Active Voice Technology: Comfortable and Dangerous

As technology continues to advance and improve, it is also heavily influencing the daily habits and behaviors of many people. Smartphones and vehicles are integrated with hands-free options and voice controls. While there are numerous advantages to using active voice technologies in vehicles, safety and attention to driving performance can be compromised. In the study by Horrey, he explains that engaging in in-vehicle tasks are interfering factors that contribute to distracted driving. Horrey defines Distracted Driving as driving with divided attention resulting from engagement in completing tasks that require cognitive, visual, or manual effort. Driving is primarily a combined task of visual, cognitive, spatial, and manual functions. In-vehicle tasks such as texting activity interfere with these demands and can lead to changes in performance and danger. For instance, the increase in texting volumes while driving in the United States has resulted in multiple car accidents and motor vehicle-related fatalities. Consequently, cell phone use while driving is banned in the majority of the states in the U.S. On the other hand, voice controls and voice-based technologies are often commended as a solution to distracted driving. Many people believe that the brain should be able to focus on driving and function better without the need to look and manually tap on a screen. However, interacting using voice assistive technology while driving is as risky as texting activity which can distract and limit driving performance. Both hand-held and hands-free technologies disrupt visual attention and cause high levels of cognitive demands which impair driving performance.

Hand-held Device, Texting, and Driving

Texting is known to be one of the leading causes of car accidents. Aside from the manual demands, using hand-held phones while driving directly impacts the visual perception that drivers need to maintain awareness of road situations. Drivers use their ability of visual scanning to recognize and respond to hazards and to control the vehicle. Visual scanning helps to predict potential threats that may arise in the driving environment visible to the driver. Studies have shown that drivers tend to recognize fewer objects and respond slower when performing secondary tasks that include taking his or her eyes off the road. The behaviors associated with texting include picking up the phone, tapping on the screen, reading and comprehending the message content, and responding. Often, it also includes social media checking, internet searches, and map navigations. Performing dual tasks such as texting while driving disrupts visual scanning which then slows the transfer of visual information into the short-term memory. The more the driver takes glances to the phone, the more he/she increases the probability of failing to detect traffic events or changes on the road.

Moreover, the driver’s capability to maintain situational awareness and visual attention also depends on his/her cognitive processing. The operational demands of being on the phone while driving lead the eyes and the mental state to shift and alter attention. With the cognitive distraction, the attention is weakened and impeded to effectively processing information present in the road environment. In such cases, change blindness can occur when the driver experience perception error and fails to notice the change on the road. According to Lee et al.’s study of change blindness, cognitive load interferes with event detection and diminishes the ability and confidence of the driver in responding to change. Consequently, when an unexpected event or change materializes, distracted drivers may not be able to adapt quickly enough. All things considered, texting while driving undermines both visual and cognitive attention necessary for safe operation in driving.

Using In-Vehicle Hands-free Device when Driving

Although using a hand-held device is seen as significantly dangerous and distrustful in driving situations, interacting with and controlling voice-based technology in the vehicle is equally compromising. Voice-based technologies are usually installed in in-car personal assistant systems and as an option to the hands-free mode in mobile phones. In Strayer et al.’s study, they examined the impact of voice-based interactions using different intelligent personal assistant programs on the cognitive workload of the driver. They tested and evaluated the cognitive demand of voice interaction such as dialing, selecting music, and sending voice-based text messages while driving. Strayer et al.’s results found that voice-based interactions put demands on the brain to try and multi-task in ways that exceed its capacity affecting driving activity. Although the voice-based control is less visually and manually demanding, the study found that the cognitive load associated with voice-based control for calling a contact, dialing a phone number, selecting music, or sending a text message, is significantly higher than drivers who perform single-task (driving only). Additionally, they concluded that the cognitive load from this secondary task was closely identical to the high levels of workload when using a hand-held smartphone, especially for voice-texting. They also compared that voice-based smartphone interactions are significantly more demanding than engaging in typical hand-held phone conversations.

Furthermore, Strayer et al. investigated that word demands and controlling speech-to-text conditions contribute a heavier burden to the brain’s cognitive load than talking to a person. Also, Strayer et al. added that if the voice-based device is error-prone, the cognitive load experienced by the driver increases. This study demonstrates that the high levels of cognitive load are not merely due to visual and manual interference like hand-held cell phones.

Both secondary hand-held and hands-free activities demand cognitive functioning and attention to be performed. Attending to multi-tasking behaviors can result in inattentional blindness where a person fails to see what he or she is directly looking at because his attention is elsewhere. Consequently, this can result in undermined detection of changes and safety-relevant events on the road. Lee et al., explain that cognitive load affects event detection because it weakens memory consolidation. Drivers fail to attend to detecting changes because the information coming in is not properly consolidated and processed in the short-term visual memory. Therefore, drivers who are not able to consolidate visual memory properly are more prone to fail to respond appropriately and quickly to arising events. With this kind of cognitive interference, the driver’s eyes may be on the road and their hands on the steering wheel, but they may fail to process the situational information critical for safe driving. Ultimately, visual attention is also disrupted when the cognitive workload reaches its capacity.

Altogether, just as how visual attention affects cognitive functioning, cognitive load also affects visual perception. The brain is distracted by any type of phone conversation whether it is a hand-held or hands-free device. The study from Strayer et al. indicates that driving performance increases danger as the cognitive load increases. The danger in driving is not only due to the visual and manual interference caused by hand-held devices. Driving impairment also occurs when the cognitive load exceeds its capacity. Therefore, the level of distraction and danger in engaging in voice-based technology while driving is comparable to using hand-held cell phones when driving.