The coding and inter-manual transfer of movement sequences

Abstract

The manuscript reviews recent experiments that use inter-manual transfer and inter-manual practice paradigms to determine the coordinate system (visual-spatial or motor) used in the coding of movement sequences during physical and observational practice. The results indicated that multi-element movement sequences are more effectively coded in visual-spatial coordinates even following extended practice, while very early in practice movement sequences with only a few movement elements and relatively short durations are coded in motor coordinates. Likewise, inter-manual practice of relatively simple movement sequences show benefits of right and left limb practice that involves the same motor coordinates while the opposite is true for more complex sequences. The results suggest that the coordinate system used to code the sequence information is linked to both the task characteristics and the control processes used to produce the sequence. These findings have the potential to greatly enhance our understanding of why in some conditions participants following practice with one limb or observation of one limb practice can effectively perform the task with the contralateral limb while in other (often similar) conditions cannot.

Keywords: coordinate system; effector transfer; movement sequences; sequence coding.

Figure 1

Illustration of the hand position and finger movement in two versions (A,B) of the normal (acquisition and retention), visual, and motor conditions. In the visual condition the display is to the same as in the normal condition, but because the hand position is changed different fingers and movements are required to move to the correct keys. In the motor condition the display is changed from the normal condition, but because the hand position has changed the same fingers and movements are required. Note that the illustration only depicts a single set. In the 2 × 10 tasks, a trial was composed of 10 sets. (redrawn from Bapi et al., 2000).

Figure 2

Illustration of the arm used during acquisition (A) and on the retention (B), motor (C) and spatial (D) tests. Note that the targets were arbitrarily labeled 1–10 from the start position (red line). (redrawn from Kovacs et al., 2009b).

Figure 3

Illustration of the arm used during acquisition (A) and on the retention (B), motor (C) and spatial (D) tests. The arm used and direction of movement is indicated by an arrow (bottom) and the goal movements (top) are displayed. Note that the start position between the upper and lower arm in this task was 85°. RMSE means and SEs by test is provided in (E). (Redrawn from Kovacs et al., 2010).

Figure 4

Illustration of the arm and task used on acquisition sessions (1 and 2) and retention tests (1 and 2) for the right start group with the same motor coordinates on the two acquisition session (A) and right start group with the same spatial coordinates on the two acquisition sessions (B). Left start group with the same motor coordinates (C) and same spatial coordinates (D) are also illustrated. Retention performance is for each condition is provided to the right (E). Note that this design does not require effector transfer test to determine the coordinate system used to code the movement sequence (Redrawn from Panzer et al, 2009a).

Figure 5

Illustration of the arm used during acquisition (A) and on the retention (B), motor (C) and spatial (D) tests. The arm used and direction of movement is indicated by an arrow (bottom) and the goal movements (top) are displayed for the physical and observational practice groups. Note that the start position between the upper and lower arm in this task was 85°. RMSE means and SEs by test is provided in (E). (Redrawn from Gruetzmacher et al., 2011).