Matching Items (2)
Description
Properly deciding to engage in or to withhold an action is a critical ability for goal-oriented movement control. Such decision may be driven by expected value from the choice of action but associating physical effort may discount such value. A novel anticipatory stopping task was developed to investigate effort discounted decision process potentially present in proactive inhibitory control. Subjects performed or abstained from target reach if they believed it was a Go or Stop trial respectively. Reward was awarded to a reach, correctly timed to hit a target at the same time as the moving bar in Go trials. During the Stop trials, correctly judging to not engage in a reach from the color of the moving bar that linked to the bar’s probability of stopping before the target resulted in gaining a reward. Resistive force field incurred additional physical effort for choosing to reach. Introducing effort expectedly decreased the tendency to respond at trials with higher stop probability. Surprisingly, tendency to respond increased and corresponding reaction time decreased in the trials with lower stop probability. Such asymmetric effect suggests that the value of context ineffective response is discounted, and the value of context effective response is flexibly enhanced by its associated effort cost to drive decision-process in goal-oriented manner. Medial frontal event related potential (ERP) locked to the onset of moving bar appearance reflected such effort discounted decision process. Theta band observed in Stop trials accounted for evaluation of effort and context possibly reinforcing such decision-making.
ContributorsTsuchiya, Toshiki (Author) / Santello, Marco (Thesis advisor) / Fine, Justin (Committee member) / McClure, Samuel (Committee member) / Arizona State University (Publisher)
Created2018
Description
The need to fully understand the possible consequences of young-adult cannabis use has become increasingly critical as a result of major cannabis policy changes. The purpose of this study was to determine if young-adult users exhibit cognitive deficits on laboratory-based tests and memory and attention deficits in everyday life. Participants were 152 students from a large U.S. university enrolled in introductory psychology courses and the top and bottom 10% of the 12-item Yale University PRIME Screening Test for psychotic-like experiences. Participants were asked about their cannabis use and were given six cognitive tests spanning executive function and memory. To test functional impairment in memory and attention, participants were asked to nominate informants (people who knew them well) and these rated the participants on an attention problems scale of four items and a memory problems scale of three items. Results showed that individuals who used cannabis more frequently were rated as having more attention and memory problems and that, consistent with prior research, more frequent cannabis use was associated with worse memory test performance, though the association was not present between frequency of use and executive function test performance. Additionally, it was found that informant-reported attention problems were associated with poorer performance on two of the executive function cognitive tests. The present findings suggest that individuals who use cannabis more frequently experience noticeable memory and attention problems in everyday life, despite the lack of significant correlation between this functional impairment and cognitive test performance. Informant reports, therefore, may be useful in future research for understanding or predicting cognitive impairment in young adults.
ContributorsCarbajal, Lucia (Author) / Meier, Madeline (Thesis director) / McClure, Samuel (Committee member) / Department of Psychology (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12