Cognitive processing of drawing abilities

Long-term ayahuasca use is associated with preserved global cognitive function and improved memory: a cross-sectional study with ritual users

Although several studies have been conducted to elucidate the relationship between psychedelic consumption and cognition, few have focused on understanding the long-term use influence of these substances on these variables, especially in ritualistic contexts.  To verify the influence of ritualistic ayahuasca consumption on the cognition of experienced ayahuasca religious users (> 20 years) and beginners (< 3 years), which participated in rituals of the Centro Luz Divina (CLD), a Santo Daime church in Brazil. Observational, descriptive, and cross-sectional study was carried out in which 48 people participated divided into three groups: (a) experienced ayahuasca users (n = 16), (b) beginner ayahuasca users (n = 16) and (c) control group (n = 16). All groups were matched by sex, age, and education and contained 8 women and 8 men. Cognition was assessed with the WASI (intelligence quotient), Digit Span (verbal working memory), Corsi Block-Tapping Task (visuospatial-related and working memory), Rey-Osterrieth Complex Figure test (visual perception, immediate memory), and Wisconsin Card Sorting and Five Digit Test (executive functions). Groups were homogenous in terms of sociodemographic characteristics, with participants presenting average intellectual performance. There was no evidence of cognitive decline amongst ayahuasca users. The experienced group showed higher scores compared to the less experienced group in the Digit Span and Corsi Block-Tapping tasks, which assess working verbal and visuospatial memories respectively. We confirmed the botanical identities of Psychotria viridis and Banisteriopsis caapi and the presence of the alkaloids both in the plants and in the brew. Short and long-term ayahuasca consumption does not seem to alter human cognition, while long-term use seems to be associated with improvements in aspects of working memory when compared with short-term use.

The Test of Visuospatial Construction: A Novel Test of Non-motoric Visuoconstruction

Objective

The Test of Visuospatial Construction (TVSC) was designed as an easily administered measure of non-motor visuoconstruction, though only preliminary data exists regarding the clinical utility of this task. The current study examined the diagnostic accuracy of the TVSC by comparing performance between healthy subjects and various clinical groups. The authors also wanted to determine whether previous findings could be replicated regarding its effectiveness at tracking cognitive decline.

Method

Archival data collected over a period of more than 10 years were utilized and the overall sample consisted of 955 individuals, 372 healthy subjects, and 583 subjects who were categorized into various clinical groups. Only TVSC test data and demographic variables were utilized for statistical analyses in this study.

Results

The control group obtained significantly higher scores on the TVSC than the clinical groups. AUC values were indicative of excellent discrimination between cases and controls. Exploratory ROC curve analyses suggested adequate to excellent discrimination between the control group and the individual clinical groups as well as between the mild cognitive impairment (MCI) subgroups and the two dementia groups.

Conclusions

This study demonstrates that the TVSC can effectively differentiate between healthy subjects and neurologically compromised individuals. Additionally, the TVSC may be able to measure the progressive decline in visuoconstructive abilities that occurs as patients traverse the spectrum of MCI and dementia.

The Visuospatial and Sensorimotor Functions of Posterior Parietal Cortex in Drawing Tasks: A Review

Drawing is a comprehensive skill that primarily involves visuospatial processing, eye-hand coordination, and other higher-order cognitive functions. Various drawing tasks are widely used to assess brain function. The neuropsychological basis of drawing is extremely sophisticated. Previous work has addressed the critical role of the posterior parietal cortex (PPC) in drawing, but the specific functions of the PPC in drawing remain unclear. Functional magnetic resonance imaging and electrophysiological studies found that drawing activates the PPC. Lesion-symptom mapping studies have shown an association between PPC injury and drawing deficits in patients with global and focal cerebral pathology. These findings depicted a core framework of the fronto-parietal network in drawing tasks. Here, we review neuroimaging and electrophysiological studies applying drawing paradigms and discuss the specific functions of the PPC in visuospatial and sensorimotor aspects. Ultimately, we proposed a hypothetical model based on the dorsal stream. It demonstrates the organization of a PPC-centered network for drawing and provides systematic insights into drawing for future neuropsychological research.

Laterality and visuospatial strategies among young children: A novel 3D-2D transcription task

Recent findings showed that children, like adults, exhibit directional biases leading to asymmetrical drawings. This appears to be the result of a complex interaction between several biological, motoric, and cultural factors. We created a drawing task designed to investigate the influence of laterality (i.e., hemispherical functional specialization and handedness) and sex on children's graphical asymmetries. This task consists of transcribing a symmetrical three-dimensional landscape model to a two-dimensional representation. Sixty-six French pre-school children, aged between 5 and 6 years, were asked to undertake the 3D-2D transcription task, as well as the classical Alter's directionality task. The novel task exhibited higher sensitivity than the Alter's directionality test when examining the spatial biases resulting from handedness, and sex. Specific drawing patterns related to these variables were identified. These results suggest that, in addition to the influence of biomechanical factors and handedness, sex plays a role in children's early graphomotor development. They also support the influence of laterality as a key factor underlying early directional biases.

The Digital Tree Drawing Test for Screening of Early Dementia: An Explorative Study Comparing Healthy Controls, Patients with Mild Cognitive Impairment, and Patients with Early Dementia of the Alzheimer Type

The digital tree drawing test (dTDT) is a newly developed screening tool for the early detection of Alzheimer's disease. It is performed with a digitizing pen, recording each pen stroke with temporal and spatial precision. It was hypothesized that movement characteristics recorded during the painting process contribute to the identification of patients with mild cognitive impairment (MCI) and early dementia of the Alzheimer type (eDAT). The study population consisted of 187 participants (67 healthy controls, 64 MCI, and 56 eDAT patients) with a mean age of 68.6±10.6 years. Between-group comparisons of the dTDT-variables were conducted with analysis of variance. The diagnostic power of dTDT variables was analyzed with stepwise logistic regressions and areas under curve (AUC) of receiver operating control curves. Cognitively impaired persons used less colors and line widths and changed them less often than healthy subjects (p-values ≤0.05). Compared to control, eDAT patients had larger not-painting periods, were slower, and their pictures had less contrast, image size, and complexity (p-values ≤0.01). Logistic regression models of stepwise selected dTDT variables resulted in an AUC of 0.84 (95% confidence interval (CI) [0.79, 0.90], sensitivity = 0.78, specificity = 0.77) for discriminating healthy subjects from all cognitive impaired, an AUC of 0.77. (95% CI [0.69; 0.85], sensitivity = 0.56, specificity = 0.83) for discriminating healthy controls from MCI patients and an AUC of 0.90 (95% CI [0.84, 0.96], sensitivity = 0.86, specificity = 0.82) for discriminating controls from eDAT patients. The results suggest that digital recording of pen-stroke data during the drawing process can contribute to the screening of cognitive impaired patients.

Focused Multisensory Anatomy Observation and Drawing for Enhancing Social Learning and Three-Dimensional Spatial Understanding

The concept that multisensory observation and drawing can be effective for enhancing anatomy learning is supported by pedagogic research and theory, and theories of drawing. A haptico-visual observation and drawing (HVOD) process has been previously introduced to support understanding of the three-dimensional (3D) spatial form of anatomical structures. The HVOD process involves exploration of 3D anatomy with the combined use of touch and sight, and the simultaneous act of making graphite marks on paper which correspond to the anatomy under observation. Findings from a previous study suggest that HVOD can increase perceptual understanding of anatomy through memorization and recall of the 3D form of observed structures. Here, additional pedagogic and cognitive underpinnings are presented to further demonstrate how and why HVOD can be effective for anatomy learning. Delivery of a HVOD workshop is described as a detailed guide for instructors, and themes arising from a phenomenological study of educator experiences of the HVOD process are presented. Findings indicate that HVOD can provide an engaging approach for the spatial exploration of anatomy within a supportive social learning environment, but also requires modification for effective curricular integration. Consequently, based on the most effective research-informed, theoretical, and logistical elements of art-based approaches in anatomy learning, including the framework provided by the observe-reflect-draw-edit-repeat (ORDER) method, an optimized "ORDER Touch" observation and drawing process has been developed. This is with the aim of providing a widely accessible resource for supporting social learning and 3D spatial understanding of anatomy, in addition to improving specific anatomical knowledge.

Representational drawing following brain injury

Research has shown that damage to either the left or right hemisphere can lead to deficits in visuoconstructional skills including drawing and figure copying. Nevertheless, research would suggest that the nature of the deficits arising from left and right brain injury are distinct in nature if not severity, with the right hemisphere, and parietal cortex specifically, seen as critical for obtaining accurate spatial relations and the left hemisphere important for effective organisation (i.e., executive function). Much of this work on drawing and figure copying following brain damage has rested on qualitative assessments or crude marking scales with descriptive anchors for what constitutes good or poor performance. We employed quantitative analyses of drawings developed to assess accuracy in novice and expert artists. We analyzed drawings of a cube and a star in 50 patients (23, left brain damaged: LBD; 27 right brain damaged: RBD) who had suffered strokes. Our analysis was sensitive to the presence of neglect on the cube (i.e., missing left sided details) with voxel-wise lesion symptom mapping (VLSM) highlighting involvement of expected brain regions (superior temporal and supramarginal gyri). With left-sided omissions removed from analyses, we failed to find any difference between LBD and RBD patients. While the presence of left neglect appeared to exaggerate errors, this was only significant for errors of scale and proportion for the star drawing. VLSM of the distinct error domains demonstrated white matter involvement (and a minor contribution from the right insula) with respect to scale errors of the cube only. Finally, blinded judgements of hemisphere of lesion based on qualitative assessment of the drawings were no better than chance. These results suggest that figure copying is a complex task relying on large scale neural networks involving both hemispheres. Clearly, models of visuoconstructional capacity that emphasise right hemisphere dominance are not entirely accurate.

Identifying neuropsychological predictors of drawing skills in elementary school children

Much evidence indicates that drawing is related to different neuropsychological abilities in children. However, a comprehensive cognitive model of drawing in children is still lacking. Here, we conducted a study on the neuropsychological predictors of drawing in a sample of 142 typically developing elementary school children (M age = 8.8 years; SD = 1.1). Based on a path analysis, we examined the contribution of visual perception (matching geometrical figures), complex spatial abilities (e.g., complex figures identification and mental rotation), visual attention, working memory, verbal and visual-motor skills, as well as of gender, age and socio-economic status, to copying the Rey-Osterrieth Complex Figure (ROCF). Results showed that ROCF copying was influenced in a specific and additive way by visual perception, visual-motor coordination, and verbal abilities as well as age, while it was indirectly related to visual attention, working memory, and to complex spatial abilities. These findings provide the grounds for identifying the neuropsychological bases of drawing in elementary school children.

Parietal Involvement in Constructional Apraxia as Measured Using the Pentagon Copying Task

Deficits in copying ("constructional apraxia") is generally defined as a multifaceted deficit. The exact neural correlates of the different types of copying errors are unknown. To assess whether the different categories of errors on the pentagon drawing relate to different neural correlates, we examined the pentagon drawings of the MMSE in persons with subjective cognitive complaints, mild cognitive impairment, or early dementia due to Alzheimer's disease. We adopted a qualitative scoring method for the pentagon copy test (QSPT) which categorizes different possible errors in copying rather than the dichotomous categories "correct" or "incorrect." We correlated (regional) gray matter volumes with performance on the different categories of the QSPT. Results showed that the total score of the QSPT was specifically associated with parietal gray matter volume and not with frontal, temporal, and occipital gray matter volume. A more fine-grained analysis of the errors reveals that the intersection score and the number of angles share their underlying neural correlates and are associated with specific subregions of the parietal cortex. These results are in line with the idea that constructional apraxia can be attributed to the failure to integrate visual information correctly from one fixation to the next, a process called spatial remapping.

Constructional apraxia

Since the classic papers of Kleist, Mayer Gross, and Critchley, constructional apraxia (CA) has been considered to be a typical sign of a parietal lobe lesion, and as a precious tool to appreciate the spatial abilities subserved by this lobe. However, the development of more sophisticated neuropsychologic models and methods of investigation has revealed several problematic aspects. It has become increasingly clear that CA is a heterogeneous construct that can be examined with very different tasks, that are only mildly interconnected, and tap various kinds of visuospatial, perceptual, attentional, planning, and motor mechanisms. On the basis of these considerations, the relationships between parietal lobe functions and constructional activities must be considered, taking into account on the one hand the heterogeneity of the tasks and of the cognitive functions requested by different kinds of constructional activities and, on the other hand, the plurality of functions and of processing streams linking different parts of the parietal lobes to the occipital and frontal lobes.

Improvements in anatomy knowledge when utilizing a novel cyclical "Observe-Reflect-Draw-Edit-Repeat" learning process

Innovative educational strategies can provide variety and enhance student learning while addressing complex logistical and financial issues facing modern anatomy education. Observe-Reflect-Draw-Edit-Repeat (ORDER), a novel cyclical artistic process, has been designed based on cognitivist and constructivist learning theories, and on processes of critical observation, reflection and drawing in anatomy learning. ORDER was initially investigated in the context of a compulsory first year surface anatomy practical (ORDER-SAP) at a United Kingdom medical school in which a cross-over trial with pre-post anatomy knowledge testing was utilized and student perceptions were identified. Despite positive perceptions of ORDER-SAP, medical student (n = 154) pre-post knowledge test scores were significantly greater (P < 0.001) with standard anatomy learning methods (3.26, SD = ±2.25) than with ORDER-SAP (2.17, ±2.30). Based on these findings, ORDER was modified and evaluated in the context of an optional self-directed gross anatomy online interactive tutorial (ORDER-IT) for participating first year medical students (n = 55). Student performance was significantly greater (P < 0.001) with ORDER-IT (2.71 ± 2.17) when compared to a control tutorial (1.31 ± 2.03). Performances of students with visual and artistic preferences when using ORDER were not significantly different (P > 0.05) to those students without these characteristics. These findings will be of value to anatomy instructors seeking to engage students from diverse learning backgrounds in a research-led, innovative, time and cost-effective learning method, in the context of contrasting learning environments. Anat Sci Educ 10: 7-22. © 2016 American Association of Anatomists.

Drawing Firmer Conclusions: Autistic Children Show No Evidence of a Local Processing Bias in a Controlled Copying Task

Drawing tasks are frequently used to test competing theories of visuospatial skills in autism. Yet, methodological differences between studies have led to inconsistent findings. To distinguish between accounts based on local bias or global deficit, we present a simple task that has previously revealed dissociable local/global impairments in neuropsychological patients. Autistic and typical children copied corner elements, arranged in a square configuration. Grouping cues were manipulated to test whether global properties affected the accuracy of reproduction. All children were similarly affected by these manipulations. There was no group difference in the reproduction of local elements, although global accuracy was negatively related to better local processing for autistic children. These data speak against influential theories of visuospatial differences in autism.

Improved Necker Cube Drawing-Based Assessment Battery for Constructional Apraxia: The Mie Constructional Apraxia Scale (MCAS)

Background/Aims

Constructional apraxia (CA) is usually diagnosed by having patients draw figures; however, the reported assessments only evaluate the drawn figure. We designed a new assessment battery for CA (the Mie Constructional Apraxia Scale, MCAS) which includes both the shape and drawing process, and investigated its utility against other assessment methods.

Methods

We designed the MCAS, and evaluated inter- and intrarater reliability. We also investigated the sensitivity, specificity, and positive and negative predictive values in dementia patients, and compared MCAS assessment with other reported batteries in the same subjects.

Results

Moderate interrater reliability was shown for speech therapists with limited experience. Moderate to substantial intrarater reliability was shown several weeks after initial assessment. When cutoff scores and times were set at 2/3 points and 39/40 s, sensitivity and specificity were 77.1 and 70.4%, respectively, with positive and negative predictive values of 80.0 and 66.7%, respectively. Dementia patients had significantly worse scores and times for Necker cube drawing than an elderly control group on the MCAS, and on other assessments.

Conclusions

We conclude that the MCAS, which includes both the assessment of the drawn Necker cube shape and the drawing process, is useful for detecting even mild CA.

Development of drawing abilities in a distinct population: Depiction of perceptual principles by three children with congenital total blindness

We studied the development of spontaneous tactile drawing in three 12-year-old children with congenital total blindness and with no previous drawing tuition. In a period of 9 months, from an initial phase in which they were taught to draw tangible straight and curve raised lines, the three blind children went on making spontaneous raised outlines representing edges, surfaces of objects, vantage point, and motion. The corpus of drawings produced by these children shows that several aspects of outline pictures can be implemented through touch. The perceptual principles represented in these drawings are comparable to those commonly found in sighted children. On the one hand, this convergence indicates similarities in the way vision and touch mediate the acquisition and the conceptualisation of spatial information from objects and the environment. On the other hand, it reflects the influence of cross-modal plasticity typically associated with early or congenital blindness. This study suggests that drawing development in general does not depend on learning pictorial conventions. Rather it seems driven by natural generativity based on children’s knowledge of space and perceptual principles.

Lesion-symptom mapping of a complex figure copy task: A large-scale PCA study of the BCoS trial

Complex figure copying is a commonly used neuropsychological test. Here we explored the neural basis of the factors underlying complex figure copying (CFC), using data from the Birmingham Cognitive Screen (BCoS) in a large group of sub-acute, ischemic stroke patients (239). We computed two analyses: in the first we assessed the contribution of co-morbid deficits (i.e. in gesture processing, object use, visual neglect, pictures naming and sustained attention) to the lesions associated with CFC. In a second analysis a Principle Component Analysis (PCA) was used to isolate different underlying task components and to link to clinical neuroimaging scans. A voxel-based morphometry (VBM) analysis showed that poor CFC performance was associated with lesions to bi-lateral thalamus, lingual, right fusiform and right inferior parietal cortices (rIPC). The latter association with the posterior parietal cortex was diminished after controlling for neglect. Follow up analysis showed the neglect partially mediated the correlation of CFC and rIPC. The PCA revealed three main underlying components: (1) a component associated with high-level motor control common to different measures of apraxia and linked to the left postcentral gyrus, the right thalamus and middle frontal gyrus; (2) a visuo-motor transformation component unique to the CFC and associated with lesions to the posterior occipital and sensory cortices; (3) a component associated with multistep object use tasks which was correlated with lesions to the left inferior frontal orbital gyrus, the right fusiform and cerebellum. Using clinical symptoms, cognitive profiles and lesion mapping we showed that beyond visual perception, CFC performance is supported by three functional networks: one for high-level motor control, a visuo-motor transformation component, and multistep object use network.

Working Memory and Cognitive Flexibility Mediates Visuoconstructional Abilities in Older Adults with Heterogeneous Cognitive Ability

Previous studies suggest that executive functions influence the performance on visuoconstructional tasks. This study aims to investigate whether the relationship between planning ability and the copy of complex figures is mediated by distinct components of executive functions (i.e., working memory, inhibitory control and cognitive flexibility). We included a 129 older adults with Alzheimer's disease (n=36, AD), mild cognitive impairment (MCI, n=67), and with no evidence of cognitive impairment (controls, n=26). We evaluated the mediation effect of planning abilities, working memory, cognitive flexibility and inhibitory control on visuoconstructional tasks using a multiple mediation models. We found a significant direct effect of planning on visuoconstructional abilities and a partial mediation effect of working memory and cognitive flexibility on visuoconstructional abilities. The present results indicate that the performance on visuoconstructional task is mediated by multiple interrelated executive functions components, in particular working memory and cognitive flexibility.

Understanding visual consciousness in autism spectrum disorders

The paper focuses on the question of what the (visual) perceptual differences are between individuals with autism spectrum disorders (ASD) and typically developing (TD) individuals. We argue against the view that autistic subjects have a deficiency in the most basic form of perceptual consciousness—namely, phenomenal consciousness. Instead, we maintain, the perceptual atypicality of individuals with autism is of a more conceptual and cognitive sort—their perceptual experiences share crucial aspects with TD individuals. Our starting point is Ben Shalom’s (2005, 2009) three-level processing framework for explaining atypicality in several domains of processing among autistics, which we compare with two other tripartite models of perception—Jackendoff’s (1987) and Prinz’s (2000, 2005a, 2007) Intermediate Level Hypothesis and Lamme’s (2004, 2006, 2010) neural account of consciousness. According to these models, whereas the second level of processing is concerned with viewer-centered visual representations of basic visual properties and incorporates some early forms of integration, the third level is more cognitive and conceptual. We argue that the data suggest that the atypicality in autism is restricted mainly to the third level. More specifically, second-level integration, which is the mark of phenomenal consciousness, is typical, yet third-level integration of perceptual objects and concepts is atypical. Thus, the basic experiences of individuals with autism are likely to be similar to typical subjects’ experiences; the main difference lies in the sort of cognitive access the subjects have to their experiences. We conclude by discussing implications of the suggested analysis of experience in autism for conceptions of phenomenal consciousness.

The role of chunking in drawing Rey complex figure

The study investigated the effects of chunking and perceptual patterns that guide the drawings of Rey complex figure. Ten adult participants (M age=22.2 yr., SD=4.1) reproduced a single stimulus in four drawing modes including delayed recall, tracing, copying, and immediate recall across 10 sessions producing a total of 400 trials. It was hypothesized that the effect of chunking is most obvious in the free recall tasks than in the tracing or copying tasks. Measures such as pauses, patterns of drawings, and transitions among patterns of drawings suggested that participants used chunking to aid rapid learning of the diagram. The analysis of the participants' sequence of chunk production further revealed that they used a spatial schema to organize the chunks. Findings from this study provide additional evidence to support prior studies that claim graphical information is hierarchically organized.

Language and visual perception associations: meta-analytic connectivity modeling of Brodmann area 37

BACKGROUND

Understanding the functions of different brain areas has represented a major endeavor of neurosciences. Historically, brain functions have been associated with specific cortical brain areas; however, modern neuroimaging developments suggest cognitive functions are associated to networks rather than to areas.

OBJECTIVE

The purpose of this paper was to analyze the connectivity of Brodmann area (BA) 37 (posterior, inferior, and temporal/fusiform gyrus) in relation to (1) language and (2) visual processing.

METHODS

Two meta-analyses were initially conducted (first level analysis). The first one was intended to assess the language network in which BA37 is involved. The second one was intended to assess the visual perception network. A third meta-analysis (second level analysis) was then performed to assess contrasts and convergence between the two cognitive domains (language and visual perception). The DataBase of Brainmap was used.

RESULTS

Our results support the role of BA37 in language but by means of a distinct network from the network that supports its second most important function: visual perception.

CONCLUSION

It was concluded that left BA37 is a common node of two distinct networks-visual recognition (perception) and semantic language functions.

Frontal-executive constructional apraxia: when delayed recall is better than copying

In assessments of visuospatial function and memory, patients are often required to copy a figure and later to reproduce that figure from memory. Whereas most people perform better on a copying task than when drawing from memory, in this study we describe an unusual pattern of performance in which patients are better at drawing from memory than copying. Consecutive patients in a neurocognitive disorders clinic were given a battery of clinical cognitive tests that included copying a figure of intersecting pentagons and then drawing the figure from memory. Patterns of drawing performance at the two time points were compared to the profile of other cognitive deficits.

RESULTS

A subgroup of four patients with frontal dysfunction showed marked improvement in drawings at a delay compared to copying. Prior studies have indicated that most patients have declines in drawing performance at a delay. The unusual pattern of better performance at a delay compared to an initial copy occurred in patients with frontal dysfunction. These patients' visuoconstructive deficit and subsequent improvement could be related to either a failure to disengage when a model is present, to memory consolidation with increased reliance on top-down processing in the delay condition, or to relative preservation of global versus local aspects of a stimulus in memory. The addition of a task to assess drawing after a delay to a standard clinical screening battery such as the Mini-Mental Status Examination (MMSE) provides the opportunity to evaluate this phenomenon that may be indicative of frontal-executive dysfunction.

The Stick Design Test on the assessment of older adults with low formal education: evidences of construct, criterion-related and ecological validity

BACKGROUND

The assessment of visuospatial abilities is usually performed by drawing tasks. In patients with very low formal education, the use of these tasks might be biased by their cultural background. The Stick Design Test was developed for the assessment of this population. We aim to expand the test psychometric properties by assessing its construct, criterion-related and ecological validity in older adults with low formal education.

METHOD

Healthy older adults (n = 63) and Alzheimer's disease patients (n = 92) performed the Stick Design Test, Mini-Mental State Examination, Digit Span Forward and the Clock Drawing Test. Their caregivers answered Personal Care and Instrumental Activities of Daily Living). Construct validity was assessed by factor analysis, convergent correlations (with the Clock Drawing Test), and divergent correlations (with Digit Span Forward); criterion-related validity by receiver operating characteristic curve analysis and binary logistic regression; and Ecological validity by correlations with ADL.

RESULTS

The test factor structure was composed by one component (R 2 = 64%). Significant correlations with the Clock Drawing Test and Digit Span Forward were found, and the relationship was stronger with the first measure. The test was less associated with formal education than the Clock Drawing Test. It classified about 76% of the participants correctly and had and additive effect with the Mini-Mental State Examination (84% of correct classification). The test also correlated significantly with measures of ADL, suggesting ecological validity.

CONCLUSIONS

The Stick Design Test shows evidence of construct, criterion-related and ecological validity. It is an interesting alternative to drawing tasks for the assessment of visuospatial abilities.

Lateralization of cognitive functions in aphasia after right brain damage

PURPOSE

The lateralization of cognitive functions in crossed aphasia in dextrals (CAD) has been explored and compared mainly with cases of aphasia with left hemisphere damage. However, comparing the neuropsychological aspects of CAD and aphasia after right brain damage in left-handers (ARL) could potentially provide more insights into the effect of a shift in the laterality of handedness or language on other cognitive organization. Thus, this case study compared two cases of CAD and one case of ARL.

MATERIALS AND METHODS

The following neuropsychological measures were obtained from three aphasic patients with right brain damage (two cases of CAD and one case of ARL); language, oral and limb praxis, and nonverbal cognitive functions (visuospatial neglect and visuospatial construction).

RESULTS

All three patients showed impaired visuoconstructional abilities, whereas each patient showed a different level of performances for oral and limb praxis, and visuospatial neglect.

CONCLUSION

Based on the analysis of these three aphasic patients' performances, we highlighted the lateralization of language, handedness, oral and limb praxis, visuospatial neglect and visuospatial constructive ability in aphasic patients with right brain damage.

When Rey-Osterrieth's Complex Figure Becomes a Church: Prevalence and Correlates of Graphic Confabulations in Dementia

Verbal confabulation (VC) has been described in several pathological conditions characterized by amnesia and has been defined as 'statements that involve distortion of memories'. Here we describe another kind of confabulation (graphic confabulation, GC), evident at the recall of the Rey-Osterrieth complex figure (ROCF). In a retrospective study of 267 patients with mild-to-moderate dementia, 14 patients (4.9 %) recalled the abstract ROCF as drawings with recognizable semantic meaning. VC was evident at the story recall test in 19.8% of the study participants. VC and GC were homogeneously distributed among the different types of dementia. VC has been proposed to originate from complex interactions of amnesia, motivational deficit and dysfunction of monitoring systems. On the contrary, GC seems to be the result of a deficit in visual memory replaced by the semantic translation of isolated parts of the ROCF along with a source monitoring deficit.

Relationships between Constructional and Visuospatial Abilities in Normal Subjects and in Focal Brain-damaged Patients

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.

A deficit of spatial remapping in constructional apraxia after right-hemisphere stroke

Constructional apraxia refers to the inability of patients to copy accurately drawings or three-dimensional constructions. It is a common disorder after right parietal stroke, often persisting after initial problems such as visuospatial neglect have resolved. However, there has been very little experimental investigation regarding mechanisms that might contribute to the syndrome. Here, we examined whether a key deficit might be failure to integrate visual information correctly from one fixation to the next. Specifically, we tested whether this deficit might concern remapping of spatial locations across saccades. Right-hemisphere stroke patients with constructional apraxia were compared to patients without constructional problems and neurologically healthy controls. Participants judged whether a pattern shifted position (spatial task) or changed in pattern (non-spatial task) across two saccades, compared to a control condition with an equivalent delay but without intervening eye movements. Patients with constructional apraxia were found to be significantly impaired in position judgements with intervening saccades, particularly when the first saccade of the sequence was to the right. The importance of these remapping deficits in constructional apraxia was confirmed through a highly significant correlation between saccade task performance and constructional impairment on standard neuropsychological tasks. A second study revealed that even single saccades to the right can impair constructional apraxia patients' perception of location shifts. These data are consistent with the view that rightward eye movements result in loss of remembered spatial information from previous fixations, presumably due to constructional apraxia patients' damage to the right-hemisphere regions involved in remapping locations across saccades. These findings provide the first evidence for a deficit in remapping visual information across saccades underlying right-hemisphere constructional apraxia.

O Desempenho de idosos quanto a tomada de decisão em duas variações do Iowa Gambling Test

O Iowa Gambling Test é utilizado na avaliação da tomada de decisão. O objetivo do presente estudo foi investigar se alterações nos procedimentos de aplicação do instrumento interferem na tarefa. Foi realizado um estudo transversal comparando dois grupos de idosos saudáveis em duas variações do instrumento. Vinte e sete participantes executaram a tarefa sem pista de reforço visual, enquanto 17 participantes foram submetidos à tarefa com pista. Os dados foram analisados por meio dos testes t de Student para amostras independentes e ANOVA para medidas repetidas. Houve diferença estatisticamente significativa entre os grupos quanto à aversão ao risco. Os resultados indicam que uma pista de reforço visual permite a alocação de recursos atencionais e de memória de trabalho, possibilitando decisões menos arriscadas.

The caricature effect in drawing: evidence for the use of categorical relations when drawing abstract pictures

Five experiments were conducted to determine how novice and expert drawers represent relative size for the purposes of drawing. Participants were shown images of two-part or three-part geometric figures composed of two spatially separated shapes. In each picture there was a small but noticeable relative-size difference between the constituent shapes (one part of the picture was always 25% larger than another part). Participants later drew the pictures from memory. The results showed that novice and expert drawers consistently exaggerated the relative size relationship between the shapes in the picture when attempting to draw it from memory and when copying (the 'caricature effect'), although the effect was reduced for the experts. The results are consistent with the idea that people represent size in memory using categorical descriptors (e.g., 'smaller than', 'larger than') rather than as precise metrics. Further, the results suggest that the process of becoming a skilled drawer may involve overcoming this categorical bias.

Non-lateralised deficits of drawing production in hemispatial neglect

Spatially lateralised deficits that typically define the hemispatial neglect syndrome have been shown to co-occur with other non-lateralised deficits of attention, memory, and drawing. However even a simple graphic task involves multiple planning components, including the specification of drawing start position and drawing direction. In order to investigate the influence of these factors in neglect we presented patients with a circle-copying task, and specified the drawing start point. The ability to draw from the instructed location was strongly related to tests that measure constructional abilities, but not related to start point laterality. In contrast, the direction in which patients drew the circle was affected by start point laterality: patients with neglect were less likely to draw in a typical direction when the cue was on the affected side of space and this was strongly related to severity of the neglect. Patients with neglect consistently produced circles that were smaller than the model; however, the scaling was not affected by the laterality of the start point, nor was the proportion of drawings correctly started at the cue. These findings demonstrate the complex relationship between neglect and even the simplest test for the syndrome.

Cube drawing performances in normal ageing and Alzheimer's disease: data from the PAQUID elderly population-based cohort

To assess the influence of age and other sociodemographical variables, depressive symptomatology and the occurrence of Alzheimer's disease (AD) on cube drawing, we examined the performance of 858 normal subjects and 17 incident AD patients in the PAQUID population-based study. Cube drawing was first performed on verbal command and, in case of failure, a model of a cube was given to the subjects to copy. Normal subjects had some difficulties in drawing a cube on verbal command, evidenced by 40% failure in the drawing-to-command condition, while only 17% still failed in the drawing-to-copy condition. Multivariate logistic regressions showed that age, gender, and educational level were associated with cube drawing failure in both conditions, but depressive symptomatology was only associated with persistent failure in the drawing-to-copy condition. Seventy-six point five percent of incident AD subjects failed in the drawing-to-command condition and 64.7% did not benefit from the presentation of the model. Analysis showed that persistent failure in the copy condition was the best level of differentiation between normal and AD subjects.

Around the clock surveillance: simple graphic disturbance in patients with hemispatial neglect carries implications for the clock drawing task

BACKGROUND

Drawing, and the clock drawing task in particular, is widely used as a diagnostic tool in the study of hemispatial neglect. It is generally assumed that the errors in graphic production, such as the misplacement of numbers, reflect a visuospatial deficit, and that drawing production itself (for example, producing the circle) is unimpaired.

OBJECTIVES

To test this assumption by examining whether the production of simple circles is affected by neglect.

METHODS

16 right hemisphere stroke patients copied circles of various sizes and their drawings were measured for size accuracy.

RESULTS

Patients with more severe neglect produced greater scaling errors, consistently drawing the circle smaller than the original. Errors were not in the horizontal axis alone--shrinkage occurred equally in both height and width axes.

CONCLUSIONS

Neglect can co-occur with constructional difficulties that serve to exacerbate the symptoms presented. This should be taken into account in the assessment of even apparently simple drawing tasks.

Drawing on either side of the brain

Although both the cerebral laterality of processing visual information and human drawing skill have long been sources of investigation, there is not much empirical work combining the two. In this study, an attempt was made to explore if known different specialisations of the two cerebral hemispheres could help in predicting qualities of drawings produced by each hand. For this purpose, an amateur artist who is able to draw with either the left or the right hand produced a series of realistic drawings of 3D objects. Then 28 participants rated the drawings for several predetermined perceptual and aesthetic properties. The participants judged drawings made with the left hand as superior to those made with the right hand. Given that the right hemisphere controls the left hand, we suggest that this hand might also benefit from the more direct access to lateralised areas that are involved in the processing aspects of visual information and spatial properties (e.g., depth and shading). These perceptual processes may thus play an important role in the ability to draw realistic depictions of objects.

Constructional apraxia after left or right unilateral stroke

The present study re-assesses the question whether deficits, after brain damage, in constructional tasks can be partitioned in different types of disorders of spatial cognition. Based on a current cognitive neuroscience account, originally proposed by Kosslyn [Kosslyn, S. M. (1987). Seeing and imagining in the cerebral hemispheres: A computational approach. Psychological Review, 94, 148-175], that posits two complementary lateralized systems for the encoding of (categorical and coordinate) spatial relations, it is here proposed that two qualitatively different types of "constructional apraxia" can occur and that the nature of the constructional impairment after unilateral lesions closely reflects the loss of lateralized components for the perceptual processing of differing types of spatial relations. New evidence is presented, based on the study of two groups of patients with unilateral posterior brain lesions, which supports such a bipartition of constructional apraxia. In addition, past evidence is reviewed in the light of this new cognitive neuroscience account.

Left on the Right or Viceversa: A Case of “Alternating” Constructional Allochiria

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.

Divided attention, selective attention and drawing: processing preferences in Williams syndrome are dependent on the task administered

The visuo-spatial abilities of individuals with Williams syndrome (WS) have consistently been shown to be generally weak. These poor visuo-spatial abilities have been ascribed to a local processing bias by some [R. Rossen, E.S. Klima, U. Bellugi, A. Bihrle, W. Jones, Interaction between language and cognition: evidence from Williams syndrome, in: J. Beitchman, N. Cohen, M. Konstantareas, R. Tannock (Eds.), Language, Learning and Behaviour disorders: Developmental, Behavioural and Clinical Perspectives, Cambridge University Press, New York, 1996, pp. 367-392] and conversely, to a global processing bias by others [Psychol. Sci. 10 (1999) 453]. In this study, two identification versions and one drawing version of the Navon hierarchical processing task, a non-verbal task, were employed to investigate this apparent contradiction. The two identification tasks were administered to 21 individuals with WS, 21 typically developing individuals, matched by non-verbal ability, and 21 adult participants matched to the WS group by mean chronological age (CA). The third, drawing task was administered to the WS group and the typically developing (TD) controls only. It was hypothesised that the WS group would show differential processing biases depending on the type of processing the task was measuring. Results from two identification versions of the Navon task measuring divided and selective attention showed that the WS group experienced equal interference from global to local as from local to global levels, and did not show an advantage of one level over another. This pattern of performance was broadly comparable to that of the control groups. The third task, a drawing version of the Navon task, revealed that individuals with WS were significantly better at drawing the local form in comparison to the global figure, whereas the typically developing control group did not show a bias towards either level. In summary, this study demonstrates that individuals with WS do not have a local or a global processing bias when asked to identify stimuli, but do show a local bias in their drawing abilities. This contrast may explain the apparently contrasting findings from previous studies.