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See detailDISSOCIATING SHORT-TERM MEMORY AND LANGUAGE IMPAIRMENT: THE IMPORTANCE OF ITEM AND SERIAL ORDER INFORMATION
Attout, Lucie ULg; VAN DER KAA, Marie-Anne ULg; GEORGE, Mercédès ULg et al

in Aphasiology (2012), 26(3-4), 355-382

BACKGROUND: Selective verbal short-term memory (STM) deficits are rare, and when they appear, they are often associated with a history of aphasia, raising doubts about the selectivity of these deficits ... [more ▼]

BACKGROUND: Selective verbal short-term memory (STM) deficits are rare, and when they appear, they are often associated with a history of aphasia, raising doubts about the selectivity of these deficits. Recent models of STM consider that STM for item information depends upon activation of the language system, and hence item STM deficits should be associated with language impairment. By contrast, STM for order information is considered to recruit a specific system, distinct from the language system: this system could be impaired in patients with language-independent STM deficits. AIM: We demonstrate here the power of the item-order distinction to separate STM and language impairments in two brain damaged cases with STM impairment and a history of aphasia. METHODS & PROCEDURES: Recognition and recall STM tasks, maximizing STM for either item or order information were administered to patients MB and CG. OUTCOMES & RESULTS: Patient MB showed mild phonological impairment. As predicted, associated STM deficits were characterized by poor item STM but preserved order STM. On the other hand, patient CG showed no residual language deficits. His STM deficit was characterized by poor order STM but perfectly preserved item STM. CONCLUSIONS: This study presents the first double dissociation between item and order STM deficits, and demonstrates the necessity of this distinction for understanding and assessing STM impairment in patients with and without aphasia. [less ▲]

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See detailDissociation between controlled and automatic processes in the behavioral variant of fronto-temporal dementia
Collette, Fabienne ULg; Van der Linden, Martial ULg; Salmon, Eric ULg

in Journal of Alzheimer's Disease [=JAD] (2011), 22(3), 897-907

A decline of cognitive functioning affecting several cognitive domains was frequently reported in patients with frontotemporal dementia. We were interested in determining if these deficits can be ... [more ▼]

A decline of cognitive functioning affecting several cognitive domains was frequently reported in patients with frontotemporal dementia. We were interested in determining if these deficits can be interpreted as reflecting an impairment of controlled cognitive processes by using an assessment tool specifically developed to explore the distinction between automatic and controlled processes, namely the process dissociation procedure (PDP) developed by Jacoby [1]. The PDP was applied to a word stem completion task to determine the contribution of automatic and controlled processes to episodic memory performance and was administered to a group of 12 patients with the behavioural variant of frontotemporal dementia (bv-FTD) and 20 control subjects (CS). Bv-FTD patients obtained a lower performance than CS for the estimates of controlled processes, but no group differences was observed for estimates of automatic processes. The between-groups comparison of the estimates of controlled and automatic processes showed a larger contribution of automatic processes to performance in bv-FTD, while a slightly more important contribution of controlled processes was observed in control subjects. These results are clearly indicative of an alteration of controlled memory processes in bv-FTD. [less ▲]

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See detailDissociation between recall and recognition memory in amnesia
Bastin, Christine ULg

Scientific conference (2004)

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See detailDissociation between recall and recognition memory in amnesia: The case of a patient with hippocampal damage following carbon monoxide poisoning
Bastin, Christine ULg; Van der Linden, Martial ULg; Charnallet, Annik et al

in Proceedings of the Joint Mid-year meeting of the International Neuropsychological Society, the Division of Neuropsychology of the British Psychological Society and the British Neuropsychological Society (2005)

There is currently a debate regarding the status of recall and recognition memory in amnesic patients with focal hippocampal damage. Proportionate deficits of recall and recognition memory have been ... [more ▼]

There is currently a debate regarding the status of recall and recognition memory in amnesic patients with focal hippocampal damage. Proportionate deficits of recall and recognition memory have been observed in some patients with selective hippocampal damage. In addition, these patients showed an impairment of both the recollection and familiarity aspects of recognition memory. In contrast, other amnesic patients with selective hippocampal lesions demonstrated relatively preserved recognition memory, despite severely impaired recall abilities. In some of them, familiarity processes were found to be intact. The resolution of this controversy has important implications for theories of episodic memory. In the present study, we examined the recall and recognition performance of an amnesic patient, MR, who suffered from bilateral hippocampal damage and temporoparietal cortical atrophy following carbon monoxide poisoning. Verbal and nonverbal recall and recognition memory were measured by tasks matched for difficulty. On these tasks, MR’s recall performance was more severely impaired than his recognition memory. In addition, MR’s recognition performance was normal on most of the tasks. In order to determine on which processes MR based his recognition decisions, we administered to the patient and to matched controls the process dissociation procedure. This evaluates the contribution of recollection and familiarity within a recognition task. The results indicated that, in this patient, familiarity was preserved, but recollection was impaired. This study thus supports the idea that amnesic patients with hippocampal damage can show preserved familiarity-based recognition memory, despite poor recall and recollection. [less ▲]

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See detailDissociation between recall and recognition memory performance in an amnesic patient with hippocampal damage following carbon monoxide poisoning.
Bastin, Christine ULg; Van der Linden, Martial ULg; Charnallet, Annik et al

in Neurocase : Case Studies in Neuropsychology, Neuropsychiatry & Behavioural Neurology (2004), 10(4), 330-344

Some patients with relatively selective hippocampal damage have shown proportionate recall and recognition deficits. Moreover, familiarity as well as recollection have been found to be impaired in some of ... [more ▼]

Some patients with relatively selective hippocampal damage have shown proportionate recall and recognition deficits. Moreover, familiarity as well as recollection have been found to be impaired in some of these patients. In contrast, other patients with apparently similar damage presented with relatively preserved recognition despite having severely impaired recall, and some of these patients have been shown to have preserved familiarity. We report here the case of an amnesic patient who suffered bilateral hippocampal damage and temporoparietal atrophy after carbon monoxide poisoning. On tests matched for difficulty, his recall performance was more severely impaired than his recognition memory, for verbal as well as for visual materials. Moreover, he performed within the range of healthy matched subjects on nine recognition tests out of ten. In a task using the process dissociation procedure, the patient’s familiarity was preserved although his recollection was impaired. These findings indicate that recall and recognition memory can be dissociated in amnesic patients with hippocampal lesions even when temporoparietal cortical atrophy is also present. [less ▲]

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See detailDissociation between the locomotor and anxiolytic effects of acetaldehyde in the elevated plus-maze : evidence that acetaldehyde is not involved in the anxiolytic effects of ethanol in mice
Tambour, Sophie ULg; Didone, Vincent ULg; Tirelli, Ezio ULg et al

in European Neuropsychopharmacology (2005), 15(6), 655-662

Acetaldehyde, the first product of ethanol metabolism, has been suggested to play a major role in many behavioral effects of ethanol. However, very few studies have directly tested the behavioral effects ... [more ▼]

Acetaldehyde, the first product of ethanol metabolism, has been suggested to play a major role in many behavioral effects of ethanol. However, very few studies have directly tested the behavioral effects of the acute administration of acetaldehyde. In particular, the role of this metabolite in ethanol-induced anxiolytic effects has never been extensively tested. The aim of the present study was to characterize the anxiolytic effects of acetaldehyde in two strains of mice, C57BL/6J and CD1 mice with the elevated plus-maze procedure. The results show that acute injections of ethanol (1-2 g/kg) induced significant dose-dependent anxiolytic effects in both strains of mice. In contrast, acetaldehyde failed to produce any anxiolytic effect, although it induced a significant hypolocomotor effect at the highest doses. In an independent experiment, cyanamide, an aldehyde dehydrogenase inhibitor, prevented the locomotor stimulant effects of ethanol, although it failed to alter its anxiolytic effects. Together, the results of the present study indicate that acetaidehyde is not involved in ethanol-induced anxiolytic effects, although it may be involved in its sedative/hypolocomotor effects. (c) 2005 Elsevier BX and ECNP. All fights reserved. [less ▲]

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See detailDissociation between unconscious motor response facilitation and conflict in medial frontal areas.
D'Ostilio, Kevin ULg; GARRAUX, Gaëtan ULg

in European Journal of Neuroscience (2012), 35(2), 332-340

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See detailDissociation entre recollection et familiarité dans la maladie d'Alzheimer : Etude des bases cérébrales en imagerie par résonance magnétique fonctionnelle.
Bastin, Christine ULg; Genon, Sarah ULg; Collette, Fabienne ULg et al

in Proceedings of the 11th Reunion Francophone sur la Maladie d’Alzheimer et les Syndromes Apparentés (2012)

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See detailDissociation entre recollection et familiarité dans la maladie d’Alzheimer: Etude des bases cérébrales en imagerie par résonance magnétique fonctionnelle
Bastin, Christine ULg; Genon, Sarah ULg; Collette, Fabienne ULg et al

Conference (2012)

1. Matériels et méthodes. Les difficultés mnésiques des patients à un stade léger d’une maladie d’Alzheimer sont marquées par une atteinte sévère de la récupération consciente des informations dans leur ... [more ▼]

1. Matériels et méthodes. Les difficultés mnésiques des patients à un stade léger d’une maladie d’Alzheimer sont marquées par une atteinte sévère de la récupération consciente des informations dans leur contexte d’apprentissage (recollection). Par contre, la reconnaissance des informations sur base d’un sentiment de familiarité (savoir qu’une information a été rencontrée auparavant sans récupérer son contexte d’apprentissage) est relativement préservée (Dalla Barba, 1997; Rauchs et al., 2007). L’objectif de cette étude était de révéler les substrats cérébraux des processus de recollection et familiarité dans la maladie d’Alzheimer au moyen d’une tâche de mémoire associative analysée selon les principes de la Procédure de Dissociation des Processus (Jacoby, 1991). Pendant une acquisition en IRM fonctionnelle, 26 patients avec une maladie d’Alzheimer probable à un stade léger et 17 témoins âgés ont étudié des paires de mots, puis ont dû les reconnaître parmi des paires recombinées (deux mots vus mais pas ensemble) et des paires nouvelles. 2. Résultats. Les analyses comportementales ont indiqué que 10 patients Alzheimer avaient des indices de recollection nuls (AD-), tandis que 16 autres patients présentaient des processus de recollection résiduels (AD+) bien que significativement moins importants que les témoins. Par contre, le score estimant la contribution des processus de familiarité était équivalent dans les trois groupes. L’analyse de l’activité cérébrale a montré que, chez les patients AD+ comme chez les témoins, la recollection activait le cortex cingulaire postérieur. Cependant, cette région était fonctionnellement connectée à l’hippocampe, au cortex pariétal inférieur et au cortex préfrontal dorsolatéral uniquement chez les témoins. Par ailleurs, dans les trois groupes, la familiarité activait le sillon intrapariétal. 3. Conclusion. Cette étude montre un déficit sévère de recollection et une relative préservation de la familiarité chez des patients Alzheimer. Lorsque les patients possèdent des capacités résiduelles de recollection, celles-ci sont soutenues par le cortex cingulaire postérieur comme chez les personnes âgées saines. Cependant, une perturbation de la connectivité fonctionnelle entre le cortex cingulaire postérieur et des régions impliquées dans la mémoire relationnelle, les aspects subjectifs de la recollection et les processus de monitoring post-récupération suggère que la qualité de la recollection résiduelle des patients Alzheimer est dégradée. 4. Références. Dalla Barba, G. (1997). Recognition memory and recollective experience in Alzheimer's disease. Memory, 5, 657-672. Jacoby, L.L. (1991). A process dissociation framework: Separating automatic from intentional uses of memory. Journal of Memory and Language, 30, 513-541. Rauchs, G., Piolino, P., Mézenge, F., Landeau, B., Lalevée, C., Pélerin, A. et al. (2007). Autonoetic consciousness in Alzheimer's disease: Neuropsychological and PET findings using an episodic learning and recognition task. Neurobiology of Aging, 28, 1410-1420. [less ▲]

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See detailDissociation of Difluoroetylene Cations: an ion-neutral complex along the fluoroethylidene+ + HF reaction path.
Leyh, Bernard ULg; Lorquet, Andrée ULg; Lorquet, Jean-Claude ULg et al

in Gelpi, E. (Ed.) 15th International Mass Spectrometry Conference: Book of Abstracts (2000)

The collision activated dissociation and dissociative photoionization of 1,1- and 1,2-C2H2F2 in the HF-loss channel are investigated. The measured KER ditributions are interpreted by the opening of two ... [more ▼]

The collision activated dissociation and dissociative photoionization of 1,1- and 1,2-C2H2F2 in the HF-loss channel are investigated. The measured KER ditributions are interpreted by the opening of two competitive reaction channels leading to two C2HF+ isomers. This hypothesis is checked by ab initio calculations. [less ▲]

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See detailDissociation of increases in plasma insulin-like growth factor I and testosterone during the onset of puberty in bulls
Renaville, Robert ULg; Massart, Serge; Sneyers, M. et al

in Journal of Reproduction and Fertility (1996), 106(1), 79-86

The present study was conducted to examine the relationship between plasma concentrations of testosterone, insulin-like growth factor I (IGF-I) and IGF-binding proteins (IGFBPs) during puberty, in male ... [more ▼]

The present study was conducted to examine the relationship between plasma concentrations of testosterone, insulin-like growth factor I (IGF-I) and IGF-binding proteins (IGFBPs) during puberty, in male calves treated with GnRH or testosterone propionate. Twelve male Holstein calves (10 weeks old) were assigned to the control group (n = 6), the GnRH-treated group (n = 3) or the testosterone-treated group (n = 3). For 8 weeks, the GnRH-treated group received a single i.v. injection of GnRH (0.5 mu g kg(-1) body mass) each day while the testosterone-treated group received an i.m. injection of testosterone propionate (0.5 mg kg(-1) body mass) twice a day. The calves were studied until they were 200 days old. Hormone treatments were stopped one month after puberty was reached in the control group. Blood samples were collected every 30 min for 8 h every third day. Hormone concentrations were determined by radioimmunoassay. Western ligand blotting and immunoblotting, using monoclonal antibodies against IGFBP-2, and IGFBP-3, were used to characterize the IGF-binding proteins. In the control group, puberty occurred at about 120 days of age and was associated with an increase in concentrations of testosterone, IGF-I and IGFBP-3 and a decrease in concentration of IGFBP-2. In the GnRH-treated group, plasma testosterone remained low until 8 weeks after establishment of puberty in the control group (4 weeks after the end of treatment). In the testosterone-treated group, testosterone was high during the treatment period and then decreased to prepubertal values when treatment was stopped. Testosterone values increased again to reach postpubertal values 5 weeks after the end of hormone treatment. Nevertheless, independent of testosterone status, the profile of IGF-I and the IGFBPs in the GnRH- and testosterone-treated groups were parallel to that reported for the control group with the transition from prepubertal to adult values at about 120 days of age. In conclusion, concentrations of testosterone, IGF-I and IGFBP-3 increase together, but probably independently, during the onset of puberty in male calves. [less ▲]

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See detailDissociation of perceptual and motor inhibitory processes in young and elderly participants using the Simon task.
Germain, Sophie ULg; Collette, Fabienne ULg

in Journal of the International Neuropsychological Society (2008), 14(6), 1014-21

Deficits in inhibitory abilities are frequently observed in normal aging. However, few studies have explored the generality of these deficits in a single group of participants. Here, we used an adaptation ... [more ▼]

Deficits in inhibitory abilities are frequently observed in normal aging. However, few studies have explored the generality of these deficits in a single group of participants. Here, we used an adaptation of the Simon task to differentially assess perceptual and motor inhibition using the same stimuli and task design and to determine whether these processes use separate or shared cognitive resources. We were interested in determining whether (1) normal aging is associated with the use of separate (as previously evidenced in young participants) or similar cognitive resources to perform perceptual and motor inhibition tasks; (2) older participants present a specific impairment in one of these two processes. Analyses of reaction times indicated that motor and perceptual inhibitory processes share some cognitive resources and both are impaired in normal aging. These results can be interpreted by considering that a dedifferentiation process is responsible for the inhibitory deficits presented by older participants. [less ▲]

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See detailDissociation par compression graduée des voies motrices et arrestatrices contenues dans le faisceau de His
Fredericq, Léon ULg

in Archives Internationales de Physiologie (1911), XI

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See detailDissociation par compression graduée des voies motriceset arrestatrices contenues dans le faisceau de His
Fredericq, Léon ULg

in Bulletin de l'Académie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique. Sciences (1911)

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See detailDissociation Pathways of Benzylpyridinium “Thermometer” Ions Depend on the Activation Regime: An IRMPD Spectroscopy Study
Morsa, Denis ULg; Gabelica, Valérie ULg; Rosu, Frédéric et al

in Journal of Physical Chemistry Letters (2014), 5

The dissociation of benzylpyridinium “thermometer” ions is widely used to calibrate the internal energy of ions produced in mass spectrometry. The fragmentation mechanism is usually believed to yield a ... [more ▼]

The dissociation of benzylpyridinium “thermometer” ions is widely used to calibrate the internal energy of ions produced in mass spectrometry. The fragmentation mechanism is usually believed to yield a benzylium cation, although recent studies suggest the possibility of a rearrangement leading to the tropylium isomer, which would compromise the accuracy of energy calibrations. In this study, we used IRMPD spectroscopy to probe the dissociation pathways of the p-(tert-butyl)- benzylpyridinium ion. Our results show that the formation of both benzylium and tropylium products is feasible depending on the activation regime and on the reaction time scale. Varying the trapping delays in the hexapole gives insight into a rearrangement mechanism occurring through consecutive reactions with an isomerization from benzylium to tropylium. Our work provides experimental validations for the established calibration procedure and highlights the adequacy of IRMPD spectroscopy to qualitatively resolve gas-phase rearrangement kinetics. [less ▲]

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