Feedback appears to be a fundamental characteristic of the phenomena of life. Elsewhere it only appears in man-made machines. These machines are always presented as being a meeting ground for laws immanent both in matter and in man. A new science has been created to study the applications of feedback: cybernetics. As feedback is closely related to questions concerning the transmission of information, cybernetics has rapidly given rise to a theory of information. The latter, with its applications, has taken on (...) an absolutely essential role in our modern world wherever problems of administration occur. (shrink)

A speed-accuracy trade-off (SAT) in behavioural decisions is known to occur in a wide range of vertebrate and invertebrate taxa. Accurate decisions often take longer for a given condition, while fast decisions can be inaccurate in some tasks. Speed-accuracy tactics are known to vary consistently among individuals, and show a degree of flexibility during colour discrimination tasks in bees. Such individual flexibility in speed-accuracy tactics is likely to be advantageous for animals exposed to fluctuating environments, such as changes in predation (...) threat. We therefore test whether individual speed-accuracy tactics are fixed or flexible under different levels of predation threat in a model invertebrate, the bumblebee Bombus terrestris. The flexibility of speed-accuracy tactics in a foraging context was tested in the laboratory using a ‘meadow’ of artificial flowers harbouring ‘robotic’ crab spider predators. We found that while the ranking of bees along the speed and accuracy continuums was consistent across two levels of predation threat, there was some flexibility in the tactics used by individual bees – most bees became less accurate at colour discrimination when exposed to predation threat when flower types were rewarding. The relationship between decision speed and accuracy was influenced by predator detectability and the risk associated with making incorrect choices during the colour discrimination task. Predator crypsis resulted in a breakdown in the relationship between speed and accuracy, especially when making an incorrect floral choice incurred a distasteful quinine punishment. No single speed-accuracy tactic was found to be optimal in terms of foraging efficiency under either predation threat situation. However, bees that made faster decisions achieved higher nectar collection rates in predator free situations, while accurate bees achieved higher foraging rates under predation threat. Our findings show that while individual bees remain relatively consistent in terms of whether they place greater emphasis on speed or accuracy under predation threat, they can respond flexibly to the additional time costs of detecting predators. (shrink)

More and more in-vehicle systems are rapidly becoming commercially available, making the driving task more and more complex. Driving performance in such multiple-task situations depends primarily on the level of task demands imposed on the driver by certain situations. The higher the perceived task difficulty, the higher the workload level of that individual. The aim of this dissertation was therefore to investigate possible trade-offs between primary task and secondary task performance in a simulated driving environment. For this purpose, the effects (...) of a standardized secondary visual search task on the primary task of driving were evaluated and compared between several conditions. Even though there was a clear tendency to protect the primary task of driving, participants seemed incapable of fully prioritising the primary task of driving over the secondary search task at all times. (shrink)