The effects of motion on in-vehicle touch screen system operation: A battle management system case study

The use of in-vehicle touch screen devices is currently common in both military and civilian vehicles; despite this, the effects of motion on touch screen device operation within vehicles remains largely unexplored. This article describes a study that examined, using driving simulation, the influences of motion on performance, workload and usability when using a touch screen in-vehicle battle management system. Acting in the role of battle management system operator, 20 participants undertook four simulated drives, two under high motion (representative of an unsealed road) and two under normal motion (representative of a sealed road), whilst performing various battle management tasks. In the high motion condition, lower accuracy and longer task completion times were found, along with greater levels of subjective and physiological workload and lower levels of perceived device usability, when compared to the normal motion condition. The findings indicate that, compared to normal motion, the high motion condition impaired key aspects of battle management system operation. In closing, the importance of considering motion and its effects during touch screen system design is discussed.     

Melatonin and jet lag syndrome: experimental model and clinical implications

What is the effect of melatonin on jet lag syndrome? Jet lag desynchronizes the internal sleep-wakefulness cycle with the environmental light/dark cycle. Advance (but not delay) of light onset is known to abolish pineal N-acetyltransferase activity and urine excretion of 6-sulphatoxymelatonin. Measurements of pineal serotonin, the substrate of melatonin biosynthesis; N-acetylserotonin (NAS), the immediate melatonin precursor; and melatonin (high-performance liquid chromatography-fluorimetric method) in the animal (rat) model of jet lag revealed that prolonged delay of dark-phase onset disrupted the rhytms in comparable ways as the advance of light-phase onset. Advance of dark phase onset resulted in less severe disturbances of rhythms as compared with the advance of light phase onset. Melatonin, but not NAS, injections at the beginning of a new dark period accelerated recovery of NAS and melatonin, but not serotonin, rhythms. Spontaneously hypertensive rats were more sensitive to advance of light onset and less responsive to melatonin injections than normotensive rats. NAS and methylene blue, an inhibitor of monoamine oxidase A, attenuated light-induced disruption of NAS but not melatonin rhythms. We draw the following conclusions from our data: the beginning of the dark period may be preferable to the beginning of light period as the arrival time on eastward flights; the efficacy of melatonin in alleviating jet lag may be enhanced by administering it before, during and after rapid transition through time zones; and hypertension may exaggerate jet lag syndrome.