Disturbance of spatial working memory and its neurophysiological correlates in alcohol dependence

Введение. У пациентов с алкогольной зависимостью наблюдаются нарушения в широком диапазоне когнитивных функций. Это приводит к неспособности контролировать употребление алкоголя, рецидивированию или постоянному употреблению алкоголя, несмотря на негативные физические, психологические и социальные последствия. Исполнительный контроль относится к группе когнитивных функций, который позволяют людям самостоятельно регулировать свое поведение и выбирать соответствующие действия в зависимости от долгосрочных целей. При этом рабочая память является одной из главных составляющих исполнительного контроля. Цель исследования - изучение пространственной рабочей памяти у пациентов с синдромом алкогольной зависимости с использованием метода количественной ЭЭГ и компьютерного теста Corsi. Методика. Обследовано 50 пациентов с диагнозом алкогольной зависимости (F10.2 по МКБ-10) после детоксикации. Группу контроля составили 30 психически и соматически здоровых лиц, сопоставимых по возрасту. Исследование пространственной рабочей памяти осуществляли с помощью компьютерного теста Корси (Corsi Block-Tapping). Регистрировали 16-канальную ЭЭГ: фон с открытыми глазами и во время выполнения теста Corsi. Анализировали абсолютные значения спектральной мощности θ-, α- и β-ритмов. Результаты. Согласно результатам теста Corsi, при алкогольной зависимости наблюдается выраженное снижение объема рабочей памяти относительно здоровой группы контроля. Изменения ЭЭГ в процессе выполнения теста Corsi у пациентов с синдромом алкогольной зависимости сопровождались десинхронизацией альфа-ритма в префронтальной коре мозга и левом височном локусе, что не выявлялось у обследуемых здоровой группы контроля. Было обнаружено снижение бета-ритма в центральной и теменной коре у пациентов с синдромом алкогольной зависимости в ответ на когнитивный стимул. У пациентов с синдромом алкогольной зависимости существенно повышалась тета-мощность в затылочной коре в ответ на когнитивный стимул, а также регистрировалась статистически значимо большая тета-активность в правом височном локусе. Заключение. Полученные результаты могут служить дополнительными диагностическими критериями когнитивных нарушений у пациентов с синдромом зависимости от алкоголя. Patients with alcohol dependence have disorders of multiple cognitive functions. This leads to inability to control alcohol consumption, relapse or continued use of alcohol despite negative physical, psychological, and social consequences. Executive control refers to a group of cognitive functions that allow people to regulate independently their behavior and to choose appropriate actions depending on their long-term goals. Working memory (WM) is one of the main components of the executive control. The aim of the study was to evaluate indexes of spatial working memory in patients with alcohol dependence syndrome using the quantitative EEG method and the Corsi computer test. Methods. 50 patients diagnosed with alcohol dependence (F10.2 on MKB-10) were evaluated after detoxification. The control group consisted of 30 mentally and somatically healthy, age-matched subjects. The study of spatial working memory was performed by a Corsi computer test (Corsi Block-Tapping). 16-channel EEGs were recorded at background with open eyes and during the Corsi test. Spectral power absolute values of θ -, α - and β - rhythms were analyzed. Results. According to the Corsi test in alcohol dependence, the WM volume was markedly decreased compared to the healthy control group. Changes in EEG during the Corsi test in patients with alcohol dependence syndrome were associated with alpha-rhythm desynchronization in the prefrontal cortex and left temporal locus, which was not observed in the healthy control group. Decreased beta rhythm was observed in the central and parietal cortex of patients with alcohol dependence syndrome in response to a cognitive stimulus. In patients with alcohol dependence syndrome, theta power was significantly increased in the occipital cortex in response to a cognitive stimulus, and theta activity was significantly greater in the right temporal locus. Conclusion. The results of this study may serve as additional diagnostic criteria for cognitive disorders in patients with alcohol dependence syndrome.

Hypnosis and learning: Pilot study on a group of students

BackgroundMilton Erickson was the first to introduce hypnosis as a form of therapy during the post-war period. Numerous studies have evaluated the effects of hypnosis on memory, focusing principally on post-hypnotic amnesia, post-hypnotic hypermnesia, faux memories and learning growth.The aim of the present study was to determine if hypnosis can influence visual-spatial memory by increasing its performance and learning; to do this, we chose to utilise the Corsi Test (backward and forward).MethodsThree hundred second-year students enrolled in the psychology faculty at the University of Catania were informed of the research and its modalities, and an e-mail was sent to inquire if they wanted to participate in the experiment.Seventy female students took part in the research; 10 were excluded because they presented a high risk of being influenced under hypnosis.The 60 subjects in the research sample were randomly divided into two groups: the Experimental Group and Control Group.The protocol prescribed administration of the Corsi Test at Time 0 (start) followed by a resting phase of 30 min. The hypnotic state was subsequently introduced, and the Corsi Test was administered again.ResultsThe results of the Corsi Test for the Experimental Group showed statistically significant results (p<0.0004 and p<0.0001), while the results obtained in the Control Group did not show any significance.ConclusionsThese results led us to believe that hypnosis has the capacity to induce a nervous plasticity that supports learning of visual-spatial memory.

Comparison of the touch-screen and traditional versions of the Corsi block-tapping test in patients with psychosis and healthy controls.

Working memory (WM) refers to the capacity system for temporary storage and processing of information, which is known to depend on the integrity of the prefrontal cortex. Impairment in working memory is a core cognitive deficit among individuals with psychotic disorders. The Corsi block-tapping test is a widely used instrument to assess visuospatial working memory. The traditional version is composed of 9 square blocks positioned on a physical board. In recent years, the number of digital instruments has increased significantly; several advantages might derive from the use of a digital version of the Corsi test. This study aimed to compare the digital and traditional versions of the Corsi test in 45 patients with psychotic disorders and 45 healthy controls. Both groups completed a neuropsychological assessment involving attention and working memory divided into two conditions. Results were consistent between the traditional and digital versions of the Corsi test. Overall, patients performed worse relative to the healthy comparison group. The traditional Corsi test was positively related to intelligence and verbal working memory, probably due to a more significant effort to execute the test. The digital version is able to discriminate between patients with psychosis and healthy controls. It would be of use in determining who is at risk of developing a psychotic disorder, and in those already with psychosis, it might provide a prognostic marker for future functional outcome. Further, it is easy to administer while ensuring a standard procedure.