Faces de bebês são um estímulo emocional extremamente saliente para humanos. O objetivo deste estudo foi comparar a interferência emocional de faces de bebês e estímulos de ameaça (faces adultas com medo) na atenção automática de homens e mulheres com e sem filhos. Após estudo piloto, recrutou-se 61 homens e mulheres de 20 a 35 anos. Os participantes responderam a uma tarefa Go/No-Go na qual imagens de bebês com expressões de sofrimento, alegria ou neutra e imagens de adultos com expressões de medo, alegria e neutra, eram apresentadas. Foram calculados os vieses de atenção para faces de bebês em sofrimento, faces de adultos com medo e faces de bebês vs. adultos. Participantes com filhos, de ambos os sexos, apresentaram mais viés de cuidado (bebês vs adultos) do que os sem filhos. Os resultados indicaram que apenas status parental influenciou o viés para faces de bebês. / Babies are extremely salient emotional stimuli to human beings. The current study aimed to compare the emotional interference of baby faces and threat stimuli (adult fearful faces) on the automatic attention of men and women, parents and non-parents. A pilot study was conducted to adapt instruments and procedures. For the main study 61 men and women aged 20 to 35 years with minimum complete elementary school were recruited. Images of distressed, happy and neutral baby faces and fearful, happy and neutral adult faces were used in a Go/No-Go paradigm. Attentional bias indexes were calculated for biases towards baby distress, adult fear and baby vs. adult faces. Parents, regardless of sex, showed a higher nurturing attentional bias (baby vs. adult faces) in comparison to non-parents. This finding demonstrates that parental status influences the attentional bias to babies.

No description available.

Cette thèse porte sur le traitement rapide des scènes naturelles par les hommes et les singes. Elle est<br />composée de trois chapitres, chacun abordant un aspect particulier de la construction des<br />représentations visuelles précoces utilisées pour catégoriser rapidement les objets.<br />Nous montrons dans le premier chapitre que les informations magnocellulaires sont probablement très<br />impliquées dans la construction des représentations visuelles précoces. Ces représentations<br />rudimentaires de la scène visuelle pourraient servir à guider les traitements effectués sur les<br />informations parvocellulaires accessibles plus tardivement.<br />Dans le deuxième chapitre, nous nous intéressons à la chronométrie des traitements visuels, en<br />analysant les résultats de tâches conçues pour diminuer le temps de réaction des sujets ainsi que la<br />latence de l'activité différentielle cérébrale. Nous étudions également la dynamique fine de ces<br />traitements grâce à un protocole de masquage dans lequel l'information n'est accessible à l'écran que<br />pendant une période de temps très courte et nous montrons ainsi toute l'importance des 20-40<br />premières millisecondes de traitement.<br />Le troisième chapitre traite de la nature des représentations visuelles précoces et des tâches qu'elles<br />permettent de réaliser. Des expériences dans lesquelles les sujets doivent catégoriser des animaux à<br />différents niveaux montrent que le premier niveau auquel le système visuel accède n'est pas le niveau<br />de base mais le niveau superordonné. Ces résultats vont à l'encontre de l'architecture classiquement<br />admise sur la base de travaux utilisant des processus lexicaux et met en évidence l'importance de<br />facteurs comme l'expertise et la diagnosticité des indices visuels pour expliquer la vitesse d'accès aux<br />différents niveaux de catégorie.<br />Ces différents résultats permettent de caractériser les représentations précoces que le système visuel<br />utilise pour extraire le sens des informations qui lui parviennent et faire émerger la représentation<br />interne du monde telle que nous la percevons.

This PhD thesis investigated the role of the basal ganglia in memory and motor inhibition. Recent neuroimaging evidence suggests a supramodal network of inhibition involving the lateral prefrontal cortex. Here we examined whether this supramodal network also includes subcortical structures, such as the basal ganglia. Despite their well-established role in motor control, the basal ganglia are repeatedly activated but never interpreted during memory inhibition. We first used a series of meta-analyses to confirm the consistent involvement of the basal ganglia across studies using memory and motor inhibition tasks (including the Go/No-Go, Think/No-Think, and Stop-signal tasks), and discovered that there may be different subprocesses of inhibition. For instance, while the Go/No-Go task may require preventing a response from taking place, the Think/No-Think and Stop-signal tasks may require cancelling an emerging or ongoing response. We then conducted an fMRI study to examine how the basal ganglia interact with other putative supramodal regions (e.g., DLPFC) to achieve memory and motor inhibition during prevention and cancellation. Through dynamic causal modelling (DCM), we found that both DLPFC and basal ganglia play effective roles to achieve inhibition in the task-specific regions (hippocampus for memory inhibition; primary motor cortex (M1) for motor inhibition). Specifically, memory inhibition requires a DLPFC-basal ganglia-hippocampus pathway, whereas motor inhibition requires a basal ganglia-DLPFC-M1 pathway. We correlated DCM coupling parameters with behavioural indices to examine the relationship between network dynamics during prevention and cancellation and the successfulness of inhibition. However, due to constraints with DCM parameter estimates, caution is necessary when interpreting these results. Finally, we used diffusion weighted imaging to explore the anatomical connections supporting functions and behaviour. Unfortunately, we were unable to detect any white matter variability in relation to effective connectivity or behaviour during the prevention or cancellation processes of memory and motor inhibition at this stage. This PhD thesis provides essential INITIAL evidence that not only are the basal ganglia consistently involved in memory and motor inhibition, but these structures are effectively engaged in these tasks, achieving inhibition through task-specific pathways. We will discuss our findings, interpretations, and future directions in the relevant chapters.

Die Dissertation besteht aus einem Einleitungsteil und drei empirischen Beiträgen. Die Einleitung gibt eine Einführung in das Themengebiet der Selbstwertschätzung und deren Erfassung mit indirekten Verfahren. Vor allem aber dient sie dazu, die empirischen Befunde der Beiträge zu integrieren. Die ersten beiden Artikel widmen sich der Überprüfung der psychometrischen Qualität indirekter Verfahren. Das Augenmerk des ersten Beitrags liegt auf der Prüfung, ob verschiedene indirekte Verfahren konvergieren und ob explizite und implizite Selbstwertschätzung korrespondieren, wenn implizite Selbstwertschätzung reliabel erfasst wird. Außerdem werden strukturelle Ähnlichkeiten der indirekten Verfahren in die Betrachtungen mit einbezogen. Der zweite Beitrag komplettiert die Untersuchungen zur Güte der Verfahren. Der Fokus dieses Beitrags liegt im Nachweis der prädiktiven Validität verschiedener indirekter Verfahren. Dabei werden Kriterien herangezogen, die nicht im Selbstbericht erhoben werden. Im Detail wird eine doppelte Dissoziation zwischen expliziter und impliziter Selbstwertschätzung geprüft. Der dritte Beitrag rundet diese Arbeit ab, da er sich auch einem anwendungsbezogenen Aspekt der Persönlichkeitspsychologie widmet. Untersucht wird der Zusammenhang zwischen defensiven Verhaltensweisen und Selbstwertdiskrepanzen, also der Kombination expliziter und impliziter Selbstwertschätzung. / The dissertation consists of an introduction and three empirical journal articles. The introduction gives the theoretical background about self-esteem and its assessment with indirect measures, and primarily, integrates the three journal articles. The first article investigates the reliability and convergent and discriminant validity of indirect measures of self-esteem. The second article complements the examination of the psychometric properties. It contributes evidence to the predictive validity of indirect self-esteem measures. With using non-self-reported criteria, a double dissociation between explicit and implicit self-esteem is tested. The third article brings into focus an applied aspect of personality psychology. It is analyzed how defensive reactions are related to self-esteem discrepancies, that are different combinations of explicit and implicit self-esteem.

A wide literature of predominantly behavioural experiments that use Stimulus Response Compatibility (SRC) have suggested that visual action information such as object affordance yields rapid and concurrent activation of visual and motor brain areas, but has rarely provided direct evidence for this proposition. This thesis examines some of the key claims from the affordance literature by applying electrophysiological measures to well established SRC procedures to determine the verities of the behavioural claims of rapid and automatic visuomotor activation evoked by viewing affording objects. The temporal sensitivity offered by the Lateralised Readiness Potential and by visual evoked potentials P1 and N1 made ideal candidates to assess the behavioural claims of rapid visuomotor activation by seen objects by examining the timecourse of neural activation elicited by viewing affording objects under various conditions. The experimental work in this thesis broadly confirms the claims of the behavioural literature however it also found a series of novel results that are not predicted by the behavioural literature due to limitations in reaction time measures. For example, while different classes of affordance have been shown to exert the same behavioural facilitation, electrophysiological measures reveal very different patterns of cortical activation for grip-type and lateralised affordances. These novel findings question the applicability of the label ‘visuomotor’ to grip-type affordance processing and suggest considerable revision to models of affordance. This thesis also offers a series of novel and surprising insights into the ability to dissociate afforded motor activity from behavioural output, into the relationship between affordance and early visual evoked potentials, and into affordance in the absence of the intention to act. Overall, this thesis provides detailed suggestions for considerable changes to current models of the neural activity underpinning object affordance.

Die Dissertation besteht aus einem Einleitungsteil und drei empirischen Beiträgen. Die Einleitung gibt eine Einführung in das Themengebiet der Selbstwertschätzung und deren Erfassung mit indirekten Verfahren. Vor allem aber dient sie dazu, die empirischen Befunde der Beiträge zu integrieren. Die ersten beiden Artikel widmen sich der Überprüfung der psychometrischen Qualität indirekter Verfahren. Das Augenmerk des ersten Beitrags liegt auf der Prüfung, ob verschiedene indirekte Verfahren konvergieren und ob explizite und implizite Selbstwertschätzung korrespondieren, wenn implizite Selbstwertschätzung reliabel erfasst wird. Außerdem werden strukturelle Ähnlichkeiten der indirekten Verfahren in die Betrachtungen mit einbezogen. Der zweite Beitrag komplettiert die Untersuchungen zur Güte der Verfahren. Der Fokus dieses Beitrags liegt im Nachweis der prädiktiven Validität verschiedener indirekter Verfahren. Dabei werden Kriterien herangezogen, die nicht im Selbstbericht erhoben werden. Im Detail wird eine doppelte Dissoziation zwischen expliziter und impliziter Selbstwertschätzung geprüft. Der dritte Beitrag rundet diese Arbeit ab, da er sich auch einem anwendungsbezogenen Aspekt der Persönlichkeitspsychologie widmet. Untersucht wird der Zusammenhang zwischen defensiven Verhaltensweisen und Selbstwertdiskrepanzen, also der Kombination expliziter und impliziter Selbstwertschätzung. / The dissertation consists of an introduction and three empirical journal articles. The introduction gives the theoretical background about self-esteem and its assessment with indirect measures, and primarily, integrates the three journal articles. The first article investigates the reliability and convergent and discriminant validity of indirect measures of self-esteem. The second article complements the examination of the psychometric properties. It contributes evidence to the predictive validity of indirect self-esteem measures. With using non-self-reported criteria, a double dissociation between explicit and implicit self-esteem is tested. The third article brings into focus an applied aspect of personality psychology. It is analyzed how defensive reactions are related to self-esteem discrepancies, that are different combinations of explicit and implicit self-esteem.