We rely heavily on our sense of touch to complete a myriad of tasks each day, yet past research focuses heavily on the visual and auditory systems, rarely concentrating on the tactile system. In the current study, we investigate human performance on a haptic categorization task and ask: what strategy do humans use to sense, interpret, and categorize objects using their sense of touch? During the experiment, participants complete 810 trials on which they receive a 3D printed object and categorize it as belonging to Category A or B. We sample the objects from a set of 25 objects, each of which differs in number of sides and dot spacing on one face. We define Categories A and B using overlapping Gaussian distributions, where Category A objects generally have fewer sides and smaller dot spacing, while Category B objects generally have more sides and larger dot spacing. Participants begin with no knowledge of the categories and learn them using feedback provided on each trial. We compared human performance to a Feature-Focused Bayesian Observer that weights the sides and dots feature information based on their reliability. It combines information from one or both features to inform a final percept and categorize each object. Our results support the hypothesis that humans employ a feature-focused categorization strategy on this task, during which they learn the categories and consider one or both of an object’s features based on their reliability. As participants complete more trials, they appear to maintain or switch to more optimal categorization strategies. Video analysis of hand movements during the experiment strongly supports these findings. / Thesis / Master of Science (MSc) / We use our senses every day to accomplish numerous categorization tasks: categorizing footsteps as originating from an ‘intruder’ or a ‘family member’, a distant animal as a ‘coyote’ or a ‘dog’, a writing utensil as a ‘pen’ or a ‘pencil’, and so on. Despite performing countless categorization tasks each day, we often overlook their complexity. Our research investigates the processing behind these tasks, specifically those tasks completed using the sense of touch. We conclude that people combine the most reliable information from their environments to determine the identity of an unknown object or stimulus. Moving forward, we can apply this deepened understanding of tactile processing to advance research in special populations and robotic applications.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/30295 |
| Date | January 2024 |
| Creators | Arthur, Grace |
| Contributors | Goldreich, Daniel, Psychology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.0031 seconds