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151.
This study was designed to determine differences in the proprioceptively guided movements of children (8-10 years) and adolescents (16-18 years). Participants were blindfolded and asked to actively match passively determined target positions of the elbow joint under three matching conditions. Overall, children were less accurate than adolescents in all matching tasks and utilized different kinematic strategies for making the matching movements. Specifically, children made larger absolute errors and utilized matching movements which, compared to adolescents, were of shorter duration and less irregular in terms of their velocity profiles. An assessment of limb asymmetry was also performed revealing a non-dominant arm matching advantage but only for children and only in the task requiring interhemispheric transfer of a memory-based model of limb position. The proprioceptive differences observed in this study are likely the result of experience-driven refinement in the utilization of somatosensory feedback throughout childhood and into adolescence. 相似文献
152.
153.
In three experiments, we explored how pigeons use edges, corresponding to orientation and depth discontinuities, in visual recognition tasks. In experiment 1, we compared the pigeon's ability to recognize line drawings of four different geons when trained with shaded images. The birds were trained with either a single view or five different views of each object. Because the five training views had markedly different appearances and locations of shaded surfaces, reflectance edges, etc, the pigeons might have been expected to rely more on the orientation and depth discontinuities that were preserved over rotation and in the line drawings. In neither condition, however, was there any transfer from the rendered images to the outline drawings. In experiment 2, some pigeons were trained with line drawings and shaded images of the same objects associated with the same response (consistent condition), whereas other pigeons were trained with a line drawing and a shaded image of two different objects associated with the same response (inconsistent condition). If the pigeons perceived any correspondence between the stimulus types, then birds in the consistent condition should have learned the discrimination more quickly than birds in the inconsistent condition. But, there was no difference in performance between birds in the consistent and inconsistent conditions. In experiment 3, we explored pigeons' processing of edges by comparing their discrimination of shaded images or line drawings of four objects. Once trained, the pigeons were tested with planar rotations of those objects. The pigeons exhibited different patterns of generalization depending on whether they were trained with line drawings or shaded images. The results of these three experiments suggest that pigeons may place greater importance on surface features indicating materials, such as food or water. Such substances do not have definite boundaries cued by edges which are thought to be central to human recognition. 相似文献
154.
Fractionating working memory: consolidation and maintenance are independent processes 总被引:3,自引:0,他引:3
In the present study, we required subjects to remember simple objects that were masked to interrupt consolidation and allow us to estimate the rate of information accrual in visual working memory. We compared a consolidation-baseline condition with a consolidation-during-maintenance condition in which subjects needed to remember a set of unmasked items and then were shown to-be-remembered masked items. We hypothesized that if the control processes of consolidation and maintenance are performed by common mechanisms, then consolidation should be less efficient when performed during maintenance than when performed alone. However, we found that an identical amount of information was encoded per unit time in the two conditions. These results indicate that working memory consolidation is not slowed by maintenance and suggest a two-step model of encoding in visual working memory. 相似文献
155.
Judith S Gordon Judy A Andrews Edward Lichtenstein Herbert H Severson Laura Akers 《Health psychology》2005,24(5):447-455
This study evaluated 2 methods of disseminating an empirically validated smokeless tobacco intervention delivered during routine dental care. Twenty cities within 12 states were stratified and then randomized to 1 of 3 groups: personalized instruction (PI), self-study (SS), or delayed training (DT) control. Dental hygienists in the SS condition were sent a manual and video. Those in the PI condition were recruited to attend a workshop. Thirty-seven percent of eligible hygienists agreed to participate. At 12 months postenrollment, hygienists in the SS and PI conditions significantly increased their "Assist" behaviors (discuss cessation techniques, help patient set a quit date, and provide cessation materials) and reported fewer perceived barriers to delivering the intervention as compared with hygienists in DT. An economic analysis suggests that SS is more cost-effective than PI. 相似文献
156.
157.
Almost all research on aggression in adolescent romantic relationships makes use of 1-time, retrospective assessment methods. In the present research, the authors compared data on the experience of adolescent relationship aggression (physical aggression and threatening behavior) collected from 125 high school students via 2 methods: (a) a 1-time, 2-month retrospective assessment and (b) a cumulative method based on four 2-week retrospective assessments, each spaced 2 weeks apart. For the cumulative method, data from the 4 assessments were aggregated to cover the same time period as the single, 2-month retrospective assessment. A greater proportion of the sample (48.0%) reported experiencing physical aggression using the cumulative method compared with the single, 2-month retrospective method (27.0%). The prevalence of threatening behavior was also higher using the cumulative method (48.8% vs. 24.8%). Adolescent trauma and anxiety symptoms correlated more strongly with physical aggression data derived from the cumulative method than from the 1-time assessment method. 相似文献
158.
After a person has become stuck on a problem, they sometimes achieve a clear and sudden solution through insight--the so-called Aha! experience. Because of its distinctive experience, the origins and characteristics of insight have received considerable attention historically in psychological research. However, despite considerable progress in characterizing insight, the underlying mechanisms remain mysterious. We argue that research on insight could be greatly advanced by supplementing traditional insight research, which depends on a few complex problems, with paradigms common in other domains of cognitive science. We describe a large set of mini-insight problems to which multiple methods can be applied, together with subjective reports to identify insight problem-solving. Behavioral priming and neuroimaging methods are providing evidence about what, where, and how neural activity occurs during insight. Such evidence constrains theories of component processes, and will help to demystify insight. 相似文献
159.
Wager TD Jonides J Smith EE Nichols TE 《Cognitive, affective & behavioral neuroscience》2005,5(2):127-143
Although task switching is often considered one of the fundamental abilities underlying executive functioning and general
intelligence, there is little evidence that switching is a unitary construct and little evidence regarding the relationship
between brain activity and switching performance. We examined individual differences in multiple types of attention shifting
in order to determine whether behavioral performance and fMRI activity are correlated across different types of shifting.
The participants (n=39) switched between objects and attributes both when stimuli were perceptually available (external) and when stimuli were
stored in memory (internal). We found that there were more switchrelated activations in many regions associated with executive
control—including the dorsolateral and medial prefrontal and parietal cortices—when behavioral switch costs were higher (poor
performance). Conversely, activation in the ventromedial prefrontal cortex (VMPFC) and the rostral anterior cingulate was
consistently correlated with good performance, suggesting a general role for these areas in efficient attention shifting.
We discuss these findings in terms of a model of cognitive-emotional interaction in attention shifting, in which reward-related
signals in the VMPFC guide efficient selection of tasks in the lateral prefrontal and parietal cortices. 相似文献
160.