Why does memory span increase with age?

Ordered recall of auditory digits was obtained from children of 4, 7, 9, and 11 years of age. Lists had one of three types of sound pattern: melody, prosody, or monotone. For each sound pattern condition, half the lists were temporally grouped. Effects of sound pattern were minor, and not obviously age-specific. Profound effects of temporal grouping and clear-cut primacy effects appeared for all age groups and all conditions. These results render less plausible the popular hypothesis that the increase of memory span with age is due to the emergence of active strategies. It is suggested that the development of span may be due to an increase in the ease with which children can identify the individual items and encode information about their order.     

Discrimination learning and stimulus generalization by impulsive and reflective children

The proposition that impulsive children inhibit expressive behavior less than reflective children was investigated by providing third grade impulsive and reflective boys with either differential or nondifferential forms or successive discrimination training prior to tests for stimulus generalization. Consistent with specific predictions derived from Spence's theory on the roles of excitation and inhibition, it was found that: (a) Reflectives acquired the discrimination more rapidly, (b) reflectives achieved a higher level of discriminative performance, (c) impulsives exhibited more variable response reates during the nonreinforced stimulus, and (d) the type of training interacted with the child's conceptual tempo to determine the elevation and shape of the post-discrimination generalization gradients. The results provide support for the construct validity of the Matching Familiar Figures Test of reflectivity-impulsivity.     

Monaural right-ear advantage in a target-identification task

Subjects were monaurally presented with consonant—vowel syllables to the right or left ear, with or without simultaneous noise to the other ear. The subject's task on each trial was to indicate whether or not the item presented was the target item /ba/. A right-ear advantage in reaction time was obtained: 14 msec for target items, 6 msec for nontarget items. The size of this effect was comparable in the presence vs. absence of competing noise. No consistent individual differences were found in the size of the right-ear advantage for this task, although such differences were obtained in a dichotic-perception pretest.It is argued that data of this type do not permit inferences about the use of particular ear/hemisphere neural pathways.     

17α-羟化酶缺陷症2例报告及文献总结

17α-羟化酶缺陷症（17α-OHD）是先天性肾上腺皮质增生症（CAH）的一种罕见类型,很容易漏诊和误诊。17α-OHD是一种常染色体隐性遗传性疾病,可导致糖皮质激素合成减少,促肾上腺皮质激素增多;性腺激素合成减少,而促性腺激素反馈性增高,同时可伴有盐皮质激素水平的升高。对该疾病的早期诊断非常重要,早期诊断并予以激素替代治疗对提高患者生活质量有很大帮助。现报道2例我科17α-OHD的诊治经过,以提高对本病的认识。     

Continuum modeling of the reverse Hall–Petch effect in nanocrystalline metals under uniaxial tension: how many grains in a finite element model?

Owing to their very high strength, nanocrystalline metals have been extensively studied over the recent years. The direct Hall–Petch law, empirically proportioning the material strength to the inverse square root of its grain size has been shown to break down below a grain size of the order of tenths of nanometers. This phenomenon has been widely rationalized as a gradual switch from intragrain mediated deformation mechanisms to grain boundary mediated deformation mechanisms. This transition has been observed in many finite element simulations, despite the intrinsic restriction of necessarily limiting the nanocrystalline representative assembly to only a few grains. Such a limitation is generally overlooked, and its influence on an uniaxial tension test – when compared to a complete sample of millions of grains – ignored. We propose here to quantify the approximation done by considering a finite number of grains by means of a simple analytical model based on the early work of Stevens [R.N. Stevens, Philos. Mag. 23 (1971) p. 265]. The finite element approximation is demonstrated to be relatively good, even down to only three grains in width, and a method to “correct” the stress-strain curves of small representative volumes is proposed.     

Revisions and Regret: The Cost of Changing your Mind

Decision reversals often imply improved decisions. Yet, people show a strong resistance against changing their minds. These are well‐established findings, which suggest that changed decisions carry a subjective cost, perhaps by being more strongly regretted. Three studies were conducted to explore participants' regret when making reversible decisions and to test the hypothesis that changing one's mind will increase post‐outcome regret. The first two studies employed the Ultimatum game and the Trust game. The third study used a variant of the Monty Hall problem. All games were conducted by individual participants playing interactively against a computer. The outcomes were designed to capture a common characteristic of real‐life decisions: they varied from rather negative to fairly positive, and for every outcome, it was possible to imagine both more and less profitable outcomes. In all experiments, those who changed their minds reported much stronger post‐outcome regret than those who did not change, even if the final outcomes were equally good (Experiments 2 and 3) or better (Experiment 1).This finding was not because of individual differences with respect to gender, tendency to regret, or tendency to maximize. Previous studies have found that those who change from a correct to wrong option regret more than those who select a wrong option directly. This study indicates that this finding is a special case of a more general phenomenon: changing one's mind seems to come with a cost, even when one ends up with favorable outcomes. Copyright © 2011 John Wiley & Sons, Ltd.     

A randomised Monty Hall experiment: The positive effect of conditional frequency feedback

The Monty Hall dilemma (MHD) is a notorious probability problem with a counterintuitive solution. There is a strong tendency to stay with the initial choice, despite the fact that switching doubles the probability of winning. The current randomised experiment investigates whether feedback in a series of trials improves behavioural performance on the MHD and increases the level of understanding of the problem. Feedback was either conditional or non-conditional, and was given either in frequency format or in percentage format. Results show that people learn to switch most when receiving conditional feedback in frequency format. However, problem understanding does not improve as a consequence of receiving feedback. Our study confirms the dissociation between behavioural performance on the MHD, on one hand, and actual understanding of the MHD, on the other. We discuss how this dissociation can be understood.     

Describing organizations as reinforcer systems: A new use for job satisfaction and employee attitude surveys

Job satisfaction data on managerial personnel were used to illustrate how organizations can be differentiated and described as reinforcer systems. Twenty-seven specific satisfaction scales were regressed on overall job satisfaction, separately for each of five groups of managers from five organizations. For all groups, overall satisfaction was found to be determined mainly by scales concerning challenge of the job and prospects of one's chosen career. Application of decremental stepwise multiple regression procedures to obtain minimum-variable-set equations resulted in different, though overlapping, sets of variables in the equations for the different organizations. These results suggest a way of describing organizations as reinforcer systems, in terms of the specific determinants of overall satisfaction for the organization.     

A multivariate investigation of the reinforcer structure of occupations

Earlier research based on 81 Occupational Reinforcer Patterns (ORPs) suggested a nine-category classification of occupations. The present research, based on 148 ORPs, investigated the ability of that classificatory system to assimilate new information. Cluster analysis of the 148 ORPs yielded an eight-category classification of occupations in which five of the original occupational clusters appeared virtually unchanged; the other four original clusters were combined into two occupational clusters. One new cluster was identified. Principal factors analysis was employed to study the factor structure of the occupational reinforcers and to highlight the essential nature of the classificatory system. Five reinforcer factors were identified.