Rat choice in rapidly changing concurrent schedules

In two experiments, experimentally naïve rats were trained in concurrent variable‐interval schedules in which the reinforcer ratios changed daily according to a pseudorandom binary sequence. In Experiment 1, relative response rates showed clear sensitivity to current‐session reinforcer ratios, but not to previous sessions' reinforcer ratios. Within sessions, sensitivity to the current session's reinforcement rates increased steadily, and by session end, response ratios approached matching to the current‐session reinforcer ratios. Across sessions, sensitivity to the current session's reinforcer ratio decreased with continued exposure to the pseudorandom binary sequence, contrary to expectations based on previous studies demonstrating learning sets. Using a second group of naïve rats, Experiment 2 replicated the main results from Experiment 1 and showed that although there were increases over sessions in both changeover rate and response rate during the changeover delay, neither could explain the accompanying reductions in sensitivity. We consider the role of reinforcement history, showing that our results can be simulated using two separate representations, one local and one nonlocal, but a more complex approach will be needed to bring together these results and other history effects such as learning sets and spontaneous recovery.     

Can we see syllables in monosyllabic words? A study with illusory conjunctions

Mathey, Zagar, Doignon, and Seigneuric (2006) reported an inhibitory effect of syllabic neighbourhood in monosyllabic French words suggesting that syllable units mediate the access to lexical representations of monosyllabic stimuli. Two experiments were conducted to investigate the perception of syllable units in monosyllabic stimuli. The illusory conjunction paradigm was used to examine perceptual groupings of letters. Experiment 1 showed that potential syllables in monosyllabic French words (e.g., BI in BICHE) affected the pattern of illusory conjunctions. Experiment 2 indicated that the perceptual parsing in monosyllabic items was due to syllable information and orthographic redundancy. The implications of the data are discussed for visual word recognition processes in an interactive activation model incorporating syllable units and connected adjacent letters (IAS; Mathey et al., 2006).     

Predicting stress patterns in an unpredictable stress language: The use of non-lexical sources of evidence for stress assignment in Russian

The main goal of this research was to examine how readers of Russian assign stress to disyllabic words. In particular, we tested the claim that the process of stress assignment in Russian can only be accomplished lexically. Eleven potential non-lexical sources of evidence for stress in Russian were examined in regression and factorial studies. In Study 1, onset complexity, coda complexity, the orthography of the first syllable (CVC1), of the second syllable (CVC2), and of the ending of the second syllable (VC2) were found to be probabilistically associated with stress in Russian disyllables. In Studies 2 and 3, it was shown that Russian speakers do use 3 of these cues (CVC1, CVC2, and VC2) when making stress-assignment decisions. These results provide evidence against the idea that the nature of stress in the Russian language is so unpredictable that stress assignment can only be accomplished lexically. These results also suggest that any successful model of stress assignment in Russian needs to contain mechanisms allowing these 3 orthographic cues to play a role in the stress-assignment process.     

An L1-script-transfer-effect fallacy: a rejoinder to Wang et al. (2003)

Do different L1 (first language) writing systems differentially affect word identification in English as a second language (ESL)? Wang, Koda, and Perfetti [Cognition 87 (2003) 129] answered yes by examining Chinese students with a logographic L1 background and Korean students with an alphabetic L1 background for their phonological and orthographic processing skills on English word identification. Such a conclusion is premature, however. We propose that the L1 phonological system (rather than the L1 writing system) of the learner largely accounts for cognitive processes in learning to read a second language (L2).     

From Environmental Factors to Outcomes: A Test of an Integrated Motivational Sequence

Research based on self-determination theory (SDT; E. L. Deci & R. M. Ryan, 1985, 2000) has shown that motivation is influenced by the social environment and also leads to outcomes. Based on such research, R. J. Vallerand (1997) has posited the existence at different levels of generality of an integrated motivational sequence where environmental factors (e.g., success/failure) influence perceptions of competence, autonomy, and relatedness (psychological mediators), which in turn determine to what extent one exhibits self-determined motivation. Motivation then leads to outcomes. The present study tested the validity of this integrated sequence at the situational level using an experimental design. Participants (N = 359) were randomly assigned to conditions of success or failure on a leisure task and elements of the integrated sequence were assessed. Structural equation modeling analyses provided support for the postulated motivational sequence. Results are discussed in light of SDT.This research was supported by grants and fellowships from the Fonds pour la formation de chercheurs et laide à la recherche (FCAR) and the Social Sciences Humanities Research Council of Canada (SSHRC) to Robert J. Vallerand. We would like to thank Sandrine Passelaigue for her help in collecting the data.     

Sublexical and morphological information in speech processing

Three experiments investigated the impact of syllabic boundary information and of morphological structure on performance in a sequence-monitoring task. In sequence monitoring, participants detect pre-specified sequences of phonemes in spoken carrier words. Sequences corresponded to the first syllable of the carrier word, to its first morpheme, or simultaneously to both. The data from Experiments 1 and 2, using different variants of the monitoring task, showed a strong impact of syllable boundary cues on monitoring latencies. An effect of morphological match between targets and carrier words was also evident. Experiment 3, in which parts of the spoken carrier words were cross-spliced, revealed that syllabic boundary information takes precedence over morphological information. The results are in line with an early process of speech processing, in which syllabic cues are used to aid lexical access. The morphological effect is better understood as a later, probably lexical, contribution of morphological decomposition to monitoring performance.     

Effects of High-Probability Request Sequences on Preschoolers' Compliance and Disruptive Behavior

A high-probability request sequence was implemented with three preschool children with developmental delays within their classroom during typical activities. A multiple baseline design across subjects was used to evaluate the effects of the high-probability request sequence on compliant responding to low-probability requests and the occurrence of disruptive behavior. Results of the study indicate that the use of the high-probability request sequence was effective in increasing compliant responding to low-probability requests delivered by two different trainers for all children. No increases in disruptive behavior were noted as a result of using the high-probability request sequence. When the high-probability request sequence was withdrawn, compliant responding to low-probability requests was maintained for all children across time and in different settings.     

Responding under sequence schedules of electric shock presentation

Lever pressing by squirrel monkeys was examined under second-order schedules of electric shock presentation in which different discriminative stimuli were associated with consecutive components (sequence schedules). Components were always two-minute fixed-interval schedules, and three different overall schedules were studied. Under an overall eight-minute fixed-interval schedule, the first component completion after at least eight minutes had elapsed produced electric shock. The number of components actually completed ranged from one to four; thus, different discriminative stimuli were occasionally associated with electric shock presentation. Under an overall “yoked” variable-ratio schedule, electric shock was presented after completion of a variable number of components; the required number and the distribution of components were matched to those obtained under the overall eight-minute fixed-interval schedule. Under an overall fixed-ratio schedule, electric shock was presented after completion of four components (chained schedule). Under all three sequence schedules, responding in early components was characterized by a pause followed by a single response after the end of the two-minute interval; responding in later components was characterized by a shorter pause followed by positively accelerated responding. Manipulation of overall schedules of shock presentation in these complex behavioral situations produced changes in responding comparable to those ordinarily obtained after similar manipulation of dependencies under both single and second-order schedules of food presentation. These experiments extend the range of conditions and levels of complexity under which responding can be maintained by presentation of electric shock.     

Subtask analysis of process data through a predictive model

Response process data collected from human–computer interactive items contain detailed information about respondents' behavioural patterns and cognitive processes. Such data are valuable sources for analysing respondents' problem-solving strategies. However, the irregular data format and the complex structure make standard statistical tools difficult to apply. This article develops a computationally efficient method for exploratory analysis of such process data. The new approach segments a lengthy individual process into a sequence of short subprocesses to achieve complexity reduction, easy clustering and meaningful interpretation. Each subprocess is considered a subtask. The segmentation is based on sequential action predictability using a parsimonious predictive model combined with the Shannon entropy. Simulation studies are conducted to assess the performance of the new method. We use a case study of PIAAC 2012 to demonstrate how exploratory analysis for process data can be carried out with the new approach.     

构建病人自主择医的现代医学伦理观

“病人选择医生”这一重大改革举措可以得到病人自主择医权和改革实践的有力辩护与支持,同时,为使其形成有序合理格局,并进入可持续发展的正常轨道,也亟需以解决现实重大问题为基础,着力的构建病人自主择医权的现代医学伦理观。这个医学伦理观应由现代的伦理理念框架1管理伦理框架、程序伦理框架构筑成主体框架。