An additive factor analysis of the effect of depression on the reaction time of old patients

Depressed participants display longer reaction times (RTs) than control participants. The present study was aimed at deciphering which stages of processing are affected by depression in old adults. Sixteen old depressed patients and 16 old healthy volunteers performed a two-choice visual RT task. Signal intensity, stimulus-response mapping and foreperiod duration were manipulated so as to affect the stages of stimulus preprocessing, response selection and motor adjustment, respectively. Reaction time data suggest that depression spares the stage of stimulus preprocessing but affects the stage of motor adjustment. An analysis of the error rate leaves open the possibility that depression alters the stage of response selection.     

Position of the Egocentric Reference and Directional Arm Movements in Right-Brain-Damaged Patients

We asked 12 right-brain-damaged patients (6 with left neglect signs and 6 without left neglect signs) to perform a straight ahead pointing task and a visual detection task with lateralized motor response, in order to investigate the relationship between the position of the egocentric reference and response time and accuracy in producing lateralized arm movements. Results showed that there was no correlation between the position of the egocentric reference and neglect signs, nor between the position of the egocentric reference and the latencies to direct a motor response toward either side of space. These findings were interpreted within the context of egocentric hypotheses of neglect. In particular, it was suggested that attentional or intentional neglect signs cannot be considered as a direct consequence of an ipsilesional deviation of the egocentric reference.     

Evidence for the Involvement of the Rat Prefrontal Cortex in Sustained Attention

Previous studies suggest that, in both humans and rats, the prefrontal cortex (PFC) is involved in both selective and divided attention. We have also shown that the PFC is involved in response selection and that its involvement is modulated by the cognitive effort required by the task. However, the role of the PFC is much less clear when no response selection is required. The purpose of the present experiments was to assess the role of the PFC in attentional functions with a low response-selection demand. We used two tasks in which information processing was effortful but where the demand on a response selection process is low. Moreover, we assessed two different types of visual attentional functions: selective attention (Experiment 1) and sustained attention (Experiment 2). The results showed a differential involvement of the PFC in the two tasks. Selective attention was not impaired by prefrontal lesions when the number of possible positions for the stimulus on which the subjects must focus was restricted to two (Experiment 1). In contrast, prefrontal rats were unable to sustain their attention long enough to detect, and react to, subtle variations in brightness (Experiment 2). This result suggests a dissociation between different types of attentional functions depending upon the integrity of the PFC. More specifically, results in Experiment 2 suggest an involvement of the PFC in sustained attention. Finally, the overall results show that even in tasks involving low demands on response selection the PFC is involved in attentional functions.     

From solidarity to autonomy: towards a redefinition of the parameters of the notion of autonomy

Starting from examples of concrete situations in France, I show that autonomy and solidarity can coexist only if the parameters of autonomy are redefined. I show on the one hand that in situations where autonomy is encouraged, solidarity nevertheless remains at the foundation of their practices. On the other hand, in situations largely infused with family solidarity, the individual autonomy may be put in danger. Yet, based on my ethnographic observations regarding clinical encounters and medical secrecy, I show that while solidarity may endanger individual autonomy, it does not necessarily endanger autonomy itself. The social practices observable in France reflect the reality of an autonomy that goes beyond the individual, a reality that involves a collective subject and includes solidarity. The opposition between these two values can then be resolved if the content of the notion of autonomy is understood to be dependent on its cultural context of application and on its social use.     

Recognition of music in long-term memory: Are melodic and temporal patterns equal partners?

The notion that the melody (i.e., pitch structure) of familiar music is more recognizable than its accompanying rhythm (i.e., temporal structure) was examined with the same set of nameable musical excerpts in three experiments. In Experiment 1, the excerpts were modified so as to keep either their original pitch variations, whereas durations were set to isochrony (melodic condition) or their original temporal pattern while played on a single constant pitch (rhythmic condition). The subjects, who were selected without regard to musical training, were found to name more tunes and to rate their feeling of knowing the musical excerpts far higher in the melodic condition than in the rhythmic condition. These results were replicated in Experiment 2, wherein the melodic and rhythmic patterns of the musical excerpts were interchanged to create chimeric mismatched tunes. The difference in saliency of the melodic pattern and the rhythmic pattern also emerged with a music-title-verification task in Experiment 3, hence discarding response selection as the main source of the discrepancy. The lesser effectiveness of rhythmic structure appears to be related to its lesser encoding distinctiveness relative to melodic structure. In general, rhythm was found to be a poor cue for the musical representations that are stored in long-term memory. Nevertheless, in all three experiments, the most effective cue for music identification involved the proper combination of pitches and durations. Therefore, the optimal code of access to long-term memory for music resides in a combination of rhythm and melody, of which the latter would be the most informative.     

Insertion of connectives by 9- to 11-year-old children in an argumentative text

The objective of the present study was to show that the use of adversative and conclusive connectives to mark off the prototypical schema of argumentative text begins to set in at approximately the age of 10 or 11. Based on Adam's (1992) proposals, we constituted an argumentative text with two blocks of arguments separated by an adversative instruction (the connective but or an equivalent) and followed by a conclusion introduced by a conclusive instruction (the connective thus or an equivalent). Four revising tasks (insertion or substitution with or without five connectives) have been used to asses children's knowledge of the argumentative schema and the use of connectives that punctuate them. The study of good and erroneous locations (concerning the placement of but and thus) showed that there was some regularity in the choices made by the children. The main result of this study shows that argumentative connectives are used differently by children aged 9 and children aged 10 or 11. The argumentative schema is used more consciously by 11-year-olds to guide revising tasks than by 10-year-olds.     

Cognitive Processing of Drawing Abilities

This critical review examines constructional apraxia from a cognitive neuropsychological perspective. To our knowledge, van Sommers (1989) is the only researcher to present a global cognitive model of drawing abilities. He organizes it into two hierarchical systems: Marr's model of visual perception and a graphic production system. The latter comprises four hierarchically organized components: depiction decisions, production strategy, contingent planning, and articulatory and economic constraints. Van Sommers' model will be discussed in light of other models and on the basis of empirical neuropsychological studies (Farah, 1984; Kosslyn & Koenig, 1992; Roncato, Sartori, Masterson, & Rumiati, 1987; van Sommers, 1989). We find that: (1) the Kosslyn and Koenig visual perception model describes more accurately the perceptual components underlying copying than the visual perception system of van Sommers' drawing model, (2) Van Sommers' arguments in favor of a depiction processing as opposed to visual imagery are not convincing, (3) Van Sommers' assumption that a production strategy is a component is unclear, and (4) articulatory and economic constraints are not cognitive components, but constraints imposed during action programming. This literature review leads to a discussion of future research topics and the specificity of constructional apraxia.     

Making the planet green again: The interplay of attitudes and group norms in the conversion to organic farming

Attitudes and social norms are key social psychological concepts that have often been considered as independent determinants of human behavior. However, questions about the interplay between the two are somewhat of a blind spot in social psychology. In the present research, we test the hypothesis that when an important change in norms is involved, behavioral intentions will be shaped by a discrepancy between personal attitudes and the perceived group norm, that is the perception of other group members’ attitudes. This proposition is tested and supported across three studies in a context of the conversion to organic farming, a behavior indicative of a significant societal and behavioral change. Farmers who did convert to organic farming were those who perceive other farmers to hold less positive attitudes toward this environmentally-friendly practice compared to their own (Study 1a & 1b, N = 1,023). Among conventional farmers, the intention to convert to organic farming is also predicted by a discrepancy between personal attitudes and the perceived group norm (Study 1b). Finally, among agricultural colleges’ students (Study 2, N = 280), the intention to become an organic farmer was influenced by an interaction between attitudes and perceived group norm and not only by independent effects of these two variables. The theoretical and practical implications of these findings for a better understanding of behavioral adaptation in times of social change are discussed.