A study of semantic memory after brain injury: Learning newly coined French words

AbstractObjectiveTo investigate semantic memory in brain-injured patients.MethodsWe used the new word questionnaire (QMN) to assess the ability of 12 brain-injured patients and 12 healthy controls to define French words, which had been admitted to the dictionary in 1996 to 1997 or in 2006 to 2007.ResultsDespite amnesia or severe executive disorders, the brain-injured patients were able to learn new words and remember those that they already learnt. They successfully selected the relevant phrase in which the new word was placed and were reasonably good at recognizing the right definition from among decoys. In contrast, they had trouble defining the words and compensated for this by giving examples. These problems were correlated with their vocabulary and executive function scores in a battery of neuropsychological tests.ConclusionOur results suggest that frontal injury leads to an impairment in accurate word selection and the scheduling abilities required to generate word definitions

Clinical characteristics and brain PET findings in 3 cases of dissociative amnesia : Disproportionate retrograde devicit and posterior middle temporal gyrus hypometabolism

Background Precipitated by psychological stress, dissociative amnesia occurs in the absence of identifiable brain damage. Its clinical characteristics and functional neural basis are still a matter of controversy. Methods In the present paper, we report 3 cases of retrograde autobiographical amnesia, characterized by an acute onset concomitant with emotional/neurological precipitants. We present 2 cases of dissociative amnesia with fugue (cases 1 and 2), and one case of focal dissociative amnesia after a minor head trauma (case 3). The individual case histories and neuropsychological characteristics are reported, as well as the whole-brain voxel-based 18FDG-PET metabolic findings obtained at group-level in comparison to 15 healthy subjects. Results All patients suffered from autobiographical memory loss, in the absence of structural lesion. They had no significant impairment of anterograde memory or of executive function. Impairment of autobiographical memory was complete for two of the three patients, with loss of personal identity (cases 1 and 2). A clinical recovery was found for the two patients in whom follow-up was available (cases 2 and 3). Voxel-based group analysis highlighted a metabolic impairment of the right posterior middle temporal gyrus. 18FDG-PET was repeated in case 3, and showed a complete functional brain recovery. Conclusion The situation of dissociative amnesia with disproportionate retrograde amnesia is clinically heterogeneous between individuals. Our findings may suggest that impairment of high-level integration of visual and/or emotional information processing involving dysfunction of the right posterior middle temporal gyrus could reduce triggering of multi-modal visual memory traces, thus impeding reactivation of aversive memories

Procedural Memory: Computer Learning in Control Subjects and in Parkinson’s Disease Patients

We used perceptual motor tasks involving the learning of mouse control by looking at a Macintosh computer screen. We studied 90 control subjects aged between sixteen and seventy-five years. There was a significant time difference between the scales of age but improvement was the same for all subjects. We also studied 24 patients with Parkinson's disease (PD). We observed an influence of age and also of educational levels. The PD patients had difficulties of learning in all tests but they did not show differences in time when compared to the control group in the first learning session (Student's t-test). They learned two or four and a half times less well than the control group. In the first test, they had some difficulty in initiating the procedure and learned eight times less well than the control group. Performances seemed to be heterogeneous: patients with only tremor (seven) and patients without treatment (five) performed better than others but learned less. Success in procedural tasks for the PD group seemed to depend on the capacity to initiate the response and not on the development of an accurate strategy. Many questions still remain unanswered, and we have to study different kinds of implicit memory tasks to differentiate performance in control and basal ganglia groups

Assessing capacity to consent for research in cognitively impaired older patients

Thomas Gilbert,1 Antoine Bosquet,2 Catherine Thomas-Antérion,3,4 Marc Bonnefoy,1 Olivia Le Saux1 1Geriatric Department, Hospices Civils de Lyon, Lyon Sud Hospital, Pierre-Bénite, France; 2Internal Medicine Unit, AP-HP – Louis Mourier Hospital, Colombes, France; 3Plein Ciel, Lyon, France; 4Laboratory for the Study of Cognitive Mechanisms, Lyon 2 University, Lyon, France Background: The number of clinical trials including older patients, and particularly patients with cognitive impairment, is increasing. While statutory provisions exist to make sure that the capacity to consent is assessed systematically for each patient, many gray areas remain with regard to how this assessment is made or should be made in the routine practice of clinical research. Objectives: The aim of this review was to draw up an inventory of assessment tools evaluating older patients’ capacity to consent specifically applicable to clinical research, which could be used in routine practice. Methods: Two authors independently searched PubMed, Cochrane, and Google Scholar databases between November 2015 and January 2016. The search was actualized in April 2017. We used keywords (MeSH terms and text words) referring to informed consent, capacity to consent, consent for research, research ethics, cognitive impairment, vulnerable older patients, and assessment tools. Existing reviews were also considered. Results: Among the numerous existing tools for assessing capacity to consent, 14 seemed potentially suited for clinical research and six were evaluated in older patients. The MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR) was the most frequently cited. Conclusion: The MacCAT-CR is currently the most used and the best validated questionnaire. However, it appears difficult to use and time-consuming. A more recent tool, the University of California Brief Assessment of Capacity to Consent (UBACC), seems interesting for routine practice because of its simplicity, relevance, and applicability in older patients. Keywords: aged, assessment tools, clinical research, decision-making capacit

Exploration of Verbal and Non-verbal Semantic Knowledge and Autobiographical Memories Starting from Popular Songs in Alzheimer\u27s Disease

BACKGROUND: In mild Alzheimer\u27s disease (AD), a deficit in episodic memory, particularly autobiographical memory, is clearly established. Several recent studies have also shown impaired semantic memory from the onset of the disease. Musical memory capacities may be especially preserved and listening to music might encourage autobiographical recall. The aim of this study was to explore recall of popular songs in AD. METHODS: We tested 12 patients with mild AD and 12 control subjects. We created a tool made up of old French popular songs: POP 10. This tool is a questionnaire composed of several subtests: melodic free recall, chorus free recall, melodic recognition, chorus recognition, semantic knowledge, autobiographical recall about the song, and autobiographical recall about the interpreter. RESULTS: We used non-parametric tests, the Mann-Whitney test (M-W), the Friedman test, and the a posteriori Wilcoxon test. Results of AD patients were rather similar to those of control participants for melodic memory. Concerning chorus memory (except recognition), semantic knowledge, and autobiographical recall about the interpreter, results of AD patients were significantly weaker than those of control participants. The most important result concerned autobiographical recall about the song: we found no impairment-related differences between the two groups. CONCLUSION: Our findings demonstrate that popular songs can be excellent stimuli for reminiscence, such as the ability to produce an autobiographical memory related to a song. Thus, we confirm that musical semantic knowledge associated with a song may be relatively preserved in the early stages of AD. This leads to new possibilities for cognitive stimulation

Superior explicit memory despite severe developmental amnesia: In-depth case study and neural correlates

International audienceThe acquisition of new semantic memories is sometimes preserved in patients with hippocampal amnesia. Robust evidence for this comes from case reports of developmental amnesia suggesting that low-to-normal levels of semantic knowledge can be achieved despite compromised epi-sodic learning. However, it is unclear whether this relative preservation of semantic memory results from normal acquisition and retrieval or from residual episodic memory, combined with effortful repetition. Furthermore, lesion studies have mainly focused on the hippocampus itself, and have seldom reported the state of structures in the extended hippocampal system. Preserved components of this system may therefore mediate residual episodic abilities, contributing to the apparent semantic preservation. We report an in-depth study of Patient KA, a 27-year-old man who had severe hypoxia at birth, in which we carefully explored his residual episodic learning abilities. We used novel speeded recognition paradigms to assess whether KA could explicitly acquire and retrieve new context-free memories. Despite a pattern of very severe amnesia, with a 44-point discrepancy between his intelligence and memory quotients, KA exhibited normal-to-superior levels of knowledge, even under strict time constraints. He also exhibited normal-to-superior recognition memory for new material, again under strict time constraints. Mul-timodal neuroimaging revealed an unusual pattern of selective atrophy within each component of the extended hippocampal system, contrasting with the preservation of anterior subhippocampal cortices. A cortical thickness analysis yielded a pattern of thinner but also thicker regional cortices, pointing toward specific temporal lobe reorganization following early injury. We thus report the first case of superior explicit learning and memory in a severe case of amnesia, raising important questions about how such knowledge can be acquired