Biomechanical analyses of prolonged handwriting in subjects with and without perceived discomfort

Since wrist-joint position affects finger muscle length and grip strength, we studied its biomechanical relevance in prolonged handwriting. We recruited participants from young adults, aged 18–24, and separated them into control (n = 22) and in-pain (n = 18) groups, based whether or not they experience pain while handwriting. The participants then performed a writing task for 30 min on a computerized system which measured their wrist-joint angle and documented their handwriting kinematics. The in-pain group perceived more soreness and had a less-extended wrist joint, longer on-paper time, and slower stroke velocity compared to control group. There was no significant difference in handwriting speed and quality between the two groups. The wrist extension angle significantly correlated with perceived soreness. Ergonomic and biomechanical analyses provide important information about the handwriting process. Knowledge of pen tip movement kinematics and wrist-joint position can help occupational therapists plan treatment for individuals with handwriting induced pain.     

Does modifying visual feedback facilitate learning to write new pseudoletters?

Learning to write relies on the efficient integration of visual and proprioceptive feedback, with a transition from a control, based on the visual inspection of the written trace at the beginning of the learning process to a more predictive control, based mainly on handwriting movement, in proficient writers. The aim of this study was to test the effect of a partial deletion of the written trace, as well as the effect of supplementary visual information, on handwriting kinematics in a learning task. Twenty-four adults learned to write six new pseudoletters using their non-dominant hand on a touch screen digital tablet. Three pseudoletters were trained with modified visual feedback conditions and the other three, in the control condition, i.e. without any visual modification. Results revealed that, in the short-term, the pseudoletters learned with modified visual feedback were traced faster and more fluently than those learned in the control condition, without spatial accuracy reduction. This method seems to be efficient in adults, which is a prerequisite before testing a method with children.     

Children’s age modulates the effect of part and whole practice in motor learning

Motor skills can be learned by practicing the whole or part of a movement. In whole practice (WP), a skill is acquired by practicing the movement in its entirety, whereas in part practice (PP), a task is learned by practicing its components before combining them. However, the effectiveness of WP and PP in children is unclear. We, therefore, examined the effects of WP and PP on the learning of juggling among first-, third-, and fifth-graders. Children of each grade were pseudo-randomly assigned to the WP or PP group to learn cascade juggling in 6 days. After baseline assessments, the WP learners practiced three-beanbag juggling. The PP learners practiced one-beanbag juggling on the first 2 days, two-beanbag juggling on the following 2 days, and three-beanbag juggling on the last 2 days. Practice consisted of 40 trials each day. Skill retention and transfer trials (juggling in the opposite direction) were measured 24 h after training (number of catches). There was no significant difference between WP and PP in skill retention (WP: 1.28 ± 0.73; PP: 1.42 ± 046, p = .40) and transfer (WP: 1.31 ± 0.78; PP: 1.37 ± 0.55, p = .49). However, a time × grade × group interaction (p < .001) was observed in retention. Children of different grades received differential benefits from the WP and PP regimens. The fifth-graders learned better using WP, whereas the first- and third-graders showed better learning with PP. We discuss the three possible explanations for the results (neural maturity, explicit learning, and coordination capabilities).     

Graphomotor skills in children with developmental coordination disorder (DCD): Handwriting and learning a new letter

The aim of the present study was to analyze handwriting difficulties in children with developmental coordination disorder (DCD) and investigate the hypothesis that a deficit in procedural learning could help to explain them. The experimental set-up was designed to compare the performances of children with DCD with those of a non-DCD group on tasks that rely on motor learning in different ways, namely handwriting and learning a new letter. Ten children with DCD and 10 non-DCD children, aged 8–10 years, were asked to perform handwriting tasks (letter/word/sentence; normal/fast), and a learning task (new letter) on a graphic tablet. The BHK concise assessment scale for children’s handwriting was used to evaluate their handwriting quality. Results showed that both the handwriting and learning tasks differentiated between the groups. Furthermore, when speed or length constraints were added, handwriting was more impaired in children with DCD than in non-DCD children. Greater intra-individual variability was observed in the group of children with DCD, arguing in favor of a deficit in motor pattern stabilization. The results of this study could support both the hypothesis of a deficit in procedural learning and the hypothesis of neuromotor noise in DCD.     

The effect of a motor skills training program in the improvement of practiced and non-practiced tasks performance in children with developmental coordination disorder (DCD)

The purpose of the present study was to examine the effect of a group-based task oriented skills training program on motor and physical ability for children with DCD. It was also investigated if there was an effect on fine motor and handwriting tasks that were not specifically practiced during the training program. Forty-one children aged 6–10 years took part in this study. Children were assigned to three groups: an experimental training group consisting of 14 children with DCD, a control non-training group consisted of 13 children with DCD and a control non-training group consisting of 14 typically developed children. The measurements included were, the Movement Assessment Battery for Children (MABC), the Modified Agility Test (MAT), the Triple Hop Distance (THD), the 5 Jump-test (5JT) and the Handwriting Performance Test. All measures were administered pre and post an 8-week training program. The results showed that 10 children of the DCD training-group improved their performance in MABC test, attaining a score above the 15th percentile after their participation in the training program. DCD training-group showed a significant improvement on all cluster scores (manual dexterity (t (13) = 5.3, p < .001), ball skills (t (13) = 2.73, p < .05) and balance (t (13) = 5.13, p < .001). Significant performance improvements were also found in MAT, THD, 5JT (t (13) = –4.55; p < .01), handwriting quality (t (12) = –2.73; p < .05) and speed (t (12) = –4.2; p < .01) after the training program. In conclusion, improvement in both practiced and non-practiced skills, in the training program, may reflect improvement in motor skill but also transfer to other skills.     

Memory for reward location is enhanced even though acetylcholine efflux within the amygdala is impaired in rats with damage to the diencephalon produced by thiamine deficiency

Sleep facilitates declarative memory processing. However, we know little about whether sleep plays a role in the processing of a fundamental feature of declarative memory, relational memory – the flexible representation of items not directly learned prior to sleep. Thirty-one healthy participants first learned at 12 pm two sets of face–object photograph pairs (direct associative memory), in which the objects in each pair were common to both lists, but paired with two different faces. Participants either were given approximately 90 min to have a NREM-only daytime nap (n = 14) or an equivalent waking period (n = 17). At 4:30 pm, participants who napped demonstrated significantly better retention of direct associative memory, as well as better performance on a surprise task assessing their relational memory, in which participants had to associate the two faces previously paired with the same object during learning. Particularly noteworthy, relational memory performance was correlated with the amount of NREM sleep during the nap, with only slow-wave sleep predicting relational memory performance. Sleep stage data did not correlate with direct associative memory retention. These results suggest an active role for sleep in facilitating multiple processes that are not limited to the mere strengthening of rote memories, but also the binding of items that were not directly learned together, reorganizing them for flexible use at a later time.     

When hearing the bark helps to identify the dog: Semantically-congruent sounds modulate the identification of masked pictures

We report a series of experiments designed to assess the effect of audiovisual semantic congruency on the identification of visually-presented pictures. Participants made unspeeded identification responses concerning a series of briefly-presented, and then rapidly-masked, pictures. A naturalistic sound was sometimes presented together with the picture at a stimulus onset asynchrony (SOA) that varied between 0 and 533 ms (auditory lagging). The sound could be semantically congruent, semantically incongruent, or else neutral (white noise) with respect to the target picture. The results showed that when the onset of the picture and sound occurred simultaneously, a semantically-congruent sound improved, whereas a semantically-incongruent sound impaired, participants’ picture identification performance, as compared to performance in the white-noise control condition. A significant facilitatory effect was also observed at SOAs of around 300 ms, whereas no such semantic congruency effects were observed at the longest interval (533 ms). These results therefore suggest that the neural representations associated with visual and auditory stimuli can interact in a shared semantic system. Furthermore, this crossmodal semantic interaction is not constrained by the need for the strict temporal coincidence of the constituent auditory and visual stimuli. We therefore suggest that audiovisual semantic interactions likely occur in a short-term buffer which rapidly accesses, and temporarily retains, the semantic representations of multisensory stimuli in order to form a coherent multisensory object representation. These results are explained in terms of Potter’s (1993) notion of conceptual short-term memory.     

Why is number word learning hard? Evidence from bilingual learners

Young children typically take between 18 months and 2 years to learn the meanings of number words. In the present study, we investigated this developmental trajectory in bilingual preschoolers to examine the relative contributions of two factors in number word learning: (1) the construction of numerical concepts, and (2) the mapping of language specific words onto these concepts. We found that children learn the meanings of small number words (i.e., one, two, and three) independently in each language, indicating that observed delays in learning these words are attributable to difficulties in mapping words to concepts. In contrast, children generally learned to accurately count larger sets (i.e., five or greater) simultaneously in their two languages, suggesting that the difficulty in learning to count is not tied to a specific language. We also replicated previous studies that found that children learn the counting procedure before they learn its logic – i.e., that for any natural number, n, the successor of n in the count list denotes the cardinality n + 1. Consistent with past studies, we found that children’s knowledge of successors is first acquired incrementally. In bilinguals, we found that this knowledge exhibits item-specific transfer between languages, suggesting that the logic of the positive integers may not be stored in a language-specific format. We conclude that delays in learning the meanings of small number words are mainly due to language-specific processes of mapping words to concepts, whereas the logic and procedures of counting appear to be learned in a format that is independent of a particular language and thus transfers rapidly from one language to the other in development.     

Sensory memory consolidation observed: Increased specificity of detail over days

Memories are usually multidimensional, including contents such as sensory details, motivational state and emotional overtones. Memory contents generally change over time, most often reported as a loss in the specificity of detail. To study the temporal changes in the sensory contents of associative memory without motivational and emotional contents, we induced memory for acoustic frequency by pairing a tone with stimulation of the cholinergic nucleus basalis. Adult male rats were first tested for behavioral responses (disruption of ongoing respiration) to tones (1–15 kHz), yielding pre-training behavioral frequency generalization gradients (BFGG). They next received three days of training consisting of a conditioned stimulus (CS) tone (8.00 kHz, 70 dB, 2 s) either Paired (n = 5) or Unpaired (n = 5) with weak electrical stimulation (～48 μA) of the nucleus basalis (100 Hz, 0.2 s, co-terminating with CS offset). Testing for behavioral memory was performed by obtaining post-training BFGGs at two intervals, 24 and 96 h after training. At 24 h post-training, the Paired group exhibited associative behavioral memory manifested by significantly larger responses to tone than the Unpaired group. However, they exhibited no specificity in memory for the frequency of the tonal CS, as indexed by a flat BFGG. In contrast, after 96 h post-training the Paired group did exhibit specificity of memory as revealed by tuned BFGGs with a peak at the CS-band of frequencies. This increased detail of memory developed due to a loss of response to lower and higher frequency side-bands, without any change in the absolute magnitude of response to CS-band frequencies. These findings indicate that the sensory contents of associative memory can be revealed to become more specific, through temporal consolidation in the absence of non-sensory factors such as motivation and emotion.     

Cognitive aspects of congenital learned helplessness and its reversal by the monoamine oxidase (MAO)-B inhibitor deprenyl

Cognitive processes are assumed to change with learned helplessness, an animal model of depression, but little is known about such deficits. Here we investigated the role of cognitive and related functions in selectively bred helpless (cLH, n = 10), non-helpless (cNLH, n = 12) and wild type (WT, n = 8) Sprague Dawley rats. The animals were exposed to an open field for 10 min on each of two test days. On the third day, an object exploration paradigm was carried out. The animals were later tested for helplessness. Both cLH and cNLH rats were more active than WTs on the first day in the open field. Over trials, cNLH and WT rats lowered their activity less than cLH rats. This resistance-to-habituation co-varied with a resistance to develop helplessness. In cLH rats, higher ‘anxiety’ or less time spent in the center of the open field co-varied with severe helplessness. In WTs, a greater reactivity to novel objects and to a spatially relocated object predicted lower levels of helplessness. In cLH rats (n = 4–5 per group), chronic treatment with a high dose of the monoamine oxidase (MAO)-B inhibitor deprenyl (10 mg/kg; i.p.), an anti-Parkinson, nootropic and antidepressant drug, attenuated helplessness. Remarkably, helplessness reversal required the experience of repeated test trials, reminiscent of a learning process. Chronic deprenyl (10 mg/kg; i.p.) did not alter locomotion/exploration or ‘anxiety’ in the open field. In conclusion, helplessness may be related to altered mechanisms of reinforcement learning and working memory, and to abnormalities in MAO-A and/or MAO-B functioning.     

What Confucius practiced is good for your mind: Examining the effect of a contemplative practice in Confucian tradition on executive functions

The short-term training effects on various executive functions (EFs) by a movement-based contemplative practice (MBCP) are examined. Three aspects of EFs (working memory capacity, inhibition, switching) are assessed before and after a month-long 12-h training period using Body-Mind Axial Awareness (BMAA) principles that Confucius followers have practiced for more than 2000 years. A mindfulness-based practice (Chan-meditation) and a waiting-list control group served as contrast groups. Our results showed that the BMAA group performed better on the task that measured working memory capacity than did the Chan-meditation and the waiting-list groups after training. In addition, the Chan-meditation groups outperformed the control group on attentional switching, a novel finding for this kind of practice. Our findings not only show a new effect of short-term MBCPs on EFs, but also indicate movement-based and mindfulness-based contemplative practices might benefit development of various aspects of EFs in different ways.     

Procedural learning and automatization process in children with developmental coordination disorder and/or developmental dyslexia

ObjectiveThere is increasing evidence to suggest that developmental dyslexia (DD) and developmental coordination disorder (DCD) actually form part of a broader disorder. Their frequent association could be justified by a deficit of the procedural memory system, that subtends many of the cognitive, motor and linguistic abilities that are impaired in both DD and DCD. However, studies of procedural learning in these two disorders have yielded divergent results, and in any case no studies have so far addressed the issue of automatization (dual-task paradigm).MethodsWe administered a finger tapping task to participants aged 8–12 years (19 DCD, 18 DD, and 22 with both DD and DCD) to explore procedural learning and automatic movements in these three groups of children, comparing motor performances at the prelearning stage, after 2 weeks of training, and in a post-training dual-task condition.ResultsFirst, results indicated that all the children were able to learn a sequence of movements and even automatize their movements. Second, they revealed between-groups differences in procedural/automatization learning abilities, setting the DCD group apart from the other two. Third, contrary to our expectations concerning comorbidity, they suggested that the DD + DCD association does not have an additional impact on behavioral performances.     

Making sense of age-related distractibility: The critical role of sensory modality

Older adults are known to have reduced inhibitory control and therefore to be more distractible than young adults. Recently, we have proposed that sensory modality plays a crucial role in age-related distractibility. In this study, we examined age differences in vulnerability to unimodal and cross-modal visual and auditory distraction. A group of 24 younger (mean age = 21.7 years) and 22 older adults (mean age = 65.4 years) performed visual and auditory n-back tasks while ignoring visual and auditory distraction. Whereas reaction time data indicated that both young and older adults are particularly affected by unimodal distraction, accuracy data revealed that older adults, but not younger adults, are vulnerable to cross-modal visual distraction. These results support the notion that age-related distractibility is modality dependent.     

Intensive video gaming improves encoding speed to visual short-term memory in young male adults

The purpose of this study was to measure the effect of action video gaming on central elements of visual attention using Bundesen's (1990) Theory of Visual Attention.To examine the cognitive impact of action video gaming, we tested basic functions of visual attention in 42 young male adults. Participants were divided into three groups depending on the amount of time spent playing action video games: non-players (< 2 h/month, N = 12), casual players (4–8 h/month, N = 10), and experienced players (> 15 h/month, N = 20). All participants were tested in three tasks which tap central functions of visual attention and short-term memory: a test based on the Theory of Visual Attention (TVA), an enumeration test and finally the Attentional Network Test (ANT). The results show that action video gaming does not seem to impact the capacity of visual short-term memory. However, playing action video games does seem to improve the encoding speed of visual information into visual short-term memory and the improvement does seem to depend on the time devoted to gaming. This suggests that intense action video gaming improves basic attentional functioning and that this improvement generalizes into other activities. The implications of these findings for cognitive rehabilitation training are discussed.     

Behavioral memory induced by stimulation of the nucleus basalis: Effects of contingency reversal

Specific behavioral associative memory induced by stimulation of the cortically-projecting cholinergic nucleus basalis (NB) is dependent on intrinsic acetylcholine and shares with natural memory such features as associativity, specificity, rapid formation, consolidation and long-term retention. Herein, we examined extinction and the effects of stimulus pre-exposure. Two groups of adult male rats (n = 4 each) were first tested for behavioral responses (disruption of ongoing respiration) to tones (1–15 kHz), constituting a pre-training behavioral frequency generalization gradient (BFGG). They next received a first session of training, 200 trials of a tone (8.00 kHz, 70 dB, 2 s) either paired with electrical stimulation of the NB (100 Hz, 0.2 s, ～67 μA, NBstm) (group IP) or unpaired (group IU). Twenty-four hours later, they were tested for behavioral memory by obtaining post-training BFGGs. Then the contingencies were reversed yet another 24 h later; the IP group received tone and NBstm unpaired and the IU group received them paired. A final set of generalization gradients was obtained the next day. All stimuli were presented with subjects under state control indexed by regular respiration. Tested 24 h post-initial training, the IP group developed specific associative behavioral memory indicated by increased responses only to CS-band frequencies, while the IU group did not. After subsequent training with unpaired stimuli, the IP group exhibited experimental extinction. Furthermore, after initial exposure to the CS and NBstm unpaired, the IU group exhibited a tendency toward reduced conditioning to CS/NBstm pairing and a significant increase in latency of conditioned responses. The present findings provide additional support for the hypothesis that engagement of the NB is sufficient to induce natural associative memory and suggest that activation of the NB may be a normal component in the formation of natural associative memory.     

Auditory processing and sensory behaviours in children with autism spectrum disorders as revealed by mismatch negativity

Sensory dysfunctions may underlie key characteristics in children with Autism Spectrum Disorders (ASD). The current study aimed to investigate auditory change detection in children with ASD in order to determine event-related potentials to meaningless and meaningful speech stimuli. 11 high functioning boys with a diagnosis of autism spectrum disorders (mean age = 13.0; SD = 1.08) and 11 typically developing boys (mean age = 13.7; SD = 1.5) participated in a mismatch negativity (MMN) paradigm. Results revealed that compared to TD controls, the children with ASD showed significantly reduced MMN responses to both words and pseudowords in the frontal regions of the brain and also a significant reduction in their activation for words in the Central Parietal regions. In order to test the relationship between sensory processing and auditory processing, children completed the Adult and Adolescent Sensory Profile. As predicted, the children with ASD showed more extreme sensory behaviours and were significantly higher than their typically developing controls across three of the sensory quadrants (sensory sensitivity, low registration and sensory avoidance). Importantly, only auditory sensory sensitivity was able to account for the differences displayed for words in the frontal and central parietal regions when controlling for the effect of group, revealing an inverse relationship of the higher sensory sensitivity scores the less activation in response for words. We discuss how the expression of sensory behaviours in ASD may result in deficient neurophysiological mechanisms underlying automatic language processing.     

Rational action selection in 1½- to 3-year-olds following an extended training experience

Previous studies failed to find evidence for rational action selection in children under 2 years of age. The current study investigated whether younger children required more training to encode the relevant causal relationships. Children between 1½ and 3 years of age were trained over two sessions to perform actions on a touch-sensitive screen to obtain video clips as outcomes. Subsequently, a visual habituation procedure was employed to devalue one of the training outcomes. As in previous studies, 2- and 3-year-olds chose actions associated with an expected valued outcome significantly more often during a subsequent choice test. Moreover, analysis of children’s first responses in the post-devaluation test revealed evidence of rational action selection even in the youngest age group (18–23 months). Consistent with dual-process accounts of action control, the findings support the view that the ability to make rational action choices develops gradually.     

Differentiating technical skill and motor abilities in selected and non-selected 3–5 year old team-sports players

This study examined the difference in 22 3–5 year old boys selected to an advanced or non-advanced group on an English community-based professional club training program. Time to complete 15 m linear sprint and 15 m zig-zag agility tests, with and without a ball, were used to assess the children’s technical skill and motor ability. Age and body mass of both groups were the same, whereas height was greater and BMI was lower in the selected group (p < 0.01). Linear sprint times without and with the ball were 3.98 ± 0.35 and 4.44 ± 0.36 s, respectively for the selected and corresponding times were 4.64 ± 1.04 and 11.2 ± 5.37 s for the non-selected (p < 0.01, ES 0.8, 1.8). Similar results were found when a change of movement was included, both with and without the ball. A model of selection indicated that performance in an agility test with the ball and height had the greatest discriminatory power and explained 95.5% of between group variance. Selected players performed significantly better in tests when ball control was required. These findings suggest that technical proficiency and physical differences may influence team selection in three to five year old children.     

d-cycloserine reverses the detrimental effects of stress on learning in females and enhances retention in males

Exposure to acute, inescapable stress produces a facilitation of subsequent classical eyeblink conditioning in male rats. The same stress exposure produces a profound deficit in classical eyeblink conditioning in females. Activation of N-methyl-d-aspartate receptors (NMDAr) is necessary for the effect of stress on learning in males while the contribution of NMDAr activation to the deficit in learning after stress is unknown. Here, we tested the influence of d-cycloserine (DCS), a positive modulator of the NMDAr, in stressed or unstressed male and female rats. Groups of males and females were exposed to an acute stressful event. One day later, they began training with four sessions of trace eyeblink conditioning. Each day before training, they were injected with DCS (15 mg/kg) or saline. Females treated with DCS during training responded similarly to those that were untreated. However, those that were stressed and the next day treated with the drug during training did not express the typical learning deficit, i.e. they learned to time the CR very well. Because the drug was administered well after the stressor, these data indicate that DCS reversed the negative effects of stress on learning in females. In males, the effect of DCS was subtle, resulting in higher asymptotic responding, and enhanced retention in a drug-free retention test. Thus, as shown previously, training in the presence of an NMDA receptor agonist enhances associative learning and memory retention. In addition, it can reverse learning deficits that have already been induced.