LATERALIZED SPATIAL STRATEGIES IN OSCILLATING DRAWING MOVEMENTS

Kinematic characteristics and lateral differences between two upper ex tremities were investigated in a unimanual graphic task involving fast and precise oscillating movements on the vertical plane. The spatial locations of sequential reversal points were used to calculate the pai rs of angles, relative to the horizontal axis. The point biserial coef ficient of correlation was used to analyze the difference between big and large angles and their sequence in each pair. Three main groups (A , B, and C) of performance models were distinguished in 132 tests by 3 3 strongly right handed male subjects. Group A showed strong variation in vertical movement, Group B covariation in vertical and horizontal vectors, while Group C reflected independent variation of both vertica l and horizontal directions. It is suggested that the movement strateg ies might reflect three different models of motor control involving co upling of an oscillator controlling pools of motoneurons which regulat e horizontal movements with an oscillator controlling vertical movemen t (Groups A+B) or with nonoscillating control signal (Group B). It is argued that Group A represents the simplest strategy and only performa nce Type A met by the left hand.