@phdthesis{TuerkPereira2010,
  author    = {T{\"u}rk Pereira, Philippe},
  title     = {Testing the sour-grapes effect - how food deprivation and reward expectancy change implicit and explicit food-liking and food-wanting},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-50591},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {The aim of the present thesis was to explore how food deprivation and reward expectancy versus frustrative nonreward change implicit and explicit food-liking and food-wanting. As a result, Experiment 1-3 were successful in revealing that liking- and wanting-related associations toward food stimuli dissociate as a function of food deprivation, given that participants were not rewarded with real food during the experiment. More specifically, whereas food-deprived participants showed more wanting-related associations toward food stimuli than satiated participants, the liking-related associations did not differ across both conditions of hunger. Overall, this effect could be replicated in 3 experiments using different manipulations of nonreward versus reward expectancy. However, neither food deprivation nor nonreward were found to influence participants' self-reported mood and frustration. Moreover, participants of Experiment 2 anticipating food consumption showed the same liking- and wanting-related responses due to food deprivation than participants in the nonreward condition. But providing participants with individual control over food consumption abolished the dissociation of liking- and wanting-related associations. In this condition, however, participants' liking- and wanting-related associations were not moderated by need state, maybe due to the (partial) consumption of snack food before the implicit attitude assessment. This, in turn, may have reduced participants' disposition to respond with more liking- and wanting-related associations when being hungry. Finally, Experiment 4 revealed that the presentation of need-relevant vs. need-irrelevant stimuli prompted different liking-related associations depending on the time participants had fasted before the experiment. Specifically, it could be demonstrated that whereas moderately-hungry compared to satiated participants responded with more positive associations toward need-relevant stimuli, 15 hours food-deprived participants responded with more negative associations compared to moderately-hungry and satiated participants. Respectively, a significant curvilinear function of need state was obtained. In addition, participants were found to immediately respond more negatively to need-irrelevant stimuli as soon as they became moderately hungry, evidencing devaluation effects (see Brendl, Markman, \& Messner, 2003) to also occur on an implicit level of responding. Contrary to the implicit liking- and wanting-related evaluations, self-reported explicit food-liking and food-wanting did not dissociate as a function of food deprivation and nonreward, revealing that participants' explicit self-reports of food-liking and food-wanting did not mirror their implicit responses. As the most important result, it could be demonstrated that explicit food-liking and food-wanting varied positively as a function of need state. The results were discussed on the background of different theoretical assumptions on the malleability of implicit and explicit need-relevant attitudes (e.g. motivational theories, frustrative nonreward).},
  subject      = {Hunger},
  language  = {en}
}
@phdthesis{Schmidt2012,
  author    = {Schmidt, Gerald},
  title     = {The Influence of Anticipation and Warnings on Collision Avoidance Behavior of Attentive Drivers},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-73789},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {This thesis deals with collision avoidance. Focus is on the question of under which conditions collision avoidance works well for humans and if drivers can be supported by a Forward Collision Warning (FCW) System when they do not react appropriately. Forward Collision Warning systems work in a way that tries to focus the driver's attention in the direction of the hazard and evoke an avoidance reaction by some sort of alert (e.g., tone or light). Research on these warning systems generally focuses on inattention and distraction as the cause for crashes. If the driver is inattentive, the results of a crash are thought to be worse as the driver's reaction is belated or might not mitigate the crash at all. To ensure effectiveness in the worst case, most of the experiments studying FCW systems have been conducted with visually distracted drivers. Research on the cause and possible countermeasures for crashes of attentive drivers are hardly available, although crash databases and field operational test data show that 40-60\% of the drivers look at the forward scene shortly before they crash. Hence, only a few studies elaborated on ideas about the reasons for crashes with attentive drivers. On the basis of the literature, it is worked out that one reason for delayed avoidance behavior can be an incorrect allocation of attention. It is further elaborated that high level attention processes are strongly influenced by interpretation of the situation and the anticipation of future status. Therefore, it is hypothesized that alert drivers react later when they can not foresee a potential threat or even when they misinterpret the situation. If the lack of threat anticipation or incorrect anticipation is a reason for crashes, a FCW system could be a great help, when the FCW is easily comprehensible. It is hypothesized that a FCW can compensate for missing threat anticipation in the driver. The results of the experiments show that the level of threat anticipation has the largest influence on driver behavior in an imminent crash situation. The results further suggest that FCW systems - especially warnings of audible or haptic modality - can help attentive drivers who do not anticipate a threat or misinterpret a situation. The negative influence of missing or mislead threat anticipation on objective measures was small when the threat appeared suddenly. This is thought to be due to the visual appearance of the introduced threat. It is assumed that this type of stimulus triggers a lower level attentional process, as opposed to a top-down attention process controlled by an anticipatory process. In the other scenario types such a lower level process may not be triggered. An important result of the second study is that (Forward) Collision Warnings have to be learned. Participants with warnings reacted slower than participants without any FCW in the first critical event. Participants with a visual warning reacted particularly slow. Later in the experiment, the probands with warnings were constantly faster than their counterparts without them. Hence, the results of this study suggest that a haptic or audible modality should be used as a primary warning to the driver. The characteristic of visual warnings to draw the visual attention is both a blessing and a curse. It is suggested to use the visual warning component for only a short period of time to attract the driver's attention to the forward scene, but then end the display to not further distract him. Car manufacturers try to avoid as many unnecessary alarms as possible. If driver monitoring would be available, it is often planned to suppress warnings when the driver is looking through the windshield. The results suggest not to do so. If a driver reaches a critical situation represented by a low Time-to-collision (TTC) or a high need to decelerate, he should always get a warning, unless he is already braking or steering. The most important arguments for this are: - Looking at the street does not mean that the driver has the correct situational awareness. - The driver has to learn the meaning of the warning. - The driver will not be annoyed by a warning when the situation is considered critical.},
  subject      = {Zusammenstoss},
  language  = {en}
}
@phdthesis{Kass2019,
  author    = {Kaß, Christina},
  title     = {Unnecessary Alarms in Driving: The Impact of Discrepancies between Human and Machine Situation Awareness on Drivers' Perception and Behaviour},
  doi       = {10.25972/OPUS-19252},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-192520},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Forward Collision Alarms (FCA) intend to signal hazardous traffic situations and the need for an immediate corrective driver response. However, data of naturalistic driving studies revealed that approximately the half of all alarms activated by conventional FCA systems represented unnecessary alarms. In these situations, the alarm activation was correct according to the implemented algorithm, whereas the alarms led to no or only minimal driver responses. Psychological research can make an important contribution to understand drivers' needs when interacting with driver assistance systems. The overarching objective of this thesis was to gain a systematic understanding of psychological factors and processes that influence drivers' perceived need for assistance in potential collision situations. To elucidate under which conditions drivers perceive alarms as unnecessary, a theoretical framework of drivers' subjective alarm evaluation was developed. A further goal was to investigate the impact of unnecessary alarms on drivers' responses and acceptance. Four driving simulator studies were carried out to examine the outlined research questions. In line with the hypotheses derived from the theoretical framework, the results suggest that drivers' perceived need for assistance is determined by their retrospective subjective hazard perception. While predictions of conventional FCA systems are exclusively based on physical measurements resulting in a time to collision, human drivers additionally consider their own manoeuvre intentions and those attributed to other road users to anticipate the further course of a potentially critical situation. When drivers anticipate a dissolving outcome of a potential conflict, they perceive the situation as less hazardous than the system. Based on this discrepancy, the system would activate an alarm, while drivers' perceived need for assistance is low. To sum up, the described factors and processes cause drivers to perceive certain alarms as unnecessary. Although drivers accept unnecessary alarms less than useful alarms, unnecessary alarms do not reduce their overall system acceptance. While unnecessary alarms cause moderate driver responses in the short term, the intensity of responses decrease with multiple exposures to unnecessary alarms. However, overall, effects of unnecessary alarms on drivers' alarm responses and acceptance seem to be rather uncritical. This thesis provides insights into human factors that explain when FCAs are perceived as unnecessary. These factors might contribute to design FCA systems tailored to drivers' needs.},
  subject      = {Fahrerassistenzsystem},
  language  = {en}
}