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871.
Properties of memory for unattended spoken syllables 总被引:1,自引:0,他引:1
N Cowan W Lichty T R Grove 《Journal of experimental psychology. Learning, memory, and cognition》1990,16(2):258-269
Whereas previous studies on memory for unattended speech have inadvertently included acoustic interference, the present study examines memory for unattended syllables during a silent period of 1, 5, or 10 s. The primary task was to read silently (Experiments 1-3) or whisper the reading (Experiment 4). Occasionally, when a light cue occurred, the subject was to recall the most recent spoken syllable, as well as the recent reading material. Memory for both the vowels and consonants of the syllables decreased across 10 s, confirming that auditory memory does decay in the absence of acoustic interference. However, the specific patterns of memory decay for vowels versus consonants depended on task demands, including the allocation of attention and the opportunity for subvocal coding. We suggest an account of performance that includes auditory sensory and phonetic memory codes with different properties, used in combination. 相似文献
872.
This paper evaluates three hypotheses about the structure of threat perceptions in the post-Cold War era: the replacement of a military conception of threat by an economic one; fluidity in threat perceptions because of an absence of a polestar nation; and Huntington's clash of civilizations theory. Using psychophysical magnitude measures of threat perception, these findings provide no support for the notion that threats are perceived economically. There is limited support for the theory that threat perceptions are unstable; most countries are clustered around a core of weakly hostile or friendly perceptions, which is suggestive of instability. At the same time, however, there does appear to be stability in perceptions of strong friends and enemies. The hypothesis best supported by these data is Huntington's theory that culture determines threat perceptions. In this study, not a single Western country is perceived as hostile, and all nations that do receive hostile scores are non-Western. 相似文献
873.
Most prior research on social support in close relationships examines perceptions of support, failing to capture fully the helping behaviors that partners exchange while interacting. We observed 60 newly married couples each engage in two 10-minute interactions. with one spouse (the helper) responding while the partner (the helper) discussed a personal characteristic or problem that he or she wanted to change. Helper and helper behaviors were coded and examined in relation to gender and negative affectivity, which have been linked in prior research to perceptions of support. Husbands and wives did not differ in helper behaviors, but wives displayed more negative helper behavior than did husbands. Helper and helper behavior covaried with negative affectivity in expected directions, and helper behavior covaried with the partner's negative affectivity. Finally, analysis of negative reciprocity sequences showed that, as helpers, husbands were more likely to reciprocate negative behavior, and to have their negative behavior reciprocated, to the extent that they were high in negative affectivity. We emphasize the value of observational data in understanding social support in marriage, we discuss the implications of the findings in terms of prevailing beliefs about gender and social support, and we outline the specific links between negative affectivity and observed support behavior in marriage. 相似文献
874.
875.
A literature search was conducted on studies of new drugs used with patients with schizophrenia reported by U.S. and non-U.S. researchers from 1966–1993, yielding 41 U.S., and a total of 24 other non-U.S. studies, among them 11 British studies. Results of the U.S. and non-U.S. studies were pooled separately and compared. Among several comparable conditions discussed, the lack of any data on suicides in the U.S. studies was observed. For a second statistical analysis of suicide rates ‘person-years’ were calculated to adjust for differing washout durations. The results obtained include findings that the percentage of patients relapsing in U.S. studies was slightly lower (37.9%) than in non-U.S. studies (46%); the percentage of patients dropping out in U.S. studies (10.5%) was higher than in non-U.S. studies (7.6%); known location of dropout patients in U.S. studies was 1.7%, compared to 2.6% in non-U.S. studies. The most interesting finding was that no suicides were reported in U.S. studies, compared to 0.6% of patients reported in British studies. Some U.S. studies used ‘challenge doses’, such as amphetamines or L-dopa; no non-U.S. studies reported their use. Compared to U.S. studies, those by non-U.S., and particularly British, researchers appeared to report adverse events in their studies. ‘Challenge’ drugs were not used; suicides were reported. It is estimated that the probability that no patients suicided who participated in the U.S. is small—one in 500. 相似文献
876.
The auditory cortex of the mustached bat shows complex multiple frequency maps, because cortical neurons in several areas are tuned to particular combinations of signal elements. Different types of combination-sensitive neurons form computational maps in which information-bearing parameters for echolocation (biosonar) are represented systematically. Neuronal response properties and multiple-frequency and computational maps were considered to be created solely by divergent-convergent interactions of neurons in the 'ascending' system. However, we have found that the 'corticofugal' system also plays an important role. Neurons in an iso-best frequency (or echo delay) 'minicolumn' of the auditory cortex augment the auditory responses of subcortical neurons tuned to that frequency (or echo delay) and sharpen their tuning. At the same time, they reduce the response and shift the tuning of subcortical neurons tuned to other frequencies (or echo delays) away from the best frequency (or delay) of the cortical neurons. Cortical neurons mediate a highly focused positive feedback, incorporated with widespread lateral inhibition, via corticofugal projections. This 'egocentric selection' is expected to play an important role in self-organizing the central auditory system. 相似文献
877.
Ronald N. Kostoff Ph.D. 《Science and engineering ethics》1997,3(2):109-120
This paper addresses some critical issues in the applicability of quantitative performance measures (including bibliometric,
economic, and co-occurrence measures) to the assessment of basic research. The strengths and weaknesses of metrics applied
as research performance measures are examined. It is concluded that metrics have a useful role to play in the evaluation of
research. Each metric employed, whether bibliometric, economic, co-occurrence, or others, brings a new dimension of potential
insight to the complex problem of research assessment. However, when used in a stand-alone mode, metrics can be easily misinterpreted
and result in misleading conclusions. Metrics should be an integral part of a more comprehensive approach to research evaluation,
in which the leading role is assumed by expert peer review. Under this structure, the reviewers must be broadly constituted,
so that the technical correctness of the research approaches being taken (doing the job right) can be evaluated by technical
experts and the correctness of the research target (doing the right job) can be evaluated as well. This comprehensive approach
insures quality in the implementation of existing research paradigms and allows the introduction of revolutionary new research
paradigms as well.
The views contained in this paper are solely those of the author and do not represent the views of the Department of the Navy.
Ronald Kostoff received a Ph.D. from Princeton University, performed technical and economic research at Bell Laboratories,
managed energy programs at U.S. Department of Energy, was Director of Technical Assessment at the Office of Naval Research
for many years and presently manages the Navy’s In-House Laboratory Independent Research Program. 相似文献
878.
Nonparametric regression techniques, which estimate functions directly from noisy data rather than relying on specific parametric models, now play a central role in statistical analysis. We can improve the efficiency and other aspects of a nonparametric curve estimate by using prior knowledge about general features of the curve in the smoothing process. Spline smoothing is extended in this paper to express this prior knowledge in the form of a linear differential operator that annihilates a specified parametric model for the data. Roughness in the fitted function is defined in terms of the integrated square of this operator applied to the fitted function. A fastO(n) algorithm is outlined for this smart smoothing process. Illustrations are provided of where this technique proves useful. 相似文献
879.
Older (n = 12) and younger (n = 12) golfers attempted to hit a golf ball into a target net a short distance away. An accelerometer attached to the back of the clubhead measured the applied force. In contrast to the more typical finding of slower perceptual-motor performance by older adults, older golfers reached their peak downswing force earlier in the shot and also exhibited a trend toward a faster overall speed or tempo of the shot. Additionally, older golfers exhibited greater changes in applied force and greater variability. A pattern of divergence among the force-time histories from multiple shots suggested that the overall person-plus-golf-club dynamics were unstable during a part of the shot. Older adults may be slower in controlling this instability. Half of the participants heard a tone whose pitch was proportional to their force. These participants had a slower follow through; however, they did not make significantly more or fewer shots than participants who had not been presented with the tone. Analyses of the temporal covariation among the backswing, downswing, and follow-through favored a chain-like temporal structure over a hierarchical, proportional structure. The pattern of covariation suggests that the tempo and rhythm of the shot are not independent and that changing one's tempo may disrupt rhythm. 相似文献
880.
John F. Dovidio Jennifer K. Smith Amy Gershenfeld Donnella Samuel L. Gaertner 《Journal of applied social psychology》1997,27(16):1468-1487
This study investigated the relationship between overt and subtle forms of racism with Whites' recommendations for capital sentencing of Black and White offenders convicted of murder. White participants (n= 104) viewed 5 other “jurors” (all Whites or 4 Whites and 1 Black) on videotape individually presenting their decisions to vote for the death penalty in the case. It was hypothesized that the bias of high prejudice-scoring participants would be overt, but that the pattern for low prejudice-scoring participants would be more complex. As predicted, among high prejudice-scoring participants, Black defendants received stronger recommendations for the death penalty than did White defendants. Among low prejudice-scoring White participants, Black offenders received stronger recommendations for the death penalty only when a Black juror advocated the death penalty. 相似文献