Is it possible to interrupt m-file execution when controlling Motorshield via Arduino

I notice that when issuing commands to the Arduino / Motor-shield (e.g. a.stepperStep( 1, 'forward', 'interleave', nSteps ) that the execution of the m-file is not interrupted while the Arduino is executing the stepper motor command. As a result if several commands are issued in quick succession these will have a tendency to queue. Is it possible to poll the Arduino / Motor-shield from Matlab to check if the previous stepper command has finished executing before issuing any subsequent commands to avoid queuing?

Best wishes,

John