Mode of execution of movement and characteristics of motor short-term memory

Investigations in the area of motor short-term memory (MSTM) have typically used an experimental paradigm in which the experimeter defines the terminal position of a response. This study compares the retention characteristics of movements executed in this manner with those in which the subject is able to define his own terminal position. It was found that whilst the temporal position of an interpolated response affected retention in both modes of execution, the relative magnitude of an interpolated response only interfered with movements executed under the classical MSTM paradigm. Theoretical reasons for this are discussed together with the methodological issues which such a discrepancy raises.