Three physiological measures of workload; heart rate, eye blink, and EEG were recorded from eight experienced A-7 attack aircraft pilots. Each pilot flew the same familiar training mission three times; one mission in the lead position of a four ship formation and the other as wing, and once in an A-7 simulator. The mission lasted approximately 90 minutes and consisted of take-off, low altitude terrain following, high G maneuvers, inflight navigational updates, weapons delivery, and a high altitude cruise to base, ending in a formation landing. The data show significant differences between simulated and actual flights for all measures. There were also significant differences between mission segments for each pilot. The heart rate data most obviously reflect the changes in workload level throughout the mission and between flight position and simulator. Blink rate and duration were sensitive to changing visual attentional demands. The EEG data showed differences between the actual flight missions and the simulator.

Two parameters of the eye blink, blink r~te and blink du~atio~, were us~d to.ass~ss workload in two independent operational studt es , Both s tud i es f nvol ved h1~h f i del i ty strategic bomber mission simulations. The first study was an extended. wart tme m1SS10n where workload was evaluated during mission segments. The seco~d study l~volved shorter, discrete training missions where task difficulty was systemat1callJ: man ipul ated •.~o~h studies produced complementary results. Results. show t,hat: (1) bl i nk ra~e~s s i qnif icantly affected by task demands; (2) blink rate 1~sens1t1ve to~ask modal1ty, !3) bl1nk duration is significantly affected by task modali ty and comp l exi ty ; and (4) bl i nk duration is a sensitive index of time on task effects.These data support the use of eye blink measurement in "noisy" complex environments as both a feasible and valuable assessment technique.

No abstract

No abstract

The public reportina burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathenng and maintainino the data needed, and completing and reviewing this collection of infomnation. Send comments regarding this burden estimate or any other aspect of this collection of infomiation, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Infomnation 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 (or failing to comply with a collection of information if it does not display a cun-entiy valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MMM-YYYY) September 2000 REPORT TYPE Interim Report TITLE AND SUBTITLE Attentional Pacing and Temporal Capture in Slow Visual Sequences AUTHOR(S)*June J. Skelly **Mari R. Jones ***Charles D. Goodyear ***Merry M. Roe PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)* SPONSOR / MONITOR'S ACRONYM AFRL-HE-WP-TR-2003-0078 SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION / AVAILABIUTY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTThree experiments examined effects of temporally interleaved sequences of relevant and irrelevant information on selective attending to relevant visual items (letter pairs). In a serial monitoring task, viewers judged the physical match (same, different) of successive letter pairs in the relevant sequence under instructions to ignore irrelevant items. Irrelevant information comprised either visual information or tones. In all experiments the relative timing of relevant and irrelevant items was manipulated in slow visual sequences. Facilitation was more likely when relevant and irrelevant items formed a 'new' coherent rhythm whereas, interference was more likely following an ill-timed irrelevant item in a less coherent rhythm. Results were discussed in terms of the attentional pacing and temporal capture of attention. (1989) remarked,"... in the real world of dynamic complexity, information does not usually arrive neatly packaged in task-by-task bundles." The workplace is filled with many dynamic visual and auditory sources of information designed to inform a human operator of status changes. Ill TfflS PAGE IS INTENTIONALLY LEFT BLANK XVTypically this information reaches the operator at different times, producing interleaved strings of elements from different sources. Perceptually, an intact string from a single source is experienced as an information "stream" (e.g., Bregman, 1990;Skelly & Jones, 1990;Sperling & Reeves, 1980). Selective attending while monitoring different sources of information, requires one to maintain an attentional focus to one sequence of relevant eleme...