Signal Processing - November 2016 - 45

EEG

ECG

Respiration

1 Second

10 Seconds

GSR

1 Minute

FIGURE 7. Example physiological measures recorded in a simulator study (setup as shown in Figure 4): EEG collected using a 14-channel wireless headset;
Respiration activities recorded using an inductive respiratory belt; ECG recorded using three disposable gel-electrodes located on the driver's chest; and
GSR recorded using two disposable gel-electrodes located on the sole of the driver's left foot.

both help and interfere with the allocation of limited attentional resources.
Overall, real-time feedback design needs to be concise, to communicate a salient message to the driver, and
be delivered through an appropriate modality that will be
perceived by the driver with minimal additional demand.
For example, an auditory alert is likely to capture a driver's attention immediately even when the driving task is
demanding [46]. However, if the driver is already cognitively overloaded, such feedback may become detrimental
by interfering with the ongoing driving task. In such cases,
delaying feedback, even for a few seconds, can mitigate
the potential disruption while still providing some positive
effects on driving.

Postdrive feedback
Postdrive feedback is provided after a trip. A driver's mental
model about safe driving can guide her decisions and intentional behaviors. For example, if a driver perceives a significant
increase in driving demands, she may allocate more attention
to driving by pausing her conversation with a passenger. While
the mental model of safe driving may be in part guided by
formal learning, it is also updated continually according to

driving experience, feedback, and perceived social norms. For
example, the memory of previous driving experiences may
influence a driver's future behaviors. However, a study has
estimated that 80% of near crashes are forgotten after only two
weeks [50]. Thus, postdrive feedback provided after driving
may facilitate long-term memory formation of critical driving
incidents to motivate behavioral changes. The Chevy Malibu
teen driver feature is an example for this type of feedback.
Another example would be to use video replays of driving
incidents (e.g., near crashes) to help strengthen the memory
of such events, and thus influencing driver's mental model of
safe driving.

SA and anticipatory driving
SA is the perception of critical elements, the comprehension
of their meaning, and the projection of their status [51]. A
high level of SA has been associated with expert operators
in complex and dynamic environments, including aviation,
healthcare, and automobile driving [51], [52]. For example,
operating at a lower level of SA, a driver may not register
the object(s) he sees, e.g., a stalled truck, to be a potential
hazard, while another driver, operating at a high level of
SA, may not only perceive and understand the stalled truck

IEEE SIgnal ProcESSIng MagazInE

November 2016

Table of Contents for the Digital Edition of Signal Processing - November 2016