Mental imagery of whole-body motion along the sagittal-anteroposterior axis.

Whole-body motor imagery is conceptualised as a mental symbolisation directly and indirectly associated with neural oscillations similar to whole-body motor execution. Motor and somatosensory activity, including vestibular activity, is a typical corticocortical substrate of body motion. Yet, it is not clear how this neural substrate is organised when participants are instructed to imagine moving their body forward or backward along the sagittal-anteroposterior axis. It is the aim of the current study to identify the fingerprint of the neural substrate by recording the cortical activity of 39 participants via a 32 electroencephalography (EEG) device. The participants were instructed to imagine moving their body forward or backward from a first-person perspective. Principal Component Analysis (i.e. PCA) applied to the neural activity of whole-body motor imagery revealed neural interconnections mirroring between forward and backward conditions: beta pre-motor and motor oscillations in the left and right hemisphere overshadowed beta parietal oscillations in forward condition, and beta parietal oscillations in the left and right hemisphere overshadowed beta pre-motor and motor oscillations in backward condition. Although functional significance needs to be discerned, beta pre-motor, motor and somatosensory oscillations might represent specific settings within the corticocortical network and provide meaningful information regarding the neural dynamics of continuous whole-body motion. It was concluded that the evoked multimodal fronto-parietal neural activity would correspond to the neural activity that could be expected if the participants were physically enacting movement of the whole-body in sagittal-anteroposterior plane as they would in their everyday environment.

Synchronised neural signature of creative mental imagery in reality and augmented reality.

Creativity, transforming imaginative thinking into reality, is a mental imagery simulation in essence. It can be incorporeal, concerns sophisticated and/or substantial thinking, and involves objects. In the present study, a mental imagery task consisting of creating a scene using familiar (FA) or abstract (AB) physical or virtual objects in real (RMI) and augmented reality (VMI) environments, and an execution task involving effectively creating a scene in augmented reality (VE), were utilised. The beta and gamma neural oscillations of healthy participants were recorded via a 32 channel wireless 10/20 international EGG system. In real and augmented environments and for both the mental imagery and execution tasks, the participants displayed a similar cortico-cortical neural signature essentially based on synchronous vs asynchronous beta and gamma oscillatory activities between anterior (i.e. frontal) and posterior (i.e. parietal, occipito-parietal and occipito-temporal) areas bilaterally. The findings revealed a transient synchronised neural architecture that appears to be consistent with the hypothesis according to which, creativity, because of its inherent complexity, cannot be confined to a single brain area but engages various interconnected networks.

Continuity in intuition and insight: from real to naturalistic virtual environment.

Intuition and insight can be deployed on the same continuum. Intuition is the unconscious ability to create links between information; insight is a process by which a sudden comprehension and resolution of a situation arises (i.e. euréka). In the present study, real and virtual environments were used to trigger intuition and insight. The study hypothesised that immersion in real primed environments would facilitate the emergence of intuition and insight in a virtual environment. Forty nine healthy participants were randomly assigned to two groups: "primed" and "non primed." "Primed" participants were immersed in a real environment with olfactory and visual cues; "non primed" participants did not receive any cues. All participants were exposed to a 3D naturalistic virtual environment which represented a district in Paris via a Head Mounted Display (HMD). Locations presented in the virtual scene (i.e. café places) were related to both olfactory and visual primes (i.e. café) and were based on the continuity between real and virtual environments. Once immersed in the virtual environment, all participants were instructed to use their intuition to envision the selected locations during which Skin Conductance Responses (SCRs) and verbal declarations were recorded. When initiation (a) and immersion (b) phases in the virtual environment were considered, "primed" participants had higher SCRs during the immersion phase than the initiation phase in the virtual environment. They showed higher SRCs during the first part of the virtual immersion than "non primed" participants. During the phenomenological interview, "primed" participants reported a higher number of correct intuitive answers than "non primed" participants. Moreover, "primed" participants "with" insight had higher SCRs during real environment immersion than "primed" participants "without" insight. The findings are consistent with the idea that intuitive decisions in various tasks are based on the activation of pre-existing knowledge, which is unconsciously retrieved, but nevertheless can elicit an intuitive impression of coherence and can generate insight.

Spatial linear navigation: is vision necessary?

In order to analyze spatial linear navigation through a task of self-controlled reproduction, healthy participants were passively transported on a mobile robot at constant velocity, and then had to reproduce the imposed distance of 2-8m in two conditions: "with vision" and "without vision". Our hypothesis was that the reproduction of distances would be longer with than without visual information. Indeed, with visual information the reproduction of all distances was overshot. In the "without vision" condition the reproduced distances were quite close to the imposed ones, but only for the shortest distances (2 and 4m) as the longest ones were clearly undershot. With vision the reproduction error was less than 10% for all distances; however the error could be smaller without vision at short distances, and therefore vision was not necessary.

Subjective posture in tridimensional space.

The internal representation of the body is intimately related to postural orientation. This assists us to correctly identify our position relative to the earth-vertical. The postural orientation about the pitch-Y axis is by default forward tilted while there is no such default about the roll-X axis. We hypothetized that the internal representation of body position would be different between the Y and X axes. We designed a study to assess the accuracy of self-driven whole-body orienting to the horizontal and the vertical about the X (roll) and Y (pitch) axes, with healthy seated subjects in complete darkness. Consistent with our hypothesis, the results showed that when trying to reach the horizontal with the X-axis, subjects remained on the same tilted direction as the initial posture. On the return way to the vertical, the subjects did not cross this (vertical) line. Whereas when reaching the horizontal with the Y-axis, there was an undershoot on the supine direction, and an overshoot on the prone direction: this discrepancy could be due to somatosensory cues to subjects in seated posture. The relevant mechanisms related to the internal representation of the body and graviceptive systems underlying the construction of an head-foot line are discussed.

Teachers' reporting of behavioural problems and cognitive-academic performances in children aged 5-7 years.

BACKGROUND: The behavioural and academic performance of young children with teachers' reported hyperactivity, conduct problems or inattention is under debate. AIM: This study investigates the associations between teachers' reported behavioural difficulties and academic and cognitive performances in two large samples of preschool and school children in France. SAMPLES AND METHOD: Behavioural data relating to two large samples of preschool (N=475) and first grade (N=465) children were collected from their teachers by means of a questionnaire. A factorial analysis of the questionnaire revealed a four-factor structure ('hyperactivity', 'inattention', 'conduct problems' and 'unsociability') that was similar in both age groups. Cognitive tests were used for each age group. RESULTS: Teachers' reporting of 'inattention' was associated with significantly lower performances in all tests in both the preschool and first grade samples. 'Hyperactivity' or 'conduct problems' were not consistently associated with the test results, when the effect of 'inattention' was taken into account. Preschool 'inattention', but not 'hyperactivity' or 'conduct/sociability problems', was related to poor performances at reading tasks in first grade. CONCLUSION: These findings question the pathological significance of teachers' report of 'hyperactivity' in young children without associated attention problems.

Cognitive associations of bimanual haptico-visual recognition in preschoolers.

We have investigated the relation between haptico-visual recognition of objects and cognitive tasks in two large samples of preschoolers (n = 534; n = 750). Children aged 6 years completed a cross-modal task in which they have first to haptically explore an object and second to visually recognize it; they also performed phonological, verbal semantic, and visual tasks. For two consecutive years, bimanual haptico-visual recognition was significantly correlated to performance at all the cognitive tasks. The meaning of this relationship is discussed. The study supports the view that haptico-visual recognition tasks should be used as screening tools for early identification of children at risk of learning difficulties.

[Behavior difficulties, attention difficulties and learning problems in children aged from 3.5 to 8 years: a longitudinal school study]. / Comportement perturbateur, difficultés d'attention et apprentissages entre 3,5 ans et 8 ans: une étude longitudinale en milieu scolaire.

AIM: To evaluate the long term impact of teacher's report of behavior difficulties in children aged 3.5 years. METHOD: Teachers assessed behavior and attention difficulties in 2054 children by questionnaire; reading performance, and behavior and attention difficulties were re-assessed in 695 of these children at second grade (7-8 years). RESULTS: Reading delay was not significantly associated with behavior and attention assessment at 3.5 years. Children with behavior problems according to the teacher were most often different at 3.5 years and at 7-8 years. CONCLUSION: Reading delay at second grade was not related to teacher's report of behavior problems at 3.5 years of age in this french longitudinal school study. These observations are discussed in relation to DSM-IV criteria of disruptive behavior and attention deficit in children.

Smooth pursuit eye movements are associated with phonological awareness in preschool children.

Phonological awareness is strongly related to reading ability, but reports are more conflicting concerning the association of high level oculomotor skills with reading. Here, we show that phonological awareness is specifically associated with the ability to perform smooth pursuit eye movements in preschool children. Two large independent samples of preschool children (n=838 and n=732) aged 5-6.4 years, without history of neurological disorder, were examined by school medical doctors for visual and oculomotor problems. Nineteen percent of the children in the first sample and 14% in the second failed at the clinical evaluation of smooth pursuit eye movements, and 17 and 15%, respectively, presented another visual or oculomotor problem. Ten short cognitive tests were performed by the same children. Visual and oculomotor problems other than a failure on smooth pursuit were not consistently related to the cognitive tasks, with one exception, the visual recognition of letters. Children who failed at smooth pursuit obtained lower scores at a number of cognitive tasks, and especially phonological awareness tasks and copy of visually presented trajectories. Poor working memory and/or failure of anticipation during the tracking of a visual or auditory stimulus related to frontal cortex immaturity may explain these associations in preschool children.

[Pertinence of parental screening for delays of language in children aged four to six years]. / Pertinence du repérage par les parents des retards de langage chez l'enfant entre quatre et six ans.

UNLABELLED: This study investigates the relevance of the information provided by parents when screening for language delays in pre-school children. METHOD: Parents of 670 pupils of medium section of nursery school (4-5 years) and of 799 pupils of the high section of nursery school (5-6 years) answered questions about their child's language and behaviour. Some of these same children passed currently available ERTL4 and BREV tasks (in medium section) and BSEDS tasks (in high section). Items concerning language delay were selected from the parents' questionnaire by the principal component analysis method, and correlation between parental answers to these items and the task results were examined. RESULTS: Parents' opinion was strongly and specifically correlated with tasks assessing the correct/incorrect aspects of speech and expressive language and less strongly with tasks assessing vocabulary or comprehension. CONCLUSION: Parents' opinion is useful when screening for delays of speech and expressive language in pre-school children.

Vestibular sensitivity and vection chronometry along the spinal axis in erect man.

A study is reported of the relations between vestibular sensitivity and vection chronometry in healthy human adults. Twenty-three subjects were examined. For both vestibular and vection investigations, the subjects were seated in an armchair with the spinal axis aligned with the earth vertical and the head normally erect. The subjects' vestibular thresholds for detection of vertical upward accelerations were assessed by a double-staircase psychophysical method. The subjects' vection onset latencies were measured for both upward and downward directions. Since the vection onset latencies are presumed to be shortened by the decrease of the conflict between visual and vestibular afferents, the less-vestibular-sensitive subjects were hypothesised to have shorter vection onset latencies than the more-vestibular-sensitive ones. As expected, the results indicate a negative correlation between vestibular thresholds and vection onset latencies: the higher the vestibular thresholds, the lower the vection onset latencies.

Linear-vection chronometry along spinal and sagittal axes in erect man.

The present study investigates the onset latencies for linear vection along both the spinal and the sagittal axis in erect human adults. For each axis, both directions have been investigated (upward vs downward, forward vs backward). The vection-onset latency is thought to be shortened by the decrease of the conflict between visual and vestibular afferents. Since this sensory conflict can be presumed to be more important in the horizontal sagittal axis than in the vertical spinal one, the vection-onset latencies have been hypothesised to be longer in the former case than in the latter. Additionally, since the magnitude of this sensory conflict can be presumed to be the same between the two opposite directions within each axis, the vection-onset latencies have been expected not to vary between directions within each axis. The results confirm both these hypotheses.

Cognitive effects on visually induced body motion in children.

Cognitive effects on linear sagittal vection in children were investigated. Forty children (7 and 11 years old) were exposed to a bilateral backward optical flow in a single physical condition (seated in a stationary armchair) but in two contrasted cognitive conditions. In one cognitive condition, the children were precisely informed that the armchair could move. In the other, they were informed that the armchair could not move. In each age group, half the children were assigned to one cognitive condition, the other half to the other condition. The results indicate that knowledge about the plausibility of a physical displacement does not affect the probability of obtaining vection. However, at both ages, the latencies for reporting vection were shorter when the physical displacement was known to be possible than when it was known to be impossible. The present results indicate that exclusively cognitive factors do not affect vection occurrence but can modulate latencies for reporting vection.