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The concept and the term of constructional apraxia have been proposed by Karl Kleist and described in his impressive book "Gehirnpathologie", published in 1934. However, the first ever paper under the heading of constructional apraxia was written by Hans Strauss, one of Kleist's pupils, and published in 1924. Nowadays, the term constructional apraxia is still in use to refer to all disorders observed in drawing and assembling activities; its assessment, performed as it was in early studies, is part of common practice in behavioral neurology and neuropsychology. Nonetheless, the concept and the neural underpinnings of constructional apraxia have been deeply revisited with respect to the original proposal. Modern studies demonstrated that drawing and assembling are based on very large and complex brain networks extending in both hemispheres, including the left angular gyrus (as hypothesized by Kleist) but well beyond the original ideas about localization of constructional apraxia. From a clinical point of view, constructional apraxia has poor localizing value but provides valuable diagnostic information for conditions of cognitive impairment.

The present study aimed at exploring relationships among the visuospatial tasks included in the Battery for Visuospatial Abilities (BVA), and at assessing the relative contribution of different facets of visuospatial processing on tests tapping constructional abilities and nonverbal abstract reasoning. One hundred forty-four healthy subjects with a normal score on Mini Mental State Examination completed the BVA plus Raven's Coloured Progressive Matrices and Constructional Apraxia test. We used Principal Axis Factoring and Parallel Analysis to investigate relationships among the BVA visuospatial tasks, and performed regression analyses to assess the visuospatial contribution to constructional abilities and nonverbal abstract reasoning. Principal Axis Factoring and Parallel Analysis revealed two eigenvalues exceeding 1, accounting for about 60% of the variance. A 2-factor model provided the best fit. Factor 1 included sub-tests exploring "complex" visuospatial skills, whereas Factor 2 included two subtests tapping "simple" visuospatial skills. Regression analyses revealed that both Factor 1 and Factor 2 significantly affected performance on Raven's Coloured Progressive Matrices, whereas only the Factor 1 affected performance on Constructional Apraxia test. Our results supported functional segregation proposed by De Renzi, suggesting clinical caution to utilize a single test to assess visuospatial domain, and qualified the visuospatial contribution in drawing and non-verbal intelligence test.

The aim of this study is to clarify the specific role of the cerebellum during prism adaptation procedure (PAP), considering its involvement in early prism exposure (i.e., in the recalibration process) and in post-exposure phase (i.e., in the after-effect, related to spatial realignment). For this purpose we interfered with cerebellar activity by means of cathodal transcranial direct current stimulation (tDCS), while young healthy individuals were asked to perform a pointing task on a touch screen before, during and after wearing base-left prism glasses. The distance from the target dot in each trial (in terms of pixels) on horizontal and vertical axes was recorded and served as an index of accuracy. Results on horizontal axis, that was shifted by prism glasses, revealed that participants who received cathodal stimulation showed increased rightward deviation from the actual position of the target while wearing prisms and a larger leftward deviation from the target after prisms removal. Results on vertical axis, in which no shift was induced, revealed a general trend in the two groups to improve accuracy through the different phases of the task, and a trend, more visible in cathodal stimulated participants, to worsen accuracy from the first to the last movements in each phase. Data on horizontal axis allow to confirm that the cerebellum is involved in all stages of PAP, contributing to early strategic recalibration process, as well as to spatial realignment. On vertical axis, the improving performance across the different stages of the task and the worsening accuracy within each task phase can be ascribed, respectively, to a learning process and to the task-related fatigue., (Copyright © 2016 Elsevier Inc. All rights reserved.)

We describe a right-brain-damaged patient with extrapersonal neglect, dysexecutive deficits, and closing-in. Because no study has investigated the relationship between spatial neglect and closing-in in patients with focal brain damage, we assessed how spatial factors (drawing direction: left-to-right, right-to-left, radial) and attentional load (single versus dual task copying; the concurrent task was counting aloud) interacted in determining our patient's closing-in. We found that her closing-in was worst when she copied the stimulus (Luria's line) from left to right; greater attentional load significantly worsened her closing-in in the right-to-left direction. Closing-in seems to be caused by a pathologic release of motor behavior, analogous to other productive manifestations of extrapersonal neglect.

Battery for Visuospatial Abilities (BVA, known in Italy as TeRaDiC) has been developed to analyse putative basic skills involved in drawing and to plan and monitor outcomes after rehabilitation of visuoconstructional disorders. It encompasses eight tasks assessing both simple "perceptual" abilities, such as line length and line orientation judgments and complex "representational" abilities, such as mental rotation. The aim of present study was to provide normative values for BVA collected in a wide sample of healthy Italian subjects. Three hundred seventeen healthy Italian subjects (173 women and 144 men) of different age classes (age range, 40-95 years) and education level (from primary to university), with a normal score on Mini Mental State Examination, completed BVA/TeRaDiC. Multiple linear regression analysis revealed that age and education significantly influenced performance on most tests of the BVA/TeRaDiC; only line length judgment was not affected by educational level. Gender significantly affected line orientation judgment and mental rotation, with an advantage for males in both tests. From the derived linear equations, a correction grid for adjusting BVA/TeRaDiC raw scores was built. Using a non-parametric technique, inferential cut-off scores were determined and equivalent scores computed. The present study provided Italian normative data for the BVA/TeRaDiC useful for both clinical and research purposes.

Environmental dependency (ED) phenomena, including utilization behavior and imitation behavior, are clinical manifestations typically observed in patients with the behavioral variant of fronto-temporal dementia (bvFTD), who may also show the closing-in (CI) phenomenon. Here, we explored the neuropsychological correlates of ED and CI in bvFTD, and the association of ED with CI to clarify the mechanisms underlying these clinical manifestations. Thirty-one bvFTD patients underwent a wide cognitive assessment in addition to special tasks to detect occurrence of CI and ED phenomena. Both ED and CI phenomena were present in more than half of the sample. Logistic regression analyses revealed that both ED and CI phenomena were significantly associated with poor scores on frontal neuropsychological tests. Although ED and CI often co-occurred, 3/12 patients with CI did not show ED, and 5/18 patients with ED did not show CI. A logistic regression model showed that the presence of ED was not significantly associated to CI. CI and ED are associated to progressive derangement of frontal functions in bvFTD. However, specific frontal dysfunctions might explain the occurrence of either phenomenon in isolation.

The present evidence-based review systematically examines the literature on the neuropsychological rehabilitation of attentional and executive dysfunctions in patients with acquired brain lesions. Four areas are considered: 1) neuropsychological rehabilitation of attentional disorders; 2) neuropsychological rehabilitation of neglect disorders; 3) neuropsychological rehabilitation of dysexecutive disorders and 4) rehabilitation trainings for patients with mild traumatic brain injury (TBI). In each area, search and selection of papers were performed on several databases and integrated by crosschecking references from relevant and recent reviews. The literature up to 2007 was examined (in some areas the search was limited from 2000 to 2007). Class of evidence for each selected study was evaluated according to the SPREAD (2010) criteria. Based on this analysis, recommendations on the effectiveness of rehabilitation trainings are proposed separately for each rehabilitation method in each of the four areas considered. Information on follow-up data and impact on activities of daily living is provided whenever available.

The purpose of this paper was to verify whether left and right parietal brain lesions may selectively impair egocentric and allocentric processing of spatial information in near/far spaces. Two Right-Brain-Damaged (RBD), 2 Left-Brain-Damaged (LBD) patients (not affected by neglect or language disturbances) and eight normal controls were submitted to the Ego-Allo Task requiring distance judgments computed according to egocentric or allocentric frames of reference in near/far spaces. Subjects also completed a general neuropsychological assessment and the following visuospatial tasks: reproduction of the Rey-Osterreith figure, line length judgement, point position identification, mental rotation, mental construction, line length memory, line length inference, Corsi block-tapping task. LBD patients presented difficulties in both egocentric and allocentric processing, whereas RBD patients dropped in egocentric but not in allocentric judgements, and in near but not far space. Further, RBD patients dropped in perceptually comparing linear distances, whereas LBD patients failed in memory for distances. The overall pattern of results suggests that the right hemisphere is specialized in processing metric information according to egocentric frames of reference. The data are interpreted according to a theoretical model that highlights the close link between egocentric processing and perceptual control of action.

Convergent findings demonstrate that numbers can be represented according to a spatially oriented mental number line. However, it is not established whether a default organization of the mental number line exists (i.e., a left-to-right orientation) or whether its spatial arrangement is only the epiphenomenon of specific task requirements. To address this issue we performed two experiments in which subjects were required to judge laterality of hand stimuli preceded by small, medium or large numerical cues; hand stimuli were compatible with egocentric or allocentric perspectives. We found evidence of a left-to-right number -- hand association in processing stimuli compatible with an egocentric perspective, whereas the reverse mapping was found with hands compatible with an allocentric perspective. These findings demonstrate that the basic left-to-right arrangement of the mental number line is defined with respect to the body-centred egocentric reference frame.

The closing-in phenomenon (CIP) is often observed in patients with severe drawing disorders, but its cognitive bases are not well understood. We describe an experimental investigation aimed to clarify the nature of closing-in and its relationships with drawing disorders in a patient with corticobasal degeneration. In copying simple or complex stimuli (Experiment 1), the patient showed adherent and near types of closing-in, not affected by stimulus complexity, and produced distorted and often unrecognisable drawings. On the contrary, in drawing to dictation (without any available model), patients' performances significantly improved with respect to copying (Experiment 2). These data were consistent with the hypothesis that in some patients closing-in may develop from frontal-related release of approach behaviour even in the absence of relevant visuoperceptual impairments. By asking the patient to reproduce given spatial locations within circular frames (Experiment 3), we could further demonstrate the sparing of visuospatial processing and the frontal genesis of closing-in. These findings allowed us to speculate on the heterogeneous nature of closing-in.

We describe the case of a patient with right hemisphere damage and left unilateral neglect. The patient was asked to draw from memory common objects, either with or without visual feedback. In the conditions without visual feedback the patient was either blindfolded or he made "invisible" drawings using a pen with the cap on, the drawings being recorded with carbon paper underneath. Results showed more neglect without than with visual feedback, contrary to previously published cases. This patient's pattern of performance may result from the contribution of a deficit of spatial working memory. Alternatively or in addition, the patient, who was undergoing cognitive rehabilitation for neglect, may have found easier to compensate for his neglect with visual feedback, which allowed him to visually explore the left part of his drawings.

The aim of the present study was to verify whether duration, order and space representations share common mechanisms. A two-alternative time estimation paradigm was implemented in two experiments in which subjects had to judge whether the first or the second tone in a pair was shorter (or longer) and to respond by pressing a left or a right key. In Experiment 1, subjects were more accurate in conditions where the first tone was shorter or the second tone was longer, with no effects of spatial information. In Experiment 2, a modification of the paradigm allowed us to demonstrate the presence of a SNARC-like effect, as evidenced by the interaction between order and response key, and of a second-order interaction among duration, order and space. These findings seem consistent with the hypothesis that processing of these three mental categories is subserved by a common mechanism, representing duration and order information according to a spatially-defined magnitude system.

When subjects are asked to compare the mental images of two analog clocks telling different times (the mental clock test), they are faster to process angles formed by hands located in the right than in the left half of the dial. In the present paper, we demonstrate that this Imaginal HemiSpatial Effect (IHSE) can be also observed in two modified versions of the mental clock test: in Experiment 1 subjects had to imagine the position occupied by two numbers within a clock face and to judge if the subtended angle was smaller or greater than 90 degrees , while in Experiment 2 subjects were asked to match two imagined positions on a clock face with two visually presented locations. The finding of the IHSE in these tasks suggested that it is a genuine phenomenon related to spatial imagery tasks, and is consistent with recent neuroimaging evidence that the left parietal lobe is mainly involved in the generation of spatial mental images.

Using repetitive transcranical magnetic stimulation (rTMS), we investigated the functional relevance of posterior parietal cortex for categorical and coordinate judgements in the spatial imagery domain. In the coordinate task, subjects were asked to imagine two analogue clock faces based on acoustically presented pairs of times, and to judge at which of the two times the clock hands form the greater angle (mental clock task); in the categorical task subjects were again asked to imagine an analogue clock face showing the time verbally presented by the examiner, but in this case they had to judge whether both hands lay in the half of the clock face cued by an auditorily presented label. We matched the performance of three groups of subjects, two of which received rTMS stimulation over left and right posterior parietal cortex, respectively, while the third group received a sham stimulation. The results showed that right parietal stimulation interfered with the execution of the coordinate task, while left parietal stimulation mainly affected the categorical task, but also reduced the learning effect on the coordinate task. The present findings support the hemispheric specialization of the posterior parietal cortex in different spatial information processing in the imagery domain.

We tested 125 normal subjects and 24 right and 22 left focal brain-damaged patients (RBD and LBD) on the Rey figure copying test and on a battery of perceptual and representational visuospatial tasks, in search of relationships between constructional and visuospatial abilities. Selected RBD and LBD were not affected by severe aphasia, unilateral spatial neglect or general intellectual defects. Both RBD and LBD showed defective performances on the constructional task with respect to normal subjects. As regards visuospatial tasks, both patient groups scored lower than normal subjects in judging angle width and mentally assembling geometrical figures; moreover, RBD, but not LBD, achieved scores significantly lower than healthy controls in judging line orientation and analyzing geometrical figures. Post-hoc comparisons did not reveal any significant differences between RBD and LBD. Multiple regression analysis showed that visuospatial abilities correlate with accuracy in copying geometrical drawings in normal subjects and in RBD, but not in LBD. From a theoretical perspective, these findings support the idea that visual perceptual and representational abilities do play a role in constructional skills.

We describe a neglect patient who showed systematic transpositions of left-sided items onto the right side in clock drawing. When the patient had to write single hours on blank clock dials he again showed allochiria, while he copied single spatial locations without transpositions. The patient also showed a variable number of spatial transpositions on imaginal tasks with well known and novel material acquired through visual modality and on controlled constructional tasks, independently from response modality (verbal, graphic or motor). From this basis, we argued that spatial transpositions may derive from an impairment of the mental representation of space. Moreover, we speculated that such errors may result from cognitive conflict between different sources of information.

We describe a patient with an ischemic right frontal lesion and mild left neglect who showed a systematic tendency to transpose drawings on one side of the page, which varied depending on the starting point (left or right) of his graphic productions. When not specifically cued, the patient started to draw in the ipsilesional (right) side and tended to show allochiria on the right, but occasionally, or under specific instructions, the patient started drawing from the left side and then showed a complete reversion of his spatial transpositions. To clarify the basic mechanisms underlying such a peculiar constructional phenomenon, we performed a series of experimental investigations, including extended copying tasks, a clock-marking test (to mark the position of single hours on a clock-face), and a line bisection task with progressive left-toright or right-to-left stimulus presentation. Findings suggested that "alternating" allochiria in copying and drawing from memory tasks is an epiphenomenon of a basic inability to move attention and action away from the starting point of graphic productions. The present case study, contrasted with observations on other brain-damaged patients, demonstrates that allochiria may have different neuro-cognitive bases and offers new insights for theoretical interpretations of unilateral spatial neglect.

In the present paper, we describe a neglect patient who showed allochiria in copying and drawing a clock from memory. To verify the mechanisms of allochiria in our patient, we designed an experimental investigation including two conditions: to write single hours and to copy their spatial locations, one at a time onto blank circles. The patient showed spatial transpositions in writing hours on blank dials, but did not show allochiria in the reproduction of spatial locations. These findings suggest that the patient could not represent in her mind appropriate spatial coordinates of each hour with respect to the whole clock face. These data are in contrast with findings reported in other patients and demonstrate that constructional allochiria associated with spatial neglect may derive from different causal mechanisms. Our experimental investigation has thus paved the way for a distinction between an "attentional" and a "representational" allochiria.

Mental imagery, the generation and manipulation of mental representations in the absence of sensory stimulation, is a core element of numerous cognitive processes. We investigate the cortical mechanisms underlying imagery and spatial analysis in the visual domain using event-related functional magnetic resonance imaging during the mental clock task. The time-resolved analysis of cortical activation from auditory perception to motor response reveals a sequential activation of the left and right posterior parietal cortex, suggesting that these regions perform distinct functions in this imagery task. This is confirmed by a trial-by-trial analysis of correlations between reaction time and onset, width, and amplitude of the hemodynamic response. These findings pose neurophysiological constraints on cognitive models of mental imagery.

Background: In recent years several attempts have been made to distinguish frontotemporal dementia (FTD) from Alzheimer's disease (AD) on neuropsychological grounds; in particular, it has been suggested that FTD patients show spared spatial abilities with respect to AD patients., Objective: We aimed at verifying whether patients with the frontal variant of frontotemporal dementia (fv-FTD) and AD patients perform differently on visuospatial and constructional tasks., Methods: We assessed a wide range of visuospatial abilities and provided a qualitative analysis of constructional performances in 14 fv-FTD patients and 11 AD patients, matched for general cognitive abilities., Results: The two groups of patients achieved similar scores on two copying tasks, presented similar drawing procedures in copying Rey complex figure and made a similar quantitative and qualitative pattern of errors in copying simple geometrical drawings. Moreover, no significant difference was found between fv-FTD and AD patients on a specific battery for visuospatial abilities., Conclusions: Our data and a review of the literature suggest that basic visuospatial and constructional skills cannot be taken as a reliable diagnostic criterion for distinguishing fv-FTD and AD at a mild to moderate disease stage and that the clinical belief of spared spatial abilities in fv-FTD has to be referred to the lack of topographic disorientation in comparison to AD., (Copyright 2002 John Wiley & Sons, Ltd.)

We aimed at verifying whether the hemispheric specialisation for categorical/coordinate spatial judgements also applies to the spatial imagery domain by the use of whole-brain fMRI. In a block-design experiment we used the "coordinate" mental clock test, contrasting it with a "categorical" task applied to the same clock stimuli; as a control task we used a syllable counting task requiring a verbal-phonological judgement on the same material of the two imagery tasks. Our results showed that categorical and coordinate spatial judgements on imagined stimuli rely on the activation of a set of cortical areas, centred upon the superior parietal lobule (SPL) bilaterally. These regions, together with other parietal and prefrontal areas, showed a pattern of relative lateralization, with the left hemisphere being mainly activated during the categorical task and the right in the coordinate task. These data confirm the strong involvement of the SPL in spatial processing. Moreover, our findings suggest that different interconnected neural networks are activated to comply with specific test requirements, giving rise to functional imaging patterns compatible with psychological theories on hemispheric specialization.

The present study aimed to investigate the acquisition of visuospatial and graphomotor capacities during the pre-school and early schooling years in order to follow the normal development of drawing-related abilities and spatial cognition. Eighty children aged 3-5 years, divided in four subgroups each different for a 6-month period, and 80 children aged 8-9 years were administered a neuropsychological battery for visuospatial and visuoconstructional analysis. The battery explored five cognitive domains: visual scanning, visuospatial perceptual and representational abilities, visuomotor control and graphomotor skills. Results showed that the total scores significantly improved in each group of children with respect to the previous one, but the pattern of skill acquisition was not homogeneous. We observed a gradient from explorative and visuomotor to perceptive, representational and graphomotor abilities. Explorative and visuomotor abilities were almost mature at a time when visuoperceptual capacities began to develop. On the contrary, at that time we found very low performances at representational and constructional tasks. Our findings could suggest that constructional abilities need both perceptual and representational competences to develop properly.

Cognitive models for developmental dyslexia are nowadays centered on the hypothesis of a specific deficit within the phonologic module of the language system. To ascertain whether defects of spatial cognition are associated with developmental reading disability, we investigated a sample of 43 school children (aged 8-9 years) found to be reading impaired during a wide screening survey for developmental dyslexia in the province of Naples, Italy. After one year all children were tested again and only 9/43 still presented reading impairment, while the remaining had achieved a variable range of spontaneous recovery. A detailed analysis was performed on all children to characterize their cognitive performances using on one hand classical conventional tests for constructional praxis, visuospatial cognition, and visuospatial memory and on the other a specific neuropsychological battery for constructional disorders. The results of our study demonstrated that children with long-lasting reading impairment exhibited normal performances on spatial cognition tasks. Moreover, one single child was found with relevant visuospatial deficits pointing to the possible existence of a visuospatial subtype for developmental dyslexia.

Do spatial operations on mental images and those on visually presented material share the same neural substrate? We used the high spatial resolution of functional magnetic resonance imaging to determine whether areas in the parietal lobe that have been implicated in the spatial transformation of visual percepts are also activated during the generation and spatial analysis of imagined objects. Using a behaviourally controlled mental imagery paradigm, which did not involve any visual stimulation, we found robust activation in posterior parietal cortex in both hemispheres. We could thus identify the subset of spatial analysis-related activity that is involved in spatial operations on mental images in the absence of external visual input. This result clarifies the nature of top-down processes in the dorsal stream of the human cerebral cortex and provides evidence for a specific convergence of the pathways of imagery and visual perception within the parietal lobes.

Five neglect patients without diffuse cognitive impairment or overt constructional disabilities were asked to bisect lines and rectangles and to copy rectangles bisected in their midplane. As a group, patients showed the usual rightward bias in bisecting lines and a milder deviation in bisecting horizontally-aligned rectangles, but showed a leftward deviation of the subjective midline in the copying task. This was due to drawing the left half shorter with respect to normal controls but three patients also drew the right half longer (the total length was the same as that of controls). A possible interpretation of rectangle copying results in these three patients is that they could create a representation of the stimulus to be copied accurately enough to reproduce its total length correctly but the subjective distribution of right and left space within that representation was unbalanced. However, specific experimental work is needed to verify why our patients with mild to moderate unilateral spatial neglect overrepresented the left side in a line bisection task and underrepresented it in a copying task.

The present study aimed at controlling two variables that may affect the visuospatial short-term memory of Alzheimer patients: visuospatial coding efficiency and response modality. Thirty patients affected by Alzheimer-type dementia with relatively spared visuo-perceptual functions were tested under three conditions, all of which employed the same kind of stimuli (visuospatial patterns). At all memory tasks, patients achieved scores significantly lower than those of 30 age- and education-matched normal subjects. Patients did not benefit from longer presentation time, nor did their performance improve with pointing response modality, although they performed perceptual pattern recognition as well as did controls. These data confirm that visuospatial immediate memory capacity is reduced in dementia.