment alters the neural patterns underlying response inhibition in early adolescence and that participating in a preventive intervention could mitigate maltreatment‐related effects on these neural systems.  相似文献   

15.
This study investigated daily states and time use patterns associated with depression. Four hundred eighty-three 5th to 9th graders reported on their experience when signalled by pagers at random times. Depressed youth reported more negative affect and social emotions, lower psychological investment, lower energy, and greater variability in affect. These differences were weaker for 5th and 6th graders, suggesting that self-reported feeling states are a poor indicator of depression prior to adolescence. No differences were found in the daily activities of depressed youths nor in the amount of time spent alone, but depressed youths experienced other people as less friendly and more often reported wanting to be alone, especially when with their families. They also spent less time in public places and more time in their bedrooms. Finally, depressed boys, but not girls, spent much less time with friends, particularly of the same sex, suggesting that social isolation is more strongly associated with depression for boys.  相似文献   

16.
17.
This article presents findings from empirical studies of the development of the use of pronouns in early child language. This presentation includes discussion of 1) when personal, reflexive, possessive, and indefinite pronominal forms appear in child-initiated contexts, 2) which errors emerge, and 3) which communicative functions utterances with pronouns have in dialogue. A first comparison of German-speaking and (American-)English-speaking children's usage is offered, focussing in particular on the use of the pronominal forms I/ich, you/du, and my/mein. This crosslinguistic comparison reveals differences in the age of first use, but simultaneously suggests similarities in functional characteristics of such usage. The findings are discussed in connection with the question of the development of children's communicative competence.  相似文献   

18.
作为儒学研究的重要内容,性命论在晚明清初儒学转型进程中呈现极为复杂的发展形态。于晚明三教合流趋势中,部分儒者所持性命论主张对佛、道思想具有极高程度的包容力,由此引发大规模的"正统""异端"之争;于心学修正思潮中,东林学派及之后刘宗周对传统儒学"性命"之说秉持更为严肃的坚守态度,如此,"性命"的客观义、超越义得到强调;清初,在形上学渐趋没落之际,部分儒学人士对"性命"的诠释多从"材质之性"谈起——侧重对现实人生延续及发展等诉求的考量,此时性命论"天"字义渐次流失,"命"的世俗义得到落实。  相似文献   

19.
Although it has frequently been reported that hyperactive children have abnormally small P3 amplitudes of the event-related potential (ERP), which are normalized by the stimulant drug methylphenidate (MPH), the literature is inconsistent concerning earlier ERP waves. The aim of the present study was to investigate whether the normalizing effect of a 10-mg dose of MPH was also apparent on earlier waves, such as the N1, the P2, and the N2, besides the P3. Twelve attention deficit with hyperactivity disorder (ADHD) children performed a Continuous Performance Test involving a button-press response to the letter X (CPT-X) under the influence of MPH in a double-blind placebo controlled acute dosage design. ERPs were recorded at Oz, Pz, Cz, and Fz. The expected increase of the parietal P3, both to targets and nontargets, was apparent, as well as a significant increase in percentage of hits. There also was a significant increase of an earlier, negative going, wave, the N2, with a frontal maximum, under the influence of MPH. This wave was probably a manifestation of an increase in processing negativity for target stimuli only, after the intake of the stimulant drug. No effect of MPH was found on the N1 or the P2.  相似文献   

20.
Two studies examined the association between depressive symptoms and romantic involvement in adolescence and tested the hypothesis that romantic involvement is associated more strongly with symptoms among adolescents who have a more preoccupied style of relating, compared to adolescents who have a less preoccupied style of relating. Study 1 (N = 96 early adolescent females) examined concurrent associations and Study 2 (N = 80 late adolescent males and females) examined longitudinal associations. In both age groups, romantic involvement was associated with greater depressive symptoms and this was most true among adolescents with a preoccupied style of relating. Implications for models of depression and adolescent romantic functioning are discussed.  相似文献   

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