Potential applications of this work include spatial knowledge-based measures to evaluate SVS prototypes as well as to assess the relationship between spatial knowledge and spatial awareness.

Including night vision capabilities in Helmet Mounted Displays has been a serious challenge for many years. The use of "see through" head mounted image intensifiers systems is particularly challenging as it introduces some peculiar visual characteristics usually referred as "hyperstereopsis". Flight testing of such systems has started in the early nineties, both in US and Europe. While the trials conducted in US yielded quite controversial results, convergent positive ones were obtained from European testing, mainly in UK, Germany and France. Subsequently, work on integrating optically coupled I² tubes on HMD was discontinued in the US, while European manufacturers developed such HMDs for various rotary wings platforms like the TIGER. Coping with hyperstereopsis raises physiological and cognitive human factors issues. Starting in the sixties, effects of increased interocular separation and adaptation to such unusual vision conditions has been quite extensively studied by a number of authors as Wallach, Schor, Judge and Miles, Fisher and Ciuffreda. A synthetic review of literature on this subject will be presented. According to users' reports, three successive phases will be described for habituation to such devices: initial exposure, building compensation phase and behavioral adjustments phase. An habituation model will be suggested to account for HMSD users' reports and literature data bearing on hyperstereopsis, cue weighting for depth perception, adaptation and learning processes, task cognitive control. Finally, some preliminary results on hyperstereopsis spatial and temporal adaptation coming from the survey of training of TIGER pilots, currently conducted at the French-German Army Aviation Training Center, will be unveiled.

No abstract

Two problems concerning anticipation effort as an important cognitive resource for improved avionics safety are addressed: (1) assessment of the probability that the random actual ('subjective') anticipation time is below the (also random) available ('objective') time and (2) evaluation of the likelihood of success of the random shortterm anticipation from the predetermined (non-random) long-term anticipation. Unlike the traditional statistical approach, when experimentations are done first and are followed by statistical analyses, our novel concept suggests that probabilistic predictive modelling is done first and is followed by experimentation. The concept proceeds from the fundamental understanding that nobody and nothing is perfect and that the difference between a success and a failure in a particular effort, a situation, or a mission is, in effect, 'merely' the difference in the level of the never-zero probability of failure.