Rice J1, Cahalin L1, Corp D2, Swarowsky A3, Levine B4,5, Rundek T4,5, Gomes-Osman J1,4,5, McInerney K4,5
1University of Miami Miller School of Medicine, Physical Therapy, Coral Gables, United States, 2Deakin University, Melbourne, Australia, 3Santa Catarina State University (UDESC), Physical Therapy, Santa Catarina, Brazil, 4University of Miami Miller School of Medicine, Neurology, Miami, United States, 5Evelyn F. McKnight Brain Institute, University of Miami, Miami, United States
Background: Performance on the timed up-and-go (TUG), a measure of functional mobility, is related to mental function in healthy active adults. The single-task TUG is associated with general cognition, while a cognitive dual-task TUG is uniquely related to executive function and attentional capacity. However, it is not clear how different speeds (self-selected vs fast) and patterns of dual-task effects (DTE) during the TUG are related to neuropsychological tests of executive function, in sedentary older adults.
Purpose: The primary purpose of this study was to investigate the relationship between neuropsychological performance and TUG performance under normal, fast, and dual-task (DT) conditions in healthy sedentary adults. The secondary purpose was to investigate the relationship between DTE on both the cognitive and motor tasks in the TUG-DT condition and neuropsychological performance.
Methods: We enrolled 13 sedentary older adults (59.2±5.2 years, 5 males) with sedentary defined as performing physical exercise twice in the past two months. Attention and executive function were assessed using the Stroop, Delis-Kaplan Executive Function System (DKEFS) verbal fluency, and the Repeated Battery for the Assessment of Neuropsychological Status (RBANS) digit span and coding. The TUG battery included 2 trials each of a self-selected pace, fast pace, and dual-task TUG (TUG-self, TUG-fast, and TUG-DT respectively). The secondary cognitive task was serial-7 subtractions, with correct response rate measured in sitting to assess baseline single-task performance. The DTE was calculated for both motor and cognitive performance (DTE-TUG, DTE-response) with a negative value indicating a decrement in performance (DT-cost). Spearman's rho was used to investigate the relationship between cognitive performance measured by neuropsychological testing and TUG scores.
Results: As expected the TUG-DT had the longest duration (M=10.35, SD ±2.63) followed by the TUG-self (M=8.9sec, SD ±1.2) and TUG-fast (M=6.8sec, SD±0.79). The mean DTE-TUG was -37.63% (SD±51.6%) and DTE-response -16.29% (SD±24.02%) with no significant differences between the DTE (p=.19) measured by a t-test.
The TUG-self and TUG-fast were correlated with processing speed tasks embedded in the Stroop, specifically with Stroop Color (rs (12)=601, p=.001) and Stroop Word (rs =-.669, p=.012) respectively. The TUG-DT was correlated to DKEFS phonemic fluency (rs = -.648, p=.017), DKEFS switching fluency (rs =-.808, p=.001), DKEFS switching accuracy (rs =-.714, p=.006), and RBANS coding (rs=-.663, p=.014). The DTE-TUG was correlated to DKEFS phonemic fluency (rs =.651, p=.016) and DTE-response to Stroop Color-Word (rs=.721, p=.005), and Stroop Interference (rs =.599, p=.030).
Conclusion(s): TUG-DT performance shows moderate to high correlations with multiple measures of verbal fluency, mental switching and attention, while the TUG-self and TUG-fast were moderately correlated with processing speed tasks. The cognitive DTE was moderately correlated to response inhibition measured by the Stroop Interference score while motor DTE was correlated to phonemic fluency.
Implications: This study suggests that TUG-DT relies on different elements of executive function compared to the single-task TUG. Additionally, raw performance measured by different TUG tasks and overall DTE seem to utilize unique elements of cognition.
Keywords: Dual-task, Cognition, Executive Function
Funding acknowledgements: Dr. Gomes-Osman was supported by a Miami Evelyn F. McKnight Brain Institute Internal Pilot Grant.
Purpose: The primary purpose of this study was to investigate the relationship between neuropsychological performance and TUG performance under normal, fast, and dual-task (DT) conditions in healthy sedentary adults. The secondary purpose was to investigate the relationship between DTE on both the cognitive and motor tasks in the TUG-DT condition and neuropsychological performance.
Methods: We enrolled 13 sedentary older adults (59.2±5.2 years, 5 males) with sedentary defined as performing physical exercise twice in the past two months. Attention and executive function were assessed using the Stroop, Delis-Kaplan Executive Function System (DKEFS) verbal fluency, and the Repeated Battery for the Assessment of Neuropsychological Status (RBANS) digit span and coding. The TUG battery included 2 trials each of a self-selected pace, fast pace, and dual-task TUG (TUG-self, TUG-fast, and TUG-DT respectively). The secondary cognitive task was serial-7 subtractions, with correct response rate measured in sitting to assess baseline single-task performance. The DTE was calculated for both motor and cognitive performance (DTE-TUG, DTE-response) with a negative value indicating a decrement in performance (DT-cost). Spearman's rho was used to investigate the relationship between cognitive performance measured by neuropsychological testing and TUG scores.
Results: As expected the TUG-DT had the longest duration (M=10.35, SD ±2.63) followed by the TUG-self (M=8.9sec, SD ±1.2) and TUG-fast (M=6.8sec, SD±0.79). The mean DTE-TUG was -37.63% (SD±51.6%) and DTE-response -16.29% (SD±24.02%) with no significant differences between the DTE (p=.19) measured by a t-test.
The TUG-self and TUG-fast were correlated with processing speed tasks embedded in the Stroop, specifically with Stroop Color (rs (12)=601, p=.001) and Stroop Word (rs =-.669, p=.012) respectively. The TUG-DT was correlated to DKEFS phonemic fluency (rs = -.648, p=.017), DKEFS switching fluency (rs =-.808, p=.001), DKEFS switching accuracy (rs =-.714, p=.006), and RBANS coding (rs=-.663, p=.014). The DTE-TUG was correlated to DKEFS phonemic fluency (rs =.651, p=.016) and DTE-response to Stroop Color-Word (rs=.721, p=.005), and Stroop Interference (rs =.599, p=.030).
Conclusion(s): TUG-DT performance shows moderate to high correlations with multiple measures of verbal fluency, mental switching and attention, while the TUG-self and TUG-fast were moderately correlated with processing speed tasks. The cognitive DTE was moderately correlated to response inhibition measured by the Stroop Interference score while motor DTE was correlated to phonemic fluency.
Implications: This study suggests that TUG-DT relies on different elements of executive function compared to the single-task TUG. Additionally, raw performance measured by different TUG tasks and overall DTE seem to utilize unique elements of cognition.
Keywords: Dual-task, Cognition, Executive Function
Funding acknowledgements: Dr. Gomes-Osman was supported by a Miami Evelyn F. McKnight Brain Institute Internal Pilot Grant.
Topic: Older people; Health promotion & wellbeing/healthy ageing
Ethics approval required: Yes
Institution: University of Miami
Ethics committee: University of Miami Institutional Review Board
Ethics number: 20161059
All authors, affiliations and abstracts have been published as submitted.
