A Cognitive examination of Top-down and Bottom-up Processes involved in the generation of False Auditory Perceptions: a Signal Detection analysis
Year: 2018
Type: dissertation
Abstract: In a recent model, Waters and colleagues (2012) proposes that auditory verbal hallucinations (AVH) arise in hallucination prone groups due to an interaction between cognitive top-down and bottom-up process. This interaction has yet to be properly empirically tested. By employing the use of a signal detection task, this study examined the effects of noise (bottom-up) and semantic expectancy (top-down) on healthy participants screened for hallucination proneness (n=43). Participants were asked to listen to semantically manipulated sentences where the last word of the sentence was embedded or replaced by two different noise types, where one was based on human language frequencies while the other was the opposite. The hallucination prone sample showed a greater tendency to reporting hearing the word in the noise regardless of its presence when exposed to trials where the noise contained human language frequencies and high semantic expectancy sentences. This supports the theoretical model that AVH arise due to an interaction between top-down and bottom-up processes. Additionally, through a series of questionnaires, it was found that encoding style predicted performance on the task. Considering the specific significance between group, noise type and semantic expectation, tentative assumptions about encoding style’s mediating effects on the interaction were made.
Author: Elena Sørvig
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2899336545