Mémoire et représentation de soi: Apport de la neuroimagerie fonctionnelle
Conference (2010, May 28)Detailed reference viewed: 14 (0 ULg)
Using phenomenology and mindset induction to assess the prospective function of mind-wandering
Stawarczyk, David ; Majerus, Steve ; D'Argembeau, Arnaud
Poster (2010, May 28)
A notable feature of the human cognitive apparatus resides in its propensity to spontaneously generate thoughts uncoupled from the “here and now”. An important function of these cognitions, often referred ... [more ▼]
A notable feature of the human cognitive apparatus resides in its propensity to spontaneously generate thoughts uncoupled from the “here and now”. An important function of these cognitions, often referred to as mind-wandering, might be to create and/or update scripts, schemata, and future plans in long-term memory. In this study, we investigated this hypothesis by examining whether priming personal projects influenced the occurrence and characteristics of mind-wandering episodes during a subsequent, unrelated cognitive task, as assessed with an experience sampling method. We found that inducing particular mindsets that were related to personal goals (i.e., writing an essay about one’s personal projects) in comparison to a control baseline condition (i.e., writing an essay about a familiar itinerary) increased the number of future-oriented mind-wandering reports while participants performed the Sustained Attention to Response Task (SART). Furthermore, participants judged most of these thoughts as having a future-oriented function (i.e., they were related to planning, decision making, or reevaluating situations). Finally, as behavioral validation of participants’ subjective reports, we found that mind-wandering was positively linked with intra-individual variability (IIV) in response times, whereas reports of being concentrated on the SART were negatively linked with IIV. These data support the view that an important function of mind-wandering resides in the anticipation and planning of the future. [less ▲]Detailed reference viewed: 55 (1 ULg)
Le rôle du vagabondage de l’esprit dans le maintien d’un état anxiété
Stawarczyk, David ; Blanchy, Sarah ; D'Argembeau, Arnaud
Poster (2010, May 25)
Le vagabondage de l’esprit (c’est-à-dire, l’apparition spontanée de pensées prenant leur origine dans la mémoire à long-terme et sans lien avec la tâche en cours de réalisation) est un phénomène fréquent ... [more ▼]
Le vagabondage de l’esprit (c’est-à-dire, l’apparition spontanée de pensées prenant leur origine dans la mémoire à long-terme et sans lien avec la tâche en cours de réalisation) est un phénomène fréquent qui représente en moyenne 10 à 30% de nos pensées journalières. Les recherches dans le domaine suggèrent que ce type de pensées est lié à la gestion de nos préoccupations actuelles et que sa fréquence peut être augmentée par l’induction d’affects négatifs. Cependant, le rôle possible de ces pensées dans le maintien des affects négatifs est encore mal connu. Dans cette étude, une préoccupation anxiogène (supposément devoir réaliser un discours filmé) ou une préoccupation neutre (supposément devoir réaliser une tâche cognitive de réflexion) a été induite immédiatement avant la réalisation d’une tâche exécutive d’inhibition durant laquelle la fréquence et le contenu des pensées distractives ont été évalués. Trois mesures de l’état émotionnel des participants ont été réalisées : (1) au début de la session, (2) après l’induction de la préoccupation et (3) après la tâche exécutive. Les résultats montrent la présence d’un plus grand nombre de pensées distractives liées à la préoccupation induite, d’un plus grand nombre d’erreurs d’inhibition ainsi que d’une augmentation significative des affects négatifs entre les temps 1 et 2 dans la condition anxiogène par rapport à la condition neutre. Par ailleurs, une corrélation négative entre le nombre de pensées distractives liées au discours et la diminution de l’anxiété entre les temps 2 et 3 est observée. Ces résultats démontrent l’importance des cognitions anticipatoires spontanées dans le maintient de l’anxiété. [less ▲]Detailed reference viewed: 81 (14 ULg)
The impact of emotional valence on short-term memory word list recall : Evidence for a conjoined influence of semantic long-term memory and attentional factors.
Majerus, Steve ; D'Argembeau, Arnaud
Conference (2010, February 12)Detailed reference viewed: 7 (0 ULg)
The commonality of neural networks for verbal and visual short-term memory.
Majerus, Steve ; D'Argembeau, Arnaud ; Martinez Perez, Trecy et al
in Journal of Cognitive Neuroscience (2010), 22(11), 2570-2593
Although many neuroimaging studies have considered verbal and visual short-term memory (STM) as relying on neurally segregated short-term buffer systems, the present study explored the existence of shared ... [more ▼]
Although many neuroimaging studies have considered verbal and visual short-term memory (STM) as relying on neurally segregated short-term buffer systems, the present study explored the existence of shared neural correlates supporting verbal and visual STM. We hypothesized that networks involved in attentional and executive processes, as well as networks involved in serial order processing, underlie STM for both verbal and visual list information, with neural specificity restricted to sensory areas involved in processing the specific items to be retained. Participants were presented sequences of nonwords or unfamiliar faces, and were instructed to maintain and recognize order or item information. For encoding and retrieval phases, null conjunction analysis revealed an identical fronto-parieto-cerebellar network comprising the left intraparietal sulcus, bilateral dorsolateral prefrontal cortex, and the bilateral cerebellum, irrespective of information type and modality. A network centered around the right intraparietal sulcus supported STM for order information, in both verbal and visual modalities. Modality-specific effects were observed in left superior temporal and mid-fusiform areas associated with phonological and orthographic processing during the verbal STM tasks, and in right hippocampal and fusiform face processing areas during the visual STM tasks, wherein these modality effects were most pronounced when storing item information. The present results suggest that STM emerges from the deployment of modality-independent attentional and serial ordering processes toward sensory networks underlying the processing and storage of modality-specific item information. [less ▲]Detailed reference viewed: 208 (72 ULg)
Neural networks involved in self-judgement in young and elderly adults
Feyers, Dorothée ; Collette, Fabienne ; D'Argembeau, Arnaud et al
in NeuroImage (2010)
Recent studies have shown that both young and elderly subjects activate the ventromedial prefrontal cortex (VMPFC) when they make self-referential judgements. However, the VMPFC might interact with ... [more ▼]
Recent studies have shown that both young and elderly subjects activate the ventromedial prefrontal cortex (VMPFC) when they make self-referential judgements. However, the VMPFC might interact with different brain regions during self-referencing in the two groups. In this study, based on data from Ruby et al (2009), we have explored this issue using psychophysiological interaction analyses. Young and elderly participants had to judge adjectives describing personality traits in reference to the self versus a close friend or relative (the other), taking either a first-person or a third-person perspective. The physiological factor was the VMPFC activity observed in all participants during self judgement, and the psychological factor was the self versus other referential process. The main effect of first-person perspective in both groups revealed that the VMPFC was coactivated with the left parahippocampal gyrus and the precuneus for self versus other judgments. The main effect of age showed a stronger correlation between activity in the VMPFC and the lingual gyrus in young compared to elderly subjects. Finally, in the interaction, the VMPFC was specifically co-activated with the orbitofrontal gyrus and the precentral gyrus when elderly subjects took a first-person perspective for self judgements. No significant result was observed for the interaction in young subjects. These findings show that, although the VMPFC is engaged by both young and older adults when making self-referential judgements, this brain structure interacts differently with other brain regions as a function of age and perspective. These differences might reflect a tendency by older people to engage in more emotional/social processing than younger adults when making self-referential judgements with a first-person perspective [less ▲]Detailed reference viewed: 51 (16 ULg)
The Iowa Gambling Task in fMRI images.
Li, Xiang ; ; D'Argembeau, Arnaud et al
in Human Brain Mapping (2010), 31
The Iowa Gambling Task (IGT) is a sensitive test for the detection of decision-making impairments in several neurological and psychiatric populations. Very few studies have employed the IGT in functional ... [more ▼]
The Iowa Gambling Task (IGT) is a sensitive test for the detection of decision-making impairments in several neurological and psychiatric populations. Very few studies have employed the IGT in functional magnetic resonance imaging (fMRI) investigations, in part, because the task is cognitively complex. Here we report a method for exploring brain activity using fMRI during performance of the IGT. Decision-making during the IGT was associated with activity in several brain regions in a group of healthy individuals. The activated regions were consistent with the neural circuitry hypothesized to underlie somatic marker activation and decision-making. Specifically, a neural circuitry involving the dorsolateral prefrontal cortex (for working memory), the insula and posterior cingulate cortex (for representations of emotional states), the mesial orbitofrontal and ventromedial prefrontal cortex (for coupling the two previous processes), the ventral striatum and anterior cingulate/SMA (supplementary motor area) for implementing behavioral decisions was engaged. These results have implications for using the IGT to study abnormal mechanisms of decision making in a variety of clinical populations. Hum Brain Mapp, 2009. (c) 2009 Wiley-Liss, Inc. [less ▲]Detailed reference viewed: 47 (4 ULg)
Modulation of medial prefrontal and inferior parietal cortices when thinking about past, present, and future selves.
D'Argembeau, Arnaud ; Stawarczyk, David ; Majerus, Steve et al
in Social Neuroscience (2010), 5
Recent functional neuroimaging studies have shown that reflecting on representations of the present self versus temporally distant selves is associated with higher activity in the medial prefrontal cortex ... [more ▼]
Recent functional neuroimaging studies have shown that reflecting on representations of the present self versus temporally distant selves is associated with higher activity in the medial prefrontal cortex (MPFC). In the current fMRI study, we investigated whether this effect of temporal perspective is symmetrical between the past and future. The main results revealed that the MPFC showed higher activity when reflecting on the present self than when reflecting on past and future selves, with no difference between past and future selves. Temporal perspective also modulated activity in the right inferior parietal cortex but in the opposite direction, activity in this brain region being higher when reflecting on past and future selves relative to the present self (with again no difference between past and future selves). These findings show that differences in brain activity when thinking about current versus temporally distant selves are symmetrical between the past and the future. It is suggested that by processing degrees of self-relatedness, the MPFC might sustain the process of identifying oneself with current representations of the self, whereas the right inferior parietal cortex might be involved in distinguishing the present self from temporally distant selves. [less ▲]Detailed reference viewed: 192 (15 ULg)
Narrative identity in schizophrenia.
; D'Argembeau, Arnaud ; et al
in Consciousness & Cognition (2010), 19(1), 328-40
This study examined narrative identity in a group of 81 patients with schizophrenia and 50 healthy controls through the recall of self-defining memories. The results indicated that patients' narratives ... [more ▼]
This study examined narrative identity in a group of 81 patients with schizophrenia and 50 healthy controls through the recall of self-defining memories. The results indicated that patients' narratives were less coherent and elaborate than those of controls. Schizophrenia patients were severely impaired in the ability to make connections with the self and extract meaning from their memories, which significantly correlated with illness duration. In agreement with earlier research, patients exhibited an early reminiscence bump. Moreover, the period of the reminiscence bump, which is highly relevant for identity development, was characterized by fewer achievements and more life-threatening event experiences, compared with controls. A negative correlation was found between negative symptoms, number of self-event connections and specificity of narratives. Our results suggest that schizophrenia patients have difficulties to organize and extract meaning from their past experiences in order to create coherent personal narratives. [less ▲]Detailed reference viewed: 65 (4 ULg)
Further characterisation of self-defining memories in young adults: a study of a Swiss sample.
; D'Argembeau, Arnaud ; et al
in Memory (2010), 18(3), 293-309
Several individual differences affecting four dimensions of self-defining memories (SDMs)--structure, content, affect, and autobiographical reasoning (Blagov & Singer, 2004; McLean & Fournier, 2008 ... [more ▼]
Several individual differences affecting four dimensions of self-defining memories (SDMs)--structure, content, affect, and autobiographical reasoning (Blagov & Singer, 2004; McLean & Fournier, 2008; Singer & Salovey, 1993)--have been observed in young adults (principally in North America). In this study we aimed to investigate the relationships between the different dimensions of SDMs, providing further evidence of the content validity of the Self-Defining Memory task. It was possible to discern two specific profiles from the three SDMs collected from each participant. Almost half the participants retrieved specific SDMs with little autobiographical reasoning and tension; the other participants retrieved an opposite profile, suggesting that there are individual differences in the cognitive and affective processes related to the construction of SDMs. The second aim of the study was to conduct across-cultural extension of research on SDMs, using a sample of Swiss young adults. The results were similar to those obtained by previous studies, suggesting a certain cultural invariability. The only difference observed concerned the number of SDMs containing meaning making. Swiss young adults attribute more explicit meanings to their memories than North American young adults, suggesting that they are more engaged in autobiographical reasoning. [less ▲]Detailed reference viewed: 47 (5 ULg)
The neural basis of personal goal processing when envisioning future events
D'Argembeau, Arnaud ; Stawarczyk, David ; Majerus, Steve et al
in Journal of Cognitive Neuroscience (2010), 22
Abstract Episodic future thinking allows humans to mentally simulate virtually infinite future possibilities, yet this device is fundamentally goal-directed and should not be equated with fantasizing or ... [more ▼]
Abstract Episodic future thinking allows humans to mentally simulate virtually infinite future possibilities, yet this device is fundamentally goal-directed and should not be equated with fantasizing or wishful thinking. The purpose of this functional magnetic resonance imaging study was to investigate the neural basis of such goal-directed processing during future-event simulation. Participants were scanned while they imagined future events that were related to their personal goals (personal future events) and future events that were plausible but unrelated to their personal goals (nonpersonal future events). Results showed that imaging personal future events elicited stronger activation in ventral medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC) compared to imaging nonpersonal future events. Moreover, these brain activations overlapped with activations elicited by a second task that assessed semantic self-knowledge (i.e., making judgments on one's own personality traits), suggesting that ventral MPFC and PCC mediate self-referential processing across different functional domains. It is suggested that these brain regions may support a collection of processes that evaluate, code, and contextualize the relevance of mental representations with regard to personal goals. The implications of these findings for the understanding of the function instantiated by the default network of the brain are also discussed. [less ▲]Detailed reference viewed: 166 (20 ULg)
Neural correlates of personal goal processing when envisioning future events
Conference (2009, December 10)Detailed reference viewed: 9 (2 ULg)
A further long-term memory effect on verbal short-term memory : The impact of emotional valence.
Majerus, Steve ; D'Argembeau, Arnaud
Conference (2009, June 03)Detailed reference viewed: 7 (0 ULg)
Functional neuroimaging of semantic and episodic forms of self-knowledge
Conference (2009, January 15)Detailed reference viewed: 15 (1 ULg)
Perspective taking to assess self-personality: What's modified in Alzheimer's disease?
; Collette, Fabienne ; D'Argembeau, Arnaud et al
in Neurobiology of Aging (2009), 30(10), 1637-1651
Personality changes are frequently described by caregivers of patients with Alzheimer's disease, while they are less often reported by the patients. This relative anosognosia of Alzheimer disease (AD ... [more ▼]
Personality changes are frequently described by caregivers of patients with Alzheimer's disease, while they are less often reported by the patients. This relative anosognosia of Alzheimer disease (AD) patients for personality changes might be related to impaired self-judgment and to decreased ability to understand their caregiver's perspective. To investigate this issue, we explored the cerebral correlates of self-assessment and perspective taking in patients with mild AD, elderly and young volunteers. All subjects assessed relevance of personality traits adjectives for self and a relative, taking either their own or their relative's perspective, during a functional imaging experiment. The comparison of subject's and relative's answers provided congruency scores used to assess self-judgment and perspective taking performance. The self-judgment "accuracy" score was diminished in AD, and when patients assessed adjectives for self-relevance, they predominantly activated bilateral intraparietal sulci (IPS). Previous studies associated IPS activation with familiarity judgment, which AD patients would use more than recollection when retrieving information to assess self-personality. When taking a third-person perspective, patients activated prefrontal regions (similarly to young volunteers), while elderly controls recruited visual associative areas (also activated by young volunteers). This suggests that mild AD patients relied more on reasoning processes than on visual imagery of autobiographical memories to take their relative's perspective. This strategy may help AD patients to cope with episodic memory impairment even if it does not prevent them from making some mind-reading errors. [less ▲]Detailed reference viewed: 65 (7 ULg)
Exploring self-defining memories in schizophrenia.
; D'Argembeau, Arnaud ; et al
in Memory (2009), 17(1), 26-38
Previous studies have shown that patients with schizophrenia are impaired in recalling specific events from their personal past. However, the relationship between autobiographical memory impairments and ... [more ▼]
Previous studies have shown that patients with schizophrenia are impaired in recalling specific events from their personal past. However, the relationship between autobiographical memory impairments and disturbance of the sense of identity in schizophrenia has not been investigated in detail. In this study the authors investigated schizophrenic patients' ability to recall self-defining memories; that is, memories that play an important role in building and maintaining the self-concept. Results showed that patients recalled as many specific self-defining memories as healthy participants. However, patients with schizophrenia exhibited an abnormal reminiscence bump and reported different types of thematic content (i.e., they recalled less memories about past achievements and more memories regarding hospitalisation and stigmatisation of illness). Furthermore, the findings suggest that impairments in extracting meaning from personal memories could represent a core disturbance of autobiographical memory in patients with schizophrenia. [less ▲]Detailed reference viewed: 51 (8 ULg)