Sequential analysis of visual habituation in preschool children

The study breaks down the data from a preschool (mean age of students, 63 months) visual habituation experiment using a second-by-second analysis of the entire process, including fixation time and onsets for habituation and recovery trials and for each intertrial interval. The results parallel those suggested by Cohen, DeLoach, and Rissman (Child Development, 1975, 46, 611–617), for infants and are described using a two-process model of visual attention.     

An experimental analysis of social traps

Social traps, such as the overgrazing of pasturelands, overpopulation, and the extinction of species, are situations where individuals in a group respond for their own advantage in a manner damaging to the group. A laboratory analog was devised to simulate conditions that produce social traps. The traps were constructed by superimposing schedules of reinforcement. Single responses were followed by multiple consequences which were opposite in valence, with the negative consequence delayed. Subjects in groups of three could respond individually for points that applied toward class credit. Each ten presses of a button added one point to the subject's total and subtracted one point from a common pool. The pool was replenished with points at fixed rates. If subjects responded for points faster than the replenishment rates, the pool would empty and the experiment would terminate before subjects could accumulate maximum credit. In addition, the maximum pool size and the ability to communicate were varied. Main effects were found for both, which indicated the least effective resource management occurred when the pool was small and no communication allowed. An analysis of cumulative records showed differing response patterns across conditions.     

Transfer of oddity-from-sample performance in pigeons

Four pigeons were trained on a modified three-key oddity-from-sample task in which an observing response to the sample (center-key) stimulus lighted a single comparison (side-key) stimulus. If the comparison stimulus was different from the sample stimulus, a single peck to the lighted comparison was reinforced. If the comparison and sample stimuli were identical, the pigeons had to refrain from pecking the comparison for 4.6 seconds to terminate the matching comparison and to produce immediately a nonmatching comparison on the remaining side key. Each peck to the matching comparison reset the 4.6-second delay interval. Three hues were used during acquisition. During tests for transfer of the oddity performance, two novel hues were substituted either individually or together for one or two of the original training hues. For three birds, latencies to novel nonmatching hues were identical to baseline nonmatching latencies. Latencies to novel matching hues were shorter than baseline matching latencies but were consistently longer than novel nonmatching latencies. These transfer data demonstrate that the pigeons learned the oddity concept.     

Extinction after aversive conditioning: An associative or nonassociative process?

A series of three eyelid-conditioning experiments with rabbits examined the traditional extinction procedure in which the CS is presented in the absence of US presentations. The first study employed a savings test to demonstrate that the rate of reacquisition is faster after a conventional extinction procedure than after a procedure in which the CS and US have been unpaired. The second experiment indicated that this readiness to respond in reacquisition was related to a carry-over effect from the initial acquisition trials. The third study demonstrated that acquisition and reacquisition are similar when the US is maintained in extinction but not when it is omitted. These results imply that procedures which retain the US during extinction are more effective than the conventional CS-alone extinction procedure in eliminating or inhibiting the associative connection between the CS and the US.     

Training strategic study time apportionment in educable retarded children

Two groups of educable retarded children differing in functioning level served as subjects. One group, the High group, consisted of 31 children drawn from the upper two classes of a five-class stream. The Low group consisted of 39 children drawn from the lowest two classes. During pretesting, on each trial but the first of a multitrial free recall procedure, subjects were allowed to select half of the to-be-remembered items to see if they would strategically select missed items for extra study. Following pretesting, subjects were divided for training into three groups for which the experimenter selected items for study: in the Standard group, missed items; in the Creeping group, recalled items plus one missed item; and in the Random group, half missed and half recalled items. Children in the High group improved in the Standard condition, and those in the Low group benefited from Creeping training. There was no evidence of maintenance of training in the Low group, but children in the High group given training in the standard strategy selected missed items for recall on the posttests. The results are discussed in terms of the stability of trained strategies in retardates, and the question of what constitutes an optimal strategy is considered.     

The interaction of locus of control expectancies and providing purpose on children's motivation

Children differing in locus of control orientation (internals, mediums, and externals' were administered an extended coding task following either a fictional rationale for the study (purpose incentive statement) or no purpose. As predicted, externals' performance under no purpose was significantly poorer and their rated interest in the task was significantly less favorable than those of internals. Also as predicted, these differences were nullified under the purpose incentive condition. The findings extend Lefcourt's (1967) suggestion that cue explication is important for externals to include external children, and support the position (Mischel, 1973; Rotter, 1975) that personality variables are increasingly important as a function of greater situational ambiguity. Implications of these findings for education and child-rearing are discussed.     

发音人和语境变异与声调知觉

本文用Garner快速分类法研究了发音人规范化和语境补偿过程与声调知觉的关系。得到的主要结果是:(1)发音人变化对声调识别产生了显著的Gar-ner干扰;声调变化对男女声判别产生了同样的十扰。(2)语境变化对声调识别也产生了显著的Garner干扰。按照Garner方法的假设,这说明发音人规范化和语境变异补偿与声调识别之问是相互联系和相互影响的。(3)虽然发音人和语境同时变化引起的声调识别反应时延长约等于它们单独变化时反应时延长量之和,但正确率下降远大于单独变化时下降量之和。说明发音人和语境变异对声调识别的干扰不是独立的,它们之间存在相互作用。这种作用增加了声调识别的难度。     

儿童最初词汇的获得及其过程

本文追踪研究了两名儿童获得最初词汇的过程。结果表明:在儿童最初语音发展过程中,所发出的音节日益丰富、分化,产生了连续音节,随意性和指向性逐渐增强。儿童获得最初词汇的过程,是连续音节逐渐被有指向的词取代的过程。根据连续音节和有指向的词的比例及沟通作用的变化,儿童获得最初词汇的过程可分为各具特点的三个阶段。两名儿童的最初词汇在其词类构成和功能意义上具有很高的一致性。结合两名儿童之间的个别差异,本文还初步探讨影响儿童获得最初词汇的因素——言语中枢和言语器官的发展、认知的发展,并探讨它们之间可能存在的相互关系。     

The effects of schedule history and the opportunity for adjunctive responding on behavior during a fixed-interval schedule of reinforcement.

The effects of schedule history and the availability of an adjunctive response (polydipsia) on fixed-interval schedule performance were investigated. Two rats first pressed levers under a schedule of food reinforcement with an interresponse time greater than 11 s, and 2 others responded under a fixed-ratio 40 schedule. All 4 were then exposed to a fixed-interval 15-s schedule. Water was continuously available under these conditions, but after responding became stable on the fixed-interval schedule, access was experimentally manipulated. With water freely available, subjects did not display characteristic fixed-interval response rates and patterns (i.e., scalloping or break-and-run). Instead, they exhibited predictable, stable patterns of behavior as a function of their schedule histories: Subjects with the interresponse-time history exhibited low response rates, and those with the fixed-ratio history exhibited high rates. Manipulating the amount of water available resulted in marked changes in response rates for rats with the interresponse-time history but not for those with the fixed-ratio history. The results illustrate the multiple causation of behavior by its previous and current schedules of reinforcement and other concurrent factors.