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Whenever people engage in tasks where both, internal and external information is available for guidance, they have to trade off costs and benefits of each information source to decide on which one to rely. In this study, we aim to investigate the underlying processes involved in this decision and to test and confirm predictions derived from a rational cue-fixation model which has been developed based on preliminary and yet unpublished results. The way that participants are required to engage in this decision process here is through an experimental paradigm in which two tasks can be executed on the same display but only one of these tasks is rewarded at a time. Rewarded tasks can switch from trial to trial with a probability which is announced prior to each block. Task cues reveal the current task upon inspection. Participants can earn or lose money depending on the performance on any given trial. The block duration is limited which gives rise to the critical decision problem in every trial: should the subject inspect the cues to guarantee good performance but at the cost of time (and money)? In other words, the subject has to optimize the rate of cue inspections depending on the manipulated variables to generate an optimal payout. In one critical previous, unpublished and preliminary experiment similar to the current one, we compared old vs. young participants with regards to their cue checking rate. On average, older adults tend to check the task cues more often compared to their younger counterparts. At the same time, relative to young adults, older adults show longer reaction times in trials even without checking the cues (primary task duration), whereas the age difference in the costs of checking are relatively minor. Based on this finding, one could argue that for older participants, the relative time cost of checking cues is lower compared to younger participants. Put another way, the longer the primary task duration for a subject, the less of a cost additional cue checking carries. Thus, it could actually be considered adaptive for older adults to inspect cues more often. This is in line with what the rational cue-fixation model predicts. The main purpose of the present study is to experimentally manipulate the primary task duration and thereby the relative time cost of cue inspections. This is achieved by implementing two different levels of perceptual difficulty of the task (for further details, see Design Plan). As a consequence, it is expected that the cue checking rate is higher in the condition in which participants take longer. |
