References of "Wansard, Murielle"
     in
Bookmark and Share    
Peer Reviewed
See detailDevelopmental Invariance in Implicit Sequence Learning
Lejeune, Caroline ULg; Wansard, Murielle ULg; Meulemans, Thierry ULg

Poster (2014, April 05)

This study was intended to test the age invariance hypothesis on implicit learning abilities using the serial reaction time paradigm and focusing on the comparison of second-order conditional (SOC ... [more ▼]

This study was intended to test the age invariance hypothesis on implicit learning abilities using the serial reaction time paradigm and focusing on the comparison of second-order conditional (SOC) sequences of two different lengths (8 and 12 elements). A total of 128 participants from 4 age groups (4 years, 7 years, 10 years, and adults) were tested. The results showed significant and similar learning effects in 4-, 7-, and 10-year-old children, as well as adults. The learning effect was more pronounced for the 8-element sequence than for the 12-element sequence for all age groups, suggesting that the shorter sequence was better learned than the longer one. In addition, the degree of explicit sequence awareness was comparable between age groups and sequence lengths. These results, showing that 4-year-old children are able to learn 8- and 12-element-long SOC sequences as well as adults, provide further support for the hypothesis that implicit learning abilities are developmentally invariant. [less ▲]

Detailed reference viewed: 34 (0 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailCortical and subcortical contributions to state- and strength-based perceptual judgments
Aly, Mariam; Wansard, Murielle ULg; Segovia-Román, Fermín ULg et al

in Neuropsychologia (2014), 64

Detailed reference viewed: 16 (3 ULg)
Full Text
Peer Reviewed
See detailVisual neglect: Is there a relationship between impaired spatial working memory and re-cancellation?
Wansard, Murielle ULg; Meulemans, Thierry ULg; Gillet, Sophie ULg et al

in Experimental Brain Research (2014)

In visual search tasks, neglect patients tend to explore and repeatedly re-cancel stimuli on the ipsilesional side, as if they did not realize that they had previously examined the rightward locations ... [more ▼]

In visual search tasks, neglect patients tend to explore and repeatedly re-cancel stimuli on the ipsilesional side, as if they did not realize that they had previously examined the rightward locations favoured by their lateral bias. The aim of this study was to explore the hypothesis that a spatial working memory deficit explains these ipsilesional re-cancellation errors in neglect patients. For the first time, we evaluated spatial working memory and re-cancellation through separate and independent tasks in a group of patients with right hemisphere damage and a diagnosis of left neglect. Results showed impaired spatial working memory in neglect patients. Compared to the control group, neglect patients cancelled fewer targets and made more re-cancellations both on the left side and on the right side. The spatial working memory deficit appears to be related to re-cancellations, but only for some neglect patients. Alternative interpretations of re-exploration of space are discussed. [less ▲]

Detailed reference viewed: 24 (4 ULg)
Full Text
Peer Reviewed
See detailIs there a relationship between perseverations and spatial short-term memory deficits in unilateral neglect?
Wansard, Murielle ULg; Bartolomeo, Paolo; Gillet, Sophie ULg et al

in Abstract Book Belgian Brain Congress (2012, October 27)

Introduction Spatial neglect is a multicomponent syndrome characterized by an inability to orient or to respond to stimuli arising in the hemispace contralateral to a brain lesion. According to many ... [more ▼]

Introduction Spatial neglect is a multicomponent syndrome characterized by an inability to orient or to respond to stimuli arising in the hemispace contralateral to a brain lesion. According to many authors, spatial neglect can be explained by an attentional deficit, and more specifically by a lateral attentional bias towards the right (magnetic attraction) and/or difficulties in disengaging attention from items to the right side. However, attentional theories are not sufficient to explain some behaviors such as revisiting and perseverations. Recently, it has been suggested that revisiting and perseveration behaviors in visual search tasks shown in parietal neglect could be related to impairments in visuo-spatial working memory (Husain et al., 2001; Malhotra et al., 2005; Malhotra, Mannan, Driver, & Husain, 2004). This hypothesis is supported by studies (1) in which a contrast is made between cancellation tasks with and without visual control, the absence of visual feedback increasing left neglect (omissions) and repeated cancellations (perseverations) towards the ipsilesional space, and (2) in which the Corsi test is administrated in a vertical way. However, Ronchi et al. (2009) did not confirm the link between impairments in spatial short-term memory and perseverations. Indeed, these authors found no correlation between perseverations in star cancellation and spatial memory performance in the Corsi test. Nevertheless, they did not use a condition without visual feedback, which is considered as involving more spatial short-term memory than a condition with visual feedback. This methodological choice could explain the lack of relationship between short-term memory and perseverations in the Ronchi et al.’s study. The purpose of our study was to test the hypothesis of a spatial short-term memory deficit being an explanatory factor of perseverations in unilateral neglect. Methods We assessed twenty right-damaged patients suffering from left neglect. Neglect signs were evaluated with the Batterie d’Evaluation de la Négligence (BEN) (Azouvi et al., 2002). Twenty healthy older participants matched for age and sociocultural level served as controls. In order to explore the relationship between perseverations and spatial short-term memory, two different tasks were administrated: a computerized version of the Corsi test and a cancellation task. All tests were computerized and presented on a touchscreen. The subject’s spatial span corresponded to the longest sequence in which at least three out of four sequences were correctly reproduced. The cancellation task consisted of 32 “O” presented in two conditions: with (visible) and without (invisible) visual feedback. Patients were instructed to cancel out all targets only once. The number of omissions and perseverations was calculated for each participant in both conditions. Results Control participants performed better than neglect patients in the Corsi test; eleven neglect patients showed a deficit in spatial short-term memory. In the cancellation tasks, Wilcoxon matched-pairs signed ranks tests highlighted that perseverations and omissions were greater in the invisible condition for each group. In this condition, neglect patients made more omissions and perseverations (all ps <.05) than control subjects, while in the visible condition there was only a significant difference for the omissions. However, spatial short-term memory did not explain perseverations in invisible condition (R² = .17, F(1,18) = 3.66, p = .07). Discussion These findings suggest that a spatial short-term memory deficit cannot be considered as an explanatory factor for the perseveration behavior in unilateral neglect. Moreover, perseverations and omissions were greater in the invisible condition than in the visible one; therefore, the hypothesis of the magnetic attraction is not confirmed either. In the neglect patients’ group, the visual feedback decreases, and even eliminates the neglect symptoms (omissions and perseverations) compared to the invisible condition. In other words, the presence of visual feedback can help patients to explore their visual environment. We propose that, in the invisible condition, difficulties to plan a visual search could exacerbate both omissions and perseverations, leading to recursive search towards the right side of the space and thus promote failure to explore left space. However, further investigations will be necessary to confirm this hypothesis. [less ▲]

Detailed reference viewed: 91 (14 ULg)
Peer Reviewed
See detailLearning and Error Reproduction in Alzheimer Disease
Wansard, Murielle ULg; Erkès, jérôme; Adam, Stéphane ULg et al

Poster (2012, July 15)

Alzheimer disease (AD) is characterized by an early impairment of explicit memory processes associated to a preservation of implicit memory processes (Fleischman & Gabrieli 1998). Due to the role of ... [more ▼]

Alzheimer disease (AD) is characterized by an early impairment of explicit memory processes associated to a preservation of implicit memory processes (Fleischman & Gabrieli 1998). Due to the role of explicit memory in the suppression of errors during learning, AD patients tend to reproduce automatically (implicitly) errors that occurred during a previous learning (Baddeley & Wilson, 1994). Consequently, errorless learning should be more efficient than a classical “trial-and-error” procedure for AD patients. Indeed, errorless learning decreases the involvement of (impaired) explicit memory by avoiding the interference caused by the production of errors (Bier et al., 2002). The present study investigates the automatic post-learning error production in mild AD patients and matched control subjects by using a word stem completion task (Adam et al., 2005) in conditions of both errorless and trial-and-error learning. Results showed a lower word stem completion performance in mild AD than control subjects, but a similar performance in the patients’ group for the two learning conditions. Moreover, in the trial-and-error procedure, the errors consisted mainly in erroneous responses already produced during the learning phase. In addition, correlation analyses indicate that the ability to suppress errors in the trial-and-error learning condition in mild AD patients is subtended by the efficiency of episodic memory processes, but not by inhibitory abilities. These results suggest that the errorless procedure improves the quality of learning of mild AD patients (production of fewer errors) but do not influence the learning rate per se. [less ▲]

Detailed reference viewed: 42 (8 ULg)
Peer Reviewed
See detailSpatial and/or visual short-term memory deficit in unilateral neglect
Wansard, Murielle ULg; Meulemans, Thierry ULg; Bartolomeo, Paolo

in 1st Joint Meeting of the Belgian Association for Psychological Science and Sociedad Espanola de Psicologia Experimental. (2012, May 11)

Patients suffering from left unilateral neglect fail to perceive or respond to stimuli presented within the contralesional space. Neglect is generally considered as involving an attentional bias towards ... [more ▼]

Patients suffering from left unilateral neglect fail to perceive or respond to stimuli presented within the contralesional space. Neglect is generally considered as involving an attentional bias towards the ipsilateral side. Recently, it has been suggested that revisiting and perseveration behaviors in visual search tasks shown in parietal neglect could be related to impairment in visuo-spatial working memory (Husain et al., 2001; Wojciulik et al., 2001). The aim of the present study was to investigate which aspect of visuo-spatial working memory is involved in unilateral neglect. Indeed, different source of evidence support the idea that visuo-spatial working memory involves at least two separate cognitive subsystems: the visual cache and the inner scribe (Logie, 1995; Pickering et al., 2001). We assessed thirteen right-damaged patients suffering from left neglect on two experimental task involving either spatial (Corsi test) or visual (Span test) working memory. Results show that visual and/or spatial working memory can be impaired in spatial neglect. This double dissociation provides neuropsychological support for the separation of visuo-spatial working memory into two subcomponents. The clinical and anatomical implications of this finding are discussed. [less ▲]

Detailed reference viewed: 93 (26 ULg)