Cognitive factors

Abstract

The opening chapter of this book noted that the primary goal of using helmet-mounted displays (HMDs) is to increase individual and unit performance. To meet such a goal, there must be an accurate transfer of information from the HMD to the user; and this transfer must occur at appropriate times. Ideally, an HMD would be designed to accommodate the abilities and limitations of users' cognitive processes. It is not enough for the information to be displayed (visually, auditorially, or tactually); the information must be perceived, attended, remembered, and organized in a way that guides appropriate decision-making, judgment, and action. Cognitive science emphasizes the scientific study of human cognition through empirical measurements of human behavior. Although philosophers have been interested in human thought for thousands of years, the field of cognitive science is relatively new, barely more than 100 years old. Given that the field is in its infancy, it is not surprising that there are more questions than answers. Indeed, one of the main discoveries of the field is just how difficult human cognition is to explain. Despite tremendous advances and discoveries over the past 100 years, the major problems remain unsolved. Indeed, outside of very constrained situations, it is very difficult to predict the cognitive properties and capabilities of any given individual or group of individuals. To appreciate the complexity of human cognition, consider the task of a Warfighter listening to auditory information with an HMD (this example is modified from a discussion in Willingham (2007), see Chapter 2, The Human-Machine Interface Challenge, for a similar description of processes involved in perception): BASE: Where are you? WARFIGHTER: I have just reached the top of the hill. The whole "conversation" lasts maybe a few seconds, and it might appear that this simple question and answer process is trivial. Indeed, people frequently do this type of activity without any trouble. In reality, though, the processes involved in even this simple behavior are exceptionally complex. Figure 15-1 schematizes some of the processes that must be involved as the Warfighter answers the question. First, the Warfighter must recognize the sounds coming from the HMD as speech rather than other kinds of sounds. Speech interpretation is quite complicated. For example, studies of speech show that there are no clear pauses between spoken words in normal speech. Instead, the end of one word flows in to the beginning of a following word. Nevertheless, the Warfighter interprets the stream of sounds as corresponding to individual words in a sentence. Once the words are recognized, the solider has to interpret the meaning of the sentence. This too is a complex process that depends on the context in which the words are presented. In some contexts, the question might not be a literal request for location, but a statement indicating that the Warfighter is not where he or she should be (e.g., Where are you?). In still other contexts, the word you might refer...