Manual asymmetries in the preparation and control of goal-directed movements

The primary purpose of this experiment was to determine if left hand reaction time advantages in manual aiming result from a right hemisphere attentional advantage or an early right hemisphere role in movement preparation. Right-handed participants were required to either make rapid goal-directed movements to small targets or simply lift their hand upon target illumination. The amount of advance information about the target for a particular trial was manipulated by precuing a subset of potential targets prior to the reaction time interval. When participants were required to make aiming movements to targets in left space, the left hand enjoyed a reaction advantage that was not present for aiming in right space: or simple finger lifts. This advantage was independent of the amount or type of advance information provided by the precue. This finding supports the movement planning hypothesis. With respect to movement execution, participants completed their aiming movements more quickly when aiming with their right hand, particularly in right space. This right hand advantage in right space was due to the time required to decelerate the movement and to make feedback-based adjustments late in the movement trajectory. (C) 2001 Academic Press.

Gaze fixation improves the stability of expert juggling

Novice and expert jugglers employ different visuomotor strategies: whereas novices look at the balls around their zeniths, experts tend to fixate their gaze at a central location within the pattern (so-called gaze-through). A gaze-through strategy may reflect visuomotor parsimony, i.e., the use of simpler visuomotor (oculomotor and/or attentional) strategies as afforded by superior tossing accuracy and error corrections. In addition, the more stable gaze during a gaze-through strategy may result in more accurate movement planning by providing a stable base for gaze-centered neural coding of ball motion and movement plans or for shifts in attention. To determine whether a stable gaze might indeed have such beneficial effects on juggling, we examined juggling variability during 3-ball cascade juggling with and without constrained gaze fixation (at various depths) in expert performers (n = 5). Novice jugglers were included (n = 5) for comparison, even though our predictions pertained specifically to expert juggling. We indeed observed that experts, but not novices, juggled significantly less variable when fixating, compared to unconstrained viewing. Thus, while visuomotor parsimony might still contribute to the emergence of a gaze-through strategy, this study highlights an additional role for improved movement planning. This role may be engendered by gaze-centered coding and/or attentional control mechanisms in the brain.

Movement-related potentials in Huntington's disease: movement preparation and execution

Movement-related potentials (MRPs) reflect increasing cortical activity related to the preparation and execution of voluntary movement. Execution and preparatory components may be separated by comparing MRPs recorded from actual and imagined movement. Imagined movement initiates preparatory processes, but not motor execution activity. MRPs are maximal over the supplementary motor area (SMA), an area of the cortex involved in the planning and preparation of movement. The SMA receives input from the basal ganglia, which are affected in Huntington's disease (HD), a hyperkinetic movement disorder. In order to further elucidate the effects of the disorder upon the cortical activity relating to movement, MRPs were recorded from ten HD patients, and ten age-matched controls, whilst they performed and imagined performing a sequential button-pressing task. HD patients produced MRPs of significantly reduced size both for performed and imagined movement. The component relating to movement execution was obtained by subtracting the MRP for imagined movement from the MRP for performed movement, and was found to be normal in HD. The movement preparation component was found by subtracting the MRP found for a control condition of watching the visual cues from the MRP for imagined movement. This preparation component in HD was reduced in early slope, peak amplitude, and post-peak slope. This study therefore reported abnormal MRPs in HD. particularly in terms of the components relating to movement preparation, and this finding may further explain the movement deficits reported in the disease.

Anticipatory Planning Reveals Segmentation of Cortical Motor Output During Action Observation

It has been argued that the variation in brain activity that occurs when observing another person reflects a representation of actions that is indivisible, and which plays out in full once the intent of the actor can be discerned. We used transcranial magnetic stimulation to probe the excitability of corticospinal projections to 2 intrinsic hand muscles while motions to reach and grasp an object were observed. A symbolic cue either faithfully indicated the required final orientation of the object and thus the nature of the grasp that was required, or was in conflict with the movement subsequently displayed. When the cue was veridical, modulation of excitability was in accordance with the functional role of the muscles in the action observed. If however the cue had indicated that the alternative grasp would be required, modulation of output to first dorsal interosseus was consistent with the action specified, rather than the action observed-until the terminal phase of the motion sequence during which the object was seen lifted. Modulation of corticospinal output during observation is thus segmented-it progresses initially in accordance with the action anticipated, and if discrepancies are revealed by visual input, coincides thereafter with that of the action seen.

Cities and The Spirit Level: Reasserting the Public Interest in Planning Governance

Urban planning in Europe has its roots in social reform movements for reform of the 18th and 19th centuries and in the UK evolved into the state-backed comprehensive planning system established as a pillar of the welfare state in 1947. This new planning system played a key role in meeting key social needs of the early post-war period, through, for example, an ambitious new town programme. However, from the late 1970s onwards the main priorities of the planning system have shifted as the UK state has withdrawn support for welfare and reasserted market values. One consequence of this has been an increased inequality in access to many of the resources that planning seeks to regulate, including affordable housing, local services and environmental quality.
Drawing on evidence from recent literature on equality, including Wilkinson and Pickett’s The Spirit Level this paper will question the role of planning in an era of post-politics and a neo-liberal state. It will review some of the consequences for the governance and practice of planning and question what this means for the core values of the planning profession. Finally, the paper will discuss the rise of the Healthy Urban Planning Movement in the US and Europe and ask whether this provides any potential for reasserting the public interest in planning process.

Perceptions of the common good in planning

There has been plenty of debate in the academic literature about the nature of the common good or public interest in planning. There is a recognition that the idea is one that is extremely difficult to isolate in practical terms; nevertheless, scholars insist that the idea ‘…remains the pivot around which debates about the nature of planning and its purposes turn’ (Campbell & Marshall, 2002, 163–64). At the point of first principles, these debates have broached political theories of the state and even philosophies of science that inform critiques of rationality, social justice and power. In the planning arena specifically, much of the scholarship has tended to focus on theorising the move from a rational comprehensive planning system in the 1960s and 1970s, to one that is now dominated by deliberative democracy in the form of collaborative planning. In theoretical terms, this debate has been framed by a movement from what are perceived as objective and elitist notions of planning practice and decision-making to ones that are considered (by some) to be ‘inter-subjective’ and non-elitist. Yet despite significant conceptual debate, only a small number of empirical studies have tackled the issue by investigating notions of the common good from the perspective of planning practitioners. What do practitioners understand by the idea of the common good in planning? Do they actively consider it when making planning decisions? Do governance/institutional barriers exist to pursuing the common good in planning? In this paper, these sorts of questions are addressed using the case of Ireland. The methodology consists of a series of semi-structured qualitative interviews with 20 urban planners working across four planning authorities within the Greater Dublin Area, Ireland. The findings show that the most frequently cited definition of the common good is balancing different competing interests and avoiding/minimising the negative effects of development. The results show that practitioner views of the common good are far removed from the lofty ideals of planning theory and reflect the ideological shift of planners within an institution that has been heavily neoliberalised since the 1970s.