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See detailNeural correlates of event clusters in past and future thoughts: How the brain integrates specific episodes with autobiographical knowledge
Demblon, Julie ULg; Bahri, Mohamed Ali ULg; D'Argembeau, Arnaud ULg

in NeuroImage (2016), 127

When remembering the past or envisioning the future, events often come to mind in organized sequences or stories rather than in isolation from one another. The aim of the present fMRI study was to ... [more ▼]

When remembering the past or envisioning the future, events often come to mind in organized sequences or stories rather than in isolation from one another. The aim of the present fMRI study was to investigate the neural correlates of such event clusters. Participants were asked to consider pairs of specific past or future events: in one condition, the two events were part of the same event cluster (i.e., they were thematically and/or causally related to each other), whereas in another condition the two events only shared a surface feature (i.e., their location); a third condition was also included, in which the two events were unrelated to each other. The results showed that the processing of past and future events that were part of a same cluster was associated with higher activation in the medial prefrontal cortex (PFC), rostrolateral PFC, and left lateral temporal and parietal regions, compared to the two other conditions. Furthermore, functional connectivity analyses revealed an increased coupling between these cortical regions. These findings suggest that largely similar processes are involved in organizing events in clusters for the past and the future. The medial and rostrolateral PFC might play a pivotal role in mediating the integration of specific events with conceptual autobiographical knowledge ‘stored’ in more posterior regions. Through this integrative process, this set of brain regions might contribute to the attribution of an overarching meaning to representations of specific past and future events, by contextualizing them with respect to personal goals and general knowledge about one's life story. [less ▲]

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See detailNeural correlates of fast and slow ocular sequence learning
Albouy, Geneviève ULg; Ruby, Perrine; Balteau, Evelyne ULg et al

in NeuroImage (2005), 26(Suppl. 1),

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See detailNEURAL CORRELATES OF GAIT HYPOKINESIA IN PARKINSON'S DISEASE: AN FMRI STUDY
Cremers, Julien ULg; Stamatakis, Julien; D'Ostilio, Kevin ULg et al

Poster (2012, May 05)

Introduction: Brisk walking (BW) is an efficient tool to study gait hypokinesia whose pathogenesis remains poorly understood in Parkinson's disease (PD). Aims: Assuming that brain regions recruited during ... [more ▼]

Introduction: Brisk walking (BW) is an efficient tool to study gait hypokinesia whose pathogenesis remains poorly understood in Parkinson's disease (PD). Aims: Assuming that brain regions recruited during imagined gait strongly overlap with those recruited during real gait, we used mental imagery of BW as a paradigm to study the neural correlates of gait hypokinesia in PD with BOLD fMRI. Methods: 15 'on-drugs' PD patients and 15 controls matched for age and gender were instructed to imagine themselves in two situations: comfortable walking (CW) and BW on a 25 meter-path. Imagined speed reserve (ISR), defined as the difference between imagined BW and CW speeds, was measured as a control of behavioral performance. The first-level individual contrast images representing the comparison between BW and CW were entered into second-level analyses with the corresponding ISRs as correlation regressors. Results: ISRs and their real counterparts measured offline were significantly decreased in patients relatively to controls. They strongly positively correlated in patients (Pearson's r = 0.88) and controls (Pearson's r = 0.59). Between-group comparison of individual contrasts BW minus CW in correlation with their corresponding ISRs showed that increasing imagined gait speed was strongly associated with increased activity of the left posterior parietal cortex (PPC) in controls and with decreased activity of this region in the patients. Conclusions: Our findings suggest that gait hypokinesia is related to an impaired function of the left PPC in PD. The left PPC may represent a target for therapeutic interventions aimed at alleviating gait disturbances in PD. [less ▲]

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See detailNeural correlates of generation and inhibition of verbal association patterns in mood disorders.
Piguet, Camille; Desseilles, Martin ULg; Cojan, Yann et al

in Social cognitive and affective neuroscience (2015), 10(7), 978-86

OBJECTIVES: Thought disorders such as rumination or flight of ideas are frequent in patients with mood disorders, and not systematically linked to mood state. These symptoms point to anomalies in ... [more ▼]

OBJECTIVES: Thought disorders such as rumination or flight of ideas are frequent in patients with mood disorders, and not systematically linked to mood state. These symptoms point to anomalies in cognitive processes mediating the generation and control of thoughts; for example, associative thinking and inhibition. However, their neural substrates are not known. METHOD: To obtain an ecological measure of neural processes underlying the generation and suppression of spontaneous thoughts, we designed a free word association task during fMRI allowing us to explore verbal associative patterns in patients with mood disorders and matched controls. Participants were presented with emotionally negative, positive or neutral words, and asked to produce two words either related or unrelated to these stimuli. RESULTS: Relative to controls, patients produced a reverse pattern of answer typicality for the related vs unrelated conditions. Controls activated larger semantic and executive control networks, as well as basal ganglia, precuneus and middle frontal gyrus. Unlike controls, patients activated fusiform gyrus, parahippocampal gyrus and medial prefrontal cortex for emotional stimuli. CONCLUSIONS: Mood disorder patients are impaired in automated associative processes, but prone to produce more unique/personal associations through activation of memory and self-related areas. [less ▲]

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See detailNeural Correlates of Human NREM Sleep Oscillations
Foret, Ariane ULg; Shaffii, Anahita ULg; Muto, Vincenzo ULg et al

in Hutt, Axel (Ed.) Sleep and Anesthesia (2011)

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See detailNeural Correlates of Human Sleep and Sleep-Dependent Memory Processing
Meyer, Christelle ULg; Muto, Vincenzo ULg; Jaspar, Mathieu ULg et al

in Frank, Marcos (Ed.) Sleep and Brain Activity (2012)

Wakefulness and sleep are associated with distinct patterns of neural activity and neuromodulation. In humans, functional neuroimaging was used to characterize the related changes in regional brain ... [more ▼]

Wakefulness and sleep are associated with distinct patterns of neural activity and neuromodulation. In humans, functional neuroimaging was used to characterize the related changes in regional brain metabolism and hemodynamics. Recent data combining EEG and fMRI described the transient responses associated with spindles and slow waves, as well as the changes in functional integration during NREM sleep. It was also shown that regional brain activity during sleep is influenced by the experience acquired during the preceding waking period. These data are currently interpreted in the framework of two theories. First, the use-dependent increase in slow oscillation during NREM sleep is associated with local synaptic homeostasis. Second, reactivations of memory traces during NREM sleep would reorganize declarative memories in hippocampal-neocortical networks, a systems-level memory consolidation which can be hindered by sleep deprivation. Collectively, these data reveal the dynamical changes in brain activity during sleep which support normal human cognition. [less ▲]

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See detailNeural correlates of hypokinetic gait in Parkinson’s disease: An fMRI study
Cremers, Julien ULg; Stamatakis, Julien; D'Ostilio, Kevin ULg et al

Poster (2012)

Objective: To investigate the neural correlates of hypokinetic gait in Parkinson’s disease (PD) using functional magnetic resonance imaging (fMRI). Background: Although hypokinetic gait is frequent and ... [more ▼]

Objective: To investigate the neural correlates of hypokinetic gait in Parkinson’s disease (PD) using functional magnetic resonance imaging (fMRI). Background: Although hypokinetic gait is frequent and has a negative impact on quality of life in PD, its underlying mechanisms remain poorly understood. Assuming that the brain regions recruited during real and imagined gait strongly overlap, mental imagery of brisk gait may be a successful approach to study hypokinetic gait in PD. Methods: Fifteen ‘‘on-drugs’’ PD patients (8 males; mean age 5 65.1 6 9.4 years) and fifteen controls matched for age, gender and mental imagery skills were trained to perform video-taped trials of comfortable and brisk gait on a 25 meter-path. The study was organ- ized as a block-design fMRI experiment where subjects were instructed to rehearse themselves performing comfortable and brisk gait and to press a key to indicate when they completed each 25 meter-imagined gait trial. The imagined speed reserve (ISR) defined as the difference between imagined brisk and comfortable gait speeds was measured as a control of behavioral performance. Imaging data processing and analyses were performed using SPM8. The first-level individual contrast images representing the comparison between brisk and comfortable gait were entered as two separate groups (controls vs patients) in an ANOVA with the corresponding ISRs as correlation regressors. Results: Compared with controls, patients showed hypokinetic gait during real gait training as their increase in speed during brisk relatively to comfortable gait was related to an increase in step ca- dence (r50.87; p<0.001) but not in step length (r50.11). ISRs meas- ured during fMRI and their real counterparts measured offline strongly correlated in patients (r50.88; p<0.001) and controls (r50.59; p50.02). Between-group comparison (p<0.001, uncorrected) of fMRI data showed that increasing imagined gait speed was strongly associated with increased activity of the left posterior parietal cortex in controls and with decreased activity of this region in patients. Conclusions: Our findings suggest that hypokinetic gait in PD is related to the impaired functioning of the left posterior parietal cortex. This area may represent a target for therapeutic interventions aimed at alleviating gait disturbances in PD. [less ▲]

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See detailThe neural correlates of implicit and explicit sequence learning : Interacting networks revealed by the process dissociation procedure
Destrebecqz, Arnaud; Peigneux, Philippe ULg; Laureys, Steven ULg et al

in Learning & Memory (Cold Spring Harbor, N.Y.) (2005), 12(5), 480-490

In two (H15O)-O-2 PET scan experiments, we investigated the cerebral correlates of explicit and implicit knowledge in a serial reaction time (SRT) task. To do so, we used a novel application of the ... [more ▼]

In two (H15O)-O-2 PET scan experiments, we investigated the cerebral correlates of explicit and implicit knowledge in a serial reaction time (SRT) task. To do so, we used a novel application of the Process Dissociation Procedure, a behavioral paradigm that makes it possible to separately assess conscious and unconscious contributions to performance during a subsequent sequence generation task. To manipulate the extent to which the repeating sequential pattern was learned explicitly, we varied the pace of the choice reaction time task-a variable that is known to have differential effects on the extent to which sensitivity to sequence structure involves implicit or explicit knowledge. Results showed that activity in the striatum subtends the implicit component of performance during recollection of a learned sequence, whereas the anterior cingulate/mesial prefrontal cortex (ACC/MPFC) supports the explicit component. Most importantly, we found that the ACC/MPFC exerts control on the activity of the striatum during retrieval of the sequence after explicit learning, whereas the activity of these regions is uncoupled when learning had been essentially implicit. These data suggest that implicit learning processes can be successfully controlled by conscious knowledge when learning is essentially explicit. They also supply further evidence for a partial dissociation between the neural substrates supporting conscious and nonconscious components of performance during recollection of a learned sequence. [less ▲]

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See detailNeural Correlates of Ongoing Conscious Experience: Both Task-Unrelatedness and Stimulus-Independence Are Related to Default Network Activity
Stawarczyk, David ULg; Majerus, Steve ULg; Maquet, Pierre ULg et al

in PLoS ONE (2011), 6(2), 16997

The default mode network (DMN) is a set of brain regions that consistently shows higher activity at rest compared to tasks requiring sustained focused attention toward externally presented stimuli. The ... [more ▼]

The default mode network (DMN) is a set of brain regions that consistently shows higher activity at rest compared to tasks requiring sustained focused attention toward externally presented stimuli. The cognitive processes that the DMN possibly underlies remain a matter of debate. It has alternately been proposed that DMN activity reflects unfocused attention toward external stimuli or the occurrence of internally generated thoughts. The present study aimed at clarifying this issue by investigating the neural correlates of the various kinds of conscious experiences that can occur during task performance. Four classes of conscious experiences (i.e., being fully focused on the task, distractions by irrelevant sensations/perceptions, interfering thoughts related to the appraisal of the task, and mind-wandering) that varied along two dimensions (“task-relatedness” and “stimulus-dependency”) were sampled using thought-probes while the participants performed a go/no-go task. Analyses performed on the intervals preceding each probe according to the reported subjective experience revealed that both dimensions are relevant to explain activity in several regions of the DMN, namely the medial prefrontal cortex, posterior cingulate cortex/precuneus, and posterior inferior parietal lobe. Notably, an additive effect of the two dimensions was demonstrated for midline DMN regions. On the other hand, lateral temporal regions (also part of the DMN) were specifically related to stimulus-independent reports. These results suggest that midline DMN regions underlie cognitive processes that are active during both internal thoughts and external unfocused attention. They also strengthen the view that the DMN can be fractionated into different subcomponents and reveal the necessity to consider both the stimulus-dependent and the task-related dimensions of conscious experiences when studying the possible functional roles of the DMN. [less ▲]

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See detailNeural Correlates of Performance Variabilty during Motor Sequence Acquisition
Albouy, Geneviève ULg; Sterpenich, V.; Vandewalle, Gilles ULg et al

in NeuroImage (2012), 60(1), 324-331

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See detailNeural correlates of personal goal processing during episodic future thinking and mind-wandering: an ALE meta-analysis
Stawarczyk, David ULg; D'Argembeau, Arnaud ULg

in Human Brain Mapping (2015), 36(8), 2928-2947

The ability to imagine the future is a complex mental faculty that depends on an ensemble of cognitive processes supported by an extended set of brain regions. Our aim here was to shed light on one key ... [more ▼]

The ability to imagine the future is a complex mental faculty that depends on an ensemble of cognitive processes supported by an extended set of brain regions. Our aim here was to shed light on one key component of future thinking—personal goal processing—and to determine its neural correlates during both directed and spontaneous forms of thoughts. To address this question, we performed separate ALE meta-analyses of neuroimaging studies of episodic future thinking, mind-wandering, and personal goal processing, and then investigated the commonalities and differences in brain activity between these three domains. The results showed that the three domains activated a common set of brain regions within the default network and, most notably, the medial prefrontal cortex. This finding suggests that the medial prefrontal cortex mediates the processing of personal goals during both episodic future thinking and mind-wandering. Differences in activation were also observed, and notably regions supporting cognitive control processes (the dorsolateral prefrontal cortex) were recruited to a lesser extent during mind-wandering than experimentally directed future thinking, suggesting that different kinds of self-generated thoughts may recruit varying levels of attentional control abilities. [less ▲]

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See detailNeural correlates of personal goal processing when envisioning future events
D'Argembeau, Arnaud ULg

Conference (2009, December 10)

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See detailThe Neural Correlates of Re-cancellation Behaviors in Unilateral Neglect: A Neuropsychological Approach
Wansard, Murielle ULg; Bastin, Christine ULg; Meulemans, Thierry ULg

Poster (2014, April)

The present study focused on re-cancellation behaviors in unilateral neglect (i.e., the tendency to search repeatedly items located on the right side in visual search tasks), and used a neuropsychological ... [more ▼]

The present study focused on re-cancellation behaviors in unilateral neglect (i.e., the tendency to search repeatedly items located on the right side in visual search tasks), and used a neuropsychological approach to identify the cerebral correlates of this deficit. Fourteen patients suffering from left neglect and 14 elderly age-matched controls performed a cancellation task without visual feedback. Neglect patients cancelled fewer targets than controls, and re-cancelled an abnormally high number of targets. Lesion maps were used to compare the location of brain damage in neglect patients with the highest versus the lowest percentage of re-cancellations. Anatomical data revealed that the right insula is commonly damaged in 5 out of 6 patients with the highest re-cancellation percentage, but is spared in the subgroup of patients with the lowest re-cancellation percentage. These results suggest that damage to the right insula may contribute to pathological visual search in spatial neglect, possibly by reducing interaction between the ventral and dorsal attention network (the latter being more directly involved in spatial processes). [less ▲]

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See detailThe neural correlates of recollection and familiarity during aging
Angel, Lucie; Bastin, Christine ULg; Genon, Sarah ULg et al

in Journal of Psychophysiology (2013), 27(Suppl 1), 48

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See detailThe neural correlates of recollection and familiarity during aging
Angel, Lucie; Bastin, Christine ULg; Genon, Sarah ULg et al

Poster (2013)

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See detailThe neural correlates of recollection and familiarity during aging
Angel, Lucie; Bastin, Christine ULg; Genon, Sarah ULg et al

in Proceedings of the XII Colloque International sur le Vieillissement Cognitif (2012)

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See detailThe neural correlates of recollection and familiarity during aging
Angel, Lucie; Bastin, Christine ULg; Genon, Sarah ULg et al

in Frontiers in Human Neuroscience (2012)

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See detailThe neural correlates of recollection and familiarity during aging
Angel, Lucie; Bastin, Christine ULg; Genon, Sarah ULg et al

Poster (2012, June)

Detailed reference viewed: 31 (7 ULg)