Procedural learning of semantic categorization: a study of 110 non-disabled individuals.

PURPOSE: This paper describes a cognitive procedural task in order to study procedural learning of semantic categorization. We evaluated age, educational level and gender effects on semantic procedural skill. METHODS: The procedural task was developed in our laboratory, applying a manual and serial reaction time paradigm to semantic categorization. We investigated this form of procedural learning in 110 non-disabled subjects. RESULTS: We observed an improvement of semantic categorization reaction times (RTs) over time from practice, even with new verbal material to categorize. Age, educational level and gender did not influence procedural learning of semantic categorization but women performed faster than men. The results suggest that semantic categorization is susceptible to procedural training. CONCLUSION: The results suggest that semantic categorization is susceptible to procedural training.

Self-consciousness and Alzheimer's disease.

OBJECTIVES: To propose a neuropsychological study of the various aspects of self-consciousness (SC) in Alzheimer's disease. METHODS: Forty-five patients with probable mild or moderate AD were included in the study. Severity of their dementia was assessed by the Mini Mental State (MMS). Fourteen questions were prepared to evaluate SC. RESULTS: No significant correlations were found between SC score and educational level, age, and duration of disease. A significant correlation was found between SC score and the severity of dementia, whereas frontal disturbances were just short of the significance threshold. The various aspects of SC were not impaired to the same degree. The most disturbed ones were awareness of cognitive deficiencies, moral judgements and prospective memory. The least disturbed aspects were awareness of identity and of mental representation of the body. Items relating to anosognosia and moral judgements were significantly correlated with the MMS score, whereas affective state, body representation disorders, prospective memory, and capacities for introspection were not related to the severity of the dementia. Consciousness of identity was sound, regardless of MMS score. CONCLUSIONS: AD clearly induces an heterogeneous impairment of SC. SC requires a convergence of many neural networks. In AD, neuronal alterations involve many cortical areas and information sent to the associative frontal cortex from memory, language and visuospatial areas is lacking or disturbed. Thus, the sequential order of successive stimuli cannot be maintained by the heteromodal associative cortex (dorsal convexity of the prefrontal cortex), and the supramodal associative cortex (located rostrally in the frontal lobes) is unable to provide reliable monitoring and assessment of simultaneous neural cognitive networks carrying insufficient and inadequate input. The core deficiency in AD patients might be impaired SC equated with the disability to maintain sequential and simultaneous "attention to life". The Self-Consciousness Questionnaire, a clinical scale providing multidimensional measurement, indicates that different aspects of consciousness are not correlated with overall cognitive deficiency as determined by the MMSE.

Memoria del contexto informacional en el envejecimiento fisiológico / Memory regarding the information context in physiological aging

OBJETIVOS: Estudiar los efectos del envejecimiento normal sobre la memoria del contexto de la información (dónde, cuándo y cómo una información se aprende) y sus posibles relaciones con un disfuncionamiento frontal asociado a la edad. MÉTODO: Se evalúan un grupo de sujetos normales, formado por 19 jóvenes adultos y otro por 18 ancianos. Ambos grupos tenían que aprender nueva información real y dos horas más tarde, tenían que recodar la información, así como el contexto en el que la han aprendido. También contestaban a una batería de tests que valoran el funcionamiento frontal: Trail Making, Stroop, Fluencia Alternada y test de Wisconsin. RESULTADOS: El grupo de ancianos cometía más errores contextuales (72 por ciento) que el grupo de jóvenes (16 por ciento). El grupo de ancianos mostraba un mayor número de errores contextuales de tipo intraexperimental (39 por ciento). Este grupo presentaba peores resultados en los tests frontales que el grupo de los jóvenes, pero esos resultados no estaban relacionados con los de la memoria contextual. CONCLUSIONES: El grupo de ancianos presenta un olvido del contexto informacional. Pero nuestros resultados no han podido confirmar que el funcionamiento frontal de nuestro grupo de ancianos estuviese relacionado con la memoria contextual (AU)

Agitación/agresividad en la demencia de tipo Alzheimer / Agitation/aggresiveness in Alzheimer's disease

INTRODUCCION: La demencia de tipo Alzheimer (DTA) es una patología degenerativa con síntomas neuropsicológicos y neuropsiquiátricos. OBJETIVOS: Describir un trastorno conductual: agitación/agresividad con sus distintas manifestaciones. Evaluar el impacto de las alteraciones de conductas sobre el bienestar de los cuidadores principales (CP). MÉTODO: 42 pacientes con DTA de severidad moderada, con una media de 78,25 años fueron evaluados con el Inventario Neuropsiquiátrico (NPI) y sus CP respondieron también al autocuestionario "Quejas familiares de los enfermos con DTA". RESULTADOS Y CONCLUSIONES: Las conductas de agitación/agresividad son bastante frecuentes (55,1 por ciento de los casos), pero de severidad moderada. El signo más frecuente fue el del rechazo o resistencia a la ayuda/cuidado que el CP ofrecía al paciente (34,8 por ciento). Además, estas conductas son los trastornos comportamentales más perturbadores para el bienestar de los CP (35,4 por ciento) (AU)

Neuropsychological disturbances in cerebellar infarcts.

BACKGROUND: Recent clinical and research reports suggest that the cerebellum may contribute to the modulation of higher cognitive functions. MATERIAL AND METHODS: We included 15 consecutive patients with isolated cerebellar infarcts (4 superior cerebellar artery territory infarcts, 1 anterior inferior cerebellar artery territory infarct and 10 posterior inferior cerebellar artery territory infarcts), all confirmed by magnetic resonance imaging. These subjects plus 15 controls matched for age, sex, and educational level underwent a neuropsychological test battery including vocabulary, similarities and block design subtests of the Wechsler Adult Intelligence Scale Revised (WAIS-R); verbal fluency tests (categorial, phonemic, and alternate categorial fluency tests); Rey's 15 auditory word learning list; the paced auditory serial addition task; the Stroop test and the Zerssen Rating Scale. One year after the cerebellar infarct, each subject with cerebellar infarct was asked to undergo a second neuropsychological examination with the same test battery. RESULTS: Patients with cerebellar infarcts exhibited significantly lower neuropsychological performances compared to those of the control group without any obvious difference between the different vascular cerebellar territories. After 1 year of follow-up, this neuropsychological impairment tended to improve. CONCLUSIONS: The pattern of deficits observed in isolated cerebellar infarcts highlights the nonmotor functions of the cerebellum and functional relationship between the cerebral cortex and the cerebellum.

[Procedural learning and neurological disorders]. / Aprendizajes procedimentales y enfermedades neurológicas.

INTRODUCTION AND DEVELOPMENT: We review the current state of learning procedures in six neurological conditions: amnesia, Alzheimer-type dementia, Huntington's disease, Parkinson's disease, progressive supranuclear paralysis and cerebellar pathology. In each condition the conservation or deterioration of different types of ability is specified: motor and percepto-motor abilities were evaluated using different tests such as following a rotating disk or signal, the labyrinth test, percepto-motor adaptation test or tests using paradigms of time of serial reaction; percepto-cognitive abilities evaluated by 'mirror-reading' and cognitive abilities evaluated by the Tower of Hanoi, of Toronto, or of London. CONCLUSION: Most of the papers published describe conservation of learning procedures in amnesic syndromes, relatively conserved in Alzheimer's disease and relatively deteriorated in Huntington's disease, in progressive supranuclear paralysis and in cerebellar dysfunction.

[Cerebral evoked potentials and semantic categorization]. / Potenciales evocados cerebrales y catagorización semántica.

INTRODUCTION: Cerebral evoked potentials represent variations in the electrical activity of the nervous system, excited by a sensory stimulus and which are recorded on the surface. They may be classified as endogenous or exogenous. Amongst the late endogenous evoked potentials (EEP) we may emphasize N400 which seems to represent the linguistic management wave, particularly for semantics. OBJECTIVE: To observe the EEP recorded throughout the process of carrying out a task involving sequential semantic categorization. PATIENTS AND METHODS: Nine healthy subjects carried out a task based on a paradigm of sequential reaction time (RT), similar to that designed by us in 1994. The data recorded were the RT and EEP at the level of the electrodes Fz, Cz and Pz in five lots of stimuli (in the first four lots the same list of words were repeated and in the fifth and final lot a different, new list appeared). CONCLUSIONS: It was seen that only N400 varied during the procedure. This variation was related to familiarity with the task. That is to say that the amplitude of N400 was reduced when the same words were repeated and increased when new words appeared for semantic classification. The reduction in parallel, although not significant for RT, allowed the reduction in N400 alone to be followed whilst the task was carried out. It may be the electrophysiological marker of the process of learning semantic categorization.

Neurobehavioral dimensions of olivopontocerebellar atrophy.

Twenty-one patients with olivopontocerebellar atrophy (OPCA) and 21 normal controls of equivalent age, gender, and educational levels underwent a series of neurobehavioral tests thought to measure frontal lobe and parietal lobe functions as well as information processing speed. The patients with OPCA had higher reaction times and movement times, confirming the results of previous experiments. They had lower scores for some tests thought to be sensitive to dysfunction of the frontal lobe, such as hand sequencing, verbal reasoning, and proverb interpretation. Deficits in copying a simple figure and in immediate visual-spatial memory, thought to be indicative of parietal lobe dysfunction, were also discerned. These results are consistent with the hypothesis that the cerebellum is involved in visual-spatial working memory that requires rapid information processing, and that it modulates parietal lobe- and frontal lobe-mediated functions.

[Procedural learning in aphasic patients]. / Aprendizaje procedimental en un grupo de afásicos.

OBJECTIVE: This study concerned the procedural learning of semantic categorization. PATIENTS AND METHODS: The procedure used was a serial reaction time in an group of aphasic patients. RESULTS: Group of aphasic patients performed slower reaction times with more errors than the controls, but everyone manifested a decreasing reaction time, even during new semantic material categorization. CONCLUSIONS: Our results showed that the semantic categorization could be facilitated by procedural learning. Furthermore, this study suggest that procedural learning of semantic categorisation is at least relatively independent from cerebral structures usually involved a group of aphasic patients.