A structural representation of the hand embedding information about the identity and relative position of fingers is necessary to counting routines. It may also support associations between numbers and allocentric spatial codes that predictably interact with other known numerical spatial representations, such as the mental number line (MNL). In this study, 48 Western participants whose typical ...

This study examined hand preference in baboons in a sample of 94 subjects for a unimanual task and in a sample of 104 subjects for a bimanual task. For the unimanual task, handedness was assessed by observing simple reaching for grains. For the bimanual task, tubes lined with peanut butter inside were presented to the baboons. The hand and the finger used to remove peanut butter were recorded. ...

Eleven right-handed subjects performed uni- and bimanual tapping tasks. Hemodynamic responses as measured with functional magnetic resonance imaging (fMRI) in the primary somato-motor cortex (SMC) showed that during bimanual activity the SMC contralateral to the hand taking the faster rate was more strongly activated than the SMC contralateral to hand taking the slower rate. There were no asymm...

Previous studies have shown that activity of neuronal populations in the primary motor cortex (MI), processed by the population vector method, faithfully predicts upcoming movements. In our previous studies we found that single neurons responded differently during movements of one arm vs. combined movements of the two arms. It was, therefore, not clear whether the population vector approach cou...

Studies of visually guided unimanual reaching have established that a saccade usually precedes each reach and that the reaction times (RTs) for the saccade and reach are highly correlated. The correlation of eye and hand RT is commonly taken as a measure of eye-hand coordination and is thought to assist visuospatial guidance of the hand. We asked what happens during a bimanual reach task. As wi...

Purpose: Poor bimanual performance is usually a major functional impairment for children with unilateral cerebral palsy (CP). This study was performed to examine the reliability and validity of Turkish version Caregiver Functional Use Survey (CFUS), which assesses manual function CP.Methods: Fifty CP their parents were included in study. The test-retest assessed using Intraclass Correlation Coe...

We have two arms, many muscles in each arm, and numerous neurons that contribute to their control. How does the brain assign responsibility to each of these potential actors? We considered a bimanual task in which people chose how much force to produce with each arm so that the sum would equal a target. We found that the dominant arm made a greater contribution, but only for specific directions...

In this study we investigated with a priming paradigm whether uni and bimanual actions presented as primes differently affected language processing. Animals' (self-moving entities) and plants' (not self-moving entities) names were used as targets. As prime we used grasping hands, presented both as static images and videos. The results showed an interference effect with unimanual action primes (...

When both hands are employed to tap in alternation, is their timing governed by a single timekeeper or oscillator, or by two slower oscillators (one for each hand) that are coupled in anti-phase? This question was addressed in two experiments by comparing unimanual and alternating bimanual synchronization with isochronous auditory sequences containing local phase perturbations. The single-oscil...