“动手不动口”：手部动作与语言进化的关系

语言进化是进化心理学研究领域的重要问题。镜像系统假说、工具制造假说与传授假说从不同角度对手部动作与语言进化间的关系进行了解释, 三种假说都认为人类语言起源于手部动作经验。相关实证研究发现：手语与口语具有一致性特征、语言与手部动作具有共同的神经基础、手势发展可以预测语言发展水平以及手势可以提高工具制造知识的传播效率, 这些研究为三种假说的具体观点提供了实证支持。未来该领域的研究需要关注手势语与口语在进化中的发展关系, 以及人类语言进化与其他认知特征的进化关系。     

Simultaneous Prompting and Instructive Feedback When Teaching Chained Tasks

This study evaluated the effectiveness of the simultaneous prompting procedure when teaching students with moderate to severe mental retardation a chained task (i.e., hand washing). This study also evaluated if students could acquire responses to instructive feedback stimuli presented during training sessions. The effectiveness of these procedures was assessed by using a multiple probe across students design. Acquisition, maintenance, and generalization data were collected and analyzed. Results indicated that the simultaneous prompting procedure was effective in teaching 3 of the 5 students to follow a 16-step task analysis to wash their hands. All students who met criterion maintained and generalized the skills with 100% accuracy. All students acquired some of the instructive feedback stimuli. Future research issues are discussed.     

Teaching effective hand raising to children with autism during group instruction

We taught 3 children with autism to raise a hand or keep both hands down depending on their status (e.g., having heard a target word, possessing a specific item) using modeling, prompting, and reinforcement. All 3 children acquired accurate hand-raising skills in response to progressively more difficult discrimination tasks during group instruction. The implications for preparing children for general education settings are discussed.     

A Fully Automated,Quantitative Test of Upper Limb Function

ABSTRACT. The Rehabilitation Joystick for Computerized Exercise (ReJoyce, Rehabtronics Inc., Edmonton, Alberta, Canada), is a workstation on which participants exercise dexterous movement tasks in the guise of computer games. The system incorporates the ReJoyce Arm and Hand Function Test (RAHFT). Here the authors evaluate the RAHFT against the Action Research Arm Test (ARAT) and the Fugl-Meyer Assessment (FMA). All 3 tests were performed in 36 separate sessions in 13 tetraplegic individuals. Concurrent and criterion validities of the RAHFT were supported by a high level of correlation with the ARAT (r² = .88). Regarding responsiveness, the effect size of the RAHFT at week 6 of 1 hr/day exercise training was 1.8. Regarding reliability, the mean test–retest difference in RAHFT baseline scores was 0.67% ± 3.6%, which was not statistically significant. The RAHFT showed less ceiling effect than either ARAT or FMA. These data help validate the RAHFT as a quantitative, automated alternative to the ARAT and FMA. The RAHFT is the first comprehensive test of arm and dexterous hand function that does not depend on human judgment. It offers a standardized, quantitative outcome evaluation, which can be performed not only in the clinic, but also in the participant's home, administered by a remote therapist over the Internet.     

Is the sense of bodily ownership related to pre-reflective bodily awareness? A reply to Kuhle

There are two ways in which we are aware of our bodies: reflectively, when we attend to them, and pre-reflectively, a kind of marginal awareness that pervades regular experience. However, there is an inherent issue with studying bodily awareness of the pre-reflective kind: given that it is, by definition, non-observational, how can we observe it? Kuhle claims to have found a way around this problem—we can study it indirectly by investigating an aspect of reflective bodily awareness: the sense of bodily ownership. Unfortunately, I argue, there is little reason to believe a relationship between pre-reflective bodily awareness and the sense of bodily ownership exists. Until more work is done, pre-reflective bodily awareness remains beyond our empirical grasp.     

Maternal cradling bias in baboons: The first environmental factor affecting early infant handedness development?

The most emblematic behavioral manifestation of human brain asymmetries is handedness. While the precise mechanisms behind the development of handedness are still widely debated, empirical evidences highlight that besides genetic factors, environmental factors may play a crucial role. As one of these factors, maternal cradling behavior may play a key role in the emergence of early handedness in the offspring. In the present study we followed 41 Papio anubis infants living in social groups with their mother for which direction (e.g., left- or right-arm) and degree of maternal cradling-side bias were available from a previous published study. We assessed hand preferences for an unimanual grasping task at three developmental stages: (A) 0–4, (B) 4—6, and (C) 9–10 months of age. We found that individual hand preferences for grasping exist as soon as the first months of age, with a population-level left-handedness predominance, being stable until 6 months; to wit the period during which juveniles are mainly carried by their mothers. More importantly, this early postnatal handedness is positively correlated with maternal cradling lateralization. Interestingly, hand preferences assessed later in the development, once juveniles are no longer carried (i.e., from 9 to 10 months of age), are less dependent from the maternal cradling bias and less consistent with the earlier developmental stages, especially in infants initially cradled on the right maternal side. Our findings suggest that the ontogenetic dynamics of the infant's hand preference and its changes might ultimately rely on the degree of infant dependence from the mother across development.     

Effect of Stress Level on Different Forms of Self-Touch in Pre- and Postadolescent Girls

Self-touch serves for regulation of both hyper- and hypoarousal. It remains unclear if different forms of self-touch occur in different contexts, and if the regulatory mechanisms are learned or innate. The authors describe forms and context of self-touch, and explore age differences in stress processing. They analyzed hand movements of 10 pre- and 10 postadolescent girls in low-stress and high-stress settings and found 3 forms of self-touch. In postadolescent participants, self-touch 2 (irregular structure, rhythmical, medium intensity) and 3 (phasic structure, single accent, medium intensity) were used for self-regulation, whereas self-touch 1 (irregular structure, single accent, low intensity) had conversational reasons. Increasing immobility might represent the inward focus of stressed participants that tried to focus on the task. No differences were found for preadolescent participants. Differences between pre- and postadolescent participants might be due to brain development during adolescence.     

Altered bodily self‐consciousness in multiple sclerosis

In this study, we assessed the impact of multiple sclerosis (MS) on bodily self‐consciousness (BSC) using the Rubber Hand Illusion. Patients with MS showed a dissociation between body ownership and self‐location: they did report an explicit ownership of the rubber hand, but they did not point towards it, showing a defective ability of localizing body parts in space. This evidence indicates that MS may affect selective components of BSC, whose impairment may contribute to, and even worsen, the functional disability of MS.     

Anarchic-hand syndrome: ERP reflections of lost control over the right hemisphere

In patients with the callosal type of anarchic-hand syndrome, the left hand often does not act as intended and counteracts the right hand. Reports are scarce about the underlying neurophysiological mechanisms. We report the case G.H. who developed the syndrome after infarction of the left arteria pericallosa. It has been suggested that the syndrome arises out of lacking inhibition from the dominant left hemisphere on the right hemisphere. Yet, in tests of spatial intelligence G.H. performed much better with his “anarchic” left hand than with his dominant right hand, similar to observations commonly reported in split-brain patients. Left-right manual choice responses and event-related EEG potentials to laterally presented stimuli were measured. Asymmetries were evident in G.H.’s behavior and EEG potentials, different from age-matched healthy participants (n = 11). His right-hand responses were fast and unaffected by incompatibility with stimulus location, whereas his left-hand responses were variable and accompanied by a large negative central-midline EEG potential, probably reflecting efforts in initiating the response. G.H.’s visual N1 component peaked earlier and was larger at the right than the left side of the scalp, and the P3 component was distinctly reduced at the right side. Both features occurred independent of side of stimulus presentation and side of responding hand. The effort indicated by the midline negativity and the asymmetrically reduced P3 might directly reflect G.H.’s lack of control on his right hemisphere’s processing. The faster visual processing of the right hemisphere suggested by the N1 asymmetry might contribute to “anarchic” processing, making the right hemisphere process stimuli before control impulses exert their effect. These neurophysiological results tend to support the split-brain account which assumes that the syndrome arises by the lack of communication between hemispheres that act according to their respective competences.     

Rubber hand illusion, empathy, and schizotypal experiences in terms of self-other representations

When participants observed a rubber hand being touched, their sense of touch was activated (rubber hand illusion: RHI). While this illusion might be caused by multi-modal integration, it may also be related to empathic function, which enables us to simulate the observed information. We examined individual differences in the RHI, including empathic and schizotypal personality traits, as previous research had suggested that schizophrenic patients would be more subject to the RHI. The results indicated that people who experience a stronger RHI might have stronger empathic and schizotypal personalites simultaneously. We discussed these relationships in terms of self-other representations.