We custom‐built a prototypical driving scenario with only basic driving task demands for accelerating, coasting and braking, in order to facilitate identifying the landmark physiological responses of the motor cortex time‐locked to driving movements (accelerating and braking) without additional cognitive demands (as with ambient traffic, pedestrians, hazards, etc.). Starting with a basic drive allows for future studies to systematically increase complexity within the driving scene for a more challenging driving scenario. Thus, this drive required starting and stopping on cue at traffic light intersections on a straight roadway (speed management), with no turns, and no other vehicles or pedestrians (see Figure 2 ). The paradigm begins with a rest period (9 s) during which the drivers were instructed to look at the rest screen (with only the word “rest” projected on screen) and relax their hands and feet away from the vehicle controls. After rest, the simulated scene begins with the driver's vehicle in a stopped position at a red traffic‐light intersection on a simple straight roadway with no other vehicles present. After 1 s, the red light turns green, signaling participants to start accelerating, with the dashboard navigation screen indicating they should drive straight forward. As they approach the next traffic‐light intersection, the green light ahead turns to yellow, and then red, signaling to the participant to brake and stop at the upcoming intersection. Once the driver comes to a complete stop (at the intersection), the rest screen appears for the next trial starting with a rest period.
All participants were given an opportunity to practice driving in a simple driving scene on a simple roadway without other vehicles or pedestrians. Basic motor movements of driving were performed: (i) accelerating (using accelerator pedal), (ii) braking (using brake pedal), and (iii) practice steering on curved sections of the road. A limited set of practice trials were conducted to allow participants to become familiar with the task and vehicle controls (i.e., steering wheel and pedal sensitivity). For the experimental drive, there was a block of 20 repeated trials consisting of a rest period (9 s) at the beginning, followed by active driving (~19 s). The trial duration of the simulated drive depends largely on how fast the car travelled per trial. Drivers were asked to accelerate and maintain a speed of ~35 mph, thus the total of 20 trials took approximately 530 s (a maximum of 30 s per trial × 20 trials, thus 600 s maximum). Maximum speed and trial duration, as well as accelerator pedal and brake pedal onset timepoints, were recorded as behavioral indices of performance.
Just out of view, on the border of the driving scene projection, a photodiode is placed over a black/white voxel that displays luminance changes built into the driving simulation software presentation as event triggers for the MEG data, for example, marking when each rest period ended and when the traffic lights changed color. These markers were used for defining the event/cue‐related epochs for MEG analysis. Mean values for each cue‐response latency were noted and mean accelerator pedal and brake pedal onset times are plotted along with the percent oscillatory power change versus time for each of the frequency bands of interest (beta [B‐ERD], gamma [MRGS], and theta [FMT]).
All participants were given an opportunity to practice driving in a simple driving scene on a simple roadway without other vehicles or pedestrians. Basic motor movements of driving were performed: (i) accelerating (using accelerator pedal), (ii) braking (using brake pedal), and (iii) practice steering on curved sections of the road. A limited set of practice trials were conducted to allow participants to become familiar with the task and vehicle controls (i.e., steering wheel and pedal sensitivity). For the experimental drive, there was a block of 20 repeated trials consisting of a rest period (9 s) at the beginning, followed by active driving (~19 s). The trial duration of the simulated drive depends largely on how fast the car travelled per trial. Drivers were asked to accelerate and maintain a speed of ~35 mph, thus the total of 20 trials took approximately 530 s (a maximum of 30 s per trial × 20 trials, thus 600 s maximum). Maximum speed and trial duration, as well as accelerator pedal and brake pedal onset timepoints, were recorded as behavioral indices of performance.
Just out of view, on the border of the driving scene projection, a photodiode is placed over a black/white voxel that displays luminance changes built into the driving simulation software presentation as event triggers for the MEG data, for example, marking when each rest period ended and when the traffic lights changed color. These markers were used for defining the event/cue‐related epochs for MEG analysis. Mean values for each cue‐response latency were noted and mean accelerator pedal and brake pedal onset times are plotted along with the percent oscillatory power change versus time for each of the frequency bands of interest (beta [B‐ERD], gamma [MRGS], and theta [FMT]).
