Repeated priming increases memory accessibility in infants

In previous research on priming (reactivation) with 3-month-olds, two primes recovered a forgotten memory faster than one, suggesting that prior priming had increased the accessibility of the forgotten memory. Exploiting the fact that the minimum duration of a prime indexes the accessibility of the forgotten memory, we currently examined whether prior priming also reduces the minimum effective prime duration. In three experiments, 60 3-month-olds learned an operant task, forgot it, and then were exposed to successive primes either 1 day and 1 week after forgetting (Experiment 1) or 1 and 2 weeks after forgetting (Experiment 2). In both cases, prior priming reduced the minimum duration of the second prime, a result that was independent of the duration of the first prime (Experiment 3). These findings confirm that priming increases the accessibility of a latent memory and raise the possibility that repeated priming underlies the extended memorability of persons and events that infants encounter sporadically.     

Sequential responding to arabic numerals with wild cards by the chimpanzee (Pan troglodytes)

One adult female chimpanzee (Pan troglodytes) was trained to respond serially to three arabic numerals between 1 and 9, presented on a cathode-ray-tube (CRT) screen. To examine the factors affecting her sequential responding behavior, wild-card items were added to the three-item sequences. When this wild-card item remained until the subject responded to the last numeral (i.e., the terminator condition), her response to the terminator at each point of the sequence was controlled by the ordinal distance between numerals. Thus, the number of responses to the terminator increased as the ordinal distance between numerals increased. When the wild-card item was eliminated by the subject’s response (wild-card conditions), the probability of responses to the wild card before the first numeral increased as a function of the serial position of the first numeral. These results were consistent with previous studies of response time and suggest both serial position and symbolic distance effects. It is suggested that the subject might form the integrated 9-item linear representations by training of possible subsets of three-item sequences. Knowledge concerning the ordinal position of each numeral was established through this training. Received: 27 October 1999 / Accepted: 22 November 1999     

Unambiguous generalization effects after treatment of non-canonical sentence production in German agrammatism

Agrammatism is-among others, characterized by a deficit in producing grammatical structures. Of specific difficulty is the utilization of complex, non-canonical sentence structures (e.g. object-questions, passives, object-clefts). Several studies have documented positive effects when applying a specific treatment protocol in terms of increasingly correct production of target complex sentence structures with some variance in generalization patterns noted across individuals. The objective of this intervention study was to evaluate an intervention program focussing on the production of non-canonical sentences. Hypotheses about the occurrence of treatment effects were formulated on the basis of syntactic complexity, referring to the amount of syntactic phrase structures necessary to generate specific German sentence structures. A multiple single case study with seven agrammatic participants was applied, each participant receiving training in the production of object-relative-clauses and who-questions. The investigation was designed to unambiguously evaluate for each individual, structure specific and generalized learning effects with respect to the production of object-relative-clauses, who-questions and passive sentences. Results showed significant improvements for all sentences types. This outcome is considered within methodological issues of treatment studies. Theoretical and clinical implications are discussed.     

不同阅读过程文章信息保持特点的实验研究

本研究主要探讨在自然的阅读与有特定的记忆任务的情况下,学生阅读记忆的特点.从某中学、小学选取高中二年级、初中二年级与小学六年级学生各60人进行实验研究.结果表明,在自然阅读文章的情况下,一般读者所进行的主要是运算性的信息加工活动,是一种筛选保持的过程,服从于中心效应;而在明确的记忆要求下,读者所进行的主要是联结性的信息加工活动,是一种一般的意义记忆过程,服从于首尾效应。     

Effects of thematic and lexical priming on readers' eye movements

The study was inspired by Ehrlich & Rayner (1981). In the study semantic context effects were investigated during on-line discourse processing. Readers' eye movements were registered to see whether words that were semantically closely related to the global theme of the text were read faster than words that did not have any apparent semantic link to the discourse theme. In addition, lexical priming was examined by presenting an identity prime earlier in the text. The results showed that non-thematic words were regressed to more often than thematic words. Regressions were typically initiated after reaching a clause or sentence boundary. Regressions were thus assumed to be made in order to integrate non-thematic words into the previous context. Modest negative correlations were found between word's fixation time and its relative predictability. No effects of lexical priming were observed. It was concluded that moderately constraining discourse contexts produce negligible effects on word recognition.     

Gentled and non-handled rats in a stressful open-field situation; differences in performance

Open-field behaviour of individually gentled and non-handled adult Wistar rats in a stressful test situation (loud noise with bright light) was studied. The behaviour on the whole of the two groups differed significantly. While the gentled rats showed mainly signs of stress and explorativity, signs of fear beside stress and, on later trials, explorativity were typical of the non-handled animals. On later trials the behaviour of the non-handled rats neared to that of the gentled ones. In the behaviour of the gentled rats there was but little change as a function of trials. We suggest that individual gentling, beside minimizing fear of human contact, also increases the stability of the rat's reactions.     

Reading strategy modulates parafoveal-on-foveal effects in sentence reading

Task demands and individual differences have been linked reliably to word skipping during reading. Such differences in fixation probability may imply a selection effect for multivariate analyses of eye-movement corpora if selection effects correlate with word properties of skipped words. For example, with fewer fixations on short and highly frequent words the power to detect parafoveal-on-foveal effects is reduced. We demonstrate that increasing the fixation probability on function words with a manipulation of the expected difficulty and frequency of questions reduces an age difference in skipping probability (i.e., old adults become comparable to young adults) and helps to uncover significant parafoveal-on-foveal effects in this group of old adults. We discuss implications for the comparison of results of eye-movement research based on multivariate analysis of corpus data with those from display-contingent manipulations of target words.     

Contributors to this issue

Judith Hubback
Roman Lesmeister
Wendy Wyman-McGinty
Hester McFarland Solomon
Elizabeth Urban
Barbara Wharton