Master of Science (MS), Ohio University, 2013, Experimental Psychology (Arts and Sciences)

Temporal perception is known to be influenced by various contextual factors and a considerable portion of the literature has explored the relationship between subjective temporal estimates (STEs) and the complexity of dynamic environmental stimuli. In general, researchers have shown that increases in stimulus complexity result in subjective time dilation. That is, complex and dynamic stimuli tend to result in STEs that are longer than STEs for less complex stimuli. In the following, the influence of stimulus structure on the perceived duration of multiple time intervals is reviewed. In doing so, we discuss an alternative approach that has been used in previous research (Vigo & Zeigler, 2013). This approach precisely quantifies the structural complexity inherent to the visual display of a temporal judgment task and has successfully accounted for STEs across multiple time intervals. Our approach is based on categorical invariance theory and one of its models (the exponential categorical invariance model; Vigo, 2009, 2011a, 2011b, 2013) and was used to model estimations of duration by participants. Further, we describe how this work can be extended to account for additional experimental conditions. Finally, we provide a comprehensive review of stimulus based variables that affect temporal processing and place these findings in the context of the relationship between perceived duration and complexity.

Committee: Ronaldo Vigo (Committee Chair) Subjects: Cognitive Psychology

Master of Arts, The Ohio State University, 2010, Linguistics

The study addresses one of the important questions in the field of speech perception: whether listeners process speech categorically as discrete units or continuously attuning to variation within phonemes. Recent research has demonstrated that listeners were able to identify stimuli with sub-phonemic variation in stop voicing contrasts and use this information during lexical processing. The present study seeks further support for this view by building categorical and continuous models based on distribution of individual listeners' responses in a goodness rating task. Lexical items varying along seven-step continua in initial stop voicing or sibilant fricative place are tested and compared against the models. The results show that listeners' perception of sub-phonemic variation is more consistent with the continuous model of speech perception.

Committee: Mary Beckman PhD (Advisor); Shari Speer PhD (Committee Member) Subjects: Linguistics

Master of Arts (MA), Bowling Green State University, 2005, Psychology/Experimental

The human perceptual system demonstrates poorer performance when discriminating between two oblique angles, rather than when horizontal or vertical angles are involved, even if angular distance is constant. Previous research does not provide a clear picture though on the cause of this. Experiments have been conducted with results that suggest a form of Categorical Perception is occurring during angle discrimination, while other experiments have found results that do not suggest a form of Categorical Perception is occurring during angle discrimination. This study was conducted to attempt to bridge the gap between previously conducted experiments. Our findings suggest that the angled stimuli we used result in a Non-Categorical Perception of angle discrimination. However, another study, using more “object like” stimuli will need to be conducted to better understand the perceptual processes occurring during angle discrimination tasks.

Committee: Dale Klopfer (Advisor) Subjects: Psychology, Experimental