Space perception

Using functional magnetic resonance imaging during word generation and spatial judgement (Landmark task), we investigated how hemispheric specializations for language and spatial processing interact in healthy individuals. We found individuals with atypical, right-hemispheric dominance for language to have more bilateral activation during spatial judgement than individuals with typical, disjunct hemispheric specialization, that is, left dominance for language and right dominance for spatial tasks.These ¢ndings suggest that hemispheric specializations for language and spatial functions interfere to some extent and favour additional recruitment of the opposite hemispheres for spatial functions. NeuroReport 16:1017^1021

The aim of this study was to assess wayfinding abilities in Down syndrome (DS). The ability to learn routes though a virtual environment (VE) and to make a novel shortcut between two locations was assessed in individuals with DS (N=10) and control participants individually matched on mental age (MA) or chronological age (CA). The results showed that most of the participants with DS was able to learn routes through VE, even though they needed more trials than the CA controls to reach the learning criterion. However, they did not have flexible wayfinding behaviour since they were not able to find a shortcut between two known locations (unlike the CA controls). The results suggested that most individuals with DS could acquire knowledge about specific routes without being able to integrate that knowledge into a configurational understanding.

Background  The present study was aimed at investigating the selection of landmarks by individuals with intellectual disability (ID). The hypothesis was that they would be less efficient than individuals without IDs in the selection of landmarks when learning a new route.Methods  The experiment took place in a natural setting with a group of participants with ID and a group of control participants matched by chronological age. The participants were first guided along a route situated in an unfamiliar district. Then, they had to guide the experimenter along the route while pointing to all the objects and features they found useful for wayfinding.Results  The designated objects were categorised as a function of their landmarks properties. There were significant differences between the two groups for non‐permanent landmarks, distant landmarks and non‐unique landmarks. The two groups selected landmarks near intersections in the same proportions. However, the individuals with ID selected...

A stimulus is described that demonstrates the spatial pooling of colour information in the visual system. Chequerboards (or gratings) consisting of alternating squares (or stripes) of complementary colours become achromatic at particular spatial scales; such stimuli have been named 'transchromatic' stimuli. Colour pools are much larger than the receptive fields that respond to luminance contrast. Some measurements are described which form the basis for estimates of the size of the colour pools. The size of colour pools varies according to the colours involved. For red-cyan and green-magenta complementary pairs colour is pooled at spatial frequencies above about 7-8 cycles deg -1 , implying pools whose diameter is around 8 min arc. For yellow-blue complementary pairs the corresponding figures are about 4 cycles deg -1 and 15 min arc. Some phenomena of normal colour vision, colour blindness, and the development of infant vision are discussed in the light of these findings.

pitch and location of the sounds were paired in an incongruent fashion. these findings indicate that pitch-space correspondence is not so strong to drive or modulate visual motion perception. however, associative exposure could increase the saliency of pitch-space relationships and then the pitch could induce visual motion perception by itself.

Peripheral vision for static form is limited both by reduced spatial acuity and by interference among adjacent features (Ôcrowd-ingÕ). However, the visibility of acuity-corrected image motion is relatively constant across the visual field. We measured whether spatial interference among nearby moving elements is similarly invariant of retinal eccentricity and assessed if motion integration could account for any observed sensitivity loss. We report that sensitivity to the direction of motion of a central target-highly visible in isolation-was strongly impaired by four drifting flanking elements. The extent of spatial interference increased with eccentricity. Random-direction flanks and flanks whose directions formed global patterns of rotation or expansion were more disruptive than flanks forming global patterns of translation, regardless of the relative direction of the target element. Spatial interference was low-pass tuned for spatial frequency and broadly tuned for temporal frequency. We show that these results challenge the generality of models of spatial interference that are based on retinal image quality, masking, confusions between target and flanks, attentional resolution limits or (simple) ''averaging'' of element parameters. Instead, the results suggest that spatial interference is a consequence of the integration of meaningful image structure within large receptive fields. The underlying connectivity of this integration favours low spatial frequency structure but is broadly tuned for speed.

Signage and wayfinding are the first elements that people come in contact with while visiting any transit or public space. The signage, information specified, branding, communications with transit staff, and efficient services all assists in creation of a wholesome experience for the transit user. Signage is more than just following directions or giving information but it is soundless pictorial interaction with the environment that provides essential message. The right signage design and branding, assists users to feel comfortable and safe and makes their travelling stress-free. This paper briefly discuss about signage & wayfinding; the most significant aspect of environmental graphics, its function, types, and elements. The study is an attempt to present the importance of visual clues in the form of signage & wayfinding system at public transit spaces in India.

Pre-verbal infants and non-human animals associate small numbers with the left space and large numbers with the right space. Birds and primates, trained to identify a given position in a sagittal series of identical positions, whenever required to respond on a left/right oriented series, referred the given position starting from the left end. Here, we extended this evidence by selectively investigating the role of either cerebral hemisphere, using the temporary monocular occlusion technique. In birds, lacking the corpus callosum, visual input is fed mainly to the contralateral hemisphere. We trained 4-day-old chicks to identify the 4th element in a sagittal series of 10 identical elements. At test, the series was identical but left/right oriented. Test was conducted in right monocular, left monocular or binocular condition of vision. Right monocular chicks pecked at the 4th right element; left monocular and binocular chicks pecked at the 4th left element. Data on monocular chicks de...

The ability to map locations in the surrounding environment is crucial for any navigating animal. Decades of research on mammalian spatial representations suggest that environmental boundaries play a major role in both navigation behavior and hippocampal place coding. Although the capacity for spatial mapping is shared among vertebrates, including birds and fish, it is not yet clear whether such similarities in competence reflect common underlying mechanisms. The present study tests cue specificity in spatial mapping in zebrafish, by probing their use of various visual cues to encode the location of a nearby conspecific. The results suggest that untrained zebrafish, like other vertebrates tested so far, rely primarily on environmental boundaries to compute spatial relationships and, at the same time, use other visible features such as surface markings and freestanding objects as local cues to goal locations. We propose that the pattern of specificity in spontaneous spatial mapping behavior across vertebrates reveals crossspecies commonalities in its underlying neural representations.

Recent work has shown that in place-finding tasks rats rely on the geometric relations between the goal object and the shape of the environment. We tested young chickens (Gallus gallus dornesticus) on similar tasks in a reference memory paradigm to determine whether differences exist between species in the ability to use geometric and nongeometric spatial information. The main findings were that chicks: (a) encoded and used both geometric and nongeometric (featural) information; (b) did not use the overall spatial arrangement of the features; (c) relied primarily on nongeometric cues when faced with contradictory information. Two mechanisms are evident in chicks' spatial representations: a metric frame for encoding the spatial arrangement of surfaces as surfaces and a cue-guidance system for encoding conspicuous landmarks near the target. The possibility of hierarchical organization and species differences in these two mechanisms are discussed. Animals may use several different orientation mechanisms to revisit desired places and objects. They can orient by using particular stimuli associated previously with motor responses . Alternatively, cognitive spatial representations of the environment may be developed to allow animals to orient irrespective of any particular motor performance and of their own locations . Evidence for the use of cognitive maps is now widespread for mammals (Menzel

Young chickens were trained to find food by ground-scratching in the centre of a closed uniform arena and were then tested in arenas of similar areas but of different shapes. Chickens showed localized searching behaviour in the square-shaped arena, and maintained this behaviour when placed in a circular or triangular (both equilateral and isosceles) arena. With a rectangular-shaped arena, obtained by doubling the original square-shaped one, chickens showed more dispersed searching along the major axis, but searching tended to be concentrated around the centres of the composing squares and around the centre of the rectangle itself. When trained in a square-or triangle-shaped arena and then tested in an arena of the same shape but a larger area, chickens displayed searching behaviour at two different distances from the wall of the arena, one corresponding to the correct distance (i.e. centre) in the smaller (training) arena, the other to the actual centre of the test arena. On the other hand, in a circular arena, chickens searched mainly at a distance midway between the radius of the small (training) and of the large (testing) circular arena. These results suggest that, during training, chickens encoded information on both the absolute and the relative distance of the food from the walls of the arena, the latter information being more accurate when the arena displayed identifiable features such as corners.

Spatial reorientation by layout geometry occurs in numerous species, but its underlying mechanisms are debated. While some argue that navigating animals' sense of place is based on geometric computations over three-dimensional representations, others claim it depends on panoramic image-matching processes. Because children reorient by subtle three-dimensional perturbations of the terrain and not by salient two-dimensional brightness contours on surfaces or freestanding columns, children's sense of place cannot be explained by image matching. To test image-matching theories in a different species, the present experiment investigates the reorientation performance of domestic chicks ( Gallus gallus ) in environments similar to those used with children. Chicks, like children, spontaneously reoriented by geometric relationships of subtle three-dimensional terrains, and not by salient two-dimensional brightness contours on surfaces or columns. These findings add to the evidence for...

Colour preference research has traditionally relied on subjective methods, which can be challenging to apply accurately in young children. This study investigates the effectiveness of eye tracking as an objective method for assessing colour preferences in children aged 6-8 years, in comparison with the two-alternative forced-choice (2-AFC) method. Six colours were considered, three primary (red, blue, yellow) and three secondary (purple, green, orange) were evaluated by 20 participants. Results showed that purple produced significantly higher fixation counts and durations, suggesting a strong visual preference. A positive correlation was observed between eye movement parameters and the choices made in the 2-AFC method, with both methods yielding similar Original Research Article

Although the representations underlying spatial language are often assumed to be schematic in nature, empirical evidence for a schematic format of representation is lacking. In this research, we investigate the psychological reality of such a format, using simulated motion during scene processing-previously linked to schematization-as a diagnostic. One group of participants wrote a verbal description of a scene and then completed a change detection task assessing simulated motion, while another group completed only the latter task. We expected that effects of simulated motion would be stronger following language use than not, and specifically following the use of spatial, relative to non-spatial, language. Both predictions were supported. Further, the effect of language was scene independent, suggesting that language may encourage a general mode of schematic construal. The study and its findings illustrate a novel approach to examining the perceptual properties of mental representations.

Context: Hormones regulate neuronal function in brain regions critical to cognition; however, the cognitive effects of postmenopausal hormone therapy are controversial. The goal was to evaluate the effect of postmenopausal hormone therapy on neural circuitry involved in spatial working memory. Design: A randomized, double-blind, placebo-controlled crossover study was performed. The study was performed in a tertiary care university medical center. Participants: Ten healthy postmenopausal women of average age 56.9 yr were recruited. Volunteers were randomized to the order they received hormone therapy (5 g ethinyl estradiol and 1 mg norethin-drone acetate). Subjects received hormone therapy or placebo for 4 wk, followed by a 1-month washout period with no medications, and then received the other treatment for 4 wk. At the end of each 4-wk treatment period, a functional magnetic resonance imaging study was performed using a nonverbal (spatial) working memory task, the Visual Delayed Matching to Sample task. The effects of hormone therapy on brain activation patterns were compared with placebo. Results: Compared with the placebo condition, hormone therapy was associated with a more pronounced activation in the prefrontal cortex (BA 44 and 45), bilaterally (P Ͻ 0.001). Hormone therapy was associated with more effective activation of a brain region critical in primary visual working memory tasks. The data suggest a functional plasticity of memory systems in older women that can be altered by hormones. (

The purpose of this article is to investigate the impact of Rudolph Hermann Lotze’s ideas on William James. The article will show that several core concepts in James’s "The Principles of Psychology" (1890) have been inspired by Lotze’s work. Both authors notably agree that psychology is not a natural science. They express a sharp criticism of scientific psychology and of the associationist view of the mind. Lotze’s arguments also underpin James’s theories of ideomotor action, of emotions and of local signs. In short, James draws heavily on Lotze’s philosophy to formulate many of the original claims in "The Principles of Psychology".

The present study sought to determine whether autonomic activity is associated with dominance in verbal over spatial reasoning tasks. A group of 19 healthy adults who performed a verbal and spatial aptitude test was evaluated. Autonomic function was assessed by means of heart rate variability analysis, before and during the tasks. The results showed that a better relative performance in verbal over spatial reasoning tasks was associated with vagal prevalence in normal subjects.

The oculomotor system is well understood compared with other motor systems; however, we do not yet know the spatial details of sensory to motor transformations. This study addresses this issue by quantifying the spatial relationships between visual and motor responses in the superior colliculus (SC), a midbrain structure involved in the transformation of visual information into saccadic motor command signals. We collected extracellular single-unit recordings from 150 visual-motor (VM) and 28 motor (M) neurons in two monkeys trained to perform a nonpredictive visually guided saccade task to 110 possible target locations. Motor related discharge was greater than visual related discharge in 94% (141/150) of the VM neurons. Across the population of VM neurons, the mean locations of the peak visual and motor responses were spatially aligned. The visual response fields (RFs) were significantly smaller than and usually contained within the motor RFs. Converting RFs into the SC coordinate system significantly reduced any misalignment between peak visual and motor locations. RF size increased with increasing eccentricity in visual space but remained invariant on the SC map beyond 1 mm of the rostral pole. RF shape was significantly more symmetric in SC map coordinates compared with visual space coordinates. These results demonstrate that VM neurons specify the same location of a target stimulus in the visual field as the intended location of an upcoming saccade with minimal misalignment to downstream structures. The computational consequences of spatially transforming visual field coordinates to the SC map resulted in increased alignment and spatial symmetry during visual-sensory to saccadic-motor transformations.

A basic problem of visual perception is how human beings recognize objects after spatial transformations. Three central classes of findings have to be accounted for: (a) Recognition performance varies systematically with orientation, size, and position; (b) recognition latencies are sequentially additive, suggesting analogue transformation processes; and (c) orientation and size congruency effects indicate that recognition involves the adjustment of a reference frame. All 3 classes of findings can be explained by a transformational framework of recognition: Recognition is achieved by an analogue transformation of a perceptual coordinate system that aligns memory and input representations. Coordinate transformations can be implemented neurocomputationally by gain (amplitude) modulation and may be regarded as a general processing principle of the visual cortex.

Posterior cortical volume changes and abnormal visuomotor performance are present in patients with Huntington's disease (HD). However, it is unclear whether posterior cortical volume loss contributes to abnormal neural activity and whether activity changes predict cognitive dysfunction. Using magnetic resonance imaging (MRI), we investigated brain structure and visual network activity at rest in patients with early HD (n=20) and healthy controls (n=20). The symbol digit modalities test (SDMT) and subtests of the visual object and space perception (VOSP) battery were completed offline. For functional MRI data a group independent component analysis was used. Voxel-based morphometry was employed to assess regional brain atrophy, and "biological parametric mapping" analyses were included to investigate the impact of atrophy on neural activity. Patients showed significantly worse visuomotor and visual object performance than controls. Structural analyses confirmed occipitotemporal atrophy. In patients and controls, two spatiotemporally distinct visual systems were identified. Patients exhibited decreased activity in the left fusiform cortex and increased left cerebellar activity. These findings remained stable after correction for brain atrophy. Higher fusiform cortex activity was associated with better SDMT performance and with lower disease burden scores. These associations were absent when relating cerebellar function to task performance and disease burden. The results of this study suggest that regionally specific functional abnormalities of the visual system can account for worse visuomotor cognition in HD. However, occipital volume changes cannot sufficiently explain abnormal neural function in patients.

Automatic multimodal spatial attention was studied in 12 dyslexic children (SRD), 18 chronological age matched (CA) and 9 reading level matched (RL) normally reading children by measuring reaction times (RTs) to lateralized visual and auditory stimuli in cued detection tasks. The results show a slower time course of focused multimodal attention (FMA) in SRD children than in both CA and RL controls. Specifically, no cueing effect (i.e., RTs difference between cued-uncued) was found in SRD children at 100 ms cue-target delay, while it was present at 250 ms cue-target delay. In contrast, in both CA and RL controls, a cueing effect was found at the shorter cue-target delay but it disappeared at the longer cue-target delay, as predicted by theories of automatic capture of attention. Our results suggest that FMA may be crucial for learning to read, and we propose a possible causal explanation of how a FMA deficit leads to specific reading disability, suggesting that sluggish FMA in dyslex...

This study investigated the gradient of visual attention in 21 children, 11 children with specific reading disorder (SRD) or dyslexia and 10 children with normal reading skills. We recorded reaction times (RTs) at the onset of a small point along the horizontal axis in the two visual fields. In 70% of the cases the target appeared inside a circle acting as focusing cue and in 30% of the cases it appeared outside, allowing us to study the distribution of attentional resources outside the selected area. Normally reading children showed a normal symmetric distribution of attention. Indeed, RTs were directly proportional to the eccentricity of the target, and no visual field effect was observable. In contrast, children with SRD showed an anomalous and asymmetric distribution. The effect of the target eccentricity influenced RTs only when the stimulus was projected in the left visual field, whereas no effect was observable when the stimulus was projected in the right visual field. Findings allowed us to discuss the relation between this anomalous spatial distribution of visual attentional resources and dyslexia. To interpret the visual perceptual difficulties of children with SRD the hypothesis was made of a selective disorder of spatial attention (left inattention and right over-distractibility) related to a right parietal cortex dysfunction.

information sampling and motor planning. Conclusions: Interception is best understood as the product of interacting biological, environmental, and learned constraints. Similar behavioral signatures can arise from distinct mechanisms, arguing against a unitary account. Progress requires integrating behavioral analyses with model-based and neural approaches to dissociate underlying computations.

Methylphenidate (MPD), a psycho-stimulant is a prescription medicine for the treatment of Attention deficit hyperactivity disorder (ADHD). The drug is also being increasingly used by general population for enhancing cognition. Only few preclinical studies have been carried out on the effects of MPD on cognition and these studies show either an enhancement or impairment of memory following the administration of MPD. The present study was designed to evaluate the effects of different doses of methylphenidate on acquisition and retention of memory in Morris water-maze test. Twenty four male Albino Wistar rats (weighing 180-220gm) were randomly assigned to four groups: (1) Control (2) 0.5mg/kg (3) 2.5mg/kg (4) 5 mg/kg methylphenidate. Animals received drug or water orally before training phase. Memory acquisition was monitored 2hrs post drug administration while memory retention was determined next day. It was found that the clinically relevant doses of methylphenidate (0.5mg/kg and 2.5mg/kg) improved memory acquisition and its retention but higher dose (5mg/kg) impaired both. We suggest that MPD-induced increase of catecholamine neurotransmission may have a role in the improvement of water maze performance while agonist activity of the drug for 5HT-1A receptor in the impaired performance at high doses. Food intake and body weight changes were not affected by MPD administration due to short-term administration of the drug. Results may help in improving pharmaco-therapeutic use of MPD for ADHD.

Understanding how tactile exploration unfolds in childhood blindness provides a unique opportunity to study self-organization in the developing brain under conditions of absent vision. The HAPTI-Child dataset offers the first trial-resolved, publicly accessible collection of videos, finger-tracking keypoints, and derived kinematic measures capturing how congenitally totally blind (CTB) and severely visually impaired (SVI) children explore and identify raised-line drawings. Sixteen participants completed two runs of an open-response identification task while an overhead camera recorded both hands throughout naturalistic tactile exploration. Markerless tracking with DeepLabCut produced twelve labeled hand and finger keypoints per frame, yielding thousands of datapoints per trial. The dataset includes raw and segmented videos, pose estimation weights, time-aligned keypoint trajectories, per-frame likelihood metrics, and quality controlled visualizations such as fingertip trajectories and dwell-time heatmaps. We detail all acquisition, annotation, and preprocessing procedures and provide a technical validation of model accuracy, missingness, and kinematic plausibility. Illustrative analyses reveal stable exploration patterns across repeated exposures, stimulus-dependent strategy variation, and group-level differences in exploration duration. Because the data preserve the fine-grained temporal structure of real haptic search, they provide a developmentally grounded benchmark for evaluating unsupervised and weakly supervised models of sequence learning, modular coordination, and local-to-global strategy formation. Beyond computational applications, the dataset supports translational work in tactile training, sensory substitution, and bio-inspired robotics by offering realistic action trajectories recorded under naturalistic constraints. HAPTI Child establishes a reproducible, high-resolution foundation for studying how coherent exploratory strategies emerge without vision and invites deeper integration with behavioral, developmental, and computational approaches.

The recent literature provides evidence that epigenetic mechanisms such as DNA methylation and histone modification are crucial to gene transcription linked to synaptic plasticity in the mammalian brain--notably in the hippocampus--and memory formation. We measured global histone acetylation levels in the rat hippocampus at an early stage of spatial or fear memory formation. We found that H3, H4 and H2B underwent differential acetylation at specific sites depending on whether rats had been exposed to the context of a task without having to learn or had to learn about a place or fear therein: H3K9K14 acetylation was mostly responsive to any experimental conditions compared to naive animals, whereas H2B N-terminus and H4K12 acetylations were mostly associated with memory for either spatial or fear learning. Altogether, these data suggest that behavior/experience-dependent changes differently regulate specific acetylation modifications of histones in the hippocampus, depending on wheth...

Objective: ''Field dependence'' is used in cognitive psychology to describe an individual's tendency to be visually distracted by the surrounding environment. Notwithstanding the role of field dependence in contexts in which spatial judgment is important, such as piloting an aircraft, to date, studies linking field dependence to surgical skills have been limited. We evaluated whether field dependence correlates with an ability to anticipate appropriate needle angles in a simulated setting. Methods: Trainees underwent field dependence testing and then participated in a surgical skills exercise. Correlations between field dependence and surgical skill were computed. Specifically, cardiothoracic surgery residents (n ¼ 11) took a battery of cognitive examinations to assess general reasoning and visuospatial judgment. Two written tests, the Rod and Frame test and the Judgment of Line Orientation test, measured the degree of field dependence. The subjects then underwent surgical skills testing. Using a standard needle driver, the participants placed curved needles into a cylindrical silicone mitral valve model with 10 premarked needle entry and exit sites. The components assessed included the ability to load a needle on driver at the appropriate angle. The test results showed a parametric distribution, with internal cognitive testing controls demonstrating valid testing techniques and methods. Performance on the cognitive tests measuring spatial judgment and field dependence correlated significantly with skill at determining the appropriate needle angle load in an inverse fashion (Judgment of Line Orientation test, r ¼ 0.61, P < .05; Rod and Frame test, r ¼ À0.52, P ¼ .05), suggesting that residents who were not distracted by surrounding objects performed better. Performance on the cognitive examinations did not correlate with resident training level. Conclusions: Although our study was of a small cohort, the findings suggest that individuals described as field independent (not easily distracted by external visual cues) might possess improved ability to determine appropriate needle angle loads compared with field-dependent individuals. Additional studies examining the role field dependence might play in the acquisition and execution of surgical tasks are warranted. (J Thorac Cardiovasc Surg 2014;148:1804-10) In recent years, medical education has increasingly shifted toward competency-based learning with usage of simulation in surgical and nonsurgical disciplines. Although this shift has prompted a surge in the use of simulation-based training by surgical programs, a paucity of investigation exists regarding the cognitive basis of how surgical skills are acquired in simulated or ''real'' environments. Effective training will likely require training in surgical environments and an understanding of the cognitive paradigms to best instruct individuals in mastering the necessary psychomotor skills. Because the published data regarding the learning processes in surgical education are limited, it would be important to provide a link between surgical skills acquisition and cognitive psychology. We selected a well-known cognitive phenotype that requires spatial judgment, namely field dependence, which classifies an individual's ability to focus on a specific visuomotor task in the setting of ''distractors.'' Subjects can have varying degrees of field dependence, with those who are more field dependent more distracted by the environment. Field dependence, a subset of spatial judgment, differs from the concept of spatial visualization. Taken together, the areas of spatial judgment and spatial visualization can characterize how individuals process objects in 3 See related commentary on page 1811.

Background Low intellectual ability is associated with an increased risk of coronary heart disease and stroke. Most studies have used a general intelligence score. We studied whether three different subscores of intellectual ability predict these disorders. Methods We studied 2,786 men, born between 1934 and 1944 in Helsinki, Finland, who as conscripts at age 20 underwent an intellectual ability test comprising verbal, visuospatial (analogous to Raven's progressive matrices) and arithmetic reasoning subtests. We ascertained the later occurrence of coronary heart disease and stroke from validated national hospital discharge and death registers. Results 281 men (10.1%) had experienced a coronary heart disease event and 131 (4.7%) a stroke event. Coronary heart disease was predicted by low scores in all subtests, hazard ratios for each standard deviation (SD) lower score ranging from 1.21 to 1.30 (confidence intervals 1.08 to 1.46). Stroke was predicted by a low visuospatial reasoning ...

Background: Low intellectual ability is associated with an increased risk of coronary heart disease and stroke. Most studies have used a general intelligence score. We studied whether three different subscores of intellectual ability predict these disorders. We studied 2,786 men, born between 1934 and 1944 in Helsinki, Finland, who as conscripts at age 20 underwent an intellectual ability test comprising verbal, visuospatial (analogous to Raven's progressive matrices) and arithmetic reasoning subtests. We ascertained the later occurrence of coronary heart disease and stroke from validated national hospital discharge and death registers. Results: 281 men (10.1%) had experienced a coronary heart disease event and 131 (4.7%) a stroke event. Coronary heart disease was predicted by low scores in all subtests, hazard ratios for each standard deviation (SD) lower score ranging from 1.21 to 1.30 (confidence intervals 1.08 to 1.46). Stroke was predicted by a low visuospatial reasoning score, the corresponding hazard ratio being 1.23 (95% confidence interval 1.04 to 1.46), adjusted for year and age at testing. Adjusted in addition for the two other scores, the hazard ratio was 1.40 (1.10 to 1.79). This hazard ratio was little affected by adjustment for socioeconomic status in childhood and adult life, whereas the same adjustments attenuated the associations between intellectual ability and coronary heart disease. The associations with stroke were also unchanged when adjusted for systolic blood pressure at 20 years and reimbursement for adult antihypertensive medication. Stroke is predicted by low visuospatial reasoning scores in relation to scores in the two other subtests. This association may be mediated by common underlying causes such as impaired brain development, rather than by mechanisms associated with risk factors shared by stroke and coronary heart disease, such as socio-economic status, hypertension and atherosclerosis.

When a person moves through the world, the associated visual displacement of the environment in the opposite direction is not usually seen as external movement but rather as a changing view of a stable world. We measured the amount of visual motion that can be tolerated as compatible with the perception of moving within a stable world during active, sinusoidal, translational and rotational head movement. Head movements were monitored by means of a low-latency, mechanical head tracker and the information was used to update a helmet-mounted visual display. A variable gain was introduced between the head tracker and the display. Ten subjects adjusted this gain until the visual display appeared stable during sinusoidal yaw, pitch and roll head rotations and naso-occipital, inter-aural and dorsoventral translations at 0.5 Hz. Each head movement was tested with movement either orthogonal to or parallel with gravity. A wide spread of gains was accepted as stable (0.8 to 1.4 for rotation and 1.1 to 1.8 for translation). The gain most likely to be perceived as stable was greater than that required by the geometry (1.2 for rotation; 1.4 for translation). For rotational motion, the mean gains were the same for all axes. For translation there was no effect of whether the movement was interaural (mean gain 1.6) or dorso-ventral (mean gain 1.5) and no effect of the relative orientation of the translation direction relative to gravity. However translation in the naso-occipital direction was associated with more closely veridical settings (mean gain 1.1) and narrower standard deviations than in other directions. These findings are discussed in terms of visual and non-visual contributions to the perception of an earth-stable environment during active head movement.

The perceived orientation of objects, gravity, and the body are biased to the left. Whether this leftward bias is attributable to biases in sensing or processing vestibular, visual, and body sense cues has never been assessed directly. The orientation in which characters are most easily recognized-the perceived upright (PU)-can be well predicted from a weighted vector sum of these sensory cues. A simple form of this model assumes that the directions of the contributing inputs are coded accurately and as a consequence participants tilted leftor right-side-down relative to gravity should exhibit mirror symmetric patterns of responses. If a left/right asymmetry were present then varying these sensory cues could be used to assess in which sensory modality or modalities a PU bias may have arisen. Participants completed the Oriented Character Recognition Test (OCHART) while manipulating body posture and visual orientation cues relative to gravity. The response patterns showed systematic differences depending on which side they were tilted. An asymmetry of the PU was found to be best modeled by adding a leftward bias of 5.68 to the perceived orientation of the body relative to its actual orientation relative to the head. The asymmetry in the effect of body orientation is reminiscent of the body-defined left-leaning asymmetry in the perceived direction of light coming from above and reports that people tend to adopt a right-leaning posture.

The perceived direction of up depends on both gravity and visual cues to orientation. Static visual cues to orientation have been shown to be less effective in influencing the perception of upright (PU) under microgravity conditions than they are on earth (Dyde et al., 2009). Here we introduce dynamic orientation cues into the visual background to ascertain whether they might increase the effectiveness of visual cues in defining the PU under different gravity conditions. Brief periods of microgravity and hypergravity were created using parabolic flight. Observers viewed a polarized, natural scene presented at various orientations on a laptop viewed through a hood which occluded all other visual cues. The visual background was either an animated video clip in which actors moved along the visual ground plane or an individual static frame taken from the same clip. We measured the perceptual upright using the oriented character recognition test (OCHART). Dynamic visual cues significantl...

This article examines gravity from the perspective of living systems rather than equations alone. Cosmic Influx Theory (CIT) is treated here as equivalent to gravity in measured effects and calculated results, but different in proposed mechanism: instead of attraction or spacetime curvature, CIT interprets the phenomenon as a continuous Influx acting on matter. The article argues that organisms do not directly register abstract gravitational theory; they register load, shear, pressure, support, balance demand, and whole-body adaptation. Special attention is given to the vestibular system, especially the otolith organs, as a biological example of sensor-level mechanical registration. The accelerometer is used as a technical parallel, since both biological and instrumental systems respond to support and relative displacement rather than to theory as such. Across posture, circulation, microgravity adaptation, and life across species, the paper proposes that CIT may offer a more direct cause-language for what living systems are responding to. The claim is limited but important: this article does not prove CIT in full, but presents biological and operational indications that the experienced phenomenon called gravity may be interpreted, at sensor level, as Influx.

Background A declining cognitive performance is a hallmark of Huntington's disease (HD). The neuropsychological battery of the Unified HD Rating Scale (UHDRS'99) is commonly used for assessing cognition. However, there is a need to identify and minimize the impact of confounding factors, such as language, gender, age, and education level on cognitive decline. Objectives Aim is to provide appropriate, normative data to allow clinicians to identify disease-associated cognitive decline in diverse HD populations by compensating for the impact of confounding factors Methods Sample data, N = 3267 (60.5% females; mean age of 46.9 years (SD = 14.61, range 18-86) of healthy controls were used to create a normative dataset. For each neuropsychological test, a Bayesian generalized additive model with age, education, gender, and language as predictors was constructed to appropriately stratify the normative dataset. Results With advancing age, there was a non-linear decline in cognitive performance. In addition, performance was dependent on educational levels and language in all tests. Gender had a more limited impact. Standardized scores have been calculated to ease the interpretation of an individual's test outcome. A web-based online tool has been created to provide free access to normative data. Conclusion For defined neuropsychological tests, the impact of gender, age, education, and language as factors confounding disease-associated cognitive decline can be minimized at the level of a single patient examination.

Spatial discrimination of ibotenic acid-lesioned C57BL/6 (B6) and DBA/2 (D2) mice was tested in two-choice water maze and plus maze tasks. B6 but not D2 mice learned the spatial discrimination in the water maze, but strains did not differ in learning a spatial discrimination in the plus maze paradigm. Ibotenic acid lesions of the hippocampus impaired percentage correct choices in the water maze spatial discrimination task in B6 but not in D2 mice, the latter of which may have been due to a floor effect. Furthermore, lesioned mice were more thigmotaxic, the distance travelled until a choice was made was longer and animals made more errors of omission. Despite the poor performance during water maze acquisition, lesioned animals, as well as sham-lesioned D2 mice, eventually acquired some place response in the water maze, as was evident when the location of the platform was reversed. However, hippocampus-lesioned mice of both strains were impaired when tested in the plus maze spatial discrimination task. Thus, ibotenic acid-induced lesions of the hippocampus impair acquisition of spatial discrimination in mice. These deficits were strain-dependent and likely comprise impaired accuracy as well as changes in non-mnemonic types of behaviour. Importantly, lesions in both strains impaired spatial learning, and whether a deficit was seen in mice of the D2 strain seemed to depend on the demands of the task.

Spatial discrimination of ibotenic acid-lesioned C57BL/6 (B6) and DBA/2 (D2) mice was tested in two-choice water maze and plus maze tasks. B6 but not D2 mice learned the spatial discrimination in the water maze, but strains did not differ in learning a spatial discrimination in the plus maze paradigm. Ibotenic acid lesions of the hippocampus impaired percentage correct choices in the water maze spatial discrimination task in B6 but not in D2 mice, the latter of which may have been due to a floor effect. Furthermore, lesioned mice were more thigmotaxic, the distance travelled until a choice was made was longer and animals made more errors of omission. Despite the poor performance during water maze acquisition, lesioned animals, as well as sham-lesioned D2 mice, eventually acquired some place response in the water maze, as was evident when the location of the platform was reversed. However, hippocampus-lesioned mice of both strains were impaired when tested in the plus maze spatial discrimination task. Thus, ibotenic acid-induced lesions of the hippocampus impair acquisition of spatial discrimination in mice. These deficits were strain-dependent and likely comprise impaired accuracy as well as changes in non-mnemonic types of behaviour. Importantly, lesions in both strains impaired spatial learning, and whether a deficit was seen in mice of the D2 strain seemed to depend on the demands of the task.

Portal hypertension is a major complication of cirrhosis that frequently leads to a neuropsychiatric disorder that affects cognition. The present study was undertaken in order to compare the performance of sham-operated rats (SHAM) and portal hypertension rats (PH) in reference memory tasks in the Morris water maze (MWM). Two groups of animals were used: SHAM group (n012) was used as a control group and PH group (n012) by the triple portal vein ligation method was used as an animal model of early evolutive phase of PH. The portal pressure was measured in the splenic parenchyma. Our work shows that spatial learning in the MWM is not impaired in PH group although this group showed a one-day delay in the task acquisition compared to the SHAM group. We assessed the brain metabolic activity of the animals by means of cytochrome c-oxidase (COx) histochemistry. Significant changes were found in the CA3, dentate gyrus, basolateral, medial, lateral and central amygdala, showing lower COx activity in the PH group as compared to the SHAM group in all cases. We found no changes in metabolic activity in prefrontal cortex and CA1 area between groups. In fact, different neural networks were shown according to the execution level of the subjects. The early PH evolution induced changes in brain metabolic activity without biggest alterations in spatial memory.

Although both attention and motivation affect behavior, how these 2 systems interact is currently unknown. To address this question, 2 experiments were conducted in which participants performed a spatially cued forced-choice localization task under varying levels of motivation. Participants were asked to indicate the location of a peripherally cued target while ignoring a distracter. Motivation was manipulated by varying magnitude and valence (reward and punishment) of an incentive linked to task performance. Attention was manipulated via a peripheral cue, which correctly predicted the presence of a target stimulus on 70% of the trials. Taken together, our findings revealed that the signal detection measure dЈ, reflecting perceptual sensitivity, increased as a function of incentive value during both valid and invalid trials. In addition, trend analyses revealed a linear increase in detection sensitivity as a function of incentive magnitude for both reward and punishment conditions. Our results suggest that elevated motivation leads to improved efficiency in orienting and reorienting of exogenous spatial attention and that one mechanism by which attention and motivation interact involves the sharpening of attention during motivationally salient conditions.

Humans are uniquely able to retrieve and combine words into syntactic structure to produce connected speech. Previous identification of focal brain regions necessary for production focused primarily on associations with the content produced by speakers with chronic stroke, where function may have shifted to other regions after reorganization occurred. Here, we relate patterns of brain damage with deficits to the content and structure of spontaneous connected speech in 52 speakers during the acute stage of a left hemisphere stroke. Multivariate lesion behavior mapping demonstrated that damage to temporal-parietal regions impacted the ability to retrieve words and produce them within increasingly complex combinations. Damage primarily to inferior frontal cortex affected the production of syntactically accurate structure. In contrast to previous work, functional-anatomical dissociations did not depend on lesion size likely because acute lesions were smaller than typically found in chronic stroke. These results are consistent with predictions from theoretical models based primarily on evidence from language comprehension and highlight the importance of investigating individual differences in brain-language relationships in speakers with acute stroke. .

Across three experiments, we examined the cuing properties of metric (distance and direction) and nonmetric (lighting) cues in different tasks. In Experiment 1, rats were trained on a response problem in a T-maze, followed by four reversals. Rats that experienced a change in maze orientation (Direction group) or a change in the length of the start arm (Distance group) across reversals showed facilitation of reversal learning relative to a group that experienced changes in room lighting across reversals. In Experiment 2, rats learned a discrimination task more readily when distance or direction cues were used than when light cues were used as the discriminative stimuli. In Experiment 3, performance on a go/no-go task was equivalent using both direction and lighting cues. The successful use of both metric and nonmetric cues in the go/no-go task indicates that rats are sensitive to both types of cues and that the usefulness of different cues is dependent on the nature of the task.