Matching Items (2)
Filtering by
- All Subjects: Fluid Intelligence
- All Subjects: Ultrasound
- Creators: Duch, Carsten
Description
Neurostimulation methods currently include deep brain stimulation (DBS), optogenetic, transcranial direct-current stimulation (tDCS), and transcranial magnetic stimulation (TMS). TMS and tDCS are noninvasive techniques whereas DBS and optogenetic require surgical implantation of electrodes or light emitting devices. All approaches, except for optogenetic, have been implemented in clinical settings because they have demonstrated therapeutic utility and clinical efficacy for neurological and psychiatric disorders. When applied for therapeutic applications, these techniques suffer from limitations that hinder the progression of its intended use to treat compromised brain function. DBS requires an invasive surgical procedure that surfaces complications from infection, longevity of electrical components, and immune responses to foreign materials. Both TMS and tDCS circumvent the problems seen with DBS as they are noninvasive procedures, but they fail to produce the spatial resolution required to target specific brain structures. Realizing these restrictions, we sought out to use ultrasound as a neurostimulation modality. Ultrasound is capable of achieving greater resolution than TMS and tDCS, as we have demonstrated a ~2mm lateral resolution, which can be delivered noninvasively. These characteristics place ultrasound superior to current neurostimulation methods. For these reasons, this dissertation provides a developed protocol to use transcranial pulsed ultrasound (TPU) as a neurostimulation technique. These investigations implement electrophysiological, optophysiological, immunohistological, and behavioral methods to elucidate the effects of ultrasound on the central nervous system and raise questions about the functional consequences. Intriguingly, we showed that TPU was also capable of stimulating intact sub-cortical circuits in the anesthetized mouse. These data reveal that TPU can evoke synchronous oscillations in the hippocampus in addition to increasing expression of brain-derived neurotrophic factor (BDNF). Considering these observations, and the ability to noninvasively stimulate neuronal activity on a mesoscale resolution, reveals a potential avenue to be effective in clinical settings where current brain stimulation techniques have shown to be beneficial. Thus, the results explained by this dissertation help to pronounce the significance for these protocols to gain translational recognition.
ContributorsTufail, Yusuf Zahid (Author) / Tyler, William J (Thesis advisor) / Duch, Carsten (Committee member) / Muthuswamy, Jitendran (Committee member) / Santello, Marco (Committee member) / Tillery, Stephen H (Committee member) / Arizona State University (Publisher)
Created2011
Description
Previous research has yielded an equivocal answer as to whether speaking aloud while performing intelligence tasks improves, impairs, or has no effect on performance. Some studies show that it impairs performance while others show it aids performance. In the studies in which speaking aloud has been shown to help, only children and older adults benefitted. The present study investigated whether college-aged students benefit from speaking aloud while performing a fluid intelligence test. Subjects performed a battery of working memory and intelligence tasks silently. Once they had completed each task, the participants took them again, though this time they spoke aloud while completing the tests. Results showed that subjects did insignificantly worse on the working memory tests when speaking aloud. However, subjects performed significantly better on the measures of fluid intelligence while speaking aloud as opposed to doing them silently. At an individual differences level, low working memory capacity participants benefited more from speaking aloud than the high working memory ones. Finally, we found a positive correlation between working memory scores and fluid intelligence scores, offering further evidence that the two constructs are related, yet different.
ContributorsRice, Z. Douglas (Author) / Brewer, Gene (Thesis director) / Duch, Carsten (Committee member) / Ball, Hunter (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2012-12