Research Article

Motor Cortical Networks for Skilled Movements Have Dynamic Properties That Are Related to Accurate Reaching

Figure 2

Kinematic analysis of task performance. Frame-by-frame analysis was performed using MATLAB in order to create two dimensional trajectory traces for the reaching movement in the coronal and horizontal planes. The coordinates were derived by locating the central point of the animal's reaching paw at each separate frame of video footage (a). In (b), the results of trajectory analysis for dataset 4 are displayed for successful (top) and unsuccessful (middle) trials. The red arrow inside the successful trajectory trace indicates the direction of the reaching motion, and the final trajectory trace (bottom) is the result of overlaying the successful and unsuccessful traces. Note the clear similarity in the trajectory paths of the successful and unsuccessful trials, but the slight difference at the end of the reach phase of the movement (circled) created by a second (or occasionally third) attempt at grasping the food pellet during unsuccessful trials. Finally, an example of frame-by-frame analysis that was performed at the end of the reaching stage (as the food pellet was secured) that allowed for the classification of trials as either unsuccessful (c) or successful (d). Note the slightly prolonged ending of the reach stage in “(c)” as the animal needs to make another attempt to grasp the food pellet; while at similar frames in “(d)”, the commencement of the withdrawal stage had already begun.
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(a)
413543.fig.002b
(b)
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(c)
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(d)