Source: FastCo Design, Nov 2013
… a study of people walking and considering their visual displays at the same time.
The participants used the head display to perform two types of tasks. One was a memory task that asked test participants to detect when a repeat number appeared in a series. The other was a visual task that had them detect the appearance of a rectangle in a series of squares. Participants performed these while sitting down and again while walking a taped path in a hallway. (The hall was closed off, for safety’s sake.)
Sitting down, the tasks weren’t too tough. The trouble began when participants started walking. Once ambulatory, the participants did a little worse on the memory task and much worse on the visual task–missing 20% more rectangles and triggering 10% more false alarms.
why is it so difficult to walk and Glass at the same time? Part of the answer may be that walking requires some actual brainpower despite how automatic it feels. If that were the whole answer, though, we would expect people to do poorly at any display task while walking. In fact, participants did much worse at the visual one than the memory one.
For that reason, the researchers suspect that the brain of someone using Glass might be competing with itself for certain cognitive resources. During the visual task of spotting rectangles, for instance, attention might have been split between seeing where to walk and watching the series of squares change shape. Using our limited visual capacity for two simultaneous visual tasks may, in effect, make us worse at each.