-
Zoology (Jena, Germany) Jun 2020This study considered possible sexual dimorphism in the relative lengths of the second, third and fourth digits (digit ratio), in calves. Furthermore, a different length...
This study considered possible sexual dimorphism in the relative lengths of the second, third and fourth digits (digit ratio), in calves. Furthermore, a different length of the bone structures of the third (3D) and of the fourth (4D) digits has been examined as an evolutionary adaptation to locomotion on soft ground. The length of the digital bones of the right fore-limb of 33 females and 15 male calves was measured in vivo using a portable X-ray machine. The vestigial structure of the second digit (2D), and 3D and 4D, from metacarpus to the third phalanx were considered in a mixed model, as well as some ratios between 2D and different parts of 3D or 4D (2D:3D and 2D:4D). A covariate for the mean finger length was considered for digit ratios to control for possible biases due to shape allometry. Shorter first phalanx and trotter were found in 3D than in 4D, and the reverse for the third phalanx. The 2D was significantly shorter in females, as well as the second phalanges of 3D and 4D. Significant sex differences in 2D:3D and 2D:4D were found for some digit parts of 3D and 4D and for the first phalanges of 3D:4D. These ratios were always shorter in females, in contrast to that found in most mammals. The asymmetry between 3D and 4D could mean a functional adaptation for locomotion. Sex differences in 2D:4D and 3D:4D were found, but with a reverse pattern than in most mammal species (males > females rather than males < females). In this regard digit ratio in calves was similar to that of Old World monkeys. This study is the first investigation of digit ratio in Ungulates, whose limbs differ from the limbs of most mammals, maintaining five digits. The reverse pattern of sex differences (digit ratios: males> females) could be due to the peculiar nature of the vestigial dewclaw of 2D and to the hormone patterns acting on this digit during development, but further research is required around this topic.
Topics: Animals; Bone Development; Bone and Bones; Cattle; Female; Forelimb; Male; Sex Characteristics; Toes
PubMed: 32248058
DOI: 10.1016/j.zool.2020.125777 -
Cognition Nov 2020Converting a multi-digit number to quantity requires processing not only the digits but also the number's decimal structure, thus raising several issues. First, are all...
Converting a multi-digit number to quantity requires processing not only the digits but also the number's decimal structure, thus raising several issues. First, are all the digits processed in parallel, or serially from left to right? Second, given that the same digit at different places can represent different quantities (e.g., "2" can mean 2, 20, etc.), how is each digit assigned to its correct decimal role? We presented participants with two-digit numbers and asked them to point at the corresponding locations on a number line, while we recorded their pointing trajectory. Crucially, on some trials, the decade and unit digits did not appear simultaneously. When the decade digit was delayed, the decade effect on finger movement was delayed by the same amount. However, a lag in presenting the unit digit delayed the unit effect by 35 ms less than the lag duration, a pattern reminiscent of the psychological refractory period, indicating an idle time window of 35 ms in the units processing pathway. When a lag transiently caused a display of just one digit on screen, the unit effect increased and the decade effect decreased, suggesting errors in binding digits to decimal roles. We propose that a serial bottleneck is imposed by the creation of a syntactic frame for the multidigit number, a process launched by the leftmost digit. All other stages, including the binding of digits to decimal roles, quantification, and merging them into a whole-number quantity, appear to operate in parallel across digits, suggesting a remarkable degree of parallelism in expert readers.
Topics: Fingers; Language; Movement; Refractory Period, Psychological; Time Perception
PubMed: 32645520
DOI: 10.1016/j.cognition.2020.104387 -
Cognition May 2020Such is the consistency by which performance on measures of short-term memory (STM) increase with age that developmental increases in STM capacity are largely accepted...
Such is the consistency by which performance on measures of short-term memory (STM) increase with age that developmental increases in STM capacity are largely accepted as fact. However, our analysis of a robust but almost ignored finding - that span for digit sequences (the traditional measure of STM) increases at a far greater rate than span for other verbal material - fundamentally undermines the assumption that increased performance in STM tasks is underpinned by developmental increases in capacity. We show that this digit superiority with age effect is explained by the relatively greater linguistic exposure to random sequences of digits versus other stimuli such as words. A simple associative learning process that learns incrementally from exposure to language accounts for the effect, without any need to invoke an STM mechanism, much less one that increases in capacity with age. By extension, using corpus data directed at 2-3 year old children, 4-6 year old children, and adults, we show that age-related performance increases with other types of verbal material are equally driven by the same basic associative learning process operating on the expanding exposure to language experienced by the child. Our results question the idea that tests such as digit span are measuring a dedicated system for the temporary maintenance and manipulation of verbal material, and as such have implications for our understanding of those aspects of typical and atypical development that are usually accounted for with respect to the operation of such a system.
Topics: Adult; Child; Child, Preschool; Humans; Language; Learning; Memory, Short-Term
PubMed: 32004933
DOI: 10.1016/j.cognition.2020.104200 -
Cortex; a Journal Devoted To the Study... Jan 2021The visual analysis of letter strings and digit strings is done by two separate cognitive processes. Recent studies have hypothesized that these processes are not only...
The visual analysis of letter strings and digit strings is done by two separate cognitive processes. Recent studies have hypothesized that these processes are not only separate but also qualitatively different, in that they may encode information specific to numbers or to words. To examine this hypothesis and to shed further light on the visual analysis of numbers, we asked adults to read aloud multi-digit strings presented to them for brief durations. Their performance was better in digits on the number's left side than in digits farther to the right, with better performance in the two outer digits than their neighbors. This indicates the digits were processed serially, from left to right. Visual similarity of digits increased the likelihood of errors, and when a digit migrated to an incorrect position, it was most often to an adjacent location. Interestingly, the positions of 0 and 1 were encoded better than the positions of 2-9, and 2-9 were identified better when they were next to 0 or 1. To accommodate these findings, we propose a detailed model for the visual analysis of digit strings. The model assumes imperfect digit detectors in which a digit's visual information leaks to adjacent locations, and a compensation mechanism that inhibits this leakage. Crucially, the compensating inhibition is stronger for 0 and 1 than for the digits 2-9, presumably because of the importance of 0 and 1 in the number system. This sensitivity to 0 and 1 makes the visual analyzer specifically adapted to numbers, not words, and may be one of the brain's reasons to implement the visual analysis of numbers and words in two separate cognitive processes.
Topics: Adaptation, Physiological; Adult; Humans; Inhibition, Psychological; Pattern Recognition, Visual; Probability; Reading
PubMed: 33279810
DOI: 10.1016/j.cortex.2020.10.012 -
Journal of the American Veterinary... Nov 2021To describe clinical findings, treatments, and outcomes for cattle with complete traumatic exungulation.
OBJECTIVE
To describe clinical findings, treatments, and outcomes for cattle with complete traumatic exungulation.
ANIMALS
10 bovines.
PROCEDURES
Record databases of 2 teaching hospitals were searched to identify cattle treated for traumatic exungulation between January 1993 and December 2018. Information about signalment, clinical signs and findings, treatment, and outcome was extracted from the records or obtained by telephone communication with the owner.
RESULTS
Records for 5 bulls, 4 heifers, and 1 cow with a median age of 2 years (range, 1 day to 10 years) and weight of 379.1 kg (range, 30 to 909.1 kg) were reviewed. Duration of clinical signs ranged from ≤ 24 hours to 3.5 days. Five of 7 animals had a lameness score > 3/5. Complete exungulation occurred in 6 medial digits (3 hind limbs and 3 forelimbs) and 5 lateral digits (1 hind limb and 4 forelimbs); 1 calf had complete exungulation of both digits of a forelimb. Treatments included bandaging (n = 9), antimicrobials (9), anti-inflammatories (8), hoof block application to the adjacent digit (7), regional anesthesia (6), cast application (4), curettage of the third phalanx (3), regional antimicrobial perfusion (1), and local application of antimicrobial-impregnated beads (1). All 7 cattle with long-term (≥ 9 months) information available returned to their intended function; 6 had no residual lameness, and 3 required regular corrective trimming of the affected digit.
CONCLUSIONS AND CLINICAL RELEVANCE
Results suggested the prognosis for long-term survival and return to intended function is fair to good for cattle with complete exungulation.
Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Female; Forelimb; Gait; Hindlimb; Hoof and Claw; Lameness, Animal; Male
PubMed: 34757941
DOI: 10.2460/javma.21.06.0300 -
Plastic Surgery (Oakville, Ont.) Aug 2023Grip strength (GS) of the human hand is vital to deal with objects of various sizes and shapes in daily life. The strength deteriorates if one or more digits of the hand...
Grip strength (GS) of the human hand is vital to deal with objects of various sizes and shapes in daily life. The strength deteriorates if one or more digits of the hand are amputated. The main aim of this study was to determine the influence of single-digit exclusions on the GS. Healthy adults ( = 102, male) with an age range of 20 to 70 years (mean ± SD, 31.92 ± 13.14 years) participated in the study. The movements of unused digits were restrained using splints to avoid digit enslaving effects. T (Thumb), (I) Index, M (Middle), R (Ring), L (Little) digits were chosen for exclusion based on the digit configurations. The digit configurations were IMRL, MRLT, IMRT IRLT and, IMLT with exclusions T, I, L, M, and, R respectively. The results of two-way ANOVA with repeated measures showed no significant interaction ( = 0.923) between hand dominance and digit configurations. But statistical significance ( = 0.000) was observed in digit configurations and hand dominance individually. The results of posthoc analysis using Bonferroni corrected pairwise comparisons showed no statistical significance ( = 0.004) between IRLT and IMLT of both hands since the corrected -value was 0.003. The outcomes of the -test showed no statistical significance ( > 0.05) between the digit configurations IMRLT, IMRL; IMRL, MRLT; MRLT, IMRT; IRLT, IMLT individually within dominant (D) and non-dominant (ND) hands. When the -test was performed using the same digit configurations between both hands, statistical significance was not observed in all the configurations except IMLT ( < 0.05). The results of the Pearson correlation of GS were observed to be very strong between the same digit configurations of D and ND hands.
PubMed: 37654540
DOI: 10.1177/22925503211055523 -
Hand (New York, N.Y.) Jun 2023Digit amputations are relatively simple and are often performed in the setting of trauma or infection. However, it is not uncommon for digit amputations to undergo...
BACKGROUND
Digit amputations are relatively simple and are often performed in the setting of trauma or infection. However, it is not uncommon for digit amputations to undergo secondary revision due to complications or patient dissatisfaction. Identifying factors associated with secondary revision may alter treatment strategy. We hypothesize that the secondary revision rate is affected by digit, initial level of amputation, and comorbidities.
METHODS
A retrospective chart review was conducted on patients undergoing digit amputations in operating rooms at our institution from 2011 to 2017. Secondary revision amputations were defined as a separate return to the operating room following initial surgical amputation, excluding emergency room amputations. Patient demographics, comorbidities, level of amputation, and complications were collected.
RESULTS
In all, 278 patients were included with a total of 386 digit amputations and mean follow-up of 2.6 months. Three hundred twenty-six primary digit amputations were performed in 236 patients (group A). Sixty digits were secondarily revised in 42 patients (group B). The secondary revision rate was 17.8% for patients and 15.5% for digits. Patients with heart disease and diabetes mellitus were associated with secondary revision, with wound complications being the leading indication overall (73.8%). Medicare covered 52.4% of patients in group B versus 30.1% in group A ( = .005).
CONCLUSION
Risk factors for secondary revision include Medicare insurance, comorbidities, previous digit amputations, and initial amputation of either the index finger or the distal phalanx. These data may serve as a prediction model to aid surgical decision-making by identifying patients at risk of secondary revision amputation.
PubMed: 37269233
DOI: 10.1177/15589447231174480 -
Hand Clinics May 2019A dysvascular digit is defined as a threatened circulatory condition of a digit caused owing to multiple reasons, such as medical illness or trauma. A dysvascular digit... (Review)
Review
A dysvascular digit is defined as a threatened circulatory condition of a digit caused owing to multiple reasons, such as medical illness or trauma. A dysvascular digit always needs surgical manipulation of the vessel in trauma cases. The revascularization of the digit is a priority in such conditions, after which reconstruction of the defect is performed. In this article, the authors present and discuss the venous free flap, thenar free flap, toe plantar free flap, free style perforator flap, hypothenar free flap, and anconeus muscle free flap.
Topics: Amputation, Traumatic; Anastomosis, Surgical; Finger Injuries; Fingers; Humans; Radial Artery; Replantation; Surgical Flaps; Toes; Vascular Patency
PubMed: 30928050
DOI: 10.1016/j.hcl.2019.01.001 -
Cerebral Cortex (New York, N.Y. : 1991) Aug 2022Previous studies aimed to unravel a digit-specific somatotopy in the primary sensorimotor (SM1) cortex. However, it remains unknown whether digit somatotopy is...
Previous studies aimed to unravel a digit-specific somatotopy in the primary sensorimotor (SM1) cortex. However, it remains unknown whether digit somatotopy is associated with motor preparation and/or motor execution during different types of tasks. We adopted multivariate representational similarity analysis to explore digit activation patterns in response to a finger tapping task (FTT). Sixteen healthy young adults underwent magnetic resonance imaging, and additionally performed an out-of-scanner choice reaction time task (CRTT) to assess digit selection performance. During both the FTT and CRTT, force data of all digits were acquired using force transducers. This allowed us to assess execution-related interference (i.e., digit enslavement; obtained from FTT & CRTT), as well as planning-related interference (i.e., digit selection deficit; obtained from CRTT) and determine their correlation with digit representational similarity scores of SM1. Findings revealed that digit enslavement during FTT was associated with contralateral SM1 representational similarity scores. During the CRTT, digit enslavement of both hands was also associated with representational similarity scores of the contralateral SM1. In addition, right hand digit selection performance was associated with representational similarity scores of left S1. In conclusion, we demonstrate a cortical origin of digit enslavement, and uniquely reveal that digit selection is associated with digit representations in primary somatosensory cortex (S1). Significance statement In current systems neuroscience, it is of critical importance to understand the relationship between brain function and behavioral outcome. With the present work, we contribute significantly to this understanding by uniquely assessing how digit representations in the sensorimotor cortex are associated with planning- and execution-related digit interference during a continuous finger tapping and a choice reaction time task. We observe that digit enslavement (i.e., execution-related interference) finds its origin in contralateral digit representations of SM1, and that deficits in digit selection (i.e., planning-related interference) in the right hand during a choice reaction time task are associated with more overlapping digit representations in left S1. This knowledge sheds new light on the functional contribution of the sensorimotor cortex to everyday motor skills.
Topics: Brain Mapping; Fingers; Humans; Magnetic Resonance Imaging; Reaction Time; Sensorimotor Cortex; Somatosensory Cortex; Young Adult
PubMed: 35029640
DOI: 10.1093/cercor/bhab452