The relative importance of pre-exposure schedule and the instructions on perceptual learning effect

This thesis examined the relative importance of the exposure schedules and the directive presented to the participants at the exposure stage on the perceptual learning effect. For this purpose, two experiments were conducted in which 201 people (113 female, 88 male) participated in total. The experiments consisted of two phases, exposure and testing. Experiment 1 was carried out with an instruction "aiming to direct attention to the distinctive features of stimuli" to all participant except for the Control group. During the 30 times pre-exposure trials, the participants were expected to look at the pairs of stimuli presented on the screen. The pre-exposure phase of Experiment 1 was conducted with two different exposure schedule for Group Simultaneous and Group Block. For Group Simultaneous, two different stimuli were presented side by side and simultaneously on the screen, while for Group Block, two different stimulus blocks were presented in trials. Immediately after the completion of the exposure phase, the testing phase started. In the control group, on the other hand, the direct test phase was started without the pre-exposure phase. During 60 test trials consisting of three blocks, the participants were expected to carry out the target detection task. It was evaluated whether the perceptual learning effect was observed by comparing the achievements of the groups in the taget detection task. In Experiment 2, it was carried out with 7 groups as Group Simultaneous with instruction, Group Simultaneous without instruction, Group Block with instruction, Group Block without instruction, Group Intermixed with instruction, Group Intermixed without instruction and Control Group. Groups with instruction was presented to the instruction in Experiment 1; Groups without instructions were presented with an instruction "emphasizing that they should only look at the stimuli". In the exposure phase of Experiment 2, the stimuli exposure schedule for two Group Simultaneous and two Group Block was carried out as in Experiment 1. In the exposure phase of Group Intermixed added to Experiment 2, the participants were exposed to the stimuli in a mixed order and successively. In the control group, the direct test phase was started without the pre-exposure phase. The testing phase proceeded as in Experiment 1 for all groups. In Experiment 1, the perceptual learning effect was found only for Group Simultaneous; In Experiment 2, the best perceptual learning performance was found for Group Simultaneous, regardless of the instruction condition. The results were evaluated in terms of different theoretical perspectives.