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231.
The ability of 3‐ and 4‐year‐old children to disregard advice from an overtly misleading informant was investigated across five studies (total n = 212). Previous studies have documented limitations in young children's ability to reject misleading advice. This study was designed to test the hypothesis that these limitations are primarily due to an inability to reject specific directions that are provided by others, rather than an inability to respond in a way that is opposite to what has been indicated by a cue. In Studies 1 through 4, a puppet identified as The Big Bad Wolf offered advice to participants about which of two boxes contained a hidden sticker. Regardless of the form the advice took, 3‐year olds performed poorly by failing to systematically reject it. However, when participants in Study 5 believed they were responding to a mechanical cue rather than the advice of the Wolf, they were better able to reject misleading advice, and individual differences in performance on the primary task were systematically correlated with measures of executive function. Results are interpreted as providing support for the communicative intent hypothesis, which posits that children find it especially difficult to reject deceptive information that they perceive as being intentionally communicated by others. 相似文献
232.
Parietal cortical areas are involved in sensori-motor transformations for their respective contralateral hemifield/body. When arms of the subjects are crossed while their gaze is fixed straight ahead, vision of the hand is processed by the hemisphere ipsilateral to the arm position and proprioception of the arm by the contralateral hemisphere. It induces interhemispheric transfer and remapping. Our objective was to investigate whether a single pulse TMS applied to the left parietal cortical area would disturb interhemispheric remapping in a similar case, and would increase a simple reaction time (RT) with respect to a control single pulse TMS applied to the frontal cortical area. Two LED were superimposed and located in front of the subjects on the saggital axis. Subjects were asked to carefully fixate on these LED during each trial. The lighting of the red LED was used as a warning signal. Following the green one was illuminated after a variable delay and served as a go-signal. The hand for the response was determined before the start of each trial. TMS was applied to the left parietal, the left frontal cortical areas, or not applied to the subject. Results revealed that: (1) Irrespective of its location, single pulse TMS induced a non-specific effect similar to a startle reflex and reduced RT substantially (15 ms on average) with respect to a control condition without TMS (mean value = 153 ms). (2) Irrespective of TMS, RT were shorter when the right or the left hand was positioned in the right visual hemi-field (i.e. normal and crossed positions respectively). (3) Finally, RT increased when single pulse TMS was applied to the left parietal area and when hands were crossed irrespective of which hand was used. We concluded that interhemispheric sensori-motor remapping was disrupted by a single pulse TMS that was applied to the left parietal cortex. This effect was also combined with some visual attention directed towards the hand located on the right visual hemi-field. 相似文献
233.
《Brain and cognition》2013,82(2):152-160
ObjectiveTo evaluate the utility of an oral fMRI-adapted version of the Symbol Digit Modalities Test (SDMT) to assess information processing speed (IPS) using three different interstimulus intervals (ISI).MethodsNineteen right-handed healthy controls performed the adapted version of the SDMT, consisting of a block design that had a total of 6 control/activation block pairs with 3 different ISIs (1.5, 2 and 2.5 s) presented in two different runs: in ascending and descending orders. The brain activation patterns during different ISIs were assessed by effective functional connectivity analysis based on independent component analysis.ResultsAs expected, all conditions yielded activations in the fronto-parietal networks (FPNs) related to attention processes. Shorter ISIs (1.5 and 2 s) not only yielded greater patterns of connectivity within fronto-parietal and occipital regions such as the FPN and fronto-occipital network (FON), but also recruited more functional networks overall. Task performance at the shortest ISI was negatively correlated with connectivity at the FPN and activity of the pre-supplementary motor area extending to the cingulate gyrus.ConclusionIncreasing IPS demands due to shorter ISIs resulted in an increased level and number of functional networks required, increased connectivity within the FPN and FON, and enhancement of the prefrontal cortex. IPS does not arise from activity of a single b area but from affective information transfer among distant cortical regions of the frontal and parietal cortices. This adapted version of the SDMT may be useful for studying alterations of IPS in clinical and nonclinical populations. 相似文献
234.
Pitch is derived by the auditory system through complex spectrotemporal processing. Pitch extraction is thought to depend on both spectral cues arising from lower harmonics that are resolved by cochlear filters in the inner ear, and on temporal cues arising from the pattern of action potentials contained in the cochlear output. Adults are capable of extracting pitch in the absence of robust spectral cues, taking advantage of the temporal cues that remain. However, recent behavioral evidence suggests that infants have difficulty discriminating between stimuli with different pitches when resolvable spectral cues are absent. In the current experiments, we used the mismatch negativity (MMN) component of the event related potential derived from electroencephalographic (EEG) recordings to examine a cortical representation of pitch discrimination for iterated rippled noise (IRN) stimuli in 4- and 8-month-old infants. IRN stimuli are pitch-evoking sounds generated by repeatedly adding a segment of white noise to itself at a constant delay. We created IRN stimuli (delays of 5 and 6 ms creating pitch percepts of 200 and 167 Hz) and high-pass filtered them to remove all resolvable spectral pitch cues. In experiment 1, we did not find EEG evidence that infants could detect the change in the pitch of these IRN stimuli. However, in Experiment 2, after a brief period of pitch-priming during which we added a sine wave component to the IRN stimulus at its perceived pitch, infants did show significant MMN in response to pitch changes in the IRN stimuli with sine waves removed. This suggests that (1) infants can use temporal cues to process pitch, although such processing is not mature and (2) that a short amount of pitch-priming experience can alter pitch representations in auditory cortex during infancy. 相似文献
235.
Human participants and recurrent (“connectionist”) neural networks were both trained on a categorization system abstractly similar to natural language systems involving irregular (“strong”) classes and a default class. Both the humans and the networks exhibited staged learning and a generalization pattern reminiscent of the Elsewhere Condition (Kiparsky, 1973). Previous connectionist accounts of related phenomena have often been vague about the nature of the networks’ encoding systems. We analyzed our network using dynamical systems theory, revealing topological and geometric properties that can be directly compared with the mechanisms of non‐connectionist, rule‐based accounts. The results reveal that the networks “contain” structures related to mechanisms posited by rule‐based models, partly vindicating the insights of these models. On the other hand, they support the one mechanism (OM), as opposed to the more than one mechanism (MOM), view of symbolic abstraction by showing how the appearance of MOM behavior can arise emergently from one underlying set of principles. The key new contribution of this study is to show that dynamical systems theory can allow us to explicitly characterize the relationship between the two perspectives in implemented models. 相似文献
236.
根据社会认知理论,探讨组织情景中领导者创新性工作表现对下属创造力的影响,将领导成员交换关系和威权型领导作为情景因素,来探索它们的交互效应对下属创造力的影响。本研究采用问卷法,选取领导-下属配对数据,通过两个子研究来验证假设。研究结果显示:(1)领导创新性工作表现与下属创造力存在积极的正相关关系,创新的内在动机在其中起着中介作用;(2)威权型领导能够有效地调节这种关系;(3)领导创新性工作表现、领导成员交换关系和威权型领导对下属创造力存在三重的交互作用。最后,文章讨论了研究的局限与启示,并指出未来可能的研究方向。 相似文献
237.
Younger women diagnosed with cancer often face compromised fertility as a result of their treatment. However, previous research has adopted a biomedical model of fertility and utilised hypothetico-deductive research methods which have not allowed for full exploration of women’s subjectivity. This study explored younger women’s construction of their fertility post-cancer, and their discussions of fertility with healthcare professionals, from a social constructionist epistemology. Semi-structured one-to-one interviews were conducted with eight women aged 18–26, across a variety of cancer types. Foucaultian Discourse Analysis identified three subject positions associated with fertility concerns: ‘Inadequate woman: Accepting the motherhood mandate’; ‘Adequate woman: Resisting the motherhood mandate’; and ‘Survival of the fittest: Woman as genetically defective’. Implications of these subject positions included feelings of inadequacy, fear and devastation; feeling undesirable to romantic partners; and concern about passing on cancer-positive genes. In describing healthcare professional interactions, women adopted positions of ‘Satisfied patient’; ‘Passive recipient patient’; or ‘Resisting the passive patient position’. Accounts of inadequate information provision were associated with anger and frustration, whereas feeling adequately informed was associated with satisfaction at making decisions about fertility preservation. These results suggest that fertility is of importance to young women cancer survivors, and that compromised fertility can negatively impact subjectivity. 相似文献
238.
In this study, (Gd1? x Nd x )2(Zr1? x Ce x )2O7 (0 ≤ x ≤ 0.5) ceramics have been prepared by pressureless sintering at 1973 K to investigate the influence of Nd and Ce co-doping on their electrical conductivity. The electrical conductivity of the ceramics was investigated by impedance spectroscopy measurements from 723 to 1173 K over the frequency range of 20 Hz to 2 MHz in air. The measured values obey the Arrhenius relation. For each composition, the grain conductivity gradually increases with increasing temperature from 723 to 1173 K. At a given temperature, it gradually decreases with increasing neodymium and cerium contents from x = 0 to 0.3; thereafter, the grain conductivity exhibits a slight increase with further increasing neodymium and cerium contents up to x = 0.5. 相似文献
239.
The effect of chemical stresses upon the relation between extended dislocations and high-temperature creep in a thin plate has been investigated. The critical stress needed for the contraction of extended jogs and its effect on the creep rate are obtained. The results indicate that the critical stress needed for the contraction increases with decreasing stacking fault energy (SFE). However, creep occurs more easily with increasing SFE and increasing angle of the Burgers vector to the dislocation line, as well as with the concentration of any diffusing atoms. 相似文献
240.
Seungwon Lee Kaveh Edalati Hideaki Iwaoka Zenji Horita Takumi Ohtsuki Takuo Ohkochi 《Philosophical Magazine Letters》2013,93(10):639-646
FeNi with the L10-ordered structure is formed over an astronomical timescale in meteorites. In this study, severe plastic deformation using high-pressure torsion (HPT) is employed for the production of the L10 structure in the laboratory. Its formation is confirmed by X-ray diffraction analysis and transmission electron microscopy. Processing of elemental nanopowders by HPT is an effective method for the formation of the L10 phase, which is enhanced by the addition of Co to FeNi or annealing after HPT. The formation of the phase must be associated with enhanced diffusion through HPT. 相似文献