Alcohol consumption and handwriting: A kinematic analysis

Handwriting Biometrics: Applications and Future Trends in e-Security and e-Health

Online handwritten analysis presents many applications in e-security, signature biometrics being the most popular but not the only one. Handwriting analysis also has an important set of applications in e-health. Both kinds of applications (e-security and e-health) have some unsolved questions and relations among them that should be addressed in the next years. We summarize the state of the art and applications based on handwriting signals. Later on, we focus on the main achievements and challenges that should be addressed by the scientific community, providing a guide for future research. Among all the points discussed in this article, we remark the importance of considering security, health, and metadata from a joint perspective. This is especially critical due to the risks inherent when using these behavioral signals.

Endogenous and Exogenous Factors Affecting the Surgical Technique (Review)

In this review, we analyzed essential factors affecting precise manual movements in microsurgery described in the medical literature. The search for publications in English and Russian languages was conducted in the PubMed database without limitation by the date of publication. The search was carried out according to the following descriptors: surgical procedures, dexterity, microsurgery, caffeine, alcohol, nicotine, physical exercise, sleep deprivation, posture. Only randomized and cohort studies involving doctors and students with surgical specialties were included in the analysis. We did not include papers in which only psychological (non-motor) aspects were studied.

Due to the limited number of publications meeting the inclusion criteria and conflicting results in some of them, the presented review does not allow us to formulate unambiguous conclusions and recommendations. Further studies (deep and fundamental) of endogenous and exogenous factors affecting the microsurgical technique are needed.

Are Motor Control and Regulation Problems Part of the ASD Motor Profile? A Handwriting Study

The primary aim of this study was to kinematically assess how children with autism spectrum disorder (ASD) plan and control their handwriting actions. Forty-three boys aged between 8 to 12 years were included in the present analysis; 23 with ASD and 20 typically developing (TD) controls. Sophisticated objective and quantifiable assessment of movement metrics and dynamics was applied across a series of basic cursive handwriting sequences. Children with ASD demonstrated atypical control of handwriting metrics and dynamics, as well as significantly greater neuromotor noise relative to age-matched peers. They also engaged in less regular monitoring and regulation of their movement during the handwriting task. This study provides new insights into the way children with ASD plan and sequence their handwriting movements. Overall, results revealed that even at a basic level, children with ASD appear to have a breakdown in their ability to control and regulate their handwriting movements. This has important implications for the school-aged child who constantly engages in handwriting tasks within the classroom environment and provides insight into possible directions for future intervention.

Automatic Analysis of Archimedes' Spiral for Characterization of Genetic Essential Tremor Based on Shannon's Entropy and Fractal Dimension

Among neural disorders related to movement, essential tremor has the highest prevalence; in fact, it is twenty times more common than Parkinson's disease. The drawing of the Archimedes' spiral is the gold standard test to distinguish between both pathologies. The aim of this paper is to select non-linear biomarkers based on the analysis of digital drawings. It belongs to a larger cross study for early diagnosis of essential tremor that also includes genetic information. The proposed automatic analysis system consists in a hybrid solution: Machine Learning paradigms and automatic selection of features based on statistical tests using medical criteria. Moreover, the selected biomarkers comprise not only commonly used linear features (static and dynamic), but also other non-linear ones: Shannon entropy and Fractal Dimension. The results are hopeful, and the developed tool can easily be adapted to users; and taking into account social and economic points of view, it could be very helpful in real complex environments.

Handwriting in children with ADHD

OBJECTIVE

Children with ADHD-combined type (ADHD-CT) display fine and gross motor problems, often expressed as handwriting difficulties. This study aimed to kinematically characterize the handwriting of children with ADHD using a cursive letter l's task.

METHOD

In all, 28 boys (7-12 years), 14 ADHD-CT and 14 typically developing (TD), without developmental coordination disorder (DCD) or comorbid autism, wrote a series of four cursive letter l's using a graphics tablet and stylus.

RESULTS

Children with ADHD-CT had more inconsistent writing size than did TD controls. In addition, ADHD-CT symptom severity, specifically inattention, predicted poorer handwriting outcomes.

CONCLUSION

In a sample of children with ADHD-CT who do not have DCD or autism, subtle handwriting differences were evident. It was concluded that handwriting might be impaired in children with ADHD in a manner dependent on symptom severity. This may reflect reports of underlying motor impairment in ADHD.

Signal-to-noise velocity peaks difference: a new method for evaluating the handwriting movement fluency in children with dysgraphia

This study evaluated handwriting movement dysfluency related to dysgraphia. A new variable, the Signal-to-Noise velocity peaks difference (SNvpd), was proposed to describe abnormal velocity fluctuations in cursive handwriting. This variable was compared to two variables most frequently used variables for assessing handwriting fluency. This comparison was carried out for three different groups, children with dysgraphia, proficient children, and adults, all of whom wrote the same single word. The adults were taken as the reference. Results revealed that, of the three variables studied, the SNvpd proved most efficient in discriminating children with dysgraphia, and that furthermore, it had the significant advantage of facilitating the localization of dysfluency peaks within a word. Our results also showed that the movement dysfluency of children with dysgraphia was specific to certain letters. In light of these results, we discuss the methodological and theoretical relevance of this new variable to the analysis of handwriting movement with the aim of characterizing dysgraphia.

Reprint of 'Development, maturation and learning influence on handwriting kinematics'

Handwriting is the result of a process in which linguistic, psychomotor and biomechanical factors interact with physical maturation, cognitive development and learning. Digital tablets, which record the writing in real time, allow a kinematic analysis of written trace: the implemented algorithms analyze parameters as length, duration and speed of the components (trace between two pen-lifts) and strokes (trace between two minima of curvilinear velocity). The purpose of this work is to fill, at least for Italy, the lack of normative data on typical handwriting processes. This cross-sectional study will present data on 218 right-handed and Italian mother-tongue students, attending classes from 2nd to 8th grade. They performed specific tasks (tests of writing speed; transcription of a sentence accurately vs. speedily) by a digital tablet. The analysis showed many changes of the considered parameters across the classes, as in the horizontal, curvilinear mean and peak velocities of components and strokes, with higher values in the last years of schooling and a parallel decrease in the number of strokes/letter (improvement of automation). In conclusion, some of these parameters are useful for studying development and learning of writing and their values can be used as references to evaluate samples with different characteristics.

Understanding macrographia in children with autism spectrum disorders

It has been consistently reported that children with autism spectrum disorders (ASD) show considerable handwriting difficulties, specifically relating to accurate and consistent letter formation, and maintaining appropriate letter size. The aim of this study was to investigate the underlying factors that contribute to these difficulties, specifically relating to motor control. We examined the integrity of fundamental handwriting movements and contributions of neuromotor noise in 26 children with ASD aged 8-13 years (IQ>75), and 17 typically developing controls. Children wrote a series of four cursive letter l's using a graphics tablet and stylus. Children with ASD had significantly larger stroke height and width, more variable movement trajectory, and higher movement velocities. The absolute level of neuromotor noise in the velocity profiles, as measured by power spectral density analysis, was significantly higher in children with ASD; relatively higher neuromotor noise was found in bands >3 Hz. Our findings suggest that significant instability of fundamental handwriting movements, in combination with atypical biomechanical strategies, contribute to larger and less consistent handwriting in children with ASD.

Neurocognitive and mood effects of alcohol in a naturalistic setting

OBJECTIVE

The current pilot study aimed to assess the effects of drinking alcohol in a naturalistic setting on aspects of performance.

METHODS

Thirty individuals were approached and tested individually in a university campus bar. They provided details regarding alcoholic drinks consumption. Each was breathalysed before and after completion of a computerised test battery administered on a handheld device. The battery consisted of visual analogue mood scales, a series of alcohol-sensitive psychomotor and cognitive tests.

RESULTS

There were highly significant correlations between measured blood alcohol concentrations, estimated units of alcohol consumed and scores on a 'sober-drunk' VAS (p < 0.001 in all cases). For performance, there was a characteristic alcohol-associated shift in the speed/accuracy trade-off (SATO), which was reflected as significantly more errors with less effect on speed across several measures (including maze performance and Serial Sevens). Individuals who were more intoxicated were also significantly less alert.

CONCLUSIONS

The data suggest that controlled laboratory tests into the effects of alcohol intoxication may have ecological validity, with SATO shifts amongst the characteristic impairments seen in both controlled and naturalistic settings.