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This study documents the age-dependent development of visual object recognition abilities in 115 children aged 6 to 11 years, using a battery of neuropsychological tests based on Marrs model (Efron test, Warringtons Figure-Ground Test, Street Completion Test, Poppelreuter-Ghent Test, a selection of stimuli from the Birmingham Object Recognition Battery, a series of color photographs of objects presented from unusual perspectives or illuminated in unusual ways). The results suggest a maturation of complex visual perceptual abilities, possibly related to the development of the cerebral processes involved in object recognition, and could be the starting point for future investigations of these skills in impaired populations. [ABSTRACT FROM AUTHOR]

We investigate the effects of hydrodynamic interactions between microorganisms swimming at low Reynolds numbers, treating them as a control system. We employ Lie brackets analysis to examine the motion of two neighboring three-link swimmers interacting through the ambient fluid in which they propel themselves. Our analysis reveals that the hydrodynamic interaction has a dual consequence: on one hand, it diminishes the system's efficiency; on the other hand, it dictates that the two microswimmers must synchronize their motions to attain peak performance. Our findings are further corroborated by numerical simulations of the governing equations of motion.

Prospective memory (PM) is essential in everyday life because it concerns the ability to remember to perform an intended action in the future. Individuals diagnosed with attention deficit hyperactivity disorder (ADHD) often show poor performance in PM. Because age can be confounding, we decided to test PM in ADHD patients (children and adults) and healthy controls (children and adults). We examined 22 children (four females; mean age = 8.77 ± 1.77) and 35 adults (14 females; mean age = 37.29 ± 12.23) with ADHD, in addition to 92 children (57 females; mean age = 10.13 ± 0.42) and 95 adults (57 females; mean age = 27.93 ± 14.35) as healthy controls. Each participant originally wore an actigraph around the non-dominant wrist and was requested to push the event-marker at get-up time. To assess the efficiency of PM performance, we calculated the time elapsing between the end of sleep in the morning and the pushing of the event-marker button. The results showed lower PM performance in ADHD participants, regardless of age. However, the differences between ADHD and control groups were more evident in the children group. Our data seem to confirm that PM efficiency is compromised in individuals diagnosed with ADHD regardless of age, and agree with the idea of considering the PM deficit as a neuropsychological marker of ADHD.

The controllability of a fully three-dimensional N -link swimmer is studied. After deriving the equations of motion in a low Reynolds number fluid by means of Resistive Force Theory, the controllability of the minimal 2-link swimmer is tackled using techniques from Geometric Control Theory. The shape of the 2-link swimmer is described by two angle parameters. It is shown that the associated vector fields that govern the dynamics generate, via taking their Lie brackets, all eight linearly independent directions in the combined configuration and shape space, leading to controllability; the swimmer can move from any starting configuration and shape to any target configuration and shape by operating on the two shape variables. The result is subsequently extended to the N -link swimmer. Finally, the minimal time optimal control problem and the minimization of the power expended are addressed and a qualitative description of the optimal strategies is provided., (© The Author(s) 2022.)

Prospective memory (PM) is essential in everyday life because it concerns the ability to remember to perform an intended action in the future. This ability could be influenced by poor sleep quality, the role of which, however, is still being debated. To examine the role of sleep quality in PM in depth, we decided to perform a retrospective naturalistic study examining different clinical populations with a primary sleep disorder or comorbid low sleep quality. If sleep is important for PM function, we could expect poor sleep to affect PM performance tasks both directly and indirectly. We examined a total of 3600 nights, recorded using actigraphy in participants belonging to the following groups: primary insomnia (731 nights); narcolepsy type 1 (1069 nights); attention deficit hyperactivity disorder (152 nights in children and 239 in adults); severe obesity (232 nights); essential hypertension (226 nights); menopause (143 nights); healthy controls (808 nights). In a naturalistic activity-based PM task, each participant originally wore an actigraph around the non-dominant wrist and was requested to push the event-marker button at two specific times of day: bedtime (activity 1) and get-up time (activity 2). Each clinical group showed significantly lower sleep quality in comparison to the control group. However, only narcolepsy type 1 patients presented a significantly impaired PM performance at get-up time, remembering to push the event-marker button around half the time compared not only to healthy controls but also to the other clinical groups. Overall, the present results seem to point to sleep quality having no effect on the efficiency of a naturalistic activity-based PM task. Moreover, the data indicated that narcolepsy type 1 patients may show a disease-specific cognitive deficit of PM.

Although much research has been concerned with the development of kinematic aspects of handwriting, little is known about the development along with age of two principles that govern its rhythmic organization: Homothety and Isochrony. Homothety states that the ratio between the durations of the single motor events composing a motor act remains invariant and independent from the total duration of the movement. Isochrony refers to the proportional relationship between the speed of movement execution and the length of its trajectory. The current study shows that children comply with both principles since their first grade of primary school. The precocious adherence to these principles suggests that an internal representation of the rhythm of handwriting is available before the age in which handwriting is performed automatically. Overall, these findings suggest that despite being a cultural acquisition, handwriting appears to be shaped by more general constraints on the timing planning of the movements.

Joubert syndrome (JS) is a recessive neurodevelopmental disorder characterized by a distinctive cerebellar and brainstem malformation recognizable on brain imaging, the so-called molar tooth sign. The full spectrum of cognitive and behavioral phenotypes typical of JS is still far from being elucidated. The aim of this multicentric study was to define the clinical phenotype and neurobehavioral features of a large cohort of subjects with a neuroradiologically confirmed diagnosis of JS. Fifty-four patients aged 10 months to 29 years were enrolled. Each patient underwent a neurological evaluation as well as psychiatric and neuropsychological assessments. Global cognitive functioning was remarkably variable with Full IQ/General Quotient ranging from 32 to 129. Communication skills appeared relatively preserved with respect to both Daily Living and Socialization abilities. The motor domain was the area of greatest vulnerability, with a negative impact on personal care, social, and academic skills. Most children did not show maladaptive behaviors consistent with a psychiatric diagnosis but approximately 40% of them presented emotional and behavioral problems. We conclude that intellectual disability remains a hallmark but cannot be considered a mandatory diagnostic criterion of JS. Despite the high variability in the phenotypic spectrum and the extent of multiorgan involvement, nearly one quarter of JS patients had a favorable long-term outcome with borderline cognitive deficit or even normal cognition. Most of JS population also showed relatively preserved communication skills and overall discrete behavioral functioning in everyday life, independently from the presence and/or level of intellectual disability. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

In this paper we address the question of the optimal design for the Purcell three-link swimmer. More precisely, we investigate the best link length ratio which maximizes its displacement. The dynamics of the swimmer is expressed as an ordinary differential equation, using the resistive force theory. Among a set of optimal strategies of deformation (strokes), we provide an asymptotic estimate of the displacement for small deformations, from which we derive the optimal link ratio. Numerical simulations are in good agreement with this theoretical estimate and also cover larger amplitudes of deformation. Compared with the classical design of the Purcell swimmer, we observe a gain in displacement of roughly 60%.

A valid tool that contributes to the diagnosis of Developmental Coordination Disorder (DCD) is represented by the Developmental Coordination Disorder Questionnaire 2007 (DCDQ'07). Recently we developed the Italian version of DCDQ (DCDQ-Italian). The aim of this study was to further analyze the psychometric properties in a sample of Italian school children aged 5-12 years and to establish cut-off scores with respect to age groups. A total of 698 parents completed the DCDQ-Italian and 45 of them repeated it after 2 weeks for test-retest reliability. One hundred and seventeen children were tested using the Movement Assessment Battery for Children. Confirmatory factor analysis supported this version to be consistent with the original. Cronbach's alpha for the total score was 0.89 and test-retest reliability was 0.88. Two-ways ANOVA for total and single subscales showed a significant main effect for age group only and not for gender. Sensitivity and specificity for our community based sample were 59% and 65% respectively, considering the cut-off scores for the 15th percentile of M-ABC and increasing when age groups were taken into account (ROC curve=0.62). The agreement with the original was good if 15th is considered. This is the first study on the psychometric property of DCDQ in a community sample of Italian children. The DCDQ-Italian could be used as a screening tool for motor coordination difficulties in Italian children. Slight differences in cut-offs should be considered when using this version., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The case of a couple of monozygotic twins, for whom the diagnosis of Specific Learning Disabilities was made when they were 14.5 years old, even if reading and writing difficulties had been present since the beginning of primary school, is described. The consultation had been required due to difficulties in relating with same age boys, with social withdrawal and depressive traits, leaving in second place school difficulties; clinical suspect has led to extend the evaluation to include the neuropsychological aspects and so to reach the diagnosis. The differences in terms of adaptive modalities facing the discomfort, probably based on temperament differences, and neuropsychological disorder (low grade dyslexia for one twin, dis-orthography and low-to-medium grade dyslexia for the other one) are discussed. The acquired awareness of being intelligent has permitted the boys to look back in a new way to the school failures they had collected through years; namely, understanding that their difficulties reflected a specific neuropsychological deficit has permitted to reconsider their own past history with a consequent modification of the ''beliefs'' about their abilities. This all has led as a consequence to an increase of life quality (with an improved school and relational adaptation), without cancelling but instead supporting the research of on individuality based on temperament differences. This was possible in spite of the evident delay in reaching the diagnosis and the consequent accumulation of frustration and inadequacy experiences for many years; it's therefore demonstrated the importance of a global evaluation of patients with anamnesis of difficulties in learning to read and write, also in order to treat the possible psychopathological aspects of the clinical picture, which can be the result of a sense of helplessness.

We describe a patient presenting with a combination of dental agenesis, agenesis of the distal phalanx of the fifth finger, small, dystrophic toenails, permanent facial erythema, short stature and mild mental retardation. The neuropsychological profile of this patient which was studied in detail and showed a significant discrepancy between verbal and performance IQ. We discuss the differential diagnosis of this case and conclude that our patient's condition could represent a new syndrome.

We set out to define visuo-perceptual impairment related to periventricular leukomalacia (PVL) using the Developmental Test of Visual Perception (DTVP). Correlations were sought between visual-perceptual deficits and DTVP profile and neuroradiological and neurophthalmological findings. The DTVP was administered to 20 children (m/f: 10/10), aged between 5 and 8 years (mean: 6.95 years), presenting with: spastic diplegia; PVL documented by brain MRI; normal or mildly impaired visual acuity; mild-moderate upper limb functional impairment. The mean General Visual-Perceptual Quotient was impaired, showing a great variability among the patients. Despite this, an uneven DTPV profile, characterised by a significant difference between the VMIQ and the Non-Motor Visual-Perceptual Quotient (P < 0.001) and a poor result on the Closure subtest (identification of whole figures from incomplete visual information) was observed in all the subjects. This profile reflects a deficit in eye-hand coordination and in praxic-constructional abilities and could be the expression of malfunctioning of the occipital-parietal pathway of visual integration, the so-called 'dorsal stream,' a hypothesis reinforced by the emergence of a statistically significant correlation between the neuroradiological data and the presence of visual-perceptual impairment.

Five experiments explored the role of the syllable in the processing of spoken Italian. According to the syllabic hypothesis, the sublexical unit used by speakers of Romance languages to segment speech and access the lexicon is the syllable. However, languages with different degrees of acoustic-phonetic transparency give rise to syllabic effects that vary in robustness. It follows from this account that speakers of phonologically similar languages should behave in a similar way. By exploiting the similarities between Spanish and Italian, the authors tested this prediction in Experiments 1-4. Indeed, Italian listeners were found to produce syllabic effects similar to those observed in Spanish listeners. In Experiment 5, the predictions of the syllabic hypothesis with respect to lexical access were tested. The results corroborated these predictions. The findings are discussed in relation to current models of speech processing.

Dichaptic scanning of Braille letters was studied in 14 skilled blind readers, using Posner's paradigm. A right-hand (left-hemisphere) advantage was found when letters could be matched on the basis of their names (Name Identity Condition), a genuinely linguistic task, while no effects of lateralization appeared when matching could be performed on the basis of perceptual identity (Perceptual Identity Condition) or on "Different" responses. This result provides information about the cerebral lateralization of Braille reading and casts doubts about the current claim that linguistic material, when presented in the tactile modality, is initially analysed in a spatial code by the right hemisphere.