Space perception

results of a single neuropsychological test than when it is based on the results of more memory tests. In epidemiological studies and clinical trials the diagnosis of MCI will likely be more stable if impairment on more than one test is required for amnestic and/or nonamnestic domains.

A tout instant, quoi que nous fassions, nous sommes environnés par des corps qui réduisent l’espace et opposent de la résistance. Que sont ces corps qui saturent notre quotidien et avec lesquels il nous faut constamment négocier l’espace ? Plus radicalement, pourquoi y a-t-il des corps ? Je soutiens dans cet ouvrage que la psychologie et la physique ne disposent plus des moyens de répondre à cette question. La désubstantialisation du réel amorcée par la révolution quantique sape les fondements de l’explication objectiviste de la perception privilégiée par la première, et elle évide de sa portée ontologique le discours de la seconde.
Expliquer pourquoi la réalité se présente sous la forme d’un agencement de corps exige en premier lieu de comprendre le rôle que remplit l’anticipation du possible dans la perception. Dans le toucher comme dans la vision, poser l’existence d’un corps implique d’anticiper les contraintes que ce corps exerce sur notre champ de possibilités pratiques, accréditer de manière présomptive la disponibilité ou l’indisponibilité de certaines possibilités d’action. C’est donc uniquement parce que notre subjectivité donne sens à ce qui est en le référant à ce qui peut être que la réalité macroscopique à laquelle nous introduit la perception consiste en un monde solide.
Pour développer cette idée, l’ouvrage dresse une critique de la conception actualiste du phénomène de corps, qui subordonne celui-ci à l’expérience en acte d’une résistance, et il déconstruit l’approche physicaliste et objectiviste, qui prétend dériver les propriétés des corps que nous percevons des propriétés de structures physiques qui leur seraient antécédentes ontologiquement. Si la sémantique des corps présuppose l’épaisseur du temps humain et une perspective foncièrement pragmatique sur l’environnement, il n’est plus question d’assimiler sans autre forme de procès le corps à une « structure physique », quelle qu’en soit la teneur. Les corps sont un produit de l’activité constructrice de notre subjectivité, et seule une incursion profonde dans les mécanismes et principes qui régissent cette activité pourra permettre d’accéder à leur vérité.

Die gerade noch wahrnehmbare, optisch induzierte Krümmung einer horizontalen Geraden wurde unter dem Einfluss von Psilocybin untersucht. Die Droge bewirkt einen deutlichen, jedoch vorübergehenden Kompensationsverlust gegenüber der optisch induzierten Krümmung.

. Reasoning about the height and location of a hidden object in 4.5 and 6.5month-old infants. Cognition, 38: 13-42. ' TkYis rescaxb was supported by a gram irom the Nationai institute of Child iieaith and Human Development (HD-21104). I thank Judy DeLoache and Usha Goswami for their careful reading of the manuscript: OOlO-0277/91/$9.50 0 1991 -Elsevier Science Publishers B.V. 14 R. Baillargeon improvement in performance brought about by the second box disappeared when this box was no longer in the same fronto-parallel plane as the box behind the screen. Different models are considered to describe the impressive quantitative and qualitative physical reasoning abilities revealed by these findings.

A general conceptual framework for large-scale neocortical dynamics based on data from many laboratories is applied to a variety of experimental designs, spatial scales, and brain states. Partly distinct, but interacting local processes (e.g., neural networks) arise from functional segregation. Global processes arise from functional integration and can facilitate (top down) synchronous activity in remote cell groups that function simultaneously at several different spatial scales. Simultaneous local processes may help drive (bottom up) macroscopic global dynamics observed with electroencephalography (EEG) or magnetoencephalography (MEG).A local/global dynamic theory that is consistent with EEG data and the proposed conceptual framework is outlined. This theory is neutral about properties of neural networks embedded in macroscopic fields, but its global component makes several qualitative and semiquantitative predictions about EEG measures of traveling and standing wave phenomena. A ...

Humans’ conscious awareness of objects in their visual periphery is limited. This limit is not entirely the result of reduced visual acuity. Rather, it is primarily caused by crowding—the difficulty identifying an object when it is surrounded by clutter. The effect of crowding on visual awareness in infants has yet to be explored. Do infants, for example, have a fine-grained “spotlight,” as adults do, or do infants have a diffuse “lantern” that sets limits on what they can register in their visual periphery? We designed an eye-tracking paradigm to psychophysically measure crowding in infants between 6 months and 15 months of age. We showed infants pairs of faces at three eccentricities, in the presence or absence of flankers, and recorded infants’ first saccade from central fixation to either face. Infants could discriminate faces in the periphery, and flankers impaired this ability. We found that the effective spatial resolution of infants’ visual perception increased with age, but...

We employed positron emission tomography to examine the functional anatomy of the exploratory-motor aspect of spatial attention. Subjects moved their right hand under nonexploratory (control) versus exploratory (active) conditions. Movement architecture and eye movements were matched across conditions. Statistical parametric maps of the exploratory (active) minus nonexploratory (control) tasks in subjects using their right hand in the right hemispace demonstrated activation in right cingulate, premotor and posterior parietal areas. The net activation of multiple right hemisphere cortical areas ipsilateral to the active limb and hemispace strongly supports the predicted, distributed network anatomy and is consistent with possible right hemispheric dominance for exploratory attentional movements.

About half of BXSB/MpJ-Yaa (BXSB) mice have neocortical ectopias (misplaced clusters of neurons located in layer I of cortex). Previous behavioral studies have suggested that ectopic mice have superior spatial, but equivalent nonspatial, reference memory learning. However, since spatial and nonspatial learning were not assessed in the same apparatus and with the same testing procedure, it is unclear if this conclusion is accurate. We have created a new nonspatial Morris maze for mice that differs from the spatial task only in the type of cues that must be utilized to efficiently locate the platform (intra-maze black/white patterns vs. extramaze room cues) and does not differ in the level of task complexity or the presence of objects within the maze. Ectopic mice were very good in utilizing extra-maze cues when learning the spatial version and in utilizing intra-maze cues when learning the nonspatial version of the Morris maze, while non-ectopics were not, suggesting that ectopics have superior spatial and nonspatial reference memory. Ectopias in BXSB mice are usually located in prefrontal and/or motor cortex. The prefrontal cortex is involved in behavioral flexibility (e.g. being able to easily switch from using spatial to nonspatial cues). Only ectopic mice with ectopias specifically located in the prefrontal region of cortex demonstrated difficulty switching from using extra-maze to intra-maze cues and vice versa. Thus, the presence of one or more ectopias in the prefrontal region of cortex disrupted one of the normal functions of the prefrontal cortex. #

In a valence induction task, one color acquired positive valence by indicating the chance to win money (in the case of fast and correct responses), and a different color acquired negative valence by indicating the danger to lose money (in the case of slow or incorrect responses). In the additional-singleton trials of a visual search task, the taskirrelevant singleton color was either the positive one, the negative one, or one of two neutral colors. We found an additional-singleton effect (i.e., longer RTs with a singleton color than in the no-singleton control condition). This effect was significantly increased for the two valent colors (with no differences between them) relative to the two neutral colors (with no differences between them, either). This result favors the hypothesis that the general relevance of stimuli elicits attentional capture, rather than the negativity bias hypothesis.

A ttention is the process by which we select stimuli in our environment for perception and action. The ability to orient to salient visual stimuli and to parse the visual world begins to emerge in the first few months of life and continues to evolve through childhood. This review addresses how visuospatial attention develops, is deployed, and can be damaged in children. In particular, we discuss orienting, lateralized attention, and global vs local processing. Advances in our basic understanding of the cognitive neuroscience of visuospatial attention are beginning to inform pediatric neurology, but much work remains to be done.

Recent empirical results suggest that there is a decrement in dividing attention between two objects in a scene compared with focusing attention on a single object. However, objects can be made of individual parts. Is there a decrement for dividing attention across different parts of a single object? We addressed this question in two experiments. In Experiment 1, we demonstrated that attention can exhibit part-based selection-that is, the subjects were more accurate in reporting two attributes from the same part of an object than they were in reporting attributes from different parts of an object. In Experiment 2, we demonstrated that part-based attentional decrements occurred simultaneously with object-based attentional decrements. The results from Experiment 2 demonstrated that part-based attention is evident at the same time as objects are processed as coherent wholes. Our results imply that there is an attentional mechanism that can select either objects or their parts.

proposed a theory of texture discrimination, based on an order statistics principle, which states that no two textures can be perceptually discriminated if they have identical second-order statistics. The experiments reported here demonstrate that this principle is not adequate to predict visual texture discriminability. Both letter and dot micropatterns were used to create texture pairs that either differed or were identical with respect to secondorder statistics. The subject's task was to decide which quadrant of an array contained a disparate texture. In Experiments 1, 2, and 3, when controlling for spatial overlap, texture pairs having identical second-order statistics were discriminated more quickly than similar texture pairs having different second-order statistics, in contradiction to the principle. Although a significant effect in the direction predicted by the order statistics principle was found in Experiment 4 for texture pairs created from the dot micropatterns, other factors, such as spatial overlap, border differences, and goodness of pattern, must also be considered in predicting texture discriminability.

Would it be helpful to inform a driver about when a conflicting traffic situation is going to occur? We tested whether temporal orienting of attention could enhance executive control to select among conflicting stimuli and responses. Temporal orienting was induced by presenting explicit cues predicting the most probable interval for target onset, which could be short (400 ms) or long (1,300 ms). Executive control was measured both by flanker and Simon tasks involving conflict between incompatible responses and by the spatial Stroop task involving conflict between perceptual stimulus features. The results showed that temporal orienting facilitated the resolution of perceptual conflict by reducing the spatial Stroop effect, whereas it interfered with the resolution of response conflict by increasing flanker and Simon effects. Such opposite effects suggest that temporal orienting of attention modulates executive control through dissociable mechanisms, depending on whether the competition between conflicting representations is located at perceptual or response levels.

A complex link exists between vision and unilateral spatial neglect (USN). Firstly, USN is not a perceptual deficit, secondly, USN is not necessarily accompanied by a visual deficit and finally, USN can be observed in non-visual modalities as well as in mental spatial imagery. This apparent supramodality of USN stands in sharp contrast to the fact that neglect signs are often more severe and more durable in the visual than in other sensory modalities (Chokron et al., 2002). The influence of vision on spatial representation has rarely been studied. In the present study we assessed six right brain-damaged patients suffering from left USN on two tasks involving spatial representations: a clock-drawing task and a drawing from memory task in two experimental conditions, with and without visual control. We confirm that even in mental imagery, the absence of visual feedback may decrease and even suppress left neglect signs (Bartolomeo and Chokron, 2001b; 2002). Since vision is largely involved in the orientation of attention in space, suppressing visual control could reduce the magnetic attraction towards the right ipsilesional hemispace and in this way could allow a re-orientation of attention towards the left neglected hemispace. We discuss the theoretical and therapeutic implications of these findings.

Multiple studies report relationships between circulating androgens and performance on sexually differentiated spatial cognitive tasks in human adults, yet other studies find no such relationships. Relatively small sample sizes are a likely source of some of these discrepancies. The present study thus tests for activational effects of testosterone (T) using a within-participants design by examining relationships between diurnal fluctuations in salivary T and performance on a male-biased spatial cognitive task (Mental Rotation Task) in the largest sample yet collected: 160 women and 177 men. T concentrations were unrelated to within-sex variation in mental rotation performance in both sexes. Further, between-session learning-related changes in performance were unrelated to T levels, and circadian changes in T were unrelated to changes in spatial performance in either sex. These results suggest that circulating T does not contribute substantially to sex differences in spatial ability in young men and women. By elimination, the contribution of androgens to sex differences in human performance on these tasks may be limited to earlier, organizational periods.

The timecourse and scalp topography of interactions between neural responses to stimuli in different visual quadrants, straddling either the vertical or horizontal meridian, were studied in 15 subjects. Visual evoked potentials (VEPs) were recorded from 64 electrodes during a simple reaction time (RT) task. VEPs to single stimuli displayed in different quadrants were summed ('sum') and compared to the VEP response from simultaneous stimulation of the same two quadrants ('pair'). These responses would be equivalent if the neural responses to the single stimuli were independent. Divergence between the 'pair' and 'sum' VEPs indicates a neural response interaction. In each visual field, interactions occurred within 72 -86 ms post-stimulus over parieto-occipital brain regions. Independent of visual quadrant, RTs were faster for stimulus pairs than single stimuli. This replicates the redundant target effect (RTE) observed for bilateral stimulus pairs and generalizes the RTE to unilateral stimulus pairs. Using Miller's 'race' model inequality (Miller J. Divided attention: evidence for coactivation with redundant signals, Cognitive Psychology 1982;14:247-79), we found that probability summation could fully account for the RTE in each visual field. Although measurements from voltage waveforms replicated the observation of earlier peak P1 latencies for the 'pair' versus 'sum' comparison (Miniussi C, Girelli M, Marzi CA. Neural site of the redundant target effect: electrophysiological evidence. Journal of Cognitive Neuroscience 1998;10:216-30), this did not hold with measurements taken from second derivative (scalp current density) waveforms. Since interaction effects for bilateral stimulus pairs occurred within 86 ms and require interhemispheric transfer, transcallosal volleys must arrive within 86 ms, which is earlier than previously calculated. Interaction effects for bilateral conditions were delayed by :10 ms versus unilateral conditions, consistent with current estimates of interhemispheric transmission time. Interaction effects place an upper limit on the time required for neuronal ensembles to combine inputs from different quadrants of visual space ( : 72 ms for unilateral and : 82 ms for bilateral conditions).

For the purpose of studying the potential neurobehavioral effects of different human apolipoprotein E (apoE) isoforms produced within the brain, transgenic (TG) mice were generated in which human apoE3 or apoE4 isoforms were under control of an astrocyte-specific, glial fibrillary acidic protein promoter and these TG mice were bred back to apoE knockout (KO) mice. Behavioral phenotypes of apoE3 and apoE4 TG mice were derived by conducting a longitudinal study in which apoE3 and apoE4 TG mice were compared with apoE KO and wild-type (WT) mice (all male) on several behavioral measures. Analysis of locomotor activity, "open-field" behaviors, acoustic startle/prepulse inhibition, and elevated plus maze data suggested that the apoE TG/KO groups were more "emotionally reactive" than WT mice, with apoE4 mice typically being the most reactive. The absence of performance differences among groups on the rotating holeboard and water navigation tasks suggested intact reference memory processing in apoE TG/KO mice. However, apoE4 mice were profoundly impaired on a working memory-based protocol in the radial arm maze (11-14 months). Nonassociative factors (sensorimotor capacities or emotionality differences) did not appear to confound interpretation of the learning/memory results. Western blot analysis revealed no alterations in the level of synaptic, neuronal, or glial markers in neocortex or hippocampus and histologic analysis revealed no evidence of Abeta deposition or neuritic plaques in the apoE KO/TG mice. Our findings suggest that apoE4 expression in the brain may have selective deleterious effects on memory function in the absence of typical Alzheimer's-like neuropathology.

O objetivo deste artigo é contribuir com uma reflexão sobre o ensino do desenho de observação, através da percepção do meio ambiente urbano nas múltiplas esferas sensoriais. Constata-se uma significativa mudança no pensamento e no comportamento das novas gerações de alunos ingressos nas universidades, inseridas em uma cultura cada vez mais tecnológica e imagética. As experiências vivenciais necessárias ao amadurecimento cognitivo estão se fundindo pela velocidade e simultaneidade.A mudança no paradigma representacional implica em novas atitudes pedagógicas, o que incide no exercício de reflexão sobre a noção de uma "perspectiva sensorial". A metodologia aborda uma revisão teórico-histórica e filosófica, assim como algumas experiências didáticas realizadas com turmas da Faculdade de Arquitetura e Urbanismo da Universidade Federal de Juiz de Fora(FAU-UFJF). Ao fim, são estabelecidas algumas recomendações para a proposição de uma disciplina eletiva em caráter experimental intitulada "Croquis Urbanos", a ser ministrada na FAU-UFJF em abril de 2016. Palavras-chave: representação; percepção multissensorial; croquis urbanos; ensino de fundamentação em arquitetura e urbanismo.

Two objects that project the same visual angle on the retina can appear to occupy very different proportions of the visual field if they are perceived to be at different distances. What happens to the retinotopic map in primary visual cortex (V1) during the perception of these size illusions? Here we show, using functional magnetic resonance imaging (fMRI), that the retinotopic representation of an object changes in accordance with its perceived angular size. A distant object that appears to occupy a larger portion of the visual field activates a larger area in V1 than an object of equal angular size that is perceived to be closer and smaller. These results demonstrate that the retinal size of an object and the depth information in a scene are combined early in the human visual system.

Temporal order judgment (TOJ) thresholds have been widely reported as valid estimates of the temporal disparity necessary for correctly identifying the order of two stimuli. Data for two auditory TOJ paradigms are often reported in the literature: (1) spatially-based TOJ in which the order of presentation of the same stimulus to the right and left ear differs; and (2) spectrally-based TOJ in which the order of two stimuli differing in frequency is presented to one ear or to both ears simultaneously. Since the thresholds reported using the two paradigms differ, the aim of the current study was to compare their response patterns. The results from three different experiments showed that: (1) while almost none of the participants were able to perform the spatial TOJ task when ISI = 5 ms, with the spectral task, 50% reached an accuracy level of 75% when ISI = 5 ms; (2) temporal separation was only a partial predictor for performance in the spectral task, while it fully predicted performa...

Despite the clinical significance of topographical disorientation in Alzheimer's disease, it is not clear which cognitive spatial processes are primarily impaired. Here, we argue that a deficit in ''mental frame syncing'' between egocentric and allocentric spatial representations causes early manifestations of topographical disorientation in AD. Specifically, patients show impairment in translating from an allocentric hippocampal representation to an egocentric parietal one for the purpose of effective spatial orientation and navigation. We suggest that a break in ''mental frame syncing'', underpinned by damage to the hippocampus and retrosplenial cortex, may be a crucial cognitive marker both for early and differential diagnosis of AD. Identification of these spatial deficits could facilitate the development of early cognitive rehabilitation interventions and the possibility of identifying individuals most at risk for progression to AD during the preclinical stages.

A complex link exists between vision and unilateral spatial neglect (USN). Firstly, USN is not a perceptual deficit, secondly, USN is not necessarily accompanied by a visual deficit and finally, USN can be observed in non-visual modalities as well as in mental spatial imagery. This apparent supramodality of USN stands in sharp contrast to the fact that neglect signs are often more severe and more durable in the visual than in other sensory modalities .

Background: Prior work shows individuals with schizotypal personality disorder (SPD) evince temporal lobe volume abnormalities similar to schizophrenia but sparing of prefrontal cortex, which may mitigate psychosis and the severe neurocognitive impairments observed in schizophrenia. This study examined the extent to which frontal-temporal gray matter volume and neurocognitive performance predict: (1) SPD group membership in a demographically-balanced sample of 51 patients and 37 healthy controls; and (2) symptom severity in SPD. Methods: Dimensional gray-matter volume (left frontal-temporal regions (Brodmann area (BA) 10, 21, 22)) and neurocognitive performance on key memory tasks (California Verbal Learning Test (CVLT), Dot Test, Paced Auditory Serial Addition Test (PASAT)), all salient to schizophrenia-spectrum disorders were examined in a multi-variable model. Results: Middle temporal gyrus (BA21) volume and spatial-working memory (Dot Test) performance were significant predictors of SPD group membership likelihood, with poorer working-memory performance indicating increased probability of SPD membership. Combining across regional volumes or cognitive measures resulted in fair-to-good discrimination of group membership, but including neurocognitive and non-collinear regional volume measures together resulted in a receiver-operating-characteristic (ROC) curve with improved diagnostic discrimination. Larger BA10 volume in dorsolateral prefrontal cortex (DLPFC) significantly predicted less symptom severity in SPD. Conclusions: These findings suggest that temporal lobe volume and spatial-working memory performance are promising biological/phenotype markers for likelihood of SPD classification, while greater DLPFC volume may serve as a protective factor.

Previous research has shown that changes to the body can influence the perception of distances in near space (Witt et al 2005). In this paper, we question whether changes to the body can also influence the perception of extents in extrapersonal space, namely the perception of aperture widths. In experiment 1, broad-shouldered participants visually estimated the size of apertures to be smaller than narrow-shouldered participants. In experiment 2, we questioned whether changes to the body, which included holding a ...

Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010), Please cite this article in press as: Craig, M.C., et al., The interactive effect of acute ovarian suppression and the cholinergic system on visuospatial working memory in young women. Psychoneuroendocrinology (2010),

Multiple-object tracking involves simultaneously monitoring positions of a number of target items as they move among distractors. Young adults are capable of tracking only 3 -5 items at once. In this study we investigated the origin of this limitation by looking for secondary tasks that interfere with tracking. We compared tracking performance (baseline condition), with performance when participants tapped three fingers in a specific order while tracking (sequential tapping) or articulated three syllables in a specific order while tracking (sequential articulation). The articulation task was used to ensure that the interference produced by sequential tapping was more than would be expected by the executive demands of carrying out any two "attention-demanding" tasks at once. Even though sequential tapping does not require vision or memorizing the positions of external items, it produced significantly more interference than did sequential articulation, as might be expected if tracking and sequential tapping shared a common (limited) resource.

The posterior parietal cortex (PPC), historically believed to be a sensory structure, is now viewed as an area important for sensory-motor integration. Among its functions is the forming of intentions, that is, high-level cognitive plans for movement. There is a map of intentions within the PPC, with different subregions dedicated to the planning of eye movements, reaching movements, and grasping movements. These areas appear to be specialized for the multisensory integration and coordinate transformations required to convert sensory input to motor output. In several subregions of the PPC, these operations are facilitated by the use of a common distributed space representation that is independent of both sensory input and motor output. Attention and learning effects are also evident in the PPC. However, these effects may be general to cortex and operate in the PPC in the context of sensory-motor transformations.

Memory for object locations and for events (comprising the receipt of an object) was tested in a case of developmental amnesia with focal hippocampal damage ("Jon"; F. . Tests used virtual reality environments and forced-choice recognition with foils chosen to equalize the performance of control participants across conditions. Memory for the objects received was unimpaired, but the context of their receipt was forgotten. Memory for short lists of object locations was unimpaired when tested from the same viewpoint as presentation but impaired when tested from a shifted viewpoint. Same-view performance was disrupted by changing the background scene. These results are consistent with Jon having preserved matching to fixed sensory-bound representations but impaired reconstructed or manipulable representations underlying shifted-viewpoint recognition and episodic recollection.

Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial attention to a second stimulus (S2). Visual-spatial attention was monitored by using the N2pc component of the ERP. In addition, we examined the sustained posterior contralateral negativity (SPCN) believed to index the retention of information in visual short-term memory. We found modulations of both the N2pc and the SPCN, suggesting that engaging mechanisms of mental rotation impairs the deployment of visual-spatial attention and delays the passage of a representation of S2 into visual short-term memory. Both results suggest interactions between mental rotation and visual-spatial attention in capacity-limited processing mechanisms indicating that response selection is not pivotal in dual-task delays and all three processes are likely to share a common resource like executive control.

The fixed oil of black cumin seeds, Nigella sativa L. (NSO), has shown considerable antioxidant and anti-inflammatory activities. Chronic cerebral hypoperfusion has been linked to neurodegenerative disorders including Alzheimer's disease (AD) and its subsequent cognitive impairment in which oxidative stress and neuroinflammation are the principal culprits. Cerebrovascular hypoperfusion was experimentally achieved by bilateral common carotid arteries occlusion (2VO) in rats. Morris water maze (MWM) test was employed to assess the effects of NSO on spatial cognitive function before and after 2VO intervention. Rats were divided into long-term memory (LTM) and short-term memory (STM) groups, each was further subdivided into 3 subgroups: sham control, untreated 2VO and NSO treated 2VO group. All subgroups were tested with MWM at the tenth postoperative week. Working memory test results for both sham control and NSO treated groups showed significantly lower escape latency time and tot...

Objective: Our purpose in undertaking the present study was to explore the existence of specific areas of cognitive deficits within the context of generalized poor performance in a group of Greek patients with schizophrenia. We also sought to identify any patients who might be cognitively normal. Method: Participants were 70 patients with schizophrenia and 42 healthy control subjects. The 2 groups were matched on age and male-female ratio but differed in their level of education. A battery of neuropsychological tests was selected to assess executive functions/abstraction, fluency, verbal and spatial working memory, verbal and nonverbal memory, attention, visuospatial ability, and psychomotor speed. Results: Patients with schizophrenia performed more poorly than healthy control subjects, when we controlled for differences in level of education, on executive functions, working memory, verbal memory, nonverbal memory, fluency, visuospatial ability, and attention. In contrast, no significant differences were found between the 2 groups on psychomotor speed. Patients showed a more pronounced deficit on executive functions, verbal and visual memory, and visuospatial ability. Overall, 13% to 62% of the patients with schizophrenia scored within 1 SD of the mean z scores of healthy control group depending on the cognitive domains examined. In the entire sample of patients with schizophrenia, however, no individual scored within 1 SD of the mean z scores of the control group in all cognitive domains. Conclusions: We found a generalized deficit in cognitive functioning in a group of patients with schizophrenia. We failed to find any individual patients who were healthy across all cognitive areas. The current neuropsychological profile, indicating widespread impairment, is comparable to that reported in the international literature and thus appears to be characteristic of schizophrenia. Our findings of increased difficulties with executive functions, verbal and visual memory, and visuospatial ability support previous suggestions of generalized brain dysfunction in the pathophysiology of schizophrenia. D