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Introduction: Harmonized neuropsychological assessment for neurocognitive disorders, an international priority for valid and reliable diagnostic procedures, has been achieved only in specific countries or research contexts.Methods: To harmonize the assessment of mild cognitive impairment in Europe, a workshop (Geneva, May 2018) convened stakeholders, methodologists, academic, and non-academic clinicians and experts from European, US, and Australian harmonization initiatives.Results: With formal presentations and thematic working-groups we defined a standard battery consistent with the U.S. Uniform DataSet, version 3, and homogeneous methodology to obtain consistent normative data across tests and languages. Adaptations consist of including two tests specific to typical Alzheimer's disease and behavioral variant frontotemporal dementia. The methodology for harmonized normative data includes consensus definition of cognitively normal controls, classification of confounding factors (age, sex, and education), and calculation of minimum sample sizes.Discussion: This expert consensus allows harmonizing the diagnosis of neurocognitive disorders across European countries and possibly beyond.

Background Growing evidence suggests that hyperhomocysteinemia (HHcy) constitutes a risk factor for Alzheimer’s Disease (AD). The impact of HHcy on cognitive functions has mainly been investigated using screening neuropsychological tests that provide general, unspecific measures of cognitive level. Since an association between HHcy and temporo-mesial atrophy has been documented, we predicted that a fine-grained analysis of neuropsychological performance should show stronger Hcy effects on memory scores than on other cognitive scores. Objective To determine the influence of Hcy level on cognitive profile evaluated with specific, sensitive neuropsychological tests in a wide AD cohort. Methods 323 patients with AD were enrolled in a cross-sectional study and underwent a neuropsychological examination exploring several cognitive domains (memory, language, visuoperception, visuospatial abilities, executive function, constructional praxis, ideomotor praxis). The effects of Hcy levels and other risk factors (including cholesterol, smoking habits, triglycerides, apoEe4 allele) were analysed. Results Generalized Linear Model detected a significant drop in performance with increasing Hcy in 6/19 measures of cognitive functions, namely, in memory performance tasks as well as in Luria’s motor planning test, with effect sizes ranging 1.4%–2.8% (Eta-squared), partialling out effects of other predictors. Conclusions HHcy was associated with poor performance in short and long-term spatial and verbal memory more than with other cognitive dysfunctions. These results support the hypothesis that medial temporal networks might be vulnerable to HHcy, consistently with data from neuroimaging studies suggesting a link in AD between temporal atrophy and HHcy; the effect on Luria’s motor planning task suggests further involvement of frontal structures.

The Tower of London (ToL) test is traditionally used to assess strategical reasoning, problem-solving, and mental planning in clinical populations. Here, we provide the Italian standardization norms for the original, 12-problem version of the ToL test. The performance of 216 Italian individuals ranging 18 to 89 in age was scored in terms of both Time ( Speed) and Accuracy—the time, and the number of attempts, necessary to find a solution. We performed univariate analyses on separate Time and Accuracy scores, using Age in years, Education in years, and Sex (male vs. female) as predictors. z scores and equivalent scores were provided. Moreover, we performed a bivariate analysis for the assessment of individuals’ performance in terms of Time and Accuracy simultaneously. This standardization allows clinicians to use the original, most widespread version of ToL with the Italian population, thus optimizing comparability with other clinical and experimental research worldwide. Critically, this article offers a new statistical perspective on how Time and Accuracy scores, which are typically related to each other, can be combined to obtain a single, consistent clinical categorization that captures most of the information contained in the patient’s performance.

Unilateral neglect is usually investigated by adminstering stimuli (targets) in different positions, with targets being responded to by the patient (Hit) or omitted. In spite of this homogeneity of data type, neglect indices and diagnostic criteria vary considerably, causing inconsistencies in both clinical and experimental settings. We aimed at deriving a standard analysis which would apply to all tasks sharing this data form.A-priori theoretical reasoning demonstrated that the mean position of Hits in space (MPH) is an optimal index for correctly diagnosing and quantifying neglect. Crucially MPH eliminates the confounding effects of deficits that are different from neglect (non-lateral) but which decrease Hit rate. We ran a Monte Carlo study to assess MPH's (so far overlooked) statistical behavior as a function of numbers of targets and Hits.While average MPH was indeed insensitive to non-lateral deficits, MPH's variance (like that of all other neglect indices) increased dramatically with increasing non-lateral deficits. This instability would lead to alarmingly high false-positive rates (FPRs) when applying a classical diagnostic procedure that compares one patient with a control sample. We solved the problem by developing an equation that takes into account MPH instability and provides correct cut-offs and close-to-nominal FPRs, even without control subjects. We developed a computerized program which, given the raw data, yields the MPH, a z-score and a p-value.We provided a standard method that allows clinical and experimental neuropsychologists to diagnose and measure neglect in a consistent way across the vast majority of tasks.

We propose STIMA, a short test for ideo-motor apraxia, allowing us to quantify the apraxic deficit according to action meaning and affected body segment. STIMA is based on a neurocognitive model holding that there are two processes involved in action imitation (i.e., a semantic route for recognizing and imitating known gestures, and a direct route for reproducing new gestures). The test allows to identify which imitative process has been selectively impaired by brain damage (direct vs. semantic route) and possible deficits depending on the body segment involved (hand/limb vs. hand/fingers). N = 111 healthy participants were administered with an imitation task in two separated blocks of known and new gestures. In each block, half of the gestures were performed mainly with the proximal part of the upper limb and the remaining half with the distal one. It resulted in 18 known gestures (nine proximal and nine distal) and 18 new gestures (nine proximal and nine distal) for a total of 36. Each gesture was presented up to a maximum of two times. Detailed criteria are used to assign the final imitation score. Cut offs, equivalent scores and main percentile scores were computed for each subscale. Participants imitated better known than new gestures, and proximal better than distal gestures. Age influenced performance on all subscales, while education only affected one subscale. STIMA is easy and quick to administer, and compared to previous tests, it offers important information for planning adequate rehabilitation programs based on the functional locus of the deficit.

A pediatric cognitive screening tool has been shaped in three versions according to school class to assess spatial and temporal orientation, language, reading, writing, drawing, number knowledge, memory, praxis and executive functions in children aged 6-13. It has been standardized on an Italian sample of 807 children. Raw scores were adjusted for critical variables (child's age and parents' education) and a cut-off for the resulting global cognitive score was made available for clinical practice. In line with previous research, adapting the Mini-Mental State Examination to pediatric neuropsychological assessment turned out to be useful in estimating global cognitive functioning in children.

Objectives: To estimate the frequency of prolonged grief disorder (PGD) in 90 primary caregivers of patients with dementia who live in the community dwelling in Milan and to identify the relationship between grief intensity (GI) and other caregiver variables; another aim was to clarify the role of the objective cognitive and functional impairment of the patients and the level of deterioration perceived by caregivers. Design: Cross-sectional study. Results: In all, 16.7% of caregivers had PGD. Caregiver variables increasing GI and the risk of developing PGD were burden, anxiety, and some sociodemographic features. The objective level of patient’s deterioration was irrelevant for PGD probability/GI, while the deterioration level perceived by the caregiver increased PGD probability and GI. Conclusions: Caregivers of patients with dementia may experience grief symptoms that are associated with low educational level, high level of burden and anxiety, and high perceived deterioration of their demented relatives’ cognitive and functional abilities.

Amyotrophic Lateral Sclerosis (ALS) is a motor neuron disease characterized by the progressive atrophy of both the first and the second motor neurons. Although the cognitive profile of ALS patients has already been defined by the occurrence of language dysfunctions and frontal deficit symptoms, it is less clear whether the degeneration of upper and lower motor neurons affects motor imagery abilities. Here, we directly investigated motor imagery in ALS patients by means of an established task that allows to examine the presence of the effects of the biomechanical constraints. Twenty-three ALS patients and 23 neurologically unimpaired participants have been administered with the (1) hand laterality task (HLT) in which participants were asked to judge the laterality of a rotated hand and the (2) mirror letter discrimination task (MLD) in which participants were asked to judge whether a rotated alphanumeric character was in its canonical or mirror-reversed form (i.e. control task). Results show that patients present the same pattern of performance as unimpaired participants at the MLD, while at the HLT, they present only partially with the effects of biomechanical constraints. Taken together, our findings provide evidences that motor imagery abilities, related to the mental simulation of an action, are affected by this progressive disease.

Neuropsychological assessment is critical in both diagnosis and prognosis of patients with epilepsy. Beyond electrophysiological and anatomical alterations, other factors including different ethnic-cultural and linguistic backgrounds might affect neuropsychological performance. Only a few studies considered migration and acculturation effects and they typically concerned nonclinical samples. The current study aimed at investigating the influence of ethnic background and time spent in Italy on a full neuropsychological battery administered to both Italian and foreign-born patients and at providing a brief interview for obtaining relevant information on each patient's transcultural and language-related history. Clinical reports from 43 foreign-born patients with drug-resistant epilepsy were collected from the archives of Milan Niguarda Hospital. Epileptogenic zone, age, education, profession, illness duration, seizure frequency, handedness, and gender were considered in selecting 43 Italian controls. Ethnicity (Italian/foreign-born) and years spent in Italy were analyzed as main predictors on 21 neuropsychological scales by means of General(ized) Linear Models. An additional analysis studied two composite scores of overall verbal and nonverbal abilities. Ethnicity significantly affected the following: the verbal overall score, Verbal Fluency, Naming, Token-test, Digit Span, Attentional Matrices, Trail-Making-Test, Line-Orientation-Test, and Raven matrices; no effects were found on the nonverbal overall score, Word Pairs Learning, Episodic Memory, reading accuracy, visual span, Bells test, Rey Figure, and face memory and recognition. No significant effects of years spent in Italy emerged. While years spent in Italy does not predict neuropsychological performance, linguistic background had a strong impact on it. With respect to Italian-speaking patients, those who were foreign-born showed large task-related variability, with an especially low performance on language-related tests. Hence, language tests should not be considered as valid measures of neuropsychological impairment in this population, not even in foreign-born patients with good Italian fluency. Clinicians should consider such asymmetries in order to improve the accuracy of neuropsychological assessment of foreign-born patients.

The Milner Landmark Task allows the disentanglement of perceptual and response-related components of unilateral neglect. If these two components reflect separate functional systems, then cases should be observed in which the two components evolve differently across time. To test this hypothesis we surveyed a continuous series of 21 right hemisphere stroke patients. Five patients from the sample were affected by unilateral neglect at the outset and could be submitted to repeated administrations of the Landmark task in the first weeks post stroke. Two versions of the task were used, Landmark-Manual and Landmark-Verbal, differing in the type of response required. Two patients showed independent changes in the perceptual and the response-related component of neglect, hence confirming the view of separate functional systems underlying them. Dissociations between the task versions were found, witnessing a role of the type of response. Unexpectedly, one patient showed an initial leftward deviation of the subjective midpoint of the stimulus line, which later reversed to a classical rightward deviation. We interpreted such a pattern in terms of co-existing "productive" and "negative" components of perceptual neglect.

In this study, a series of tests exploring long-term verbal memory (the Short Story Test), attention (a modified version of Attentional Matrices and the Trail Making Test) and frontal functions (a modified version of the Frontal Assessment Battery) have been standardised on an Italian population of 283 children aged 5-14. Raw scores for each test have been adjusted for a series of variables (child's age, years of parents' education, handedness, gender) and transformed in equivalent scores enabling direct comparison across measures. This study was promoted by LICE (the Italian League Against Epilepsy) in order to provide Italian instruments standardised on the developmental age population and to study some of the most frequently impaired cognitive functions in epilepsy.

Twelve children with developmental dyslexia underwent a four-month treatment with tachistoscopic presentation of words, according to Bakker's methodology. One group received standard lateral presentation of words on a PC screen, while the other group received the same stimuli in random lateral position. The spatial distribution of visual attention was measured by means of the Form-Resolving Field (FRF; ), which was administered along with reading tests, before and after treatment. The FRF of children who received random presentation widened at -12.5 degrees on the left side, while the FRF in the group that received standard lateral presentation narrowed at that position. Both groups significantly improved in reading accuracy for both words and nonwords. Some hypotheses are proposed concerning the mechanisms responsible for the changes in the FRF and their correlation with improvements in word and nonword reading. The results of the present study are also compared with data suggesting a left "minineglect" in dyslexia.

Neglect of contralesional stimuli and perseverative behavior on ipsilesional stimuli may co-occur on a target cancellation task. Our aim was to investigate whether the presence vs. absence of contralesional targets can modify perseveration on ipsilesional targets. We studied four right brain-damaged patients with left neglect and perseverative behavior on screening cancellation tasks. We compared their cancellation performance in two conditions: (i) targets equally distributed on both sides of space and (ii) targets confined to the right side. One patient showed no significant difference in perseveration between these two conditions; in contrast, three patients perseverated significantly more in condition (i) than in condition (ii). These results suggest that, at least in some patients, information from the ‘neglected’ targets is not completely lost, but rather it affects behavior in the ipsilesional side. The traditional dichotomy ‘bad space–good space’ would not apply here.

Bisiach and his colleagues have developed a new version of Milner’s ‘‘landmark task’’ for the purpose of separating ‘‘perceptual’’ and ‘‘response’’ biases in neglect patients. Subjects are required to decide which is the longer (or the shorter) of the two portions of a pre-bisected horizontal line. The authors proposed two indices to measure perceptual and response bias respectively. However, these indices are not mathematically independent of one another. Moreover, they do not exploit all of the information available in the data, since they do not consider the effect of the different transection locations across trials. We now propose an alternative means of analyzing data from the revised Landmark task, which generates independent estimates of perceptual and response biases. The method and its theoretical foundation are summarized, and illustrative data obtained from brain damaged patients and control subjects are presented. ≈ 2002 Elsevier Science (USA)

Long-term caregiving of patients with Alzheimer disease (AD) frequently induces a relevant distress enhanced by inadequate coping strategies. This study aimed to explore the impact of cognitive and behavioral therapy (CBT) group intervention on AD patients' caregivers. In particular, reduction in caregivers' global care needs and in anxiety and depression has been investigated. About 100 caregivers were divided into the following groups: CBT group intervention, self-help manual, and control have been enrolled in the study. CBT group intervention seems to be more effective than the other 2 conditions in reducing caregivers' anxiety. Furthermore, only caregivers of the CBT group showed significant needs related to reduction in care. The proposed treatment could be the core of a more structured and systematic intervention for AD patients' caregivers in Italy.

Neglect patients' performance during cancellation tasks is characterized by left sided omissions and, in many cases, by the production of inappropriate material of various kinds in the ipsilesional space, e.g. additional marks over already cancelled targets, marks drawn away from targets, scribbles, irrelevant drawings. It is unclear whether these behaviours, which have collectively been called perseverative, are functionally and anatomically connected and whether they correlate with the severity of neglect. Here we report a retrospective study on 33 right brain damaged patients with neglect after right hemisphere lesions in whom we measured the intensity of perseveration of the three following kinds: (1) 'additional marks' (AM) perseveration where patients cancelled a target with two or more well separated marks; (2) 'scribble' perseveration, where patients, instead of cancelling the target with a single pen stroke as required by the task, performed multiple pen strokes without breaking the pen-to-paper contact, with the final product being a scribble; (3) 'flying marks' (FM) perseveration where patients produced cancellation marks well away from the targets. We found that AM and FM perseveration correlated with neglect severity, while 'scribble' perseveration did not. The lesion-symptom mapping showed three separate anatomical areas in the right hemisphere: 'scribble' perseveration was associated with lesions of the orbitofrontal cortex and caudate nucleus; AM perseveration was associated with damage to the rolandic operculum, superior temporal gyrus and inferior frontal gyrus; FM perseveration was associated with damage to the dorsal premotor cortex and the temporal pole. Neglect severity followed damage to a region which grossly corresponds to the sum of the regions associated with AM and FM perseveration respectively. This complex behavioural and anatomical pattern is interpreted in terms of a three-factor model, in which AM perseveration is caused by a deficit of disengagement of attention from the right side (also causing omissions), FM perseveration is caused by directional hypokinesia (also causing left-side omissions), and 'scribble' perseveration is the consequence of a failure to inhibit an initiated motor act, which is completely separate (both anatomically and functionally) from the disorder inducing omissions. © 2013 Elsevier Ltd.

Both real action control and execution and motor imagery abilities require knowledge of the spatial location of body parts, in other words efference copy information and feedbacks from the sensory system (Frith et al., 2000, Philos. Trans. R. Soc. Lond. B. Biol. Sci., 355, 1771). Spinal cord injuries induce severe motor disability, due to a damage of the descending motor pathways (Cramer et al., 2007, Exp. Brain. Res., 177, 233). Patients' motor imagery competences are variably reported as either normal or defective (Decety & Boisson, 1990, Eur. Arch. Psychiatry Clin. Neurosci., 240, 39; Lacourse et al., 1999, Behav. Brain Sci., 104, 73). We explored biomechanical constraint effects in Spinal Cord Injury (SCI) patients, as they are considered the most reliable indexes of motor imagery abilities (Parsons, 1987b, Cogn. Psychol., 19, 178). Sixteen spinal cord injuries patients and 16 neurologically unimpaired subjects have been administered with (1) the Hand Laterality Task (HLT), in which subjects were asked to judge the laterality of a rotated hand; and (2) the Mirror Letter Discrimination Task (MLD), in which subjects were asked to judge if a rotated character was in its correct upright position or mirror-reversed form. Our patients did not present the effect of stimulus orientation, neither did they show any effect related to biomechanical constraints. Based on these data, the hypothesis is that SCI patients' performance may be ascribed to the use of a different strategy to solve the tasks, based on memory rather than on mental rotation.

To clarify the role of epilepsy and genetic background in determining the cognitive outcome of patients with Dravet syndrome.In this retrospective study, we reviewed the clinical history and cognitive development of 26 patients who had been followed with standardized evaluations since seizure onset. The cognitive outcome was quantified as differential general quotient (dGQ) between ages 12 and 60 months. Statistical analysis correlated the dGQ with genotype and epilepsy course.Epilepsy started at the mean age of 5.6 months. All patients experienced prolonged convulsive seizures, whereas absences and myoclonus were reported in 17. Cognitive outcome was poor in almost all patients; the mean dGQ was 33 points, varying from 6-77 points. The analysis of individual cognitive profiles identified seven patients in whom the dGQ was20 points; the main clinical characteristic in this subset of patients was lack of early absences and myoclonus. The statistical analysis of the whole series failed to reveal significant differences in cognitive outcome with regard to the presence of SCN1A mutations and their type. In particular, mutation-carrier patients with the best cognitive outcome harbored either missense or truncating mutations.Dravet syndrome encompasses different epileptic and cognitive phenotypes that probably result from both genetic and epigenetic factors. In this series, early appearance of myoclonus and absences was associated with the worst cognitive outcome.

It is widely recognized that mental rotation is a cognitive process which engages a distributed cortical network including the frontal, premotor and parietal regions. Like other visual-spatial transformations it could require operations on both metric and categorical spatial representations. Previous reports have implicated respectively the right hemisphere being involved in the metric processing and the left hemisphere in the categorical processing. By using a modified version of the Bricolo et al.'s task (2000), we attempted to establish the cortical regions relevant for the categorical and metric aspects of mental rotation transformations. Two groups of patients were found to be impaired in our study, namely the left prefrontal and the right parietal. In particular, whereas the right parietal group made poor use of categorical information, the left prefrontal patients showed a broader mental rotation impairment with a significant number of metric errors. The results are discussed in terms of the model of Kosslyn et al. (1989) about the possible mental transformation impairments following brain lesions.

A recently proposed theory on frontal lobe functions claims that the prefrontal cortex, particularly its dorso-lateral aspect, is crucial in defining a set of responses suitable for a particular task, and biasing these for selection. This activity is carried out for virtually any kind of non-routine tasks, without distinction of content. The aim of this study is to test the prediction of Frith's 'sculpting the response space' hypothesis by means of an 'insight' problem-solving task, namely the matchstick arithmetic task. Starting from Knoblich et al.'s interpretation for the failure of healthy controls to solve the matchstick problem, and Frith's theory on the role of dorsolateral frontal cortex, we derived the counterintuitive prediction that patients with focal damage to the lateral frontal cortex should perform better than a group of healthy participants on this rather difficult task. We administered the matchstick task to 35 patients (aged 26-65 years) with a single focal brain lesion as determined by a CT or an MRI scan, and to 23 healthy participants (aged 34-62 years). The findings seemed in line with theoretical predictions. While only 43% of healthy participants could solve the most difficult matchstick problems ('type C'), 82% of lateral frontal patients did so (Fisher's exact test, P < 0.05). In conclusion, the combination of Frith's and Knoblich et al.'s theories was corroborated.

Neglect patients typically show motor perseveration while canceling targets on the ipsilesional side. This behavior can be influenced by the presence vs. absence of targets on the (neglected) contralesional side (Bottini & Toraldo, 2003). As alternative explanations, the authors proposed (i) directional hypokinesia-the patient cannot perform reaching movements towards detected left-sided targets, and thus carries on canceling on the right side, and (ii) allochiria-the patient misperceives left-sided targets as located on the right side, and cancels them there. We report here data from a patient (EZ) that might confirm the second hypothesis. EZ was presented with 19 displays in which the number and position of cancellation targets on both sides were varied systematically. EZ showed motor perseveration while canceling, but this tendency did not vary across conditions. Interestingly though, EZ also drew cancellation marks in the empty space between the ipsilesional targets, and this phenomenon was significantly more intense when there were more targets on the neglected side. As EZ's comments suggested, such a behavior might reflect the attempt to cancel out delusional targets. Our speculation is that those objects were generated by allochiria. © 2004 Elsevier Inc. All rights reserved.

It has been suggested that neglect patients misrepresent the metric spatial relations along the horizontal axis (anisometry). The “fabric” of their internal spatial medium would be distorted in such a way that physically equal distances appear relatively shorter on the contralesional side (canonical anisometry). The case of GL, a 76-year-old lady with left neglect on visual search tasks, is presented. GL showed severe relative overestimation on the left (contralesional) side on two independent tasks evaluating the metrics of her internal representation. A qualitatively similar pattern was found in two out of 10 other neglect patients who performed the second task. This behavior cannot be accounted for by the canonical anisometry hypothesis. Nevertheless, GL produced a relative left overextension (underestimation) when trying to set the endpoints of a virtual line given its midpoint (Endpoints Task). An interpretation of these results is offered in terms of a misprojection of relevant landmarks onto the internal representation without assuming distortion of its “fabric.”

In order to better disentangle ‘perceptual’ and ‘response’ biases in neglect patients, Bisiach and his co-workers developed a new version of the ‘landmark task’. In their version, subjects are required to choose which is the longer (first condition) or the shorter (second condition) of the two portions of a pre-bisected horizontal line. Two indices were proposed, for the purpose of measuring perceptual and response bias respectively. The perceptual bias index (PB) is the constant error across conditions, while the response bias index (RB) is the degree of response consistency between conditions. Although valuable in a clinical context, these indices are not mathematically independent of one another. Furthermore, they do not exploit all of the information available in a given set of landmark data, since the responses made at the different landmark locations are all averaged together. To overcome these problems, we propose two new indices that can be derived from the revised landmark task. Our perceptual bias index is the Point of Subjective Equality (PSE) – the mean landmark location that appears to be halfway along the line. The response bias index, M, is the mean probability of making a response that opposes the patient's subjective midpoint. PSE and M are mathematically independent of each other and use most of the landmark information. The method and its theoretical foundation are summarized, and illustrative data obtained from brain damaged patients and control subjects are presented. Finally, computational procedures are provided for both PSE and M.

Deficits in the mental rotation of body parts and of external objects can be doubly dissociated ( Rumiati, Tomasino, Vorano, Umilta, & De Luca, 2001 ; Sirigu & Duhamel, 2001 ; Tomasino, Rumiati, & Umilta, in press ). The aim of this study was to replicate this finding and to then investigate the relevance of the specific hemispheres in these deficits. Nine patients with unilateral lesions (five in the Left Hemisphere and four in the Right) and 20 control subjects, performed a single task requiring mental rotation of hands, and two tasks requiring mental rotation of external objects. RH patients were impaired in the rotation of external objects, but showed intact performance on the rotation of hands; the opposite pattern was found for LH patients. These results support the view that the LH contributes to the mental rotation of hands, recruiting processes specific to motor preparation, while the RH is specialized for mental rotation of external objects.

The conceptualisation of apraxia has often been linked to the clinicalassessment of the disorder (Rothi et al., 1997). Thus Ideomotor Apraxia(hereafter IMA) has been described as a failure to imitate actions. One of thetasks more widely employed by clinicians is that devised by De Renzi et al.,(1980). The 24 gestures of this test vary according to a 2x2x2 design, the threefactors being (i) gestures composed of a single posture (‘positions’) vs. asequence of postures (‘sequences’); (ii) involving hand and/or arm vs. fingers;(iii) symbolic vs. non-symbolic (see De Renzi and Faglioni, 1999, for detailsabout the items). Specific predictions involving all these gestures were madebased on a model that comprises a Long-Term Memory (LTM), a ‘MotorProgramming’ (MP) component, and a Working Memory (WM) (Baddeley,1986) including a Short-Term Memory component specific for gestures (STM;Smyth and Pendleton, 1988; Rumiati and Tessari, in press) and the SupervisoryAttentional System (SAS, Norman and Shallice, 1986) (Fig. 1).The gesture to be imitated is temporarily held in the STM (while the SASselects, whenever necessary, alternative strategies for the gesture encoding), andthen transferred to the MP system. When a gesture is symbolic, the WM loadcan be reduced by accessing its LTM representation. IMA per sewouldcorrespond to a breakdown at MP level, while damage to the WM componentwould produce an inability to maintain the gesture (STM) or to selectappropriate strategies (SAS) beforethe MP stage.The WM and LTM components have an overall probability wof maintainingand transferring to MP an accurate copy of the input gesture. When a non