Matching Items (16)
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- All Subjects: Executive Function
- Creators: Ringenbach, Shannon
- Creators: Azuma, Tamiko
- Creators: School of Nutrition and Health Promotion
Description
It is commonly known that the left hemisphere of the brain is more efficient in the processing of verbal information, compared to the right hemisphere. One proposal suggests that hemispheric asymmetries in verbal processing are due in part to the efficient use of top-down mechanisms by the left hemisphere. Most evidence for this comes from hemispheric semantic priming, though fewer studies have investigated verbal memory in the cerebral hemispheres. The goal of the current investigations is to examine how top-down mechanisms influence hemispheric asymmetries in verbal memory, and determine the specific nature of hypothesized top-down mechanisms. Five experiments were conducted to explore the influence of top-down mechanisms on hemispheric asymmetries in verbal memory. Experiments 1 and 2 used item-method directed forgetting to examine maintenance and inhibition mechanisms. In Experiment 1, participants were cued to remember or forget certain words, and cues were presented simultaneously or after the presentation of target words. In Experiment 2, participants were cued again to remember or forget words, but each word was repeated once or four times. Experiments 3 and 4 examined the influence of cognitive load on hemispheric asymmetries in true and false memory. In Experiment 3, cognitive load was imposed during memory encoding, while in Experiment 4, cognitive load was imposed during memory retrieval. Finally, Experiment 5 investigated the association between controlled processing in hemispheric semantic priming, and top-down mechanisms used for hemispheric verbal memory. Across all experiments, divided visual field presentation was used to probe verbal memory in the cerebral hemispheres. Results from all experiments revealed several important findings. First, top-down mechanisms used by the LH primarily used to facilitate verbal processing, but also operate in a domain general manner in the face of increasing processing demands. Second, evidence indicates that the RH uses top-down mechanisms minimally, and processes verbal information in a more bottom-up manner. These data help clarify the nature of top-down mechanisms used in hemispheric memory and language processing, and build upon current theories that attempt to explain hemispheric asymmetries in language processing.
ContributorsTat, Michael J (Author) / Azuma, Tamiko (Thesis advisor) / Goldinger, Stephen D (Committee member) / Liss, Julie M (Committee member) / Arizona State University (Publisher)
Created2013
Description
Military veterans have a significantly higher incidence of mild traumatic brain injury (mTBI), depression, and Post-traumatic stress disorder (PTSD) compared to civilians. Military veterans also represent a rapidly growing subgroup of college students, due in part to the robust and financially incentivizing educational benefits under the Post-9/11 GI Bill. The overlapping cognitively impacting symptoms of service-related conditions combined with the underreporting of mTBI and psychiatric-related conditions, make accurate assessment of cognitive performance in military veterans challenging. Recent research findings provide conflicting information on cognitive performance patterns in military veterans. The purpose of this study was to determine whether service-related conditions and self-assessments predict performance on complex working memory and executive function tasks for military veteran college students. Sixty-one military veteran college students attending classes at Arizona State University campuses completed clinical neuropsychological tasks and experimental working memory and executive function tasks. The results revealed that a history of mTBI significantly predicted poorer performance in the areas of verbal working memory and decision-making. Depression significantly predicted poorer performance in executive function related to serial updating. In contrast, the commonly used clinical neuropsychological tasks were not sensitive service-related conditions including mTBI, PTSD, and depression. The differing performance patterns observed between the clinical tasks and the more complex experimental tasks support that researchers and clinicians should use tests that sufficiently tax verbal working memory and executive function when evaluating the subtle, higher-order cognitive deficits associated with mTBI and depression.
ContributorsGallagher, Karen Louise (Author) / Azuma, Tamiko (Thesis advisor) / Liss, Julie (Committee member) / Lavoie, Michael (Committee member) / Arizona State University (Publisher)
Created2017
Description
This study examines cognitive planning in adolescents with Down syndrome (DS) following an 8-week assisted cycling therapy intervention. Forty-three participants were randomly assigned to assisted cycling (AC) (i.e., at least 30% faster than self-selected cadence accomplished by a motor), voluntary cycling (VC) (self-selected cadence), and no cycling (NC) control group. Both AC and VC rode a stationary bicycle three times/week, 30 minutes/session, for eight weeks in duration. Participants completed cognitive testing that assessed cognitive planning at the beginning (i.e., pretest) and end (i.e., posttest) of the 8-week intervention. Consistent with our hypothesis, the results showed that cognitive planning improved following eight weeks of cycling for the AC group. The same results were not seen for individuals in the VC or NC groups. Our results suggest that assisted cycling therapy may induce permanent changes in the prefrontal cortex in adolescents with DS.
ContributorsMillar, Kelsey Leann (Author) / Ringenbach, Shannon (Thesis director) / Amazeen, Eric (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
This study examines cognitive and motor function in adolescents with Down syndrome (DS) following an 8-week assisted cycling therapy intervention. Forty-four participants were randomly assigned to three groups consisting of an assisted cycling (AC) (i.e., exercise accomplished through the use of a motor), a voluntary cycling (VC) (self-selected cadence), and a no cycling (NC) control group. Both ACT and VC groups rode a stationary bicycle for three 30-minute sessions a week, for a total of eight weeks. Participants completed cognitive testing that assessed information processing and manual dexterity at the beginning and at the end of the 8-week intervention. Consistent with our hypothesis, the results showed that information processing and manual dexterity improved following 8 weeks of cycling for the ACT group. These results were not seen for individuals in the voluntary and non-exercise groups. Our results suggest that assisted cycling therapy may induce permanent changes in the prefrontal cortex in adolescents with DS.
ContributorsJimenez, Andrew (Author) / Ringenbach, Shannon (Thesis director) / Kulinna, Pamela (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
Adaptive behavior consists of the social, conceptual and practical skills an individual must execute to function independently in their everyday life. Individuals with Down syndrome have limitations in their adaptive behavior due to cognitive and physical deficits. The aim of this study was to examine if an exercise program would improve the adaptive behavior skills in persons with Down syndrome. The exercise intervention, Exercise for Adults with Down Syndrome (ExDS), was a semester long program where adults with Down syndrome participate in twice weekly workouts planned and executed by Arizona State University students. The workouts consisted of an aerobic warm up, aerobic exercises, resistance exercises, balance exercises and stretches. The participants' adaptive behavior and cognitive planning ability were assessed before ExDS and after ExDS. The Adaptive Behavior Assessment System Second Edition (ABAS-II) was used to measure adaptive behavior. The ABAS-II consisted of a forum that addressed the Social, Conceptual and Practical domains of adaptive behavior and was filled out by the participants' caregiver. The Tower of London (ToL) was used to measure cognitive planning ability. The change in the ABAS-II scores from pre- to post-testing were statistically insignificant. The change from pre- to post-testing in the ToL scores approached statistical significance. Limitations included bias caregiver perception and respondent inconsistency. There is a need for further research on the effect of exercise on the adaptive behavior in adults with Down syndrome.
ContributorsRoss, Alexandra Jill (Author) / Holzapfel, Simon (Thesis director) / Ringenbach, Shannon (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
This study examines the one month retention of executive function benefits gained by adolescents with Down syndrome after an 8-week aerobic exercise intervention. Sixteen participants were randomly divided between voluntary (VC) (i.e., self-selected cadence) and assisted (AC) (i.e., 30% faster than self-selected cadence accomplished by a motor) cycling groups, with one participant used as a control (NC). Both cycling groups rode a stationary bicycle, for 30 minutes, three times a week, for eight weeks. At the beginning (i.e., pretest) and end (posttest) of the 8-week session, three executive functions including: set-switching, inhibition, and cognitive planning, were tested. Approximately one month after the posttest, all participants underwent the cognitive testing again. The results showed that for the AC group cognitive planning improved after eight weeks of assisted cycling and these improvements were maintained after one month of no cycling. However, no significant differences were found between the cycling groups for our measure of inhibition. Set-switching appeared to be improved by both types of exercise, rather than only assisted, but the improvements were not maintained during the one month retention period for either group. Thus, our results suggest that Assisted Cycling causes potentially permanent changes in the brain in regards to cognitive planning.
ContributorsRichter, Madeline B. (Author) / Ringenbach, Shannon (Thesis director) / Amazeen, Eric (Committee member) / Maraj, Brian (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
The aim of this study was to examine the influence of Assisted Cycling Therapy (ACT) on information processing measured by simple reaction time in older adults with Down Syndrome (DS). Twenty-one participants were randomly assigned to one of three interventions over eight weeks. 1) Eleven older adults with Down Syndrome completed the ACT intervention, which is stationary cycling with the assistance of a motor to maintain a cadence at least 35% greater than voluntary cycling. 2) Eight older adults with Down Syndrome completed the voluntary cycling (VC) intervention and 3) two older adults with Down Syndrome were in our no cycling (NC) intervention. Both exercise groups participated in the eight-week, supervised exercise protocol for at least three, 30-minute sessions per week. None of our results reached conventional levels of significance. However, the greatest improvements in reaction time occurred following the voluntary cycling (VC) intervention. Our results are discussed with respect to physiological differences in older adults with DS that may limit improvements in executive function following exercise. These physiological differences and limitations include muscle atrophy and reduced perceptions, age related latency between motor cortex activation and onset of muscle activity, as well as general age related slowing in reaction time. Although it may be difficult to improve executive function in older adults with DS, we suggest other benefits to exercise which include improving social communication, gross motor skills, and exercise perception. Future research should continue to investigate the effects of exercise on multiple areas in older adults with DS with the hopes of improving quality of life.
ContributorsCahill, Colleen Mary (Author) / Ringenbach, Shannon (Thesis director) / Amazeen, Eric (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Executive function is vital for activities of daily living especially in stroke survivors because it is critical to everyday tasks (e.g., driving, cooking, etc.). An innovative way to improve executive function may be Assisted Cycling Therapy (ACT). This is among the first studies to use a Stroop task to measure inhibition, selective attention, and information processing speed following ACT in stroke survivors. Twenty-three participants post-stroke performed ACT, voluntary cycling (VC) and no cycling (NC). The results showed that there were improvements in the Stroop task following an acute session of ACT but not following VC or NC. These results suggest that ACT resulted in increased afferent information which may have resulted in increased arousal and excitability in regions of the prefrontal cortex. These factors have been shown to improve executive function.
ContributorsCooper, Aspen (Author) / Ringenbach, Shannon (Thesis director) / Holzapfel, Simon (Committee member) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The influence of exercise on cognitive function is an important topic. This study examines the effects of different interventions on executive functioning, specifically on cognitive planning, which is a sub-category of executive function, in adults with Down syndrome. Research has shown that an acute bout of Assisted Cycle Therapy improved manual motor functioning, cognitive planning, and information processing in adolescents with Down syndrome but there is a lack of research when it comes to resistance training. Fourteen adults with Down syndrome completed acute sessions of Assisted Cycle Therapy, Resistance Training, and No Training. Cognitive planning was measured by the Tower of London test. The results show that cognitive planning can be improved following Assisted Cycle Therapy. An increase in cognitive planning was also present in the No Training group which may be a result of cognitive stimulating games that were played. In conclusion, this study suggests that teachers, therapists, etc. that work with adults with DS, should be sure to include a cognitive component in all activities.
ContributorsMyer, Brandon Michael (Author) / Ringenbach, Shannon (Thesis director) / Arnold, Nathanial (Committee member) / Morgan, Don (Committee member) / College of Health Solutions (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
This study examines the effectiveness of two modes of exercise on inhibitory control in adults with Down Syndrome (DS). Thirteen participants attended four sessions: a baseline assessment, an Assisted Cycling Therapy (ACT) session, a Resistance Training (RT) session, and a session of No Training (NT). In the baseline assessment, 1-repetition max (1RM) measurements and voluntary pedal rate measurements were taken. In the resistance training session, the leg press, chest press, seated row, leg curl, shoulder press, and latissimus pulldown were performed. In the cycling intervention, the participant completed 30 minutes of cycling. The Erikson Flanker task was administered prior to each session (i.e., pretest) and after the intervention (i.e., post-test). The results were somewhat consistent with the hypothesis that inhibition time improved more following RT and ACT than NT. there was also a significant difference between ACT and NT. Additionally, it was hypothesized that all measures would improve following each acute exercise intervention, but the most significant improvements were seen following ACT. In conclusion, an acute session of ACT demonstrated a significant trend towards improvements in inhibitory control in adults with DS which we interpreted using a model of neural changes.
ContributorsHayes, Claire (Author) / Ringenbach, Shannon (Thesis director) / Arnold, Nate (Committee member) / Rand, Miya (Committee member) / Edson College of Nursing and Health Innovation (Contributor) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05