ABSTRACT
Visuospatial memory (VSM) is the ability to represent and manipulate visual and spatial information. This cognitive function depends on the functioning of the hippocampal formation (HF), located in the medial portion of the temporal cortex. The present study aimed to investigate whether there is an association between the volume of the HF and performance in VSM tests. High-resolution structural images (T1) and neuropsychological tests evaluating VSM were performed on 31 healthy individuals. A VSM index was created by grouping 5 variables from 5 tasks (4 from the CANTAB battery and 1 from the Rey-Osterrieth Complex Figure test). Multiple linear regression models using the volumes of HF subregions as independent variables and the VSM index as the dependent variable were conducted to test the hypothesis that memory performance could be predicted by HF volumes. We also conducted analyses to explore the role of covariates that may mediate this relationship, specifically age and intelligence quotient (IQ). We found significant associations between the hippocampal subregions of the left hemisphere and the VSM index (F(7,22)=2.758, P=0.032, R2a=0.298). When IQ was accounted for as a covariate, we also found significant results for the right hemisphere (F(8,21)=2.804, P=0.028, R2a=0.517). We concluded that the bilateral hippocampal formations contributed to performance on VSM tasks. Also, VSM processing is essential for a diverse set of daily activities and may be influenced by demographic variables in healthy subjects.
Subject(s)
Humans , Hippocampus , Memory , Magnetic Resonance Imaging , Neuropsychological TestsABSTRACT
The parahippocampal gyrus-orbitofrontal cortex (PHG-OFC) circuit in humans is homologous to the postrhinal cortex (POR)-ventral lateral orbitofrontal cortex (vlOFC) circuit in rodents. Both are associated with visuospatial malfunctions in Alzheimer's disease (AD). However, the underlying mechanisms remain to be elucidated. In this study, we explored the relationship between an impaired POR-vlOFC circuit and visuospatial memory deficits through retrograde tracing and in vivo local field potential recordings in 5XFAD mice, and investigated alterations of the PHG-OFC circuit by multi-domain magnetic resonance imaging (MRI) in patients on the AD spectrum. We demonstrated that an impaired glutamatergic POR-vlOFC circuit resulted in deficient visuospatial memory in 5XFAD mice. Moreover, MRI measurements of the PHG-OFC circuit had an accuracy of 77.33% for the classification of amnestic mild cognitive impairment converters versus non-converters. Thus, the PHG-OFC circuit explains the neuroanatomical basis of visuospatial memory deficits in AD, thereby providing a potential predictor for AD progression and a promising interventional approach for AD.
ABSTRACT
Acute vestibular neuritis (VN) is characterized by acute/subacute vertigo with spontaneous nystagmus and unilateral loss of semicircular canal function. Vestibular system in human is represented in the brain bilaterally with functional asymmetries of the right hemispheric dominance in the right handers. Spatial working memory entails the ability to keep spatial information active in working memory over a short period of time which is also known as the right hemispheric dominance. Three patients (patient 1, 32-year-old female; patient 2, 18-year-old male; patient 3, 63-year-old male) suffered from acute onset of severe vertigo, nausea and vomiting. Patients 1 and 2's examination revealed VN on the right side showing spontaneous left beating nystagmus and impaired vestibular ocular reflex on the right side in video head-impulse and caloric tests. Patient 3's finding was fit for VN on the left side. We also evaluated visuospatial memory function with the block design test in these 3 VN patients which discovered lower scores in patients 1 and 2 and the average level in patient 3 compare to those of healthy controls. Follow-up block design test after resolved symptoms showed within normal range in both patients. Our cases suggest that the patients with unilateral peripheral vestibulopathy may have an asymmetrical effect on the higher vestibular cognitive function. The right VN can be associated with transient visuospatial memory dysfunction. These findings add the evidence of significant right hemispheric dominance for vestibular and visuospatial structures in the right-handed subjects, and of predominant dysfunction in the hemisphere ipsilateral to the peripheral lesion side.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Brain , Caloric Tests , Cognition , Follow-Up Studies , Memory , Memory, Short-Term , Nausea , Reference Values , Reflex , Semicircular Canals , Vertigo , Vestibular Neuronitis , VomitingABSTRACT
La memoria a corto plazo es un sistema que mantiene poca información durante segundos; se subdivide en memoria inmediata si sólo mantiene la información, y en memoria de trabajo, si además de mantener dicha información opera sobre ella de manera simultánea. Una prueba que se ha utilizado ampliamente para evaluar la memoria a corto plazo visoespacial es "los cubos de Corsi", la cual consiste en recordar secuencias crecientes de toques de cubos. En este artículo se presenta el funcionamiento y ventajas del programa CubMemPc, una versión computarizada de "los cubos de Corsi" diseñada para evaluar la memoria a corto plazo (inmediata y de trabajo) visoespacial. El programa permite la aplicación de distintas secuencias de "toques de cubos", el registro tanto de las secuencias efectuadas por los sujetos como su tiempo de ejecución e incluir estímulos visuales como distractores. Esto último permite el estudio del efecto de las emociones sobre la memoria a corto plazo. Dada su disponibilidad, flexibilidad y manejabilidad CubMemPc puede ser utilizado tanto por investigadores en el área de las neurociencias cognitivas, como por profesionales de la psicología en la evaluación de la memoria a corto plazo visoespacial con o sin distractores.
Short-term memory is a system that holds a small amount of information during seconds; it is subdivided into immediate memory, if the information is only stored temporarily and working memory, if the information is stored and manipulated simultaneously. "Corsi block task" is a test that has been widely used to assess visuospatial working memory; in this task the assessed subject must to remember increasing sequences of cubes touches. This article describes the operation and advantages of CubMemPc program, which is a computerized version of "Corsi block task" designed to assess visuospatial short-term memory (immediate and working memory). The program makes it possible the application of different sequences of "cube touches", the registration of both the subject's responses and execution time. Besides, it allows including visual stimuli as distracters, which permit to study the effects of emotion on short-term memory. Given its availability, flexibility and manageability CubMemPc can be used by researchers in the field of cognitive neuroscience and for psychology professionals in the assessment of visuospatial immediate memory and working memory with or without distracters.
ABSTRACT
Nós investigamos a memória visuoespacial e cinestésica de curto prazo em crianças entre 7 e 10 anos utilizando a tarefa de Blocos de Corsi. O desempenho melhora com a idade, é afetado pela extensão das séries e pelo número de cruzamentos. O desempenho é melhor na modalidade visual do que na cinestésica; ambas as modalidades são afetadas da mesma forma pela extensão e pelo número de cruzamentos. As curvas de posição serial apresentam forte efeito de primazia; o efeito de recência está presente apenas na modalidade visual. Nas séries com seis e sete blocos, quando considerado o número de cruzamentos, o desempenho tende a melhorar numa taxa mais elevada para a modalidade visual do que para cinestésica. Os resultados não permitem supor um sistema de memória cinestésico independente do espacial, mas sugere que ambos contribuem para o desempenho na tarefa de Corsi.
We investigated the visuo-spatial and kinesthetic short term memory in children aged between 7 and 10 years through the Corsi Block test. The results showed that performance gets better with age that it is affected by sequence extension and by number of crossings paths. The performance is better in the visual modality than in the kinesthetic one; both modalities are affected in the same way by the sequence extension and number of crossing paths. Serial position curves are marked by primacy effect; recency effect is present just in visual modality. In sequences with six and seven blocks, when considered the number of crossing paths, the performance tends to get better in a higher tax for visual modality than for kinesthetic. The results do not support a kinesthetic memory independent of the spatial system, but suggests that both components contribute to the performance in the Corsi block test.
Subject(s)
Humans , Male , Female , Child , Intelligence Tests , Memory, Short-Term , Psychological TestsABSTRACT
The anteromedial extrastriate complex has been proposed to play an essential role in a spatial orientation system in rats. To gain more information about that possible role, in the present work, two questions were addressed: 1. Are allocentric visual cues relevant for acquisition of the orientation task in the Lashley III maze? 2. Is this integration of allocentric inputs in the anteromedial visual complex relevant in the retention of this test? While a control group of rats was trained keeping the maze in the same position, the experimental group was trained with the maze rotated counterclockwise by 144 degrees from session to session. Control rats reached learning criterion significantly earlier and with less errors than the experimental ones (p<.05). After 11 sessions, rats of both groups received stereotaxic injections of ibotenic acid in the anteromedial complex. In the retention test one week after surgery, the control group, which had been able to learn using egocentric and allocentric visual cues, showed a greater deficit than the experimental animals (p<.05). These results confirm the role of the anteromedial complex in the processing of visuospatial orientation tasks and demonstrate the integration of allocentric visual cues in the solution of those tasks.
Subject(s)
Animals , Male , Rats , Maze Learning/physiology , Orientation/physiology , Retention, Psychology/physiology , Visual Cortex/physiology , Cues , Excitatory Amino Acid Agonists/pharmacology , Ibotenic Acid/pharmacology , Visual Cortex/drug effectsABSTRACT
OBJECTIVE: This study was conducted to evaluate the impairment of cognitive functions, which include verbal and visual memory, visuospatial function, and executive function, and also to investigate if there is improvement of cognitive impairment after antidepressant treatment in patients with major depressive disorder (MDD). METHODS: Fifteen female patients with non-psychotic MDD in mild to moderate severity and 25 age-matched female normal control subjects participated in this study. Clinical severity of depression was measured by Beck Depression Inventory (BDI), Zung's Self-Rating Depression Scale (Zung), and Hamilton Rating Scale for Depression (HAMD). Cognitive functions were tested using Ray Complex Figure Test (RCFT) to evaluate visuospatial function and visual memory, Stroop test to evaluate conflict monitoring, Wisconsin Card Sorting Test (WCST) to evaluate executive function, and Seoul Verbal Learning Test (SVLT) to evaluate verbal memory. Both clinical depression scales and cognitive function tests were conducted at baseline and after 12 months of antidepressant treatment. RESULTS: At baseline, there were deficits in immediate and delayed recall of SVLT in patients with MDD compared to normal control subjects, while the impairment in visuospatial function, visual memory, and executive function was not clear. After antidepressant treatment, improvement of executive function, i.e. percent of error response and perseverative response of WCST in MDD patients was greater than that in normal control subjects. Improvement of executive function, however, did not show a significant correlation with the change of clinical severity of depression. CONCLUSION: The verbal memory was the most prominent domain of cognitive dysfunction in non-psychotic depression with mild to moderate severity. Of further note, differential improvement in executive function was observed in MDD patients after antidepressant treatment, although the improvement in executive function was not directly associated with the improvement of clinical depression.
Subject(s)
Female , Humans , Depression , Depressive Disorder, Major , Executive Function , Memory , Prospective Studies , Stroop Test , Verbal Learning , Weights and Measures , WisconsinABSTRACT
OBJECTIVES: Phencyclidine(PCP) or PCP-like substances such as ketamine have been know to rekindle the cognitive dysfunction in schizophrenia. The aims of this study were to identify whether PCP-like substances can produce cognitive deficit in schizophrenia, to discuss relation with aging process, and finally to speculate underlying neurochemical mecha-nisms by various drug responses. METHODS: In experiment I, radial maze tests were done in 24 Sprague-Dawley rats for 3 days to get baseline data. Being divided into 4 groups(6 rats respectively) of normal aged, normal adult controls, atropine-treated and ketamine-treated, the radial maze tests were repeated on every week for 6 weeks, and then the rats were sacrificed by intracardiac perfusion with phosphate-buffered 10% formaldehyde solution for histology. The brain specimen was stained with hematoxylin-eosin to count cells in the prefrontal cortex and hippocampus. In experiment II, radial maze tests were done for 48 rats before any drug treatment and only after ketamine administration. Thereafter, haloperidol, bromocriptine, clonidine, nimodipine, tacrine, valproic acid, naloxone and fluoxetine were intramuscularly injected on every other day in addition to ketamine. Radial maze tests were repeated on every week for 6 weeks, and then rats were prepared by the same procedure for histology. RESULTS: 1) Reaction times of radial maze tests of atropine-treated rats were significantly prolonged than those of normal aged(p<0.05) or normal adult controls(p<0.05). Cell numbers of prefrontal cortex & hippocampus in ketamine-treated rats were significantly reduced than those in normal aged(p<0.05) or normal adult controls(p<0.005). 2) Reduced cell numbers by ketamine became significantly raised by tacrine administration in prefrontal cortex $ hippocampus(p<0.05), while there were no significant changes on radial maze test. Cell numbers also tended to be raised by nimodipine, fluoxetine and haloperidol administration. CONCLUSIONS: In conclusion, the visuospatial memory disorders in ketamine-induced psychotic rats might be partly associated with aging process. Furthermore, the responses to the various drugs suggested cholinergic system might have an important role in the neurochemical mechanism of the cognitive dysfunction in ketamine-induced psychosis. Otherwise, calcium metabolism as well as serotonergic and dopaminergic systems seemed to be possibly related.