The effect of mechanical context on attentional cost in unimanual coordination

The purpose of this study was to address the attentional cost of sensorimotor coordination by determining if changes to the mechanical context of movement would influence the ability to attend and respond to an alternate stimulus. Nine right-handed participants performed rhythmic pronation and supination movements of the forearm in time with an auditory metronome. A secondary task, consisting of a pedal response to visual probe stimuli, was employed to infer the attentional cost of the coordination task. When the axis-of-rotation (AOR) was placed below the long axis of the forearm, the average time to react (RT) to the probe stimuli was greater for the supinate-on-the-beat condition than for the pronate-on-the-beat condition. Conversely, with the AOR above the forearm, RT for the pronate-on-the-beat pattern was greater than that for the supinate-on-the-beat pattern. Thus, changing the mechanical context of an upper limb coordination task altered the central processing cost required to maintain pattern stability. This finding provides further evidence that the attentional resources required to produce a particular movement are determined by the ease with which the action is executed by the sensorimotor system.     

Inter-limb coordination and control in boys with and without DCD in ball catching

The purpose of the study was to examine the nature of inter-limb coordination and control, exhibited by ten boys with (M = 10.5 years, SD = 1.0) and without Developmental Coordination Disorder (DCD), in a ball catching task across different ball speeds. In line with the predictions of coordinated structure theory boys who were typically developing preserved strong and effective temporal relations when catching balls in baseline and fast conditions. Boys with DCD exhibited temporal symmetry in baseline but not in fast attempts, where the decoupling was uniformed across the group, coinciding with failures on ≥ 50% of the attempts. In terms of stability, no differences in intra-individual variability were observed between the groups. The analysis of spatial and temporal adaptations showed that boys who were typically developing, in essence, covered the same “ground” by decreasing their movement time. The opposite was true for boys with DCD who contacted the ball closer to the body, while failing to adapt the velocity of their hands. Taken together, both groups exhibited strong and stable coordinative relations, in a steady-state but not in a fast condition, where all boys with DCD failed to preserve the desired symmetry. This decoupling also coincided with different and less effective spatio-temporal adaptations at the effector level. Thus, it appears that movement control, hence flexibility of their synergistic relations, represents a movement limiter for boys with DCD who exhibit specific balls skills issues, at inter-limb level of organization. It should be noted, however, that large intra-group variance observed across some variables warrants caution when interpreting the aggregate data.     

Auditory information is beneficial for adults with Down syndrome in a continuous bimanual task

Much recent research using discrete unimanual tasks has indicated that individuals with Down syndrome (DS) have more difficulty performing verbal-motor tasks as compared to visual-motor tasks (see Perceptual-Motor Behavior in Down Syndrome, Human Kinetics, Champaign, IL, 2000, p. 305 for a review). In continuous tasks, however, individuals with DS perform better when movement is guided by auditory information compared to visual information (Downs Syndr.: Res. Prac. 4 (1996) 25; J. Sport Exercise Psy. 22 (2000) S90). The aim of the present study was to investigate if there are any differences for adults with DS between visual, auditory and verbal guidance in a continuous bimanual task. Ten adults with DS, 10 adults without DS and 10 typically developing children drew lines bimanually towards the body (down) and away from the body (up) following three different guidance conditions: visual (flashing line), auditory (high tone, low tone), and verbal (“up”, “down”). All participants produced mostly in-phase movements and were close to the 1000 ms target time for all guidance conditions. The adults with DS, however, displayed greater variability in their movement time, movement amplitude and bimanual coordination than adults without DS. For all groups, the left hand was slower and more variable in producing the lateral movements than the right hand. The results regarding guidance information suggest that auditory information is beneficial for repetitive bimanual tasks for adults with DS. Possible mechanisms that cause these results will be discussed.     

The relation of age, gender, ethnicity, and risk behaviors to self-esteem among students in nonmainstream schools

This cross-sectional study investigated self-esteem in relation to age, gender, ethnicity, and risk behaviors among a sample of nonmainstream students. Participants were 149 students in the 6th to 12th grades from two nonmainstream schools (one charter and one alternative school). Self-esteem and youth risk behaviors were determined by using a modified version of the Rosenberg Self-Esteem Scale (Rosenberg, 1965) and the National Alternative High School Youth Risk Behavior Survey (Grunbaum et al., 1999), respectively. Results indicated that nonmainstream students with high self-esteem were more likely to engage in their first sexual experience and to begin marijuana use later in life. African American students reported having their first sexual experience at an older age, but having more sexual partners than did Latino students. The implications of these findings are discussed.     

Points of Departure: Insiders,Outsiders, and Social Relations in Caribbean Field Research

In traditional ethnographies, it is customarily assumed that the field researcher is an outsider who seeks to acquire an insider’s understanding of the social world being investigated. While conducting field research projects on education and tourism in Trinidad (West Indies) we found that the standard distinction between insider and outsider became problematic for us. Our experiences can be understood in terms of two competing conceptions of fieldwork. One, rooted in classical ethnography, views fieldwork as a process whereby the researcher learns to translate the cultural practices of a little-known or misunderstood group into terms understandable to the ethnographic audience. The other, growing out of the institutional ethnography approach pioneered by Dorothy E. Smith, views fieldwork as a process of mapping the relations that govern an institutional complex. In the latter approach, local experiences provide the point of departure for exploring a wider set of social arrangements. In this article, we treat our own fieldwork experiences as points of departure for a reflexive examination of this alternative ethnographic strategy.     

Feminist Organizing and the Politics of Inclusion

This paper examines the attempts of one mainstream women's organization to organize and include women of color. Using the approach to social organization developed in the work of Dorothy Smith, I aim to make visible the complex of relations within which the work of this organization is embedded. In mapping the institutional relations structuring the activities in a local setting, the concern is to articulate how activities in the local setting are organized by and in relation to others. My analysis takes as its point of departure my work involvements with this organization over a period of two years. Beginning with my own activities and others' within the setting, the analysis problematizes the concepts of "organizing women of color" and "inclusion/exclusion." What comes into view are the ways in which "organizing" and "inclusion" are ideological constructs brought into service to account for the practices in which various members of the organization were engaged. Their ideological character came to be unveiled in the "troubles" the organization encountered in its attempts to "organize" women of color. The inquiry shows that those troubles arose out of the organization's location at the juncture between private foundations, grassroots women, and the state. On the one hand, the activities of the organization are articulated to an understanding of what funders might be willing to support, and on the other hand the organization's activities have to be seen as serving women of color by both women of color and others. Displayed through the mapping of institutional relations is the deep mismatch between the institutional characterization of what it means to be "organized" and the actual activities women of color were engaged in. I argue that the activities and practices of the mainstream organization embedded in a complex of relations with funding agencies, public policy makers and so on actually produce the definition of women of color as "unorganized."     

Standing distance in climbability of stairs.

The purpose of this experiment was to make a preliminary examination of the distance one needs to stand from a stair to successfully climb up without using arms for support. Using an adjustable stair structure to create different heights of risers, a group of 10 tall and of 10 short participants made perceptual judgments and physical attempts at heights that represented 83% and 93% of each group's mean leg length. Choice of maximum and minimum distance from the stair was measured for each participant. Analysis showed that perceptual judgments and physical capabilities were highly correlated (tall: Pearson r = .92); short: Pearson r = .93). Moreover, the ability to climb the two heights depended on the standing distance from the stair. The findings suggest that standing distance may be a consideration in stair climbing and that stair height alone may not be sufficient to specify climbability.