Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY)2. REPORT TYPE 3. DATES COVERED (From -To) SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S)AFRL; AFRL/HEA SPONSOR/MONITOR'S REPORT NUMBER(S) Air Force Research Laboratory Human Effectiveness Directorate Warfighter Readiness Research Division 6030 South Kent Street Mesa AZ 85212-6061 AFRL-HE-AZ-TP-2007-03 DISTRIBUTION / AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTESThis paper was originally published in the journal Human Factors (Volume 48, Fall 2006). ABSTRACTObjective: We provide a review and analysis of much of the published literature on visual perception issues that impact the design and use of head-mounted displays (HMDs). Background: Unlike the previous literature on HMDs, this review draws heavily from the basic vision literature in order to help provide insight for future design solutions for HMDs. Method: Included in this review are articles and books found cited in other works as well as articles and books obtained from an Internet search. Results: Issues discussed include the effect of brightness and contrast on depth of field, dark focus, dark vergence, and perceptual constancy; the effect of accommodation/vergence synergy on perceptual constancy, eyestrain, and discomfort; the relationship of field of view to the functioning of different visual pathways and the types of visualmotor tasks mediated by them; the relationship of binocular input to visual suppression; and the importance of head movements, head tracking, and display update lag. Conclusion: This paper offers a set of recommendations for the design and use of HMDs. Application: Consideration of the basic vision literature will provide insight for future design solutions for HMDs.

Objective: We provide a review and analysis of much of the published literature on binocular rivalry that is relevant to the design and use of head-worn displays (HWDs). Background: This review draws heavily from both the basic vision literature and applied HWD literature in order to help provide insight for minimizing the effects of binocular rivalry when HWDs are worn. Method: Included in this review are articles and books found cited in other works as well as articles and books obtained from an Internet search. Results: Issues discussed and summarized are (a) characteristics of binocular rivalry, (b) stimulus factors affecting rivalry, (c) cognitive variables affecting rivalry, and (d) tasks affected by rivalry. Conclusion: This paper offers a set of recommendations for minimizing the effects of binocular rivalry when HWDs are used as well as recommendations for future research. Application: Considerations of the basic vision literature on binocular rivalry will provide insight for future design solutions for HWDs.

Implicit learning involves the largely unconscious learning of dynamic statistical patterns and features, which leads to the development of tacit knowledge. This kind of learning is a ubiquitous, robust phenomenon that likely occurs in most, if not all, tasks in which individuals engage throughout their lives. In this paper, we argue that implicit learning and its end state, tacit knowledge, may assist in the acquisition, retention, and transfer of expertise and thus provide a form of tacit scaffolding for expertise development. The notion of tacit scaffolding represents a novel and interesting area of future research for the field of naturalistic decision making and naturalistic cognition.

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S)AFRL; AFRL/HEA SPONSOR/MONITOR'S REPORT NUMBER(S)Air DISTRIBUTION / AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTESThis paper was originally published in the 2006 Proceedings of the Human Factors and Ergonomics Society conference. ABSTRACTAs monocular head-mounted displays (HMDs) are introduced into existing flight simulators for training and mission rehearsal it will be important to determine whether binocular rivalry affects the visibility of HMD presented symbology or the out-the-window (OTW) flight simulator display imagery. In the present study, we examined whether rivalry suppression could be objectively measured under conditions that simulated a monocular HMD and OTW display, and whether voluntary attention and moving imagery influenced the strength of rivalry suppression. The results indicated that strength of suppression under these conditions was less than that found under classic dichoptic viewing conditions, and that attention had little influence on performance. SUBJECT TERMSHead-mounted displays, HMD, binocular rivalry, flight simulation ABSTRACTAs monocular head-mounted displays (HMDs) are introduced into existing flight simulators for training and mission rehearsal it will be important to determine whether binocular rivalry affects the visibility of HMD presented symbology or the out-the-window (OTW) flight simulator display imagery. In the present study, we examined whether rivalry suppression could be objectively measured under conditions that simulated a monocular HMD and OTW display, and whether voluntary attention and moving imagery influenced the strength of rivalry suppression. The results indicated that strength of suppression under these conditions was less than that found under classic dichoptic viewing conditions, and that attention had little influence on performance.

No abstract

We examined (i) perceived slant of a textured surface about a vertical axis as a function of disparity magnitude for horizontal-size disparity, vertical-size disparity, and overall-size disparity; and (ii) interactions between patterns with various types and magnitudes of size disparity and superimposed or adjacent zero-disparity stimuli. Horizontal-size disparity produced slant which increased with increasing disparity, was enhanced by superimposed zero-disparity stimuli, and induced contrasting slant in superimposed or adjacent zero-disparity stimuli. Vertical-size disparity produced opposite slant (induced effect) which was reduced to near zero by a superimposed zero-disparity pattern and both patterns appeared as one surface. Adjacent vertical-size-disparity and zero-disparity patterns appeared as separate surfaces with a wide curved boundary. Overall-size disparity produced slant which was enhanced by a superimposed zero-disparity pattern and less so by a zero-disparity line, and induced more slant in a zero-disparity line than in a zero-disparity pattern. The results are discussed in terms of depth underestimation of isolated surfaces, depth enhancement, depth contrast, and the processing of deformation disparity.

With increased reliance on head-mounted displays (HMDs), such as the Joint Helmet Mounted Cueing System and F-35 Helmet Mounted Display System, research concerning visual performance has also increased in importance. Although monocular HMDs have been used successfully for many years, a number of authors have reported significant problems with their use. Certain problems have been attributed to binocular rivalry when differing imagery is presented to the two eyes.With binocular rivalry, the visibility of the images in the two eyes fluctuates, with one eye's view becoming dominant, and thus visible, while the other eye's view is suppressed, which alternates over time. Rivalry is almost certainly created when viewing an occluding monocular HMD. For semi-transparent monocular HMDs, however, much of the scene is binocularly fused, with additional imagery superimposed in one eye. Binocular fusion is thought to prevent rivalry.The present study was designed to investigate differences in visibility between monocularly and binocularly presented symbology at varying levels of contrast and while viewing simulated flight over terrain at various speeds. Visibility was estimated by measuring the presentation time required to identify a test probe (tumbling E) embedded within other static symbology. Results indicated that there were large individual differences, but that performance decreased with decreased test probe contrast under monocular viewing relative to binocular viewing conditions. Rivalry suppression may reduce visibility of semi-transparent monocular HMD imagery. However, factors, such as contrast sensitivity, masking, and conditions such as monofixation, will be important to examine in future research concerning visibility of HMD imagery.

We provide a review and analysis of much of the published literature on decision making that is relevant to the design of immersive environments. This review draws from the basic and applied literature in order to provide insight for the design of such synthetic environments. Included in this review are articles and books cited in other works, and articles and books obtained from an Internet search. Issues discussed are (a) an overview of immersive decision environments; (b) dual-process decision making; (c) training robust intuitive decision making; (d) combining analytical and intuitive processing in immersive environments; and (e) concluding remarks. For the development of robust decision making in immersive environments, intuitive reasoning should be emphasized by creating an immersive situation and by providing for the development of automatic processing through implicit learning, with the latter reinforced by explicit thought processes. Considerations of the literature on decision making will provide insight for future design solutions for immersive decision environments.