Degree

Doctor of Philosophy (PhD)

Department

Cognitive and Brain Science

Document Type

Dissertation

Abstract

Successful semantic cognition requires that we encode the meaning of objects around us and their relationship to other items and to us, as well as extract that information in a task relevant way. The kind of semantic task as well as the context we are performing the task in dictate the degree of top-down cognitive control necessary to provide task-relevant responses. Recent models of semantic control posit that context can facilitate automatic retrieval of information that is suited to the task and context at hand, though none have tested this model with a real-world ecologically valid context manipulation. The studies in this dissertation were designed to address gap by 1) providing evidence of a neural dissociation for context-related processing vs. category processing, 2) establishing behavioral differences in word association generation when responding in a child-oriented context versus to a rule, and 3) testing these association abilities in an autistic population that typically experience difficulties in social cognition and semantic processing. We find that participants are better able to access semantic information tied to how items relate in contexts when that information is required by the task as well as inhibit that information when the task emphasizes relationships along categorical features. This selective access of information is less obvious for items that relate categorically. We also observe that word association responses in a child-oriented context consistently show characteristics of child-directed speech, even under additional cognitive load, whereas responses in a condition requiring following an explicit rule (i.e., respond with short words) are much more susceptible to load. This suggests a facilitation effect for familiar contexts on semantic retrieval. Autistic adults show similar performance on the child-oriented task compared to non-autistic adults and even inhibit their natural inclination for creative responses when in the context of responding to a child. These studies suggest that context may facilitate automatic processing by emphasizing relevant information pre-retrieval, while other kinds of explicit rule-based retrieval rely more on top-down domain general executive control.

Date

7-7-2026

Committee Chair

Cox, Christopher R.

LSU Acknowledgement

1

LSU Accessibility Acknowledgment

1

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