Effect Of Handedness Research Articles

The effect of handedness and biological sex on fingermark ridge height and volume as examined by 3D imaging.

For decades, detectives and forensic scientists have relied on friction ridge skin comparisons to identify individuals in criminal investigations. This method involves examining (latent) fingermarks, typically captured as two-dimensional (2D) images, and comparing them with known inked impressions or scans. The comparisons focus on general patterns, the location and orientation of minutiae, and additional characteristics like scars or pores. However, this common process overlooks other potentially valuable factors, such as handedness, biological sex, and the time since deposition, which could provide crucial investigative leads, especially in cases with partial or unclear ridge patterns. This study explored the potential of three-dimensional (3D) optical profilometry (OP) to observe changes in fingermarks ridge height and volume over 7 days while considering hand dominance and biological sex. The results indicated that all the assessed 3D metrics were generally consistent in detecting the effects of sex and handedness, mostly noticeable on aged fingermarks. Specifically, females and impressions from their non-dominant hand exhibited higher values. Additionally, the influence of time was evident, with fresh fingermarks showing significantly larger ridges in terms of height and volume. These findings suggest that 3D OP can enhance the probative value of fingermarks by inferring additional characteristics such as sex, handedness, and the age of the impression. These activity-level propositions could provide useful information in cases where only partial or poor-quality fingermarks are recovered, providing new data dimensions that could lead to more comprehensive forensic examinations.

A Dual Role for the Dorsolateral Prefrontal Cortex (DLPFC) in Auditory Deviance Detection.

In the oddball paradigm, the dorsolateral prefrontal cortex (DLPFC) is often associated with active cognitive responses, such as maintaining information in working memory or adapting response strategies. While some evidence points to the DLPFC's role in passive auditory deviance perception, a detailed understanding of the spatiotemporal neurodynamics involved remains unclear. In this study, event-related optical signals (EROS) and event-related potentials (ERPs) were simultaneously recorded for the first time over the prefrontal cortex using a 64-channel electroencephalography (EEG) system, during passive auditory deviance perception in 12 right-handed young adults (7 women and 5 men). In this oddball paradigm, deviant stimuli (a 1500 Hz pure tone) elicited a negative shift in the N1 ERP component, related to mismatch negativity (MMN), and a significant positive deflection associated with the P300, compared to standard stimuli (a 1000 Hz tone). We hypothesize that the DLPFC not only participates in active tasks but also plays a critical role in processing deviant stimuli in passive conditions, shifting from pre-attentive to attentive processing. We detected enhanced neural activity in the left middle frontal gyrus (MFG), at the same timing of the MMN component, followed by later activation at the timing of the P3a ERP component in the right MFG. Understanding these dynamics will provide deeper insights into the DLPFC's role in evaluating the novelty or unexpectedness of the deviant stimulus, updating its cognitive value, and adjusting future predictions accordingly. However, the small number of subjects could limit the generalizability of the observations, in particular with respect to the effect of handedness, and additional studies with larger and more diverse samples are necessary to validate our conclusions.

Adult Normative Data for the Moberg Pick-Up Test in an Israeli Cohort

Abstract Date Presented 03/22/24 This study examining the effect of age, gender and handedness of 218 healthy adults, adds to the limited worldwide normative data on the Moberg Pick-Up Test, and challenges findings from previous studies regarding gender differences. Primary Author and Speaker: Tal Mazor-Karsenty Additional Authors and Speakers: Danit Langer

Do sex and handedness influence general cognition and financial capacity in patients with aMCI and healthy older adults? Emphasis on women's performance.

The effects of sex and handedness on financial capacity performance remain unexplored both in healthy older adults and in patients with amnestic mild cognitive impairment (aMCI). The aim of this study was to study the effect of the above factors (sex, handedness, and health condition), following a factorial experimental design; hence, eight groups (each with ten individuals) with similar demographic characteristics (age and education level) were formed consisting of right/left-handed, women/men and healthy/not healthy (with a diagnosis of aMCI) older adults. Mini-Mental State Examination (MMSE) was administered as a measure of general cognitive ability, and Legal Capacity for Property Law Transactions Assessment Scale (LCPLTAS) was used as an indicator of financial capacity; moreover, GDS-15 was used to assess depressive symptomatology. Self-reports of hand preference were also included. Although as expected healthy men and women regardless of their handedness outperformed aMCI patients on MMSE and LCPLTAS, performance on cash transactions, bank statement management, bill payment, financial decision making, and knowledge of personal assets from LCPLTAS is significantly higher for right-handed aMCI women compared with left-handed aMCI women. Future research should further elucidate the reasons for this left-handed female patient with aMCI profile in larger groups of patients. This is an exploratory study, and the small sample size limits the strength of conclusions; further studies on this topic are needed.

Saccade Induced Retrieval Enhancement, Handedness & the Retrieval of Central & Peripheral Details in Eyewitness Memory

Two experiments are presented that investigated the effects of horizontal saccadic eye movements and handedness on eyewitness memory for central and peripheral information. In both experiments, participants viewed a short video depicting a bank robbery and episodic memory was tested after a short delay. Experiment 1 used recognition memory and found an interaction between eye movement, handedness and type of information recalled. This indicated that eye movements enhanced memory to a greater extent for peripheral information for individuals classified as consistently handed. Experiment 2 used free-recall and found eye movement enhancement effects of similar magnitude for central and peripheral items. A similar pattern of eye movement effects was observed for both consistent and inconsistent-handed individuals. Inconsistent handers also had superior memory overall. The results are discussed in terms of theoretical accounts of eye movement effects and implications for the enhancement of eyewitness memory.

Side of chute and handedness does not affect the sensitivity of Tritrichomonas foetus sample collection in bulls

Tritrichomonas foetus, a sexually transmitted pathogen of cattle, continues to plague the cattle industry despite control efforts. Pre-analytical diagnostic considerations such as sample collection and sample handling continue to be a shortcoming in the diagnosis of T. foetus in bulls. Preputial scraping is the most common means of sample collection. Previous studies have shown an effect of handedness of the sample collector and the side of the chute that collection was made from as factors that affected the diagnostic sensitivity of the test. The aim of our study was to determine if being right or left-handed and the side of the chute the collection occurred on impacted the diagnostic sensitivity or specificity. Eleven sexually mature bulls naturally infected with T. foetus were enrolled in a 2-factor cross-over study design. Samples were taken once a week for 8 weeks by either a right-handed or left-handed veterinarian from either the left then the right side of the chute or right then left side of the chute, only using their dominant hand to make the scraping motion used to obtain the sample. Utilizing a 2-way ANOVA, we found no significant difference in the chance of acquiring a positive sample per bull (P = 0.8708) regardless of whether the sample was taken from the right or left side of the chute and regardless of dominant hand. In conclusion, using current RT-qPCR methods, the authors found no effect of handedness or side of chute on diagnostic sensitivity.
 
 
 
 
 
 
 
 
 

A Study of the Effects of Handedness on Portable Angle Grinder Risk

This study investigates the underlying cause of occupational hazards for left-handed construction workers when using portable angle grinders on construction sites. The study was conducted through a survey of 42 participants in South Korean construction companies to gather information on their tasks involving portable angle grinders. The survey covered handle preferences, grip strength assessment, and work posture observations. Furthermore, a qualitative comparison of the work risk for left-handed and right-handed construction workers using a handheld angle grinder for cutting was conducted. Results showed that the grip strength of a left-handed worker’s dominant and non-dominant hands did not significantly vary, implying that grip strength does not significantly affect their work performance. However, left-handed workers exhibited a higher likelihood of accidents due to poor work postures. Improvements to workplace safety by ensuring the use of ambidextrous tools and promoting tailored safety measures and training for left-handed workers were recommended.

No link between handedness and spatial navigation: evidence from over 400 000 participants in 41 countries.

There is an active debate concerning the association of handedness and spatial ability. Past studies used small sample sizes. Determining the effect of handedness on spatial ability requires a large, cross-cultural sample of participants and a navigation task with real-world validity. Here, we overcome these challenges via the mobile app Sea Hero Quest. We analysed the navigation performance from 422 772 participants from 41 countries and found no reliable evidence for any difference in spatial ability between left- and right-handers across all countries. A small but growing gap in performance appears for participants over 64 years old, with left-handers outperforming right-handers. Further analysis, however, suggests that this gap is most likely due to selection bias. Overall, our study clarifies the factors associated with spatial ability and shows that left-handedness is not associated with either a benefit or a deficit in spatial ability.

The effect of handedness on upper extremity isometric strength symmetry

BackgroundUnderstanding upper extremity strength symmetry can have important implications for ergonomics assessment and design. Few studies have examined isometric joint strength symmetry of left-handed individuals, or examined how handedness can influence strength. As such, the purpose of this study was to investigate the influence of handedness on dominant/non-dominant (D/ND) strength ratio in several moment directions about the shoulder, elbow, wrist, and hand. It was hypothesized that the isometric strength symmetry of left-handed individuals would be significantly different from that of right-handed individuals. MethodsThe study recruited 28 participants to perform a series of maximal voluntary isometric contractions (MVCs) with both arms for various efforts about the shoulder, elbow, and wrist, as well as handgrip for a total of 68 MVCs. Strength symmetry ratios were computed, and a two-way mixed-model ANOVA evaluated the effects of handedness and MVC test on strength symmetry. InterpretationSignificant differences in D/ND ratios between right and left-handed individuals were found for 11 of the 17 explored exertion directions. Left-handed individuals tended to possess greater strength in their non-dominant limb, while right-handed individuals tended to have greater strength in their dominant limb. Left- and right-handed individuals often significantly differed in D/ND ratio, suggesting that separate normative values should be created to account for handedness when considering return-to-work or strength-based ergonomics design criterion.

Exactly solvable complex PT symmetry potential A[sech(λx) + i tanh(λx)

We obtained the exact solutions of the PT symmetric potential V(x) = A[sech(λx) + i tanh(λx)] and found that this system has no bound-state. The PT symmetric potential was first studied in this article, and the handedness effect is shown from reflection coefficients. As the asymptotically non-vanishing imaginary potential component, when the direction of the incident wave is opposite, the transmission coefficient will emerge a complex phase factor.

Epworth sleepiness scale is associated with increased striatal dopamine uptake in Parkinson's disease: a cross-sectional study.

A cross-sectional study was designed to investigate the possible association between Epworth sleepiness scale (ESS) scores and striatal dopamine uptake in the early stages of Parkinson's disease (PD). Two groups of PD patients (n = 464) and healthy controls (HC) (n = 162) were enrolled in the current study from the Parkinson's progression markers initiative cohort ( https://www.ppmi-info.org ). All the subjects were evaluated for excessive daytime sleepiness (EDS) using the ESS. They also completed specific measures to be assessed for motor and non-motor symptoms, including cognitive, gait, autonomic, and olfactory dysfunction. Dopamine transporter (DaT) scans were used to identify dopamine transporter impairments. Spatial normalization for DaTscan imaging of participants was performed to reach consistent orientation. A significant correlation was found between ESS score and right putamen (P < 0.001; correlation coefficient = 0.186) and left putamen (P = 0.003; correlation coefficient = 0.139) dopamine uptake in PD patients. The same results were revealed after adjusted Pearson's correlation for the effects of handedness, age, gender, and education. No significant correlation was found between the ESS score and the amount of caudate nucleus dopamine uptake in PD patients. Moreover, there was a significant association between caudate nucleus dopamine uptake and ESS score in neither PD patients nor HCs. The results of our study suggest that increased dopaminergic function of putamen nuclei may be associated with ESS scores in the early stages of PD. Further studies are needed at different PD stages and evaluate PD progression as a possible confounder.

Handedness effects on imagery of dominant- versus non-dominant-hand movements: An electroencephalographic investigation.

Mental representations of our bodies are thought to influence how we interact with our surroundings. We can examine these mental representations through motor imagery, the imagination of movement using scalp EEG recordings. The visual modality of motor imagery emphasises 'seeing' the imagined movement and is associated with increased activity in the alpha rhythm (8-14 Hz) measured over the occipital regions. The kinaesthetic modality emphasises 'feeling' the movement and is associated with decreased activity in the mu rhythm (8-14 Hz) measured over the sensorimotor cortices. These two modalities can be engaged in isolation or together. We recorded EEG activity while 37 participants (17 left-hand dominant) completed an objective hand motor imagery task. Left-handers exhibited significant activity differences between occipital and motor regions only during imagery of right-hand (non-dominant-hand) movements. This difference was primarily driven by less oscillatory activity in the mu rhythm, which may reflect a shift in imagery strategy wherein participants placed more effort into generating the kinaesthetic sensations of non-dominant-hand imagery. Spatial features of 8-14 Hz activity generated from principal component analysis (PCA) provide further support for a strategy shift. Right-handers also exhibited significant differences between alpha and mu activity during imagery of non-dominant movements. However, this difference was not primarily driven by either rhythm, and no differences were observed in the group's PCA results. Together, these findings indicate that individuals imagine movement differently when it involves their dominant versus non-dominant hand, and left-handers may be more flexible in their motor imagery strategies.

Telling Your Right Hand from Your Left: The Effects of DNA Supercoil Handedness on the Actions of Type II Topoisomerases.

Type II topoisomerases are essential enzymes that modulate the topological state of DNA supercoiling in all living organisms. These enzymes alter DNA topology by performing double-stranded passage reactions on over- or underwound DNA substrates. This strand passage reaction generates a transient covalent enzyme-cleaved DNA structure known as the cleavage complex. Al-though the cleavage complex is a requisite catalytic intermediate, it is also intrinsically dangerous to genomic stability in biological systems. The potential threat of type II topoisomerase function can also vary based on the nature of the supercoiled DNA substrate. During essential processes such as DNA replication and transcription, cleavage complex formation can be inherently more dangerous on overwound versus underwound DNA substrates. As such, it is important to understand the profound effects that DNA topology can have on the cellular functions of type II topoisomerases. This review will provide a broad assessment of how human and bacterial type II topoisomerases recognize and act on their substrates of various topological states.

Effects of handedness on brain oscillatory activity during imagery and execution of upper limb movements.

Brain activation during left- and right-hand motor imagery is a popular feature used for brain-computer interfaces. However, most studies so far have only considered right-handed participants in their experiments. This study aimed to investigate how handedness influences brain activation during the processes of imagining and executing simple hand movements. EEG signals were recorded using 32 channels while participants repeatedly squeezed or imagined squeezing a ball using their left, right, or both hands. The data of 14 left-handed and 14 right-handed persons were analyzed with a focus on event-related desynchronization/synchronization patterns (ERD/S). Both handedness groups showed activation over sensorimotor areas; however, the right-handed group tended to display more bilateral patterns than the left-handed group, which is in contrast to earlier research results. Furthermore, a stronger activation during motor imagery than during motor execution could be found in both groups.

The effect of handedness on mental arithmetic: A longitudinal large-scale investigation through smart mobile devices.

The effect of handedness on mental arithmetic: A longitudinal large-scale investigation through smart mobile devices.

Handedness and Musicality in Secondary School Students

This article investigates the relationship between handedness and abilities in secondary school students, specifically analyzing the effect of handedness on subjective and objective musicality and academic performance. Previous research on the association between handedness and musicality has yielded mixed conclusions. Some studies have documented a positive correlation between musicality and non-right-handedness, but other studies have found no relationship. Here we aim to address some of this uncertainty, using a greater diversity of relevant covariates and a considerably larger sample than previous research. Our dataset of 2,902 participants (age range 10–18) comes from the LongGold project: an international longitudinal study of educational development in secondary school students. Musicality was measured through a self-report questionnaire (Gold-MSI) and perceptual tests; academic ability was determined using a Matrix Reasoning test and school grades. Using regression analyses, our main result is a lack of relationship between musicality and handedness, both for self-reported musicality and objective perceptual ability. In contrast, we found a significant association between right-handedness and higher academic ability. Our results provide a clearer perspective on the nature of handedness and its relationship to abilities, as well as highlighting changing dexterity as an area for future research.

The role of hand preference in cognition and neuropsychiatric symptoms in neurodegenerative diseases.

Handedness has been shown to be associated with genetic variation involving brain development and neuropsychiatric diseases. Whether handedness plays a role in clinical phenotypes of common neurodegenerative diseases has not been extensively studied. This study used the National Alzheimer's Coordinating Center database to examine whether self-reported handedness was associated with neuropsychological performance and neuropsychiatric symptoms in cognitively unimpaired individuals (n = 17 670), individuals with Alzheimer's disease (n = 10 709), behavioural variant frontotemporal dementia (n = 1132) or dementia with Lewy bodies (n = 637). Of the sample, 8% were left-handed, and 2% were ambidextrous. There were small differences in the handedness distributions across the cognitively unimpaired, Alzheimer's disease, behavioural variant frontotemporal dementia and dementia with Lewy bodies groups (7.2-9.5% left-handed and 0.9-2.2% ambidextrous). After adjusting for age, gender and education, we found faster performance in Trail Making Test A in cognitively unimpaired non-right-handers (ambidextrous and left-handed) compared with right-handers. Excluding ambidextrous individuals, the left-handed cognitively unimpaired individuals had faster Trail Making Test A performance and better Number Span Forward performance than right-handers. Overall, handedness had no effects on most neuropsychological tests and none on neuropsychiatric symptoms. Handedness effect on Trail Making Test A in the cognitively unimpaired is likely to stem from test artefacts rather than a robust difference in cognitive performance. In conclusion, handedness does not appear to affect neuropsychological performance or neuropsychiatric symptoms in common neurodegenerative diseases.

Effect of Handedness on Learned Controllers and Sensorimotor Noise During Trajectory-Tracking.

In human-in-the-loop control systems, operators can learn to manually control dynamic machines with either hand using a combination of reactive (feedback) and predictive (feedforward) control. This article studies the effect of handedness on learned controllers and performance during a trajectory-tracking task. In an experiment with 18 participants, subjects perform an assay of unimanual trajectory-tracking and disturbance-rejection tasks through second-order machine dynamics, first with one hand then the other. To assess how hand preference (or dominance) affects learned controllers, we extend, validate, and apply a nonparametric modeling method to estimate the concurrent feedback and feedforward controllers. We find that performance improves because feedback adapts, regardless of the hand used. We do not detect statistically significant differences in performance or learned controllers between hands. Adaptation to reject disturbances arising exogenously (i.e., applied by the experimenter) and endogenously (i.e., generated by sensorimotor noise) explains observed performance improvements.

Persistent Unilateral Force Production Deficits Following Hand Injury in Experienced Climbers: A Reliability and Retrospective Injury Study.

In climbing, research is needed to guide clinical and training advice regarding strength differences between hands. The objectives of this study were to establish test-retest reliability of a field-based apparatus measuring sport-specific unilateral isometric hand strength and to investigate whether these measures detect between-hand differences in climbers with and without a history of unilateral hand injury. A reliability and case-control injury study was carried out. Seventeen intermediate-advanced climbers without and 15 intermediate-advanced climbers with previous unilateral hand injury participated. Unilateral isometric fingertip flexor strength was assessed during maximal voluntary contraction (MVC) and peak rate of force development (RFD) tests in full-crimp overhead position. The magnitude of within-group between-hand differences was calculated using a generalized estimating equation to evaluate if prior injury was associated with lower MVC and RFD outcomes and whether hand dominance influenced the magnitude of these effects. The control group was assessed 1 wk later to determine intraclass correlation coefficients (ICCs) for all measures. The MVC (ICC 0.91-0.93) and the RFD (ICC 0.92-0.83) tests demonstrated moderate-to-high reliability. When accounting for handedness, those with prior injury showed 7% (P=0.004) reduced MVC and 13% (P=0.008) reduced RFD in the injured hand. The nondominant hand was also significantly weaker in MVC (11%, P<0.001) and RFD (12%, P=0.02) outcomes. For uninjured climbers, MVC and RFD were not significantly higher in the dominant hand (differing by 4% and 5%, respectively). Previous climbing injury was associated with persistent weakness in the injured limb and exacerbated handedness effects. Therefore, recommendations for rehabilitation should be considered.

Wrist motion is distinct between touch screen and manual or digital devices.

Restricted motion during touch screen device use may contribute to wrist overuse injuries. Wrist radioulnar deviation and extension while using touch screen devices and digital or manual counterparts in male and female medical professional dominant and non-dominant hands were quantified to test the hypothesis that mobile touch screen device use reduces wrist motion. An active motion detection system was used to record wrist motion of 12 participants while: tablet swiping and turning book pages; raising a cell and traditional phone to the ear; texting and typing; and entering numbers on a cell phone and manual calculator. Medial and lateral wrist surface range of motion (ROM) and minimum and maximum wrist radial-ulnar deviation and flexion-extension were quantified. Device, sex and handedness effects were determined (P<0.05). Maximum medial radial deviation and ROM were greater using a cell versus traditional phone. Maximum medial radial deviation was higher in the nondominant wrist during backward tablet swiping and while backward page turning versus tablet swiping. Maximum and minimum medial extension angles and ROM were greater while typing versus texting. Female nondominant hand maximum lateral extension and ROM were greater for typing versus texting and maximum medial extension and lateral extension ROM greater during manual versus cell phone calculator use with handedness combined. Maximum lateral extension and ROM were greater in females versus males using manual calculators. Sex and handedness should instruct touch screen, digital and manual device design and use for optimal performance and injury prevention.