Imagining handwriting movements in a usual or unusual position: effect of posture congruency on visual and kinesthetic motor imagery.

Motor imagery has been used in training programs to improve the performance of motor skills. Handwriting movement may benefit from motor imagery training. To optimize the efficacy of this kind of training, it is important to identify the factors that facilitate the motor imagery process for handwriting movements. Several studies have shown that motor imagery is more easily achieved when there is maximum compatibility between the actual posture and the imagined movement. We, therefore, examined the effect of posture congruency on visual and kinesthetic motor imagery for handwriting movements. Adult participants had to write and imagine writing a sentence by focusing on the evocation of either the kinesthetic or visual consequences of the motion. Half the participants performed the motor imagery task in a congruent posture (sitting with a hand ready for writing), and half in an incongruent one (standing with arms crossed behind the back and fingers spread wide). The temporal similarity between actual and imagined movement times and the vividness of the motor imagery were evaluated. Results revealed that temporal similarity was stronger in the congruent posture condition than in the incongruent one. Furthermore, in the incongruent posture condition, participants reported greater difficulty forming a precise kinesthetic motor image of themselves writing than a visual image, whereas no difference was observed in the congruent posture condition. Taken together, our results show that postural information is taken into account during the mental simulation of handwriting movements. The implications of these findings for guiding the design of motor imagery training are discussed.

Motor imagery development and proprioceptive integration: Which sensory reweighting during childhood?

It is widely accepted that motor imagery development during childhood may be due to refinement of internal models of action. At the same time, gradual improvement of predictive motor control in children may reflect an increasing ability to integrate the proprioceptive afferences with other sources of sensory information (especially vision). The current study investigated the extent to which motor imagery refinement observed between 5 and 9 years of age was related to the increasing ability to integrate proprioceptive afferences with vision and audition signals. To attain this goal, we compared motor imagery performances of 96 children (32 5-year-olds, 32 7-year-olds, and 32 9-year-olds) who received either visual and auditory inputs (VA condition) or visual, auditory, and proprioceptive inputs (VAP condition) during the imagery task. Motor imagery capacity was evaluated by means of mental chronometry paradigm based on a walking task. Our results revealed that correlations between overt and covert movements gradually increased across age in either the VA or VAP condition. Most important, in 5- and 7-year-olds, covert walking times were significantly longer than overt walking times in the VAP condition, whereas covert walking times were not different from actual walking times in the VA condition. In 9-year-olds, covert walking times were not different from overt walking times in either the VAP or VA condition. We suggest that motor imagery refinement during childhood can be partially related to the ability to integrate proprioceptive inputs with other sources of sensory information. Furthermore, our results shed light on the sensory content of motor images in children.

Active touch in late-preterm and early-term neonates.

An infant-controlled tactile habituation without visual control procedure was used to evaluate the ability of 32 late-preterm neonates (mean gestational age: 34 weeks) and 32 early-term neonates (mean gestational age: 38 weeks) to actively explore with hands objects varying in texture (smooth, granular). Holding time and Hand Pressure Frequency (HPF) were recorded. Holding time decreased as habituation progressed in both group of neonates. Holding time increased from habituation trials to test trials only in early-term neonates. A reaction to novelty was only observed in early-term neonates. During habituation, HPF remained unchanged in late-preterm infants whereas HPF decreased in early-term infants. HPF increased from habituation trials to test trials in early-term neonates and in late-preterm infants. However, reaction to novelty was only observed for early-term infants. The significance of these results is discussed in reference to brain maturation in preterm infants.

Complete mitochondrial genomes of three vulnerable cave bat species and their phylogenetic relationships within the order Chiroptera.

The IUCN Red List of Threatened Species contains 175 Brazilian bat species that are threatened by extinction in some degree. From this perspective, it is essential to expand the knowledge about the genetic diversity of vulnerable bats. Genomic sequencing can be useful to generate robust and informative genetic references, increasing resolution when analyzing relationships among populations, species, or higher taxonomic levels. In this study, we sequenced and characterized in detail the first complete mitochondrial genomes of Furipterus horrens, Lonchorhina aurita, and Natalus macrourus, and investigated their phylogenetic position based on amino acid sequences of protein-coding genes (PCGs). The mitogenomes of these species are 16,516, 16,697, and 16,668 bp in length, respectively, and each comprises 13 PCGs, 22 tRNA genes, two rRNA genes, and a putative control region (CR). In the three species, genes were arranged similarly to all other previously described bat mitogenomes, and nucleotide composition was also consistent with the reported range. The length and arrangement of rrnS and rrnL were also consistent with those of other bat species, showing a positive AT-skew and a negative GC-skew. Except for trnS1, for which we did not observe the DHU arm, all other tRNAs showed the cloverleaf secondary structure in the three species. In addition, the mitogenomes showed minor differences in start and stop codons, and in all PCGs, codons ending in adenine were more common compared to those ending in guanine. We found that PCGs of the three species use multiple codons to encode each amino acid, following the previously documented pattern. Furthermore, all PCGs are under purifying selection, with atp8 experiencing the most relaxed purifying selection. Considering the phylogenetic reconstruction, F. horrens was recovered as sister to Noctilio leporinus, L. aurita and Tonatia bidens shared a node within Phyllostomidae, and N. macrourus appeared as sister to Molossidae and Vespertilionidae.

New taxonomic insights for Brazilian Syrbatus Reitter (Coleoptera: Staphylinidae: Pselaphinae), including three new species and their mitochondrial genomes.

Here we present a taxonomic treatment for the Brazilian species of Syrbatus (Reitter, 1882), including the description of three new species (Syrbatus moustache Asenjo & Valois sp. nov., Syrbatus obsidian Asenjo & Valois sp. nov. and Syrbatus superciliata Asenjo & Valois sp. nov.) from the Quadrilátero Ferrífero (Minas Gerais, Brazil). In addition, we designated lectotypes for the Brazilian species of species-group 2, Syrbatus centralis (Raffray, 1898), Syrbatus hetschkoi (Reitter, 1888), Syrbatus hiatusus (Reitter, 1888), Syrbatus transversalis (Raffray, 1898), and Syrbatus trinodulus (Schaufuss, 1887), besides recognizing the holotype for Syrbatus brevispinus (Reitter, 1882), Syrbatus bubalus (Raffray, 1898), and Syrbatus grouvellei (Raffray, 1898). The mitochondrial genomes (mitogenomes) of the three new species are presented, for which we present the phylogenetic placement among Staphylinidae with previously published data.

Haptic processing in newborns of depressed and nondepressed mothers.

This study was conducted to compare how newborns of depressed mothers and newborns of nondepressed mothers gather tactile information about texture. Spontaneous manual activity on objects with a smooth or rough texture was recorded in 20 newborns born of mothers with a high risk of depression or a low risk of depression. An important result of the present study is that texture-based modulation of hand-pressing frequency was observed in both neonates born of depressed mothers and neonates born of nondepressed mothers. Moreover, hand-pressing frequency did not depend on the pressure exerted on the object, since all neonates displayed comparable pressure on the held object. Lastly, the results revealed that newborns of depressed mothers held the rough object twice as long as newborns of nondepressed mothers. These results are analyzed in reference to deregulated biochemical functions in neonates born of mothers with a high risk of depression.

Modifying Sensory Afferences on Tablet Changes Originality in Drawings.

According to some recent empirical studies revealing that creativity is linked to sensorimotor components, the current research was aimed at evaluating whether sensory afferences could modulate originality in drawing of children and adolescents. Sixty-nine children from 1st, 3rd, 6th, and 8th grades were required to produce a man who exists and a man who doesn't exist with fingers or stylus on a tablet and with a pen on paper. Drawings were assessed with an originality scale comparing original drawings to unoriginal ones. Since, in comparison to drawings made on paper with a pen, drawing with fingers enhances proprioceptive information, this condition was expected, according to cognitive load theory, to favor originality in drawing by reducing cognitive resources devoted to motor control of the graphic gesture (lowering intrinsic load). On the contrary, since the use of a stylus involves a proprioceptive loss of information, which enhances intrinsic load by increasing cognitive resources devoted to motor control, it was expected that drawing with a stylus on the tablet would lead to the least original drawings. Results only partially confirmed these hypotheses. While the use of fingers on the tablet led to the highest original scores, using a stylus on the tablet did not impair originality in drawing of children and adolescents. On the opposite, the use of a stylus led 3rd-8th graders to perform better than with pen on paper. This modulation of the tool on originality does not confirm the hypotheses formulated in accordance with the cognitive load framework. However, it could be explained according to an embodied perspective of creativity considering the creative process as relying on a sensorimotor prediction process in which sensory afferences are central to generating and evaluate creative ideas. This research opens new avenues on creativity and proposes to consider the development of predictive motor control as a significant part of creativity development.

Weight perception in neonate infants.

A recent research revealed the capacity of the newborn to haptically detect, the weight of an object [12]. In this research, we tried to determine the means by which newborn infants, not having yet exploratory procedures, are able to treat this object property. We support the assumption that tactile perceptive capacities of the newborn infants derive from a fundamental property of the sensorimotor system: its primary variability. After a period of habituation with a heavy or light object, an object of new weight is presented (period test). Three parameters of the sensorimotor activity were analyzed during these two periods: holding times, amplitude of the pressure exerted on the object and frequency of the pressure. Analyses of these parameters demonstrate the neonate's capacity to discriminate objects weight.

Rôle des afférences proprioceptives dans le développement de l'imagerie motrice chez l'enfant.

To which extent is motor imagery (MI) development, commonly observed between the ages of 5 and 9, related to the increasing ability to integrate proprioceptive afferences for the control of action? This question was addressed in a study evaluating MI performance of 108 children aged 5, 7 and 9 years old. A mental chronometry paradigm based on a walking task was used. Integration of proprioceptive information was evaluated by comparing MI performance when children held an external load (5 % of the children weight) to when they did not. Results revealed that the external load affected MI performances of the 5 year olds. In 7 years old, MI performances remained unchanged whether they held an external load or not. At 9 years, holding an external load improved MI performances. Taken together, these results reveal that MI development could be linked to proprioceptive acuity refinement during childhood. These results are discussed according to the relation between MI, proprioceptive development and development of internal models of action during childhood. (PsycINFO Database Record

Motor imagery for walking: a comparison between cerebral palsy adolescents with hemiplegia and diplegia.

The goal of the study was to investigate whether motor imagery (MI) could be observed in cerebral palsy (CP) participants presenting a bilateral affected body side (diplegia) as it has been previously revealed in participants presenting a unilateral body affected sided (hemiplegia). MI capacity for walking was investigated in CP adolescents diagnosed with hemiplegia (n=10) or diplegia (n=10) and in adolescents with typical motor development (n=10). Participants were explicitly asked to imagine walking before and after actually walking toward a target located at 4 m and 8 m. Movement durations for executed and imagined trials were recorded. ANOVA and Pearson's correlation analyses revealed the existence of time invariance between executed and imagined movement durations for the control group and both groups of CP participants. However, results revealed that MI capacity in CP participants was observed for the short distance (4 m) but not for the long distance (8 m). Moreover, even for short distance, CP participants performed worse than typical adolescents. These results are discussed inline of recent researches suggesting that MI in CP participants may not depend on the side of the lesion.

Early integrative cognitive development in human infants.

This article argues that the multimodal processing of sensorial flows is a biological property of organisms. Already effective at birth, the multimodal processing of flows organizes the infant's environment and unifies his/her perception, permitting the perception of multimodal but unified objects. The multimodal processing of sensorial flows is also a setting event for self-perception because it allows the infant to resolve two crucial questions: what is the source of the flow and where is the action. Lastly the multimodal processing of sensorial flows identifies very early cognitive processes in newborn infants.

Young children's mapping between arrays, number words, and digits.

This study investigates when young children develop the ability to map between three numerical representations: arrays, spoken number words, and digits. Children (3, 4, and 5 years old) had to map between the two directions (e.g., array-to-digit vs. digit-to-array) of each of these three representation pairs, with small (1-3) and large numbers (4-6). Five-year-olds were at ceiling in all tasks. Three-year-olds succeeded when mapping between arrays and number words for small numbers (but not large numbers), and failed when mapping between arrays and digits and between number words and digits. The main finding was that four-year-olds performed equally well when mapping between arrays and number words and when mapping between arrays and digits. However, they performed more poorly when mapping between number words and digits. Taken together, these results suggest that children first learn to map number words to arrays, then learn to map digits to arrays and finally map number words to digits. These findings highlight the importance of directly exploring when children acquire digits rather than assuming that they acquire digits directly from number words.

Assessment of motor imagery in cerebral palsy via mental chronometry: the case of walking.

Recent studies show varying results on whether motor imagery capacity is compromised in individuals with cerebral palsy (CP). Motor imagery studies in children predominantly used the implicit hand laterality task. In this task participants judge the laterality of displayed hand stimuli. A more explicit way of studying motor imagery is mental chronometry. This paradigm is based on the comparison between the movement durations of actually performing a task and imagining the same task. The current study explored motor imagery capacity in CP by means of mental chronometry of a whole body task. Movement durations of 20 individuals with CP (mean age=13 years, SD=3.6) were recorded in two conditions: actual walking and imagined walking. Six unique trajectories were used that varied in difficulty via manipulation of walking distance and path width. We found no main effect of condition (actual walking versus imagining) on movement durations. Difficulty of the walking trajectory did affect movement durations. In general, this was expressed by an increase in movement durations with increasing difficulty of the task. No interaction between task difficulty and movement condition was found. Our results show that task difficulty has similar effects on movement durations for both actual walking and imagined walking. These results exemplify that the tested individuals were able to use motor imagery in an explicit task involving walking. Previous studies using the implicit hand laterality task showed varying results on motor imagery capacity in CP. We therefore conclude that motor imagery capacity is task dependent and that an explicit paradigm as the one used in this study may reveal the true motor imagery capacity. The implications of these findings for the use of motor imagery training are discussed.

The emergence of motor imagery in children.

A total of 80 children (40 5-year-olds and 40 7-year-olds) took part in an experiment to evaluate their capacity to mentally evoke a motor image of their own displacement. Using a chronometry paradigm, movement duration was compared in a task where children were asked to move in order to take a puppet back to its home (actual) and to think about themselves executing the same action (virtual). Movement durations for actual and virtual displacements were obtained in two conditions, where either no information was provided about the weight of the puppet to be displaced (standard situation) or the puppet was described as being heavy (informed situation). A significant correlation between actual and virtual walking durations was observed for 7-year-olds in the informed condition. This result provides evidence for a motor imagery process emerging in 7-year-olds when children are required to think about themselves in action.

Haptic intramodal comparison of texture in human neonates.

We investigated neonates' capacity to haptically compare objects varying in texture property. Right-hand manual activity, assessed by holding time and hand-pressure frequency, was recorded for objects in the presence (test period) or absence (pretest and post-test periods) of an object simultaneously held in the left hand. Thirty-two babies were assigned to four experimental conditions according to the texture density of the object held in each hand: Objects had either the same (matching conditions) or different (non-matching conditions) texture density. Although holding time decreased during test period in both conditions, hand-pressure frequency changed according to the matching and non-matching conditions. In the matching condition, hand-pressure frequency of the right hand did not differ from hand-pressure frequency of the left hand. In the non-matching condition, hand-pressure frequency recorded from the right hand was significantly higher than hand-pressure frequency recorded from the left hand. These results point to neonates' capacity to compare information between simultaneously held objects. These results are interpreted in relation to existing data on the early capacity for intermodal exploration of objects.