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251.
A unified fielder theory is presented that explains how humans navigate to intercept targets that approach from either above
or below the horizon. Despite vastly different physical forces affecting airborne and ground-based moving targets, a common
set of invariant perception-action principles appears to guide pursuers. When intercepting airborne projectiles, fielders
keep the target image rising at a constant optical speed in a vertical image plane and moving in a constant optical direction
in an image plane that remains perpendicular to gaze direction. We confirm that fielders use the same strategies to intercept
grounders. Fielders maintained a cotangent of gaze angle that decreases linearly with time (accounting for 98.7% of variance
in ball speed) and a linear optical trajectory along an image plane that remains perpendicular to gaze direction (accounting
for 98.2% of variance in ball position). The universality of maintaining optical speed and direction for both airborne and
ground-based targets supports the theory that these mechanisms are domain independent. 相似文献
252.
Spatial updating relies on an egocentric representation of space: Effects of the number of objects 总被引:1,自引:0,他引:1
Wang RF Crowell JA Simons DJ Irwin DE Kramer AF Ambinder MS Thomas LE Gosney JL Levinthal BR Hsieh BB 《Psychonomic bulletin & review》2006,13(2):281-286
Models of spatial updating attempt to explain how representations of spatial relationships between the actor and objects in
the environment change as the actor moves. In allocentric models, object locations are encoded in an external reference frame,
and only the actor’s position and orientation in that reference frame need to be updated. Thus, spatial updating should be
independent of the number of objects in the environment (set size). In egocentric updating models, object locations are encoded
relative to the actor, so the location of each object relative to the actor must be updated as the actor moves. Thus, spatial
updating efficiency should depend on set size. We examined which model better accounts for human spatial updating by having
people reconstruct the locations of varying numbers of virtual objects either from the original study position or from a changed
viewing position. In consistency with the egocentric updating model, object localization following a viewpoint change was
affected by the number of objects in the environment. 相似文献
253.
Reticent behavior and experiences in peer interactions in Chinese and Canadian children 总被引:2,自引:0,他引:2
In this study, the authors examined relations between reticent behavior in unfamiliar peer situations and experiences in interactions in Chinese and Canadian children. Observational data were collected from samples of children at 4 years of age in the People's Republic of China and Canada. The results indicated that relations between reticent behavior and peer initiations were similar in the 2 samples. The differences between the samples were mainly in peer responses. Reticent behavior was associated with peer rejection such as overt refusal and disagreement in the Canadian sample but with positive responses such as approval in the Chinese sample, particularly when children made low-power initiations. The results suggest that reticent children in China and Canada may have similar as well as different experiences in social interactions. 相似文献
254.
A great deal of work has been devoted to the question of which spatial frequencies, if any, are optimal for various visual tasks, such as face and object recognition. However, to date these studies have all been carried out with stimuli set against a uniform background. It is possible that this type of stimulus does not produce ecologically valid results. The natural world in which visual tasks normally take place involves a great deal of luminance variation and distracting visual structure, which may alter the spatial frequencies necessary for a task. We conducted two experiments that examined the effects of image background on the spatial-frequency thresholds (50% maximum of a low-pass or high-pass Butterworth filter) for face recognition by the psychophysical methods of adjustment and constant stimuli. In both experiments we found no significant difference in spatial-frequency thresholds between uniform-grey backgrounds and natural-scene backgrounds, and only minor differences between uniform-grey backgrounds and fractal noise backgrounds. This suggests that results obtained with uniform backgrounds are ecologically valid and that background effects, if they exist, are small. 相似文献
255.
The present study examined relations between choice preference and reaction time to emotionally valenced words, dysphoric symptoms (BDI), and dysfunctional attitudes (DAS) in clinically depressed (CD; n= 61), previously depressed (PD; n= 42), and never depressed controls (ND; n= 46). The results showed: (1) NDs and PDs exhibited a choice preference for the relatively more positive words and differed significantly from CDs; (2) PDs and CDs exhibited longer reaction time and differed significantly from NDs; and (3) BDI and DAS were positively associated with reaction time to positively valenced words, whereas no associations were found for reaction time to negatively valenced words. The increased reaction time, in PDs and CDs, is discussed as a possible vulnerability factor to depression, which may be related to decreased approach motivation. 相似文献
256.
We used a contextual priming paradigm to examine top-down influences on the face-inversion effect. Adult participants were primed with either faces or Chinese characters and then tested on ambiguous figures that could be perceived as either faces or Chinese characters, dependent on the priming condition. The ambiguous figures differed from one another in their configural information, which is crucial for processing faces but not Chinese characters. The inversion effect was observed in the face-priming condition, but not in the character-priming condition. The present results provide the first direct evidence that top-down activation of the face-processing expertise system plays a crucial role in the face-inversion effect. 相似文献
257.
《田家半月报》是一份基督教性质的刊物,主要目标是面向农村、服务农民大众。由于战争的影响,迁到四川出版。抗战时期的《田家半月报》栏目丰富多彩,并积极应对时局要求,克服经济困难,采取各种措施扩大发行量。该刊物对基督教的传播、农村社会的改良和宣传抗战救国有一定的影响,其办刊的某些特点、内容和方式对于当今社会有一定的借鉴意义。 相似文献
258.
Most Chinese characters are composed of a semantic radical on the left and a phonetic radical on the right. The semantic radical provides the semantic information; the phonetic radical provides information concerning the pronunciation of the whole character. The pseudo‐characters in the study consisted of different sub‐lexical parts of real Chinese characters and consequently they also had the semantic radical and the phonetic radical. But they were not readable and had no actual meaning. In order to investigate the spatiotemporal cortical activation patterns underlying the orthographic, phonological and semantic processing of Chinese characters, we used event‐related brain potentials (ERPs) to explore the processing of Chinese characters and pseudo‐characters when 14 healthy Chinese college students viewed the characters passively. Results showed that both Chinese characters and pseudo‐characters elicited an evident negative potential peaking around 120 ms (N120), which appeared to reflect initial orthographic distinction and evaluation. Then, Chinese pseudo‐characters elicited a more positive ERP deflection (P220) than did Chinese characters 200–250 ms after onset of the stimuli. It was similar to the recognition potential (RP) and might reflect the integration processes of phonological and semantic processing on the basis of early orthographic information. Dipole source analysis of the difference wave (pseudo‐characters minus characters) indicated that a generator localized in the left temporal‐occipital junction contributed to this effect, which was possibly related to phonological and perceptual–semantic information integration. Between 350–450 ms, a greater negativity (N360) in pseudo‐characters as compared to characters was found over midline fronto‐central scalp regions. Dipole analysis localized the generator of N360 in the right parahippocampal cortex. Therefore, the N360 might be an N400 component and reflect the higher‐level semantic activation on the basis of orthographic, phonological and perceptual–semantic processing. 相似文献
259.
The present experiments explored the resolution of activated background information in text comprehension. In Experiment 1, participants read passages that contained an elaboration section that was either consistent or qualified (inconsistent but then corrected to be consistent) with respect to the subsequently presented target sentence (see O'Brien et al., 1998). However, the experiment used two target sentences, and several filler sentences were inserted between the first and second target sentence. The results showed that the reading times for the first target sentence in the qualified elaboration version were significantly longer than those in the consistent elaboration version. These were consistent with O'Brien's study, and further indicated that the basic process captured by the memory-based view appears to generalize to the Chinese reader better than does the here-and-now view. More importantly, the results showed that the reading times for the second target sentence in the qualified elaboration version were as long as those in the consistent elaboration version. These further indicated that the activation of background information not only maintained the coherence of the text, but also allowed for the relevant information to be updated, resulting in a unified information set. When the information was reactivated during ongoing reading, it would be in the form of unified information. In Experiment 2, the first target sentence in each passage from Experiment 1 was converted to a filler sentence, and the second target sentence became the target sentence. The results of Experiment 2 showed that the reading times for the target sentence in the qualified elaboration version were significantly longer than those for the consistent elaboration version. These indicated that the delay between the target sentences and the elaboration section was not responsible for the lack of differences in Experiment 1, and confirmed the conclusion of Experiment 1. 相似文献
260.
Kirby Deater‐Deckard Charles Beekman Zhe Wang Jungmeen Kim Stephen Petrill Lee Thompson Laura DeThorne 《Journal of personality》2010,78(3):991-1010
ABSTRACT We examined mothers' ratings of children's affective and behavioral aspects of approach tendencies and links with overt aggressive behavior problems while considering the genetic etiology of these processes. Approach/positive anticipation (AP), frustration/anger (FA), and overt aggression in 4–9‐year‐olds were assessed using mothers' reports in a diverse national sample (n=992) and a sample of same‐sex twins (n=195 pairs). AP and FA were positively correlated with each other and with overt aggression (r from .2 to .5), and these associations were very similar for boys and girls. AP and FA provided overlapping as well as independent statistical prediction of aggression. AP statistical prediction of aggression was substantially mediated by FA, an effect that was accounted for by underlying genetic and nonshared environmental influences. 相似文献