The effects of skill demands and object position on the distribution of preferred hand reaches

Performance-based measures of hand preference have been developed as an objective method of examining handedness. Previous research using this method showed that both skill demands and the position of the object in working space affect preferential hand reaching. Specifically, preferred hand reaches predominated in left hemispace, in spite of the biomechanical inefficiency involved in reaching across the body midline. This was mediated by the skill demands, with a higher frequency of preferred hand reaches for tasks requiring more skill. To further examine this issue, we increased the task skill demands. Twenty-two right-handed adults reached for five tools located in an array of five positions in front of them. Participants were required to pick up the tool, pick up and demonstrate how to use it, or pick up and actually use the tool on the materials provided. The results showed that the frequency of right hand reaches was greatest for the tool use condition. This effect was mediated by the position of the object in hemispace, with more right hand reaches occurring for the Use task in left hemispace than the other tasks, in support of our previous work.     

Preference and performance measures of handedness

Handedness cannot be predicted using a single performance measure, and preference measures of handedness are unreliable because of their subjectivity. This report was designed to examine the relationship between hand performance and hand preference using six different measures: the Waterloo Handedness Questionnaire (a measure of hand preference), the Wathand Box (a performance-based indicator of hand preference), two pegboard tasks, finger tapping, and grip strength and to determine the most accurate performance-based predictor of hand preference as measured by the Waterloo Handedness Questionnaire. Multiple linear regression analysis showed that together, the Wathand Box score and the lateralized place phase of the grooved pegboard task were the most accurate predictors of hand preference.     

A developmental analysis of the relationship between hand preference and performance: I. Preferential reaching into hemispace

The present study describes a developmental performance measure of hand preference that considers task complexity and position in hemispace. Eighty right-handed children and adults (ages 3-4, 6-7, 9-10, 18-24) were observed for hand selection responses to 2 unimanual tasks (simple vs complex) across positions in hemispace. Results revealed an age-related trend in the tendency to use the preferred hand in right and left hemispace. While the adult's and 3- to 4-year-old's preferred hand use decreased as they moved into left hemispace, children between the ages of 6 and 10 years tended to use their preferred hands consistently throughout both regions of hemispace. The relationship between hand preference and skilled, cost-efficient performance throughout development are discussed.     

Cultural Difference in Hand Preference: Evidence from India and Japan

Indian (N = 400) and Japanese (N = 502) adult subjects were examined for their hand preference on a 7-point scale (1 = left always, 7 = right always) of the 32-item Waterloo Handedness Questionnaire (Steenhuis & Bryden, 1989). Factor analyses of the data yielded a two-factorial structure of hand preference: skilled and unskilled. Interaction of Culture × Hand preference indicated that Indians had more right-hand preference for unskilled activities whereas Japanese subjects had more right-hand preference for skilled activities. Further analyses revealed that the frequency of middle category responses was more common in Japanese subjects. Indian subjects were found to give more extreme responses for either right- or left-hand preference. Findings are discussed in the light of cultural training given to the individuals in these two societies, which are essentially collective in nature.     

Which factors affect hand selection in children's grasping in hemispace? Combined effects of task demand and motor dominance

Sixty-five right- and left-handed preschool and school children were tested on three reach-to-grasp tasks of different levels of complexity, performed in three space locations. Our goal was to evaluate how the effect of attentional information related to object location interacts with task complexity and degree of handedness on children's hand selection. Results revealed a shift to the non-preferred hand in the contralateral hemispace, which was more or less pronounced according to the level of task complexity. The subject's degree of handedness also influenced this shift, since strongly lateralized children exhibited a greater use of their preferred hand than less lateralized ones for actions in the contralateral hemispace. These findings confirm that hand selection is to some extent adaptable to task demand and environmental context.     

Handedness and footedness in Korean college students

This study was conducted to obtain normative data on foot preference and to compare footedness and handedness in a large sample (N = 866) of college students in Korea, where left-hand use for writing and other public acts is severely restricted (Kang & Harris, 1993). Based on scores from Korean-language versions of the Edinburgh Handedness Inventory (EHI; Oldfield, 1971) and the Waterloo Footedness Questionnaire Revised (WFQ-R; Elias, Bryden, & Bulman-Fleming, 1988), 11% of the subjects were left-footed but only 4.2% as left-handed. A significantly higher percentage of left-handers than right-handers showed crossed lateral preference, that is, for preference of the opposite-side foot. Of the left-handers with crossed preference, the majority were inconsistent left-handers (ILH; Peters & Servos, 1989), whereas most of those with uncrossed preference were consistent left-handers (CLH). Factor analysis of the EHI and WFQ-R revealed 2 handedness factors and 2 footedness factors. The footedness factors for skilled unipedal actions and for balancing-stabilizing varied in direction, strength, and relation to handedness in mixed-footers and left-handers, consistent with the possibility that the division of footedness into these categories might be neuropsychologically meaningful.     

The performance of left-handed participants on a preferential reaching test

Previous research in our laboratory has examined the distribution of preferred hand (PH) reaches in working space with right-handed participants. In one study, we examined the effects of tool position and task demands on the frequency of PH reaches with right-handers (Mamolo, Roy, Bryden, & Rohr, 2004). We found that PH reaches were at a maximum within ipsilateral space, and predominated within contralateral space. This was mediated by the task demands, as shown by an increased frequency of PH reaches for the more skill demanding tasks. In the current study, we tested left-handed participants on the same procedure. Five different tools were placed in an array in front of the participant, who was required to reach for, and perform one of three tasks with the tool: Lift the tool; lift and Pantomime its use; or lift and Use the tool on its corresponding object. The results showed that PH reaches were at a maximum within ipsilateral space for all three tasks. Significantly fewer PH reaches were made for tools in contralateral space. In particular, almost no PH reaches were made for the Lift task at the most extreme contralateral position. This indicates the willingness of left-handers to use their non-preferred (i.e., right) hand. One possible explanation supported by these results is that left-handers have adapted to an environment designed for right-handers.     

Development of handedness: comparison of questionnaire and performance-based measures of preference

Hand preference has been assessed primarily using questionnaires. This approach is difficult to use with children so researchers have frequently used observation of hand choice when children pick up and use tools. Recently we developed such a performance-based measure, the WatHand Box Test (WBT). Participants ranging in age from 2 to 24 years each completed the WBT and the Revised Waterloo Handedness Questionnaire. Analyses revealed a strong preference for the right hand across all age groups on both tests with no significant differences across age and a significant correlation between the two measures. These findings do not concur with other work showing children younger than six years exhibited a much smaller right-hand preference. The concordance between these two preference measures is consistent with our previous findings. However, the relatively small common variance explained in this relationship suggests that these two tests may reflect somewhat different components of preference.     

Hand preference in simultaneous unimanual tasks: a preliminary examination

The aim of the current investigation was to determine the pattern of hand use during simultaneous unimanual tasks. Two studies were conducted. The first experiment examined the pattern of hand use in a catching task, while performing a secondary writing task. Results showed that individuals had a decreased tendency to catch with their preferred hand when their preferred hand was occupied, in comparison to when the preferred hand was unoccupied. The second experiment examined the pattern of hand use during a support and reach task, where the use of both hands was required. Here, results indicated that participants preferred to support themselves with their nonpreferred hand and reach with preferred hand toward right hemispace. With respect to left hemispace, participants showed the reverse pattern. This pattern of hand use indicates an important role for the nonpreferred hand, which has been relatively unexplored by researchers.     

Cross-modal correlation of auditory and visual language laterality tasks: a serendipitous finding

Two experiments were conducted to investigate whether auditory and visual language laterality tasks test the same brain processes for verbal functions. In the first experiment, 48 undergraduate students (24 males, 24 females) completed both an auditory monitoring task and a visual monitoring task, with the Waterloo Handedness Questionnaire administered between the two tasks. The visual task was an analogue of the dichotic listening task used. It was hypothesized that a significant cross-modal correlation would be found, indicating that the dichotic listening task and the visual analogue task do, in fact, test the same brain processes for verbal functions. Results revealed a right ear advantage in the auditory task, a left visual field advantage (LVFA) in the visual task, and a cross-modal correlation of asymmetries of -.09. The LVFA observed in the visual task was replicated in Experiment 2, thus establishing its legitimacy. Results are discussed in relation with the type of processing that might produce such an unexpected finding on the visual task.     

Hand preference and its flexibility according to the position of the object: a study in cercopithecines examining spontaneous behaviour and an experimental task (the Bishop QHP task)

The extant literature on manual laterality in non-human primates is inconclusive, plagued by inconsistent or contradictory findings and by disturbing methodological issues (e.g. uncontrolled influential factors, comparability issues). The present study examined hand preference and its flexibility in 15 red-capped mangabeys (C. t. torquatus) and 13 Campbell's monkeys (C. c. campbelli), two species that differ in their degree of arboreality. We investigated the influence of the spatial position of the object on hand preference for reaching. We considered spontaneous behaviour (reaching for food during daily feeding) and an experimental task: the QHP task. The QHP is a task that is used in humans. This is a simple reaching task that involves high spatial constraints on hand use. In our study, the subject had to reach for items that were placed on a semi-circle in front of it on five positions, including in the centre position, in the ipsilateral space and in the contralateral space. We assessed hand preference for reaching in front (baseline condition), and we examined how this preference changed when reaching in lateral positions. For reaching in front, about half of the subjects were lateralized and no group-level bias occurred, for both spontaneous and experimental conditions. When considering reaching in the lateral positions, we observed that the position of the object influenced hand use: individuals used the hand that was closest to the object. The results are discussed in relation to previous findings in humans and in non-human primates and regarding theories on handedness and flexibility of hand preference.     

Unimanual performance across the age span

The purpose of the current investigation was to examine the age-related changes in the performance of the two hands on the Annett pegboard (Annett, 1970). The current study was part of a large-scale study investigating the development of unimanual and bimanual performance. Three hundred and two right-handed individuals participated in the present study, comprising five different age groups (3-5 year olds, 6 and 7 year olds, 8 and 9 year olds, 10-12 year olds, and 19-24 year olds). All participants completed the Waterloo Handedness Questionnaire and the standard Annett pegboard. Analyses revealed significant overall performance differences between the hands, as expected, where the right hand was significantly faster than the left hand. Additionally, significant performance differences between the hands were noted as a function of age. More specifically, the adults showed a much smaller performance difference between the hands than the other age groups. The results are discussed in light of current theories of the development of hand preference and manual asymmetry.     

利手与内隐左右空间情感效价关系的眼动研究

为探明手动作流畅性和情感材料呈现空间在不同利手者左右空间情感偏好中的关系,本研究将情绪Stroop范式和眼动测量相结合,通过反应速度和眼动数据将动作流畅性和空间情感注意偏向相分离,并考察其交互作用。结果发现右利手个体的反应速度存在优势手效应,不同利手者在使用左手时表现出对优势手同侧空间的内隐情感偏好,表明右利手个体的反应速度存在优势手流畅性的主导作用,手动作流畅性和内隐空间情感偏好的作用可以分离。     

Hemispace and information control by the two cerebral hemispheres: which interaction?

Two experiments employing subjects with different experience in tactile discrimination (blind and seeing subjects) were carried out to investigate the effect of the space location of stimuli on the information processing activity of the two cerebral hemispheres. An angle discrimination task that yields a right hemisphere superiority was used. In Experiment 1, seeing subjects showed a general superiority of the left hand (right hemisphere) which was more pronounced in the left hemispace with respect to the central and the right hemispace performance. In Experiment 2, blind subjects showed a significant superiority of the left hand in the central and in the left hemispace and no difference between the two hands in the right hemispace. In both experiments hemispace differences were due only to the modification of the left hand (right hemisphere) performance. These results suggest that the hemispace control by the contralateral hemisphere interacts only with the activity of the hemisphere dominant in the information processing.     

The use of bouts and frequencies in the evaluation of hand preferences for a coordinated bimanual task in chimpanzees (Pan troglodytes): an empirical study comparing two different indices of laterality

Hand preferences for a coordinated bimanual task were assessed in 109 chimpanzees (Pan troglodytes). Hand preference was evaluated for 4 test sessions using bouts and frequencies of hand use to compare the sensitivity of each level of analysis in evaluating individual variation in handedness. Overall, significant population-level right-handedness was found using several different measures of hand use. Handedness indices based on bouts and frequencies were highly and significantly correlated. Moreover, hand preferences were consistent across tests despite efforts to situationally bias preference during each test. Taken together, these data do not support the view that bouts are a better level of analysis for evaluating hand preference. The results further suggest that hand preferences for coordinated bimanual actions are not influenced by situational factors and may reflect an inherent specialization of the left hemisphere for motor skill.     

Intermanual differences on neuropsychological motor tasks in a Japanese university student sample

We explored the intermanual difference scores of 128 Japanese university students for five typical neuropsychological motor tasks (grip strength, finger tapping, two versions of the grooved pegboard, and the dot‐filling test) and examined the relation between hand preference and intermanual difference in motor proficiency. Using the Edinburgh Handedness Inventory, 18 and 110 participants were identified as left‐ and right‐handed, respectively. Although the right hand performed better than the left for right‐handed participants, and vice versa, in all five tasks, the degree of intermanual difference varied between tasks. A discriminant function analysis using the laterality quotients of the five motor tasks as independent variables indicated that hand preference was predictable from the task performances with an accuracy of 90% or more. The dot‐filling test and finger tapping had stronger canonical loadings than the other tasks.     

A developmental analysis of the relationship between hand preference and performance: II. A performance-based method of measuring hand preference in children

The present study describes a performance-based method of measuring hand preference in children. Three aspects of handedness were considered to be important in developing the paradigm (a) overall hand preference across a number of tasks, (b) consistency of hand use and, (c) the use of the preferred hand in a bimanual task. The new paradigm, termed the WatHand Box Test (WBT), requires participants to perform a variety of unimanual tasks such as, using a hammer, tossing a ball, and opening a lock with a key. To determine the validity of the WBT and examine the developmental trends in hand preference, eighty right-handed children and adults (ages 3-4, 6-7, 9-10, and 18-24 years) performed the WBT. First, the WBT was found to correlate significantly with scores on a standard hand preference questionnaire for the adults. As well, significant developmental trends were noted in hand preference as measured by the WBT. Most specifically, three- and four-year-olds had significantly lower scores on the WBT indicating a less stable pattern of hand preference than in the other three age groups.     

Control of Integrated Task Sequences Shapes Components of Reaching

Reaching toward an object usually consists of a sequence of elemental actions. Using a reaching task sequence, the authors investigated how task elements of that sequence affected feedforward and feedback components of the reaching phase of the movement. Nine right-handed adults performed, with their dominant and nondominant hands, 4 tasks of different complexities: a simple reaching task; a reach-to-grasp task; a reach-to-grasp and lift object task; and a reach-to-grasp, lift, and place object task. Results showed that in the reach-to-grasp and lift object task more time was allocated to the feedforward component of the reach phase, while latency between the task elements decreased. We also found between-hand differences, supporting previous findings of increased efficiency of processing planning-related information in the preferred hand. The presence of task-related modifications supports the concept of contextual effects when planning a movement.     

Bimanual handedness in adults who stutter

25 adult stutterers and 29 nonstutterers who were right-handed as defined by a positive Laterality Quotient on the Edinburgh Handedness Inventory were compared with respect to their pattern of hand use in performing seven common tasks that involve bimanual cooperation. Among the stutterers was a higher proportion of participants who showed anomalies in how they carried out the two tasks that required synchronous manipulation by the two hands. On two other tasks that required speeded performance, the groups were similar in dealing playing cards with the right or left hands, but the stutterers were slower than nonstutterers and did not show a right-hand advantage on a task requiring removal of a nut from a bolt. The results were interpreted as indicating difficulty by stutterers in carrying out synchronously different response elements of motoric tasks.     

Imagined and actual limb selection: a test of preference

Imagined and actual motor performance were compared to determine what factor(s) drive limb selection for programming movements in contralateral hemispace. Forty right-handed blindfolded subjects were asked to 'reach' via auditory stimulus for a small object placed at multiple locations in hemispace. Two conditions were included: arms uncrossed and arms crossed. With the uncrossed condition, responses were similar. With arms crossed, subjects had the choice of keeping the limbs crossed, reacting to proximity, or uncrossing the arms to reach ipsilaterally. In this condition subjects 'imagined' that they would maintain the crossedposition and reach with the hand closest to the stimulus in both right and left hemispace. However, during 'actual' reaching, responses differed. For left-field stimuli, participants kept the arms crossed, but in response to right-field stimuli, subjects preferred to uncross the limbs in order to reach with the dominant hand. These findings suggest that while motor dominance is the primary factor in limb choice for action in ipsilateral hemispace, it appears that object proximity drives limb selection for reaching in contralateral hemispace.