In situ characterization of the martensitic transformation temperature of NiTi shape memory alloys via instrumented microindentation

A novel, instrumented microindentation technique was successfully used to measure the temperature associated with the martensitic transformation leading to the recovery of plastic strain in a Nickel–Titanium (NiTi) shape memory alloy. Following a standard indentation cycle, the indenter was partially unloaded such that a good contact was maintained between indenter and specimen surface. The onset and finish temperature of the martensitic transformation, the associated volume contraction, and the amount of the recovered plastic deformation were determined by quantifying the indenter displacement as a function of temperature. These experiments were compared to conventional measurements of the transformation temperature by differential scanning calorimetry and compression testing.     

Generation and associative encoding in young and old adults: the effect of the strength of association between cues and targets on a cued recall task

The generation effect (i.e., better recall of the generated items than the read items) was investigated with a between-list design in young and elderly participants. The generation task difficulty was manipulated by varying the strength of association between cues and targets. Overall, strong associates were better recalled than weak associates. However, the results showed different generation effect patterns according to strength of association and age, with a greater generation effect for weak associates in younger adults only. These findings suggest that generating weak associates leads to more elaborated encoding, but that elderly adults cannot use this elaborated encoding as well as younger adults to recall the target words at test.     

Early perception of written syllables in French: An event-related potential study

The present study examined whether written syllable units are perceived in first steps of letter string processing. An illusory conjunction experiment was conducted while event-related potentials were recorded. Colored pseudowords were presented such that there was a match or mismatch between the syllable boundaries and the color boundaries. The results showed that congruent stimuli for which the syllable and color boundaries coincided produced a greater positive-going waveform than incongruent stimuli for which the syllable and color boundaries did not coincide. This syllable–color congruency effect was observed to occur both prior to 100 ms, and in a time window commencing at 150 ms. This finding suggests that syllable units are perceived in the initial steps of French visual word processing. Moreover, this study underlines the specificity of the illusory conjunction paradigm as a relevant and powerful tool of investigation of sublexical units that are automatically evoked from word perception.     

Weitere Versuche an der Rabenkrähe

Ohne Zusammenfassung     

Characterization of long-term memory, resistance to extinction, and influence of temperament during two instrumental tasks in horses

The present study investigated the influence of temperament on long-term recall and extinction of 2 instrumental tasks in 26 horses. In the first task (backward task), horses learned to walk backward, using commands given by an experimenter, in order to obtain a food reward. In the second task (active avoidance task), horses had to cross an obstacle after a bell rang in order to avoid emission of an air puff. Twenty-two months after acquisition, horses exhibited perfect recall performance in both tasks. Accordingly, no influence of temperament on recall performance could be observed for either task. In contrast, in the absence of positive or negative outcomes, the horses’ ability to extinguish their response to either task was highly variable. Resistance to extinction was related to some indicators of temperament: The most fearful horses tended to be the most resistant to extinction in the backward task, while the least sensitive horses tended to be the most resistant to extinction in the active avoidance task. These findings reveal extensive long-term memory abilities in horses and suggest an influence of temperament on learning processes other than acquisition.     

Maternal Sensitivity: a Resilience Factor against Internalizing Symptoms in Early Adolescents Born Very Preterm?

Compared with full-terms, preterm individuals are more at risk from infancy to adulthood for developing internalizing symptoms. Early maternal interactive behavior, especially maternal sensitivity, has been found to be a resilience factor in the developmental outcome of preterm children. The present longitudinal study aimed at examining whether early interactive parenting behaviors have a long term impact on the internalizing symptoms of preterm-born young adolescents. A total sample of 36 very preterm and 22 full-term children participated in an 11-year follow-up study. Maternal interactive behavior was assessed during a mother–infant interaction when the infant was 18 months old. At 11 years, internalizing symptoms were assessed with the Child Behavior Checklist (CBCL). Hierarchical regression analyses revealed that the interaction between groups (preterm/full-term) and maternal sensitivity at 18 months significantly explained CBCL internalizing symptoms at 11 years (β = ?0.526; p < 0.05). Specifically, although prematurity was related to internalizing problems, preterm children with higher maternal sensitivity did not differ from their full-term-born peers on the CBCL internalizing problems domain. These results suggest that maternal sensitivity is a long-term resilience factor preventing the development of internalizing problems at early adolescence in very preterm individuals.     

Awareness of time distortions and its relation with time judgment: a metacognitive approach

The perception of time cannot be reduced to a simple percept produced by an internal clock. The aim of the present study was therefore to investigate the role of the individual consciousness of time on temporal judgments. In the present study, the participants' awareness of attention-related time distortions was assessed using a metacognitive questionnaire. The participants were also required to verbally judge a series of stimulus durations in a single or a dual task condition. The results revealed that time was underestimated in the dual task compared to the single task. However, the accuracy of time judgments improved in line with the participants' individual awareness of attentional time distortion: The more aware they were of the role of attention in time perception, the lower the time distortions they exhibited. Conscious awareness of time therefore plays a role in the accuracy of the time judgments made by human beings.