The effect of nonmasking distractors on the priming of motor responses

Masked stimuli (primes) can affect the preparation of a motor response to subsequently presented target. In numerous studies, it has been shown that the compatibility effect is biphasic as it develops over time: positive (benefits for compatible trials and costs for incompatible trials) for short prime-target temporal distances and negative (benefits for incompatible trials and costs for compatible trials) for long ones. What triggers the 2nd phase is the matter of the current debate. According to the self-inhibition hypothesis, the motor response elicited by a prime is automatically followed by an inhibition phase. The object-updating and mask-triggered inhibition hypotheses assume that this phase is triggered by the mask, provided that it contains features calling for the alternative response. In the present study, the author shows that the compatibility effect is modulated on the temporal position of a nonmasking distractor presented after the prime and before the target. With a distractor possessing task-relevant features, the compatibility effect was found to be negative for short prime- distractor intervals and for moderate prime-target intervals. The consequences of these results for the 3 hypotheses are discussed.     

Temporal aspects of stimulus-driven attending in dynamic arrays

Auditory sequences of tones were used to examine a form of stimulus-driven attending that involves temporal expectancies and is influenced by stimulus rhythm. Three experiments examined the influence of sequence timing on comparative pitch judgments of two tones (standard, comparison) separated by interpolated pitches. In two of the experiments, interpolated tones were regularly timed, with onset times of comparison tones varied relative to this rhythm. Listeners were most accurate judging the pitch of rhythmically expected tones and least accurate with very unexpected ones. This effect persisted over time, but disappeared when the rhythm of interpolated tones was either missing or irregular.     

Temporal changes in visual and acoustic codes in a letter-matching task

The objective of the present experiment was to examine the nature of the coding process in a letter-matching task. Letter pairs that were either visually confusable or acoustically confusable or both visually and acoustically confusable were presented tachistoscopically with a variable interval between the first letter and the comparison letter. The dependent measure was RT for the “different” responses to the three types of confusable items which were each assessed at four interstimulus intervals ranging from 0 to 2 sec. The results indicate that a visual code appears to be emphasized for approximately 1 sec, after which an acoustic code seems to be dominant. There is also evidence which indicates that the acoustic code does not immediately replace the visual code and that both may coexist for a brief period of time.     

Temporal construal and time-dependent changes in preference

Five studies tested the predictions of temporal construal theory and time-discounting theories regarding evaluation of near future and distant future options (outcomes, activities, products). The options had abstract or goal-relevant features (called high-level construal features) as well as more concrete or goal-irrelevant features (called low-level construal features). The studies varied the valence (positive vs. negative) and the type of valence (affective vs. cognitive) of the low-level and high-level construal features. The results show that the weight of high-level construal features, compared with the weight of low-level construal features, is greater in determining distant future preferences than near future preferences. The implications of the results for extant theories of time-dependent changes in preference are discussed.     

An effect size index for comparing two independent alpha coefficients

Since Cronbach proposed the α coefficient in 1951, researchers have contributed to the derivation of its sampling distribution and the testing of related statistical hypotheses. Yet, there has been no research on effect size index relevant to coefficient α to our knowledge. Considering the importance of effect size in understanding quantitative research findings, we therefore developed an effect size index Δ for the comparison of two independent αs with equal test length based on the asymptotic distribution of under the assumptions of normality and compound symmetry. Simulations indicated that the index was applicable when the sample size was at least 100. The robustness of the derived index when the required assumptions were violated was also explored. It is suggested that the index should be applicable in most cases of unequal test lengths and could be extended to non‐normally distributed component scores. Moreover, a small simulation was conducted to explore the behaviour of Δ with correlated errors, a frequently studied situation violating the assumption of compound symmetry. The proposed index was found to be robust unless a large number of highly correlated errors were present in the data.     

The effect of small sequential changes in fixed-ratio size upon the post-reinforcement pause

Duration of the post-reinforcement pause was measured for three pigeons on fixed-ratio schedules of reinforcement ranging from 10 to 160. Small sequential changes were made in the ratio values without disrupting stable performance. The post-reinforcement pause increased consistently for all birds within three sessions as the ratio requirement increased. A frequency analysis of the individual pauses at selected fixed ratios revealed an increase in dispersion for all animals as the ratio size increased. Response rate tended to decrease for two of the birds and remained relatively stable for the third; but there were many reversals in these data.     

Directional separation and the size cue to distance

Summary The effectiveness of the relative size cue to distance as a function of directional separation was investigated with the successive presentation of two luminous frames of the same shape but different visual angle. Either 0° or 180° of separation occurred between the successive presentations. In Exp. I the frames at 5 feet were viewed monocularly through a restrictive aperture. In Exp. II, the same frames were viewed monocularly through a lens such that the frames were at an accommodative distance of 100 feet. Reports of both the size and distance of the frames were obtained in each of the experiments. The results were analyzed in terms of the absolute size cue to distance occurring on the first presentations as well as the relative size cue to distance occurring between presentations. There was a tendency (not always statistically significant) to report the smaller frame at a farther distance than the larger frame, but only in Exp. II is there evidence that this tendency was greater on second than on first presentations. Therefore in Exp. II the relative size cue to distance was demonstrated to occur independently of the absolute size cue and it occurred at least as readily for the 180° as for the 0° separation between successive presentations. In both experiments the results from the size reports provide evidence for the presence of the relative size cue between successive presentations for both the 180° and 0° separations. It is concluded that the relative size cue is as effective when O must turn 180° to view the successive stimuli as when the successive stimuli are presented along the same line of sight. The procedure that is sometimes used of employing large directional separations in an attempt to avoid the relative size cue is, therefore, considered to be inappropriate. The results of the study were discussed in relation to a distinction between cognitive and perceptual processes in judgments of size and distance. Both the data of the present study and other results in the literature such as the size-distance paradox were analyzed in terms of a schema in which perceptual processes provided a basis for the rapid utilization of cognitive information.This investigation was supported by PHS Research Grant No. NS 08883, from the National Institute of Neurological Diseases and Strokes.     

Temporal processing and phonological impairment in dyslexia: effect of phoneme lengthening on order judgment of two consonants

The evidence of supporting phonological deficit as a cause of developmental dyslexia has been accumulating rapidly over the past 2 decades, yet the exact mechanisms underlying this deficit remain controversial. Some authors assume that a temporal processing deficit is the source of the phonological disorder observed in dyslexic children. Others maintain that the phonological deficit in dyslexia is basically linguistic, not acoustic, in nature. Three experiments were conducted and tested the impact of the temporal alteration and the impact of complex syllabic structure on consonant order judgments. Thirteen phonological dyslexics (age 10-13) and 10 controls matched for chronologial age were compared on a Temporal Order Judgment (TOJ) task using the succession of two consonants (/p/ /s/) within a cluster. In order to test the possible relevance of the temporal deficit hypothesis, the task also included two additional conditions where either the two stimuli were artificially slowed or two phonological structures were opposed (CCV and CVCV). As expected, the TOJ performance was significantly poorer in dyslexics than in controls. Moreover, in the "slowed speech" condition dyslexics' performance improved to reach the normal controls' level, whereas manipulating the phonological structure complexity provided no significant improvement. Finally dyslexics' performances, especially on the slowed condition, were found correlated with several tests of phonological processing. These results lend support to the general temporal deficit theory of dyslexia.     

幼儿心理理论与时序记忆的关系——来自时序记忆分离的证据

研究检验了时序记忆与心理理论的关系.实验一对39个3.5～5.5岁儿童的时序记忆能力以及心理理论表现进行测查,考察了因果关系、相关关系、无因果无相关关系三类不同性质的材料测得的时序记忆与心理理论的关系;90个儿童参与了实验二,通过正叙、倒叙、预叙三种叙述方式将时序记忆分离为理解性时序记忆和机械性时序记忆,再分别考察与心理理论的关系.结果发现,在不同性质的实验材料中,时序记忆与心理理论相关均不显著;5.5岁儿童的理解性时序记忆显著高于3.5岁儿童,4.5岁、5.5岁儿童的机械性时序记忆显著高于3.5岁儿童;只有理解性时序记忆能够预测儿童的心理理论成绩.     

Confidence intervals and sample size calculations for the standardized mean difference effect size between two normal populations under heteroscedasticity

The use of effect sizes and associated confidence intervals in all empirical research has been strongly emphasized by journal publication guidelines. To help advance theory and practice in the social sciences, this article describes an improved procedure for constructing confidence intervals of the standardized mean difference effect size between two independent normal populations with unknown and possibly unequal variances. The presented approach has advantages over the existing formula in both theoretical justification and computational simplicity. In addition, simulation results show that the suggested one- and two-sided confidence intervals are more accurate in achieving the nominal coverage probability. The proposed estimation method provides a feasible alternative to the most commonly used measure of Cohen’s d and the corresponding interval procedure when the assumption of homogeneous variances is not tenable. To further improve the potential applicability of the suggested methodology, the sample size procedures for precise interval estimation of the standardized mean difference are also delineated. The desired precision of a confidence interval is assessed with respect to the control of expected width and to the assurance probability of interval width within a designated value. Supplementary computer programs are developed to aid in the usefulness and implementation of the introduced techniques.     

从效应量应有的性质看中介效应量的合理性

效应量的作用有两个方面, 一是弥补了统计检验的不足, 二是使得效应有可比性。结合统计显著性和效应量, 才能得出适当的统计结论。效应量应当具有一些基本性质, 包括与测量单位无关、单调性、不受样本容量的影响。国际上流行的中介效应量κ平方就是因为缺乏单调性而引发质疑和研究, 从而被彻底终结了其作为中介效应量的合法性。R平方型中介效应量同样有缺乏单调性的问题。文末讨论了如何报告中介效应量以及有待研究的问题。     

An alternative to Cohen's standardized mean difference effect size: a robust parameter and confidence interval in the two independent groups case

The authors argue that a robust version of Cohen's effect size constructed by replacing population means with 20% trimmed means and the population standard deviation with the square root of a 20% Winsorized variance is a better measure of population separation than is Cohen's effect size. The authors investigated coverage probability for confidence intervals for the new effect size measure. The confidence intervals were constructed by using the noncentral t distribution and the percentile bootstrap. Over the range of distributions and effect sizes investigated in the study, coverage probability was better for the percentile bootstrap confidence interval.     

Measures of effect size

Two different approaches have been used to derive measures of effect size. One approach is based on the comparison of treatment means. The standardized mean difference is an appropriate measure of effect size when one is merely comparing two treatments, but there is no satisfactory analogue for comparing more than two treatments. The second approach is based on the proportion of variance in the dependent variable that is explained by the independent variable. Estimates have been proposed for both fixed-factor and random-factor designs, but their sampling properties are not well understood. Nevertheless, measures of effect size can allow quantitative comparisons to be made across different studies, and they can be a useful adjunct to more traditional outcome measures such as test statistics and significance levels.     

Dissociation of the distance effect and size effect in one-digit numbers

Magnitude comparison of single digits is robustly characterized by a distance effect (close numbers are more difficult to compare than numbers further apart) and a size effect (for a given distance, comparison difficulty increases with increasing size). The distance effect indicates access to the mental number line (Dehaene, 1997), and the size effect is usually interpreted as indicating that the mental number line represents larger numbers more vaguely than smaller ones. In contrast, we have argued earlier (Verguts, Fias, & Stevens, 2005) that for symbolic numbers (Arabic or verbal notation), the size effect does not originate from the mental number line but, instead, originates from mappings to relevant output components that are specific for magnitude comparison. If the latter is true, it should be possible to dissociate the distance effect from the size effect in tasks other than magnitude comparison. In two experiments, we observed a robust distance effect insame/different judgments, which implies access to the mental number line. Yet the size effect was absent. Consistent with our prediction, this finding establishes a dissociation between the size effect and the distance effect.     

Temporal changes in the affective experience of new fathers and their spouses

Our aim was to study temporal changes in fathers' affective experience during the first year of parenthood. For comparison, data also were collected from their spouses. Fifty‐five Israeli couples comprised the initial sample, and both partners were interviewed during the prepartum period and at 3, 6, and 12 months' postpartum. Measures of emotionality, positive affect, negative affect, and mood regarding self, infant, and spouse/marriage were derived by finely coding parents' answers to interview questions. Analyses show that, for fathers and mothers, time effects were most substantial between the prepartum period and 3 months postpartum, and most of the changes were in a positive direction. Fathers and mothers showed continuity in positive affect and in negative affect, respectively. Overall, the sample experienced heightened positive affect and more positive moods after the birth of their infant than prior to it.