The word-superiority effect under conditions that approximate reading

Observers detected a briefly flashed target letter embedded in word, pronounceable nonword, and unpronounceable nonword contexts. The word context facilitated perception under both holistic and analytical processing strategies; the facilitative effect was enhanced when processing was analytical.     

Development of organization in recall: A stages-of-learning analysis

An experiment is reported in which the effects of taxonomic organization on 7-year-old and 11-year-old children's free and cued recall of two- and four-category lists were examined. The data were analyzed using a stages-of-learning model that simultaneously delivers estimates of the impact of these manipulations on storage and retrieval components of recall. The results indicated that for the Grade 2 children providing a category label at the time of recall primarily enhanced storage whereas increasing the number of categories primarily enhanced retrieval. For Grade 6 children, on the other hand, the use of category labels to cue recall primarily enhanced retrieval, whereas increasing the number of categories affected both storage and retrieval in free recall, but only retrieval in cued recall. In addition, while older children were superior to younger children at both storing and retrieving information, age differences at retrieval were generally larger than those at storage.     

Technology and the structuring of jobs: Employee satisfaction,performance, and influence

This research investigated the relationships between technology, interdependence, job characteristics, and employee satisfaction, performance, and influence. Technology was operationalized at the individual level of analysis to include the dimensions of input uncertainty, conversion uncertainty, and output uncertainty. Pooled, sequential, and reciprocal interdependence was assessed. The results indicated that input and conversion uncertainty and interdependence were strongly related to such job characteristics as autonomy, skill variety, task identity, task significance, and task feedback. While the job characteristics related positively to employee satisfaction, input and conversion uncertainty related negatively to satisfaction, thus creating a mutual suppression effect. Although the uncertainty dimensions did not relate significantly to performance, there is some evidence that this negative relationship was being suppressed by the positive relationship between job characteristics and performance. Both the job characteristics and the technology dimensions related positively to influence. Results were discussed in terms of appropriate matches between technology and job characteristics.     

Stimulus control of free-operant avoidance: The contribution of response rate and incentive relations between multiple-schedule components

The associations formed in the components of a multiple schedule can be classified as (1) stimulus-response (S-R) associations and (2) stimulus-reinforcer (S-S^R) associations. The present experiments sought to determine the individual contribution of these S-R and S-S^R associations to stimulus control by manipulating them independently. Responses postponed shocks by 25 sec in the presence of a tone alone and a light alone in all experiments. The contingencies programmed in the absence of both tone and light established a reference for the S-R and S-S^R associations in tone and in light. All four possible combinations of signalling response increase or decrease together with incentive increase or decrease were studied. Although the influence of the contingencies operating in the absence of tone and light was difficult to detect from response rates in tone or light, presenting tone and light together revealed clear effects. Response rates in tone and light together relative to those in either alone depended upon the contingency operating in the absence of tone and light. Stimulus-response and stimulus-reinforcer associations appeared to counteract each other when in opposition and combine together to enhance each other when in agreement. This suggested that the associations of a stimulus to response and to incentive combine algebraically in determining stimulus control. An algebraic analysis in terms of the S-R and S-S^R associations conditioned to the stimulus elements comprising the training and test stimuli accounted for the observed patterns of data.     

Effect of sample presentation time on long-delay matching in the pigeon

The effect of sample stimulus presentation time on long-delay matching in highly practiced pigeons was investigated. The birds were found capable of above chance matching performance at a delay of 60 sec provided the sample stimulus was presented for 4 sec or longer. Matching accuracy increased as a negatively accelerated function of sample stimulus presentation time and decreased as a negatively accelerated function of time since the termination of the sample. The rate of forgetting was found to be independent of sample stimulus presentation time. The data were inconsistent with a temporal discrimination interpretation of the effect of presentation time on delayed matching. The data were interpreted as supporting a simple trace strength and decay model of pigeon delayed matching.     

Effects of schedule and magnitude of reinforcement under conditions of thirst motivation

In contrast to a recent finding (Macdonald, G. E., & De Toledo, L. Learning and Motivation, 1974, 5, 288–298.) the results of three experiments investigating various partial reinforcement (PRF) manipulations under conditions of thirst motivation demonstrated strong similarity to analogous manipulations involving food reward. Specifically, for animals receiving water reinforcement, PRF was shown to generate greater resistance to extinction than continuous reinforcement (Expt 1 & 3), the schedule of reinforcement was shown to interact with level of acquisition (Expt 1 and 2), and the magnitude of the partial reinforcement extinction effect was shown to be a function of reward magnitude (Expt 3). These results provide strong evidence that mechanisms which operate in partial reinforcement situations are highly similar, regardless of the type of appetitive reinforcement.     

Startbox-goalbox confinement durations as determinants of self-punitive behavior

Two levels of confinement duration (5 or 60 sec) in either startbox or goalbox were factorially combined with presence or absence of shock during extinction of a runway escape response in a self-punitive paradigm under a spaced-trials procedure. All groups were equated for amount and temporal spacing of handling before and after each trial. Shocked rats were more resistant to extinction than nonshocked rats only when startbox confinement was short. When startbox confinement was long, shock facilitated extinction. Long goalbox confinement enhanced running speed for shocked rats, but only in the presence of shock. It was suggested that duration of startbox confinement affects strength of conditioned fear, with long confinement leading to its extinction.     

The temporal dynamics of first versus second language production

In this study we explored the temporal origin of processing differences between first and second language production. Forty highly proficient bilinguals named objects of high and low lexical frequency aloud for both L1 and L2 separately while event-related brain potentials (ERPs) were recorded. The first electrophysiological differences elicited by response language occurred at the same early P2 peak (∼140–220 ms) where we observed the onset of the lexical frequency effect, but only for those bilinguals who started naming in an L1 context and afterwards switched to an L2 naming context. The bilinguals who named objects in the reverse direction did not display a language effect in the ERPs. Taken together, the data show that the L2 naming disadvantage originates during the onset of lexical access and seems to be driven by both representational strength, which is lower for L2 words, and language control demands, which are higher for L2 words.     

Categorization of two-dimensional and three-dimensional stimuli by 18-month-old infants

In two experiments, 18-month-old infants’ categorization of 3D replicas and 2D photographs of the same animals and vehicles were compared to explore infants’ flexibility in categorization across different object representations. Using a sequential touching procedure, infants completed one superordinate and two basic-level categorization tasks with 3D replicas, 2D cut out photographs, or 2D images on photo cubes (“2D cubes”). For superordinate sets, 3D replicas elicited longer mean run lengths than 2D cut outs, and 3D replicas elicited equivalent mean run lengths as 2D cubes. For basic-level sets, infants categorized high-contrast animal sets when presented with 3D replicas, but they failed to categorize any of the 2D photograph sets. Categorization processes appear to differ for 3D and 2D stimuli, and infants’ discovery of object properties over time while manipulating objects may facilitate categorization, as least at the superordinate level. These findings are discussed in the context of infants’ representation abilities and the integration of perception and action.     

阿卡波糖、二甲双胍联合胰岛素类似物治疗肥胖糖尿病短期疗效

观察阿卡波糖、二甲双胍联合胰岛素类似物治疗肥胖2型糖尿病的短期疗效。将60例符合标准患者随机分为观察组和对照组各30例,均给予重组甘精胰岛素联合赖脯胰岛素强化治疗控制血糖,观察组同时给予阿卡波糖及二甲双胍口服,出院时进行疗效评价。观察组血糖达标时间、胰岛素用量少于对照组,餐时胰岛素停用比例大于对照组,差异有统计学意义（P＜0．05）;两组患者出院时体重较入院时均有所下降,观察组较对照组体重变化更明显（P＜0．01）。阿卡波糖、二甲双胍联合胰岛素类似物治疗方案,可作为初诊肥胖2型糖尿病治疗的理想方法之一。