THE ROLE OF SELF-ESTEEM IN COMPETITIVE CHOICE BEHAVIOR1

Le rôle de L'estime de soi dans les choix compétitifs — Un programme transnational de recherche sur les déterminants des processus de décision s'est concentré dans une première phase sur la relation entre L'estime de soi et le comportement compétitif dans un jeu de type « Dilemme du prisonnier ». Des étudiants américains, chez lesquels une grande estime de soi avait été induite, firent davantage de choix compétitifs que les sujets chez lesquels on avait induit une faible estime de soi. Une des deux expériences avec des étudiants français a reproduit les mêmes résultats, alors que des expériences avec des sujets italiens ont produit des résultats inverses. Différentes interprétations théoriques des résultats sont proposées et critiquées.     

Controlled and automatic uses of memory in depressed patients: effect of retention interval lengths

The present study examines controlled and automatic uses of memory in clinically depressed patients by applying the Process Dissociation Procedure developed by Jacoby (1991) to a stem completion memory task with short and long retention intervals. The results show that the contribution of controlled processes is lower in depressed patients than in controls, especially for the longest retention interval, whereas the contribution of automatic processes is equivalent in both groups and unaffected by the length of the retention interval. These findings are discussed in a cognitive control framework.     

Changes in acetylcholine extracellular levels during cognitive processes

Measuring the changes in neurotransmitter extracellular levels in discrete brain areas is considered a tool for identifying the neuronal systems involved in specific behavioral responses or cognitive processes. Acetylcholine (ACh) is the first neurotransmitter whose diffusion from the central nervous system was investigated and whose extracellular levels variations were correlated to changes in neuronal activity. This was done initially by means of the cup technique and then by the microdialysis technique. The latter, notwithstanding some technical limitations, makes it possible to detect variations in extracellular levels of ACh in unrestrained, behaving animals. This review summarizes and discusses the results obtained investigating the changes in ACh release during performance of operant tasks, exposition to novel stimuli, locomotor activity, and the performance of spatial memory tasks, working memory, and place preference memory tasks. Activation of the forebrain cholinergic system has been demonstrated in many tasks and conditions in which the environment requires the animal to analyze novel stimuli that may represent a threat or offer a reward. The sustained cholinergic activation, demonstrated by high levels of extracellular ACh observed during the behavioral paradigms, indicates that many behaviors occur within or require the facilitation provided by the cholinergic system to the operation of pertinent neuronal pathways.     

Time monitoring and executive functioning in children and adults

This study examined time-based prospective memory performance in relation to individual and developmental differences in executive functioning. School-age children and young adults completed six experimental tasks that tapped three basic components of executive functioning: inhibition, updating, and mental shifting. Monitoring performance was examined in a time-based prospective memory task in which participants indicated the passing of time every 5min while watching a movie. Separate analyses of the executive functioning data yielded a two-factor solution for both age groups, with the updating and inhibition tasks constituting a common factor and the shifting tasks constituting a separate factor. Both children and adults showed accelerating monitoring functions with low rates of clock checking during the early phase of each 5-min interval. However, compared with adults, children needed more clock checks for obtaining the same level of response accuracy. Executive functioning had selective effects on time-based prospective memory performance. In both children and adults, monitoring performance was related to the inhibition and updating components, but not to the shifting component, of executive functioning. We conclude that difficulties in temporary maintenance and updating of working memory contents may create discontinuities in sense of time, leading to an increased reliance on external cues for time keeping.     

Space coding for sensorimotor transformations can emerge through unsupervised learning

The posterior parietal cortex (PPC) is fundamental for sensorimotor transformations because it combines multiple sensory inputs and posture signals into different spatial reference frames that drive motor programming. Here, we present a computational model mimicking the sensorimotor transformations occurring in the PPC. A recurrent neural network with one layer of hidden neurons (restricted Boltzmann machine) learned a stochastic generative model of the sensory data without supervision. After the unsupervised learning phase, the activity of the hidden neurons was used to compute a motor program (a population code on a bidimensional map) through a simple linear projection and delta rule learning. The average motor error, calculated as the difference between the expected and the computed output, was less than 3°. Importantly, analyses of the hidden neurons revealed gain-modulated visual receptive fields, thereby showing that space coding for sensorimotor transformations similar to that observed in the PPC can emerge through unsupervised learning. These results suggest that gain modulation is an efficient coding strategy to integrate visual and postural information toward the generation of motor commands.     

Space coding for sensorimotor transformations can emerge through unsupervised learning

The posterior parietal cortex (PPC) is fundamental for sensorimotor transformations because it combines multiple sensory inputs and posture signals into different spatial reference frames that drive motor programming. Here, we present a computational model mimicking the sensorimotor transformations occurring in the PPC. A recurrent neural network with one layer of hidden neurons (restricted Boltzmann machine) learned a stochastic generative model of the sensory data without supervision. After the unsupervised learning phase, the activity of the hidden neurons was used to compute a motor program (a population code on a bidimensional map) through a simple linear projection and delta rule learning. The average motor error, calculated as the difference between the expected and the computed output, was less than 3°. Importantly, analyses of the hidden neurons revealed gain-modulated visual receptive fields, thereby showing that space coding for sensorimotor transformations similar to that observed in the PPC can emerge through unsupervised learning. These results suggest that gain modulation is an efficient coding strategy to integrate visual and postural information toward the generation of motor commands.     

Children's ability to control the facial expression of laughter and smiling: Knowledge and behaviour

A total of 64 children, aged 7 and 10, watched a clown performing three sketches rated as very funny by the children. Two experimental conditions were created by asking half of the participants to suppress their laughter. Facial expressions were videotaped and analysed with FACS. For both ages, the results show a significant shorter duration (but not a lower frequency) of episodes of laughter and Duchenne smiles, and greater frequency of facial control movements in the suppression compared to the free expression group. The detailed results on individual facial action units used to control amusement expressions suggest hypotheses on the nature of the underlying processes. The participants' explicit knowledge of their control strategies was assessed through standardised interviews. Although behavioural control strategies were reported equally frequently by the two age groups, 10-year-olds verbalised more mental control strategies than 7-year-olds. This theoretically expected difference was not related to the actual ability to control facial expression. This result challenges the commonly held assumption that explicit knowledge of control strategies results in a greater ability to execute such control in ongoing social interactions.     

What I like is How I Am: Impact of Alexithymia on Aesthetic Preference

Aim of this work was to explore the impact of alexithymia on art works appreciation, to examine the influence of emotion regulation on art judgment. While observing a painting, the viewer's cognitive structure contains several types of information (semantic, episodic, and strategic) and is the repository of personal traits, motivations, and emotional dispositions that are involved in this interaction. The study of how personal traits influence work of art appreciation, and especially the study of the way emotion regulation impacts on art judgment, was aimed at improving the comprehension of the aesthetic experience costruct. One hundred adults, divided into 2 groups (high and low scores in alexithymia), observed 20 works of art and were then asked to give an evalutative judgment on three dimentions: cognitive, emotional, aesthetic. As hypothesized, the two groups had significant differences in their aesthetic preferences. Although subjects without affective regulation disorders preferred excitation related pictures, subjects with alexithymia appreciated works evoching emotions of pleasure inhibition. These results confirm the impact of personality traits on aesthetic preference and support the need to include emotional regulation in a comprehensive model of aesthetic experience.     

Sense of Time and Executive Functioning in Children and Adults

A number of patient studies suggest that impairments in frontal lobe functions are associated with disorders in temporal information processing. One implication of these findings is that subjective experience of time should be related to executive functions regardless of etiology. In two experiments, we examined sense of time in relation to components of executive functioning in healthy children and adults. In Experiment 1, children between 8 to 12 years completed six experimental tasks that tapped three components of executive functioning: inhibition, updating, and mental shifting. Sense of time was examined in a duration judgment task in which participants reproduced stimulus durations between 4 to 32 s. In Experiment 2, adult participants completed the time reproduction task under varying concurrent task demands. Both experiments showed selective effects in that time reproduction errors were related to the inhibition and updating, but not to the shifting, components of executive functioning. However, the observed effects were modulated by task demands and age-related differences in cognitive competence. We conclude that individual differences in executive functioning are only weakly related to time reproduction performance in healthy children and adults.