Interference effects demonstrate distinct roles for visual and motor imagery during the mental representation of human action

Four experiments were completed to characterize the utilization of visual imagery and motor imagery during the mental representation of human action. In Experiment 1, movement time functions for a motor imagery human locomotion task conformed to a speed-accuracy trade-off similar to Fitts' Law, whereas those for a visual imagery object motion task did not. However, modality-specific interference effects in Experiment 2 demonstrate visual and motor imagery as cooperative processes when the action represented is tied to visual coordinates in space. Biomechanic-specific motor interference effects found in Experiment 3 suggest one basis for separation of processing channels within motor imagery. Finally, in Experiment 4 representations of motor actions were found to be generated using only visual imagery under certain circumstances: namely, when the imaginer represented the motor action of another individual while placed at an opposing viewpoint. These results suggest that the modality of representation recruited to generate images of human action is dependent on the dynamic relationship between the individual, movement, and environment.     

Interlimb coordination in prosthetic walking: effects of asymmetry and walking velocity

The present study focuses on interlimb coordination in walking with an above-knee prosthesis using concepts and tools of dynamical systems theory (DST). Prosthetic walkers are an interesting group to investigate from this theory because their locomotory system is inherently asymmetric, while, according to DST, coordinative stability may be expected to be reduced as a function of the asymmetry of the oscillating components. Furthermore, previous work on locomotion motivated from DST has shown that the stability of interlimb coordination increases with walking velocity, leading to the additional expectation that the anticipated destabilizing effect of the prosthesis-induced asymmetry may be diminished at higher walking velocities. To examine these expectations, an experiment was conducted aimed at comparing interlimb coordination during treadmill walking between seven participants with an above-knee prosthesis and seven controls across a range of walking velocities. The observed gait patterns were analyzed in terms of standard gait measures (i.e., absolute and relative swing, stance and step times) and interlimb coordination measures (i.e., relative phase and frequency locking). As expected, the asymmetry brought about by the prosthesis led to a decrease in the stability of the coordination between the legs as compared to the control group, while coordinative stability increased with increasing walking velocity in both groups in the absence of a significant interaction. In addition, the 2:1 frequency coordination between arm and leg movements that is generally observed in healthy walkers at low walking velocities was absent in the prosthetic walkers. Collectively, these results suggest that both stability and adaptability of coordination are reduced in prosthetic walkers but may be enhanced by training them to walk at higher velocities.     

Development of preferences for the human body shape in infancy

Two studies investigated the development of infants' visual preferences for the human body shape. In Study 1, infants of 12, 15 and 18 months were tested in a standard preferential looking experiment, in which they were shown paired line drawings of typical and scrambled bodies. Results indicated that the 18-month-olds had a reliable preference for the scrambled body shapes over typical body shapes, while the younger infants did not show differential responding. In Study 2, 12- and 18-month-olds were tested with the same procedure, except that the typical and scrambled body stimuli were photographic images. The results of Study 2 again indicated that only the 18-month-olds had a reliable preference for the scrambled body shapes. This finding contrasts sharply with infants' precocious preferences for human faces, suggesting that infants' learning about human faces and human bodies follow different developmental trajectories.     

A typology of mid-life career changers

This study examines the motivations for and the outcomes of mid-life career change among a sample of 73 men who had left professional and managerial careers between the ages of 34 and 54. Measures of personal desire for change and external pressure to leave were dichotomized to produce a typology of career changers: Drift-outs, Opt-outs, Force-outs, and Bow-outs. The four types of changers were found to differ on a number of variables, including: amount of education completed, additional schooling undertaken to change careers, time taken to make the change, radicalness of change, and the importance of personal values in deciding to leave their former careers. Overall, respondents were found to be highly satisfied with their career redirection.     

Ability rise in NAEP and narrowing ethnic gaps?

US National Assessment of Educational Progress (NAEP) results from 1971 to 2008 enable four different effects to be distinguished: Cohort rise effects, gap-narrowing between ethnic groups, trends due to demographic changes in by NAEP listed or not listed ethnic groups. NAEP means and percentiles in reading and mathematics were transformed to conventional IQs and SDs. The total increase from 1971 to 2008 was in the scale of 4.34 IQ points (dec = 1.17 IQ per decade). The ability distribution became more homogenous (down from SD = 15.00 in 1971 to SD = 13.56 in 2008). Increases were larger for younger students (9-year olds: 2.02 IQ per decade; 13-year olds: 1.20; 17-year olds: 0.30); larger at the lower ability level (10th percentile dec = 1.79 vs. 90th percentile dec = 1.03). The largest increase was for Blacks (Whites dec = 1.29 IQ, Hispanics 2.27, Blacks 3.04). White–Hispanic-differences were reduced from 11.59 to 8.46 IQ, White–Black from 16.33 to 9.94 IQ. If the racial composition of the population had not changed, the mean gain for the 17-year-old group would have been 2.47 IQ points higher. Had the gap between Whites and the two other groups not narrowed, the mean gain would have been 1.70 IQ points lower. Demographic change has accounted for a loss of 2.47 IQ points and according to cognitive human capital theory $2001 GDP per capita per year, but total ethnic gap-narrowing has provided a gain of $1377.     

Tuning Clinical Recruitment around Cultural Taboos in a Human Microbiome Study

ABSTRACT

Human microbial communities are bodies of microorganisms that reside in or on different body parts. Importantly, they have been found to affect human health. However, scientific research on human microbial communities has created new challenges for human subject recruitment. First, individuals are asked to collect samples of bodily substances that can be seen as repulsive (e.g. feces and urine). Second, because scientists want to understand how human microbial communities evolve over time, individuals are asked to commit to a regular sample collection for extended periods of time. A longitudinal qualitative study of the work of scientists, physicians, research staff, and study coordinators involved in a human microbiome research project has found that these actors can bypass some aspects of these recruitment and retention challenges through ‘tuning work’. Tuning work is a collaborative process where professionals agree to adjust their practices towards shared goals. Such professionals reconfigure their work practices, personal routines, and the study protocol in an effort to obviate cultural taboos against handling bodily substances. The burden of long-term participation provides fewer opportunities for tuning work for these professionals, however. As such, long-term commitment by human subjects remains a recruitment and retention obstacle.     

Animals,humans and x-men: Human uniqueness and the meaning of personhood

Research in animal intelligence suggests to some that humans are different only in degree from animals, possibly eroding the traditional theological doctrine of the imago dei. In this paper, several critical boundary areas between humans and animals are examined for scientific evidence about human distinctiveness. These include communication and language capacity, cultural creativity, spirituality, and ethical capacity. Chimpanzee language studies and research in Neanderthal mentality are examined as the closest known natural approximations to human communication and intelligence. The implications of the findings are explored in relation to human culture, ethics, and spirituality in a context consistent with evolutionary continuity. Aspects of human uniqueness are apparent, can be fruitfully encompassed in the idea of personhood, and are coherent with Trinitarian theology's anthropological focus.     

Personhood: Elusive But Not Illusory

Bioethics as a field has been fortunate that its values and concerns have mirrored the values and concerns of society. In light of the September 11th attacks, it is possible that we are witnessing the beginning of a transition in American culture, one fraught with implications for bioethics. The emphasis on autonomy and individual rights may come to be tempered by greater concern over the collective good. Increased emphasis on solidarity over autonomy could greatly alter public response to research abuses aimed at defense from bioterrorism, to privacy of genetic information, and to control of private medical resources to protect the public health.     

Cosmopolitan ethics and global legalism

This article analyses the legal and ethical dimensions of the wide gap between commitments to universal human rights and the reality of their widespread and systematic abuse, particularly as related to poverty and inequality. The argument put forward is that, properly conceived, global legalism, that is, the quest to apply the rule of law across and among states and societies, and cosmopolitan ethics, both support restricting harms imposed on weak and vulnerable individuals worldwide by an unjust institutional order. Therefore, those who have tended to value either a global rule of law or cosmopolitan ethics independently have good reason to pursue their requirements together. The article also considers the problem of legalism and cosmopolitanism being used by powerful agents in global politics to enhance their prerogatives and their freedoms from legal and ethical restraints.