Memory for sequences of tone bursts in the rat: Reliance on temporal cues and evidence for an instructional ambiguity explanation of the choose-few effect

Two groups of rats were trained in a symbolic delayed matching-to-sample task with a 0-s delay to discriminate sample stimuli that consisted of sequences of tone bursts. For one group, sequences varied in number with total sequence duration controlled. For the other group, total sequence duration, sum of the tone durations, and sum of the gap durations were all controlled. The former group of rats acquired the discrimination, but the latter group of rats were not able to learn the discrimination with the additional temporal cues controlled. Retention functions for the group that acquired the discrimination exhibited a choose-many bias at the 1-s delay and a choose-few bias at the 8-s delay regardless of the similarity in the intertrial interval and delay interval illumination condition. The asymmetrical retention functions appeared to be due to instructional ambiguity which resulted from the similarity of the delay interval to temporal features of the tone burst sequence, such as the gap between tone bursts and the total duration of tone. In Experiment 2, diagnostic tests provided evidence that rats discriminated the sequences of tone bursts by timing and summing the duration of individual tone bursts rather than using an event switch to count tones. Like pigeons, rats use multiple temporal features rather than number to discriminate sequences of successive events.     

Movement adaptations in 7- to 10-year-old typically developing children: evidence for a transition in feedback-based motor control

We used a modified double-step pointing task to study movement adaptations in 7- to 10-year-old typically developing children. We found that the majority (63%) were able to optimally adapt fast, goal-directed visually-guided movements to a late change in target location meeting the requirements of speed and accuracy. A minority (35%) failed to meet the requirement of accuracy resulting in a less optimal adaptation. The results showed that the ability to adapt movements optimally develops before the age of 7 years in typically developing children. Literature proposes a transition in development of motor control around the age of 8 years. The present results replicate and extend this by suggesting that this transition affects the later phases of fast, goal-directed visually-guided movements rather than the early phases, such as movement programming and acceleration. Finally, the results indicate that the optimally adapted movements were the result of a specific strategy in which a specific component of movement execution was slowed on all trials. This suggests that 7- to 10-year-old typically developing children have developed implicit knowledge about which movement components are the most efficient to adapt.     

Visual word recognition by bilinguals in a sentence context: evidence for nonselective lexical access

Recent research on bilingualism has shown that lexical access in visual word recognition by bilinguals is not selective with respect to language. In the present study, the authors investigated language-independent lexical access in bilinguals reading sentences, which constitutes a strong unilingual linguistic context. In the first experiment, Dutch-English bilinguals performing a 2nd language (L2) lexical decision task were faster to recognize identical and nonidentical cognate words (e.g., banaan-banana) presented in isolation than control words. A second experiment replicated this effect when the same set of cognates was presented as the final words of low-constraint sentences. In a third experiment that used eyetracking, the authors showed that early target reading time measures also yield cognate facilitation but only for identical cognates. These results suggest that a sentence context may influence, but does not nullify, cross-lingual lexical interactions during early visual word recognition by bilinguals.     

Pain-related correlates of MMPI profile subgroups among back pain patients

The MMPI profiles of 96 male and 218 female patients attending a back pain clinic in a private university-affiliated, orthopedic hospital were analyzed by a hierarchical clustering procedure. The clustering procedure produced four male and four female profile subgroups. The subgroups were compared with one another on the basis of patients' responses to the Cornell Medical Index and revised McGill Pain Assessment Questionnaire. Within the male and female patient cohorts it was found that profile subgroups featuring elevated clinical scales showed greater disruptions of daily activities than did subgroups with relatively unelevated profiles. However, profile subgroups with elevations primarily on the neurotic triad scales reported greater affective disturbance and disruption of daily activities than did subgroups with elevations on both the neurotic triad and relatively psychotic scales. In addition, profile subgroups with subclinical elevations on the neurotic triad scales appeared to have adjusted to their pain experience more poorly than did subgroups that featured scores on nearly all clinical scales that were within one standard deviation of the mean. Suggestions are provided for the use of the MMPI in assessing chronic pain patients and future research regarding cluster analyses of patients' MMPI profiles.     

Values and Justice as Predictors of Perceived Stress in Lebanese Organisational Settings

Research investigating predictors of stress perceptions in organisational settings has been extensive. Value incongruence between employees and the organisation as well as organisational justice (distributive, procedural, informational, and interpersonal) are thought to be significant predictors of organisational outcomes. The current study investigated value incongruence and organisational justice as predictors of perceived stress in a sample of 362 organisational employees in Beirut, Lebanon. Results indicated that incongruence on value types of benevolence, power, and self‐direction are weakly predictive of perceived stress, while perceptions of interpersonal and distributive injustice are strongly predictive of perceived stress in the Lebanese organisational context. Implications of these differential findings for organisational and cross‐cultural research are discussed. Nombreuses ont été les recherches sur les prédicteurs du vécu du stress dans les organisations. La contradiction des valeurs des salariés et de l'organisation ainsi que la justice organisationnelle (distributive, procédurale, informationnelle et interpersonnelle) sont considérées comme étant des prédicteurs efficaces des réalités organisationnelles. Ce travail porte sur l'incohérence des valeurs et la justice organisationnelle en tant que prédicteurs du stress ressenti dans un échantillon de 362 salariés de Beyrouth (Liban). Les résultats montrent que des contradictions sur des valeurs comme la bienveillance, le pouvoir et l'autonomie sont peu prédictives du stress perçu, tandis que la perception des injustices interpersonnelle et distributive est fortement prédictive du stress ressenti dans le contexte organisationnel libanais. On discute des retombées de ces résultats différentiels sur les travaux organisationnels et transculturels.