Browsing by Author "Stephens, Jaclyn, advisor"

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Open Access
Evaluating attention allocation in children to young adults with a single and dual task EEG paradigm
(Colorado State University. Libraries, 2019) Cawthorne, Justine, author; Stephens, Jaclyn, advisor; Davies, Patricia, advisor; Fling, Brett, committee member
Objectives. The ability to effectively allocate attentional resources between tasks has implications for participation in activities of daily living (ADLs) and instrumental activities of daily living (IADLs) across the lifespan. Neuroimaging techniques, such as electroencephalography (EEG) can measure cognitive processing with more precision than some behavioral paradigms and can evaluate the neural underpinnings of cognitive processes such as attention. Further, EEG has excellent temporal resolution, as it can measure changes in attention occurring at the neural level in milliseconds. This study's purpose is to understand how neural markers of attention are impacted in neurotypical participants under different task demands (i.e. single versus dual). This study also seeks to understand if attention is different across age under different task demands. Methods. All EEG data were collected for this study using a portable QuickTrace system (Neuroscan (Compumedics USA, 5015 West WT Harris Blvd, Suite E, Charlotte, NC 28269, USA)) from 29 scalp sites according to the 10-20 system. Data from 206 neurotypical participants age 7-25 (M= 13.64 years, SD= 4.21) were analyzed for this study. Each participant completed the novelty oddball paradigm (single task) and novelty dual task paradigm. Three distinct tone types (standard, target, and novel) are used in the novelty oddball (NOD) paradigm. Participants were instructed to press a button with their right index finger in response to the target tone. Participants were instructed to not respond to any other tones. In the novelty dual task (NDT) paradigm, participants continued to respond to target tone and simultaneously viewed numbers displayed on a computer monitor. Participants were instructed to press a button with their left index finger when there were three sequentially-presented odd numbers. Results. P3 amplitude and latency from Fz and Pz scalp sites during target tone presentation were analyzed. There was a negative correlation between participant age and P3 amplitude and latency at both Fz and Pz. There was no main effect of task nor an interaction of task and age on either P3 amplitude or latency at Pz. However, there was a significant main effect of task on P3 amplitude at Fz, as single task amplitudes were smaller than dual task amplitudes. There was also a significant interaction of task and age for P3 amplitude at Fz, demonstrating that the P3 amplitude in response to dual tasks decreased more with increasing participant age than P3 amplitude in response to single tasks. A significant interaction of task and age for latency at Fz was found, demonstrating that the latency of the P3 in response to single tasks decreases more with increasing participant age than the latency in response to dual tasks. Conclusions. These findings suggest that attention changes with age and that dual tasks are more effortful in younger participants compared to older participants. Future directions of this research include exploration of how manipulating the probability of hearing each stimulus affects amplitude and latency of the P3 in a three-tone novelty paradigm. Other future directions include exploration of the effects of differing task demands in populations such as those who may have attention deficits.
Embargo
Investigating the neural mechanisms of rhythmic entrainment and auditory priming using EEG
(Colorado State University. Libraries, 2023) Mingils, Susan, author; Davies, Patricia, advisor; Stephens, Jaclyn, advisor; Atler, Karen, committee member; LaGasse, Blythe, committee member
A body of literature on rhythmic entrainment, the synchronization of behaviors to rhythmic stimuli in the environment, shows auditory rhythmic cuing can improve motor performance in neurotypical and clinical populations. This is thought to be driven by underlying communication, i.e., functional connectivity, between auditory and motor brain regions. Surprisingly, some clinical research shows rhythmic entrainment interventions, designed to enhance motor performance, may improve cognitive performance as well. However, it is unclear if improved cognitive performance during rhythmic entrainment reflects changes in functional connectivity. Evidence from cognitive neuroscience suggests rhythmic auditory stimuli may direct attentional resources through the synchronization of certain neural oscillations with the rhythmic pulse. Neural oscillations are repetitive patterns of brain activity which can be measured noninvasively at the scalp using electroencephalography (EEG). Measuring how neural oscillations from spatially distinct brain regions synchronize with each other reflects changes functional connectivity. Before functional connectivity during rhythmic entrainment can be studied, research is first needed to establish connectivity patterns when processing auditory rhythmic stimuli (auditory condition) and during self-paced rhythmic motor performance (motor condition), which was the goal of Study 1. Overall, the results of Study 1 provide evidence that the auditory condition may promote more efficient functional connectivity with increased activation in localized brain regions, while the motor condition may utilize long-range low-frequency neural oscillations to suppress activity in task-irrelevant brain regions to sustain attention. A recent EEG study by our lab compared the neural oscillations of participants who listened to auditory rhythmic stimuli presented for a little over five minutes (auditory-first group) to participants who completed a self-paced rhythmic motor task for about minutes (motor-first group) prior to tapping along to auditory rhythmic cues (rhythmic entrainment condition). One important finding was a greater "priming effect" in the auditory-first group, who showed reduced neural resources needed during rhythmic entrainment compared to the motor-first group. Thus, auditory priming, compared to motor priming, may result in a more efficient use of neural resources during rhythmic entrainment. However, the optimal duration of auditory priming to promote efficient brain and behavior function is unknown. Therefore, the goal of Study 2 was to determine how different durations of auditory priming affect brain efficiency in neurotypical individuals, as measured using EEG. Overall, the results of Study 2 found that a duration of about two minutes may be optimal for auditory processing of rhythmic stimuli. However, more research is needed to confirm if auditory priming reduces neural resources needed during rhythmic entrainment compared to no priming and if auditory priming improves motor performance. Rhythmic entrainment and auditory priming are both important principles of rhythm-based interventions used in rehabilitation. A better understanding of their neural mechanisms in neurotypical individuals provides a necessary foundation for future research examining these processes in clinical populations and as a component of clinical interventions.