Exp Brain Res (2015) 233:1181–1188 DOI 10.1007/s00221-015-4196-x
RESEARCH ARTICLE
A 3‑month intervention of Dance Dance Revolution improves interference control in elderly females: a preliminary investigation Lan‑Ya Chuang · Hsiao‑Yun Hung · Chung‑Ju Huang · Yu‑Kai Chang · Tsung‑Min Hung
Received: 6 August 2014 / Accepted: 4 January 2015 / Published online: 17 January 2015 © Springer-Verlag Berlin Heidelberg 2015
Abstract Exercise regimens suitable to the elderly remain under investigated; therefore, this study examined the effects of Dance Dance Revolution (DDR) on cognitive control in elderly females. Twenty-six healthy elderly females leading a sedentary lifestyle were assigned to a DDR, brisk walking, or control group. Participants in the DDR and brisk walking groups engaged in moderate physical exercise three times per week for 3 months, whereas the control group maintained a sedentary lifestyle. Each participant performed a flanker task before and after the intervention. The results revealed that both DDR and brisk walking shortened reaction time, N2 latency, and P3 latency relative to those of the control group. These findings suggest that DDR intervention is as effective as that of brisk walking in improving inhibitory control for elderly people. Therefore, DDR can be used as a viable alternative exercise to enhance cognitive function for the elderly and motivate individuals who are less willing to be active.
L.‑Y. Chuang · T.‑M. Hung (*) Department of Physical Education, National Taiwan Normal University, No. 162, Sec. 1, Heping E. Rd., Da’an Dist., Taipei City 106, Taiwan, ROC e-mail: [email protected] H.‑Y. Hung Department of Physical Education, University of Taipei, Taipei, Taiwan C.‑J. Huang Graduate Institute of Sport Pedagogy, University of Taipei, Taipei, Taiwan Y.‑K. Chang Graduate Institute of Athletics and Coaching Science, National Taiwan Sport University, Taoyuan, Taiwan
Keywords Executive function · Event-related potential · Aging · Exergame · Cognition
Introduction Given that the proportion of elderly people aged 65 and over in the world is expected to increase drastically over the next few decades, which will be accompanied by a major financial impact on the healthcare system (WHO 2012), there is an urgent need for measures that enhancing an independent lifestyle into old age. Aging can culminate in memory loss, reduced learning ability, and the degradation of cognitive function, all of which undermine the independence of older people in their activities of daily living and generate stress on the family, society, the healthcare system, and the economy (Pang et al. 2002). Kramer et al. (1999) indicated that physical exercise (PE) can decrease the risk of cognitive decline and cognitive impairment in old age by inducing changes in hippocampal structure (Cotman et al. 2007), increasing brain-derived neurotrophic factor (Neeper et al. 1995), insulin-like growth factor (Carro et al. 2001), and increasing neurogenesis in the dentate gyrus (van Praag et al. 1999). Moreover, the greater amounts of PE and higher fitness levels are associated with increased gray matter volume; greater white matter integrity (Colcombe et al. 2006); elevated functional dynamics, including heightened connectivity of fronto-parieto-hippocampal circuits (Colcombe et al. 2004); and enhanced cognitive performance (Colcombe and Kramer 2003; Smith et al. 2010). Executive function is particularly sensitive to the effects of aging but may benefit most from the impact of PE (Colcombe and Kramer 2003). Interference control, an important aspect of executive function (Kok 1999), involves
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the detection and resolution of conflicts (Carter and van Veen 2007; Friedman and Miyake 2004) and facilitates relational reasoning (Krawczyk et al. 2004, 2005; Markman 1997). Those abilities are important for performing instrumental activities of daily living. Several studies using flanker paradigms have demonstrated a positive relationship between PE and/or aerobic fitness and interference control in the elderly. Colcombe et al. (2004) found that, in comparison with the control, brisk walking three times per week for 6 months significantly improved cardiovascular capacity and reduced behavioral conflict. Similarly, Voelcker-Rehage et al. (2011) revealed that both cardiovascular training and coordination training led to a significant improvement in flanker accuracy across a 12-month study interval. Furthermore, studies with event-related potential (ERP), which was characterized by high temporal resolution suitable for revealing the underlying neurocognitive processes, have shown that the amplitude of N2, an ERP component that reflects the processes of response conflict monitoring in a flanker task (Folstein and Van Petten 2008), was smaller in individuals who were more fit compared with individuals who were less fit (Stroth et al. 2009). In addition to N2, several studies indicated greater P3 amplitude (e.g., Hillman et al. 2005, 2009) and shorter P3 latency (Pontifex et al. 2011) in individuals who were more fit compared with individuals who were less fit while executing flanker task. These results further support that PE are associated with reduced conflict activation and superior ability to recruit more neural resources to process stimuli. Although PE promotes health, participation rates in general are not high (e.g., sport participation in European countries was found to be less than 40 % in a study by Van Tuyckom et al. 2010), worsen with increasing age and have not improved in decades despite multiple public health efforts (e.g., McGowan et al. 2012). The repetitive nature of some forms of exercise may be perceived as boring and is one potential contributing factor to poor participation (Studenski et al. 2010). Identifying more enjoyable ways of acquiring recommended levels of PE may motivate more elders to participate in physical activities. Exergame, a concatenation of “exercise” and (video) “game,” has an important entertainment factor, which may motivate some users more than traditional exercise modes. The exergame Dance Dance Revolution (DDR), which instructs participants to jump and move quickly, requires full body exercise with the constant involvement of lower and upper limb musculature. Luke et al. (2005) found that energy expenditure and exercise intensity (78 % of age-predicted heart rate) during DDR exercise met recommendations by the American College of Sports Medicine (ACSM). Specifically, the majority of evidence suggests that DDR can be used not only to meet minimum requirements for moderate physical activity, but also to achieve vigorous activity levels through gaming
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Exp Brain Res (2015) 233:1181–1188
(Bailey and McInnis 2011). This implied that DDR provides potential workout progression from basic to advanced physical challenges. Recently, DDR also has been used with older adults for improving physical functions or mental health (e.g., Studenski et al. 2010); however, the effects on cognition are seldom examined. Therefore, DDR could be an alternative exercise mode for the promotion of cognitive function in the elderly. The main purpose of this study was to examine whether DDR training would exert similar effect on interference control as that brisk walking in elderly individuals. We hypothesize that elderly participants in both the DDR and brisk walking groups may have greater flanker performance compared with participants in the control group, and this difference may be reflected by a smaller N2 and larger P3.
Methods Participants This study used flyers and posters to recruit 32 females (age range 65–75 years) leading a sedentary lifestyle (all participants had not engaged in weekly regular physical exercise for the past 3 years) from senior community centers and civic groups in an urban setting (2,660,000 inhabitants). Inclusion criteria were (a) healthy, with self-reported normal or corrected-to-normal eyesight; (b) right-handed; (c) having adequate mental status (a minimum score of 25 on MMSE); and (d) free of medications that could affect cardiovascular health or cognitive functions for 6 months prior to testing. Participants who can come to laboratory three times a week for 3 months were included into either DDR group (DDRG) or brisk walking group (BWG). The rest of participants were assigned to control group (CG). One participant in DDRG dropped out due to injury and two in CG were excluded from the following analyses due to too many physical activities per week. In addition, data from three participants also discarded because of excessive contaminated EEG. Thus, analyses were conducted on 26 participants (CG: 8, DDRG: 7, and BWG: 11). The main characteristics of participants are shown in Table 1. The study was approved by the Institutional Review Board of Taipei Medical University. Procedure The whole procedure included the pretest, intervention, and posttest phases. At the beginning of the pretest phase, participants provided written informed consent. Health and demographics questionnaires were administered followed by the assessment of blood pressure. Once the measurements were completed, participants were then fitted with
Exp Brain Res (2015) 233:1181–1188
1183
Table 1 Group means and standard deviation for participant characteristics Groups DDRG
BWG
CG
Age (years) Years of education (years) VO2max (ml/kg*min) (pretest)
69.43 ± 3.82 13.71 ± 3.30
67.01 ± 1.67 14.18 ± 1.66
68.25 ± 3.96 14.75 ± 1.83
15.30 ± 1.56
16.96 ± 4.05
18.07 ± 6.31
VO2max (ml/kg*min) (posttest)
24.57 ± 7.05
21.44 ± 4.30
16.99 ± 5.93
currency valued approximately USD170 (DDRG, BWG) or USD70 (CG). Submaximal cycle ergometer testing was completed using the YMCA protocol (Golding et al. 1989), a submaximal, 3-stage branching program dependent on heart rate responses to given workloads. A steady-state heart rate must be achieved before progressing to the next stage. Steady-state heart rates for each stage were matched against workload and VO2. A regression equation was used to estimate VO2max. This test procedure was employed for both the pretest and posttest. Flanker task
a Lycra electrode cap, and impedances and EEG signal quality were checked. At the beginning of the experiment, participants were given a detailed description of the flanker task and asked to respond as quickly and accurately as possible. The flanker task started after a block of 20 practice trials. Participants completed a total of 220 trials that were divided into five blocks, with breaks lasting 2.5 min between blocks. Each participant was tested individually in a sound-attenuated cubicle with a computer screen at a viewing distance of 60 cm. During the intervention phase, DDRG and BWG participants received a total of three sessions of 30 min of PE each week for 12 weeks. Each session was conducted at the same time on different days in a week. The resting and exercise heart rates were recorded by a Polar watch (Johnson-POLAR RS800CX, sampling rate of 1,000), which has been validated as a reliable measure of heart rate (Jonckheer-Sheehy et al. 2012; Weippert et al. 2010). Taking the age and sedentary lifestyle of participants into account, the target heart rate range was large. That is, although the preferred exercise intensity was 50 % of maximal heart rate (HRmax) during both exercises, the range was set from 40 to 60 % of HRmax so that the participant could progressively adapt to the intensity of exercise and maintain the exercise intensity at 50 % HRmax. In order to monitor and maintain exercise intensity within the target heart rate, heart rate and perceived exertion were reported every 5 min during exercise for the adjustment of exercise intensity. In doing so, the possible confounding effect of exercise intensity on cognition was controlled. CG participants were instructed to maintain their original lifestyle and received a weekly telephone interview to provide social support and ascertain their compliance. The posttest was conducted 1 day after the last intervention session, and the procedure and requests were the same as those of the pretest. During their final visit, participants were given their oral and written report on information related to their blood pressure, PE, and cognitive performance and were compensated local
The flanker task is a selective attention paradigm, often employed to examine interference control, one aspect of executive control (Eriksen and Eriksen 1974). This task requires individuals to respond as quickly as possible to the direction of a central target arrow in an array of arrows presented on a screen. Stimuli were presented in white against a black background and consisted of a horizontal array of five arrows, which were equally likely to point to the left (). Further, the flanking stimuli (i.e., the four arrows surrounding the centrally placed target stimulus) were equally likely to be congruent (>>>>>) or incongruent (>>>) with the target arrow. One response box (Neuroscan STIM response pad) containing a left and a right button were placed in front of the participant. Participants were instructed to respond to the central target arrow by pressing a left button with left index finger if the center target arrow was pointing to left and a right button with right index finger if the center target arrow was pointing to right. Each block consisted of 22 congruent and 22 incongruent trials with left and right target arrows occurring with equal probability. The stimuli were 3-cm-tall white arrows, which were presented focally for 120 ms with a response window of 1,000 ms. The intertrial interval (ITI) were 1,100, 1,300, and 1,500 ms and randomly distributed throughout the task for preventing participants from expecting a specific frequency of responding. Total task duration of one block was approximately 2 min. Electroencephalogram recording EEGs were recorded by NeuroScan NuAmps acquisition amplifiers (Neuroscan, Charlotte, NC, USA). An electrode cap was placed on the subject according to the 10–20 International System (Jasper 1958). The signals were referenced to linked earlobes, and Fpz served as the ground. In addition, vertical and horizontal eye movement artifacts (VEOG and HEOG, respectively) were assessed through collection of bipolar electro-oculographic activity (EOG). A 60-Hz notch filter was also employed during the data collection.
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Exp Brain Res (2015) 233:1181–1188
The band pass filter was between 1 and 100 Hz. Scalp electrode impedances were below 10 KΩ. Data were acquired at a sampling rate of 500 Hz using Neuroscan software that was installed on an IBM computer. Data analysis Behavioral data Reaction time (RT) and accuracy were used to evaluate performance. All error trials or trials with responses faster than 200 ms or slower than 1,000 ms ( .30). There were no significant age differences among the three groups [F(2, 23) = 1.306, p = .290, partial η2 = .102]. The analysis for VO2max revealed a significant interaction of Time × Group [F(2, 23) = 10.252, p = .001, partial η2 = .471]. The follow-up analyses demonstrated no difference between groups in the pretest, but a difference was observed in the posttest [F(2, 23) = 3.646, p = .048, partial η2 = .231]. DDRG participants exhibited a greater
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1185
Table 2 Mean RT (ms) and response accuracy rate (%) across groups and conditions Accuracy rate (%)
RT-congruent (ms)
RT-incongruent (ms)
DDRG (N = 7) Pretest Posttest
96.16 ± 3.82 97.26 ± 2.21
478.71 ± 45.63 429.14 ± 25.33
520.14 ± 59.26 466.86 ± 51.39
BWG (N = 11) Pretest Posttest
96.10 ± 5.33 97.92 ± 1.99
435.31 ± 51.41 411.46 ± 43.62
462.77 ± 66.93 440.08 ± 58.20
CG (N = 8) Pretest Posttest
97.49 ± 4.21 97.82 ± 1.23
421.88 ± 25.00 460.13 ± 45.94
477.50 ± 60.46 515.13 ± 78.15
Total (N = 26) Pretest
96.51 ± 4.21
442.32 ± 47.86
481.32 ± 65.42
97.73 ± 1.82
429.79 ± 44.38
468.21 ± 68.62
Posttest
VO2max than CG participants [p = .016, d = 1.16, 95 % CI (1.54, 13.61)], while the difference between BWG and CG participants was only marginally significant [p = .102, d = .86, 95 % CI (−.96, 9.87)] (see Table 1). Behavioral measurement The ANOVA showed neither interaction, F(2,23) = .32, p = . 727, partial η2 = .03, nor main effects (Group: F(1,23) = .51, p = .610, partial η2 = .04; Time: F(1,23) = 4.00, p = .057, partial η2 = .15) in response accuracy. Although ANOVA for the RTs failed to show significant three way interaction effect, F(2,23) = .56, p = .579, partial η2 = .05, a significant Time × Group interaction was found, F(2,23) = 30.43, p
RESEARCH ARTICLE
A 3‑month intervention of Dance Dance Revolution improves interference control in elderly females: a preliminary investigation Lan‑Ya Chuang · Hsiao‑Yun Hung · Chung‑Ju Huang · Yu‑Kai Chang · Tsung‑Min Hung
Received: 6 August 2014 / Accepted: 4 January 2015 / Published online: 17 January 2015 © Springer-Verlag Berlin Heidelberg 2015
Abstract Exercise regimens suitable to the elderly remain under investigated; therefore, this study examined the effects of Dance Dance Revolution (DDR) on cognitive control in elderly females. Twenty-six healthy elderly females leading a sedentary lifestyle were assigned to a DDR, brisk walking, or control group. Participants in the DDR and brisk walking groups engaged in moderate physical exercise three times per week for 3 months, whereas the control group maintained a sedentary lifestyle. Each participant performed a flanker task before and after the intervention. The results revealed that both DDR and brisk walking shortened reaction time, N2 latency, and P3 latency relative to those of the control group. These findings suggest that DDR intervention is as effective as that of brisk walking in improving inhibitory control for elderly people. Therefore, DDR can be used as a viable alternative exercise to enhance cognitive function for the elderly and motivate individuals who are less willing to be active.
L.‑Y. Chuang · T.‑M. Hung (*) Department of Physical Education, National Taiwan Normal University, No. 162, Sec. 1, Heping E. Rd., Da’an Dist., Taipei City 106, Taiwan, ROC e-mail: [email protected] H.‑Y. Hung Department of Physical Education, University of Taipei, Taipei, Taiwan C.‑J. Huang Graduate Institute of Sport Pedagogy, University of Taipei, Taipei, Taiwan Y.‑K. Chang Graduate Institute of Athletics and Coaching Science, National Taiwan Sport University, Taoyuan, Taiwan
Keywords Executive function · Event-related potential · Aging · Exergame · Cognition
Introduction Given that the proportion of elderly people aged 65 and over in the world is expected to increase drastically over the next few decades, which will be accompanied by a major financial impact on the healthcare system (WHO 2012), there is an urgent need for measures that enhancing an independent lifestyle into old age. Aging can culminate in memory loss, reduced learning ability, and the degradation of cognitive function, all of which undermine the independence of older people in their activities of daily living and generate stress on the family, society, the healthcare system, and the economy (Pang et al. 2002). Kramer et al. (1999) indicated that physical exercise (PE) can decrease the risk of cognitive decline and cognitive impairment in old age by inducing changes in hippocampal structure (Cotman et al. 2007), increasing brain-derived neurotrophic factor (Neeper et al. 1995), insulin-like growth factor (Carro et al. 2001), and increasing neurogenesis in the dentate gyrus (van Praag et al. 1999). Moreover, the greater amounts of PE and higher fitness levels are associated with increased gray matter volume; greater white matter integrity (Colcombe et al. 2006); elevated functional dynamics, including heightened connectivity of fronto-parieto-hippocampal circuits (Colcombe et al. 2004); and enhanced cognitive performance (Colcombe and Kramer 2003; Smith et al. 2010). Executive function is particularly sensitive to the effects of aging but may benefit most from the impact of PE (Colcombe and Kramer 2003). Interference control, an important aspect of executive function (Kok 1999), involves
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the detection and resolution of conflicts (Carter and van Veen 2007; Friedman and Miyake 2004) and facilitates relational reasoning (Krawczyk et al. 2004, 2005; Markman 1997). Those abilities are important for performing instrumental activities of daily living. Several studies using flanker paradigms have demonstrated a positive relationship between PE and/or aerobic fitness and interference control in the elderly. Colcombe et al. (2004) found that, in comparison with the control, brisk walking three times per week for 6 months significantly improved cardiovascular capacity and reduced behavioral conflict. Similarly, Voelcker-Rehage et al. (2011) revealed that both cardiovascular training and coordination training led to a significant improvement in flanker accuracy across a 12-month study interval. Furthermore, studies with event-related potential (ERP), which was characterized by high temporal resolution suitable for revealing the underlying neurocognitive processes, have shown that the amplitude of N2, an ERP component that reflects the processes of response conflict monitoring in a flanker task (Folstein and Van Petten 2008), was smaller in individuals who were more fit compared with individuals who were less fit (Stroth et al. 2009). In addition to N2, several studies indicated greater P3 amplitude (e.g., Hillman et al. 2005, 2009) and shorter P3 latency (Pontifex et al. 2011) in individuals who were more fit compared with individuals who were less fit while executing flanker task. These results further support that PE are associated with reduced conflict activation and superior ability to recruit more neural resources to process stimuli. Although PE promotes health, participation rates in general are not high (e.g., sport participation in European countries was found to be less than 40 % in a study by Van Tuyckom et al. 2010), worsen with increasing age and have not improved in decades despite multiple public health efforts (e.g., McGowan et al. 2012). The repetitive nature of some forms of exercise may be perceived as boring and is one potential contributing factor to poor participation (Studenski et al. 2010). Identifying more enjoyable ways of acquiring recommended levels of PE may motivate more elders to participate in physical activities. Exergame, a concatenation of “exercise” and (video) “game,” has an important entertainment factor, which may motivate some users more than traditional exercise modes. The exergame Dance Dance Revolution (DDR), which instructs participants to jump and move quickly, requires full body exercise with the constant involvement of lower and upper limb musculature. Luke et al. (2005) found that energy expenditure and exercise intensity (78 % of age-predicted heart rate) during DDR exercise met recommendations by the American College of Sports Medicine (ACSM). Specifically, the majority of evidence suggests that DDR can be used not only to meet minimum requirements for moderate physical activity, but also to achieve vigorous activity levels through gaming
13
Exp Brain Res (2015) 233:1181–1188
(Bailey and McInnis 2011). This implied that DDR provides potential workout progression from basic to advanced physical challenges. Recently, DDR also has been used with older adults for improving physical functions or mental health (e.g., Studenski et al. 2010); however, the effects on cognition are seldom examined. Therefore, DDR could be an alternative exercise mode for the promotion of cognitive function in the elderly. The main purpose of this study was to examine whether DDR training would exert similar effect on interference control as that brisk walking in elderly individuals. We hypothesize that elderly participants in both the DDR and brisk walking groups may have greater flanker performance compared with participants in the control group, and this difference may be reflected by a smaller N2 and larger P3.
Methods Participants This study used flyers and posters to recruit 32 females (age range 65–75 years) leading a sedentary lifestyle (all participants had not engaged in weekly regular physical exercise for the past 3 years) from senior community centers and civic groups in an urban setting (2,660,000 inhabitants). Inclusion criteria were (a) healthy, with self-reported normal or corrected-to-normal eyesight; (b) right-handed; (c) having adequate mental status (a minimum score of 25 on MMSE); and (d) free of medications that could affect cardiovascular health or cognitive functions for 6 months prior to testing. Participants who can come to laboratory three times a week for 3 months were included into either DDR group (DDRG) or brisk walking group (BWG). The rest of participants were assigned to control group (CG). One participant in DDRG dropped out due to injury and two in CG were excluded from the following analyses due to too many physical activities per week. In addition, data from three participants also discarded because of excessive contaminated EEG. Thus, analyses were conducted on 26 participants (CG: 8, DDRG: 7, and BWG: 11). The main characteristics of participants are shown in Table 1. The study was approved by the Institutional Review Board of Taipei Medical University. Procedure The whole procedure included the pretest, intervention, and posttest phases. At the beginning of the pretest phase, participants provided written informed consent. Health and demographics questionnaires were administered followed by the assessment of blood pressure. Once the measurements were completed, participants were then fitted with
Exp Brain Res (2015) 233:1181–1188
1183
Table 1 Group means and standard deviation for participant characteristics Groups DDRG
BWG
CG
Age (years) Years of education (years) VO2max (ml/kg*min) (pretest)
69.43 ± 3.82 13.71 ± 3.30
67.01 ± 1.67 14.18 ± 1.66
68.25 ± 3.96 14.75 ± 1.83
15.30 ± 1.56
16.96 ± 4.05
18.07 ± 6.31
VO2max (ml/kg*min) (posttest)
24.57 ± 7.05
21.44 ± 4.30
16.99 ± 5.93
currency valued approximately USD170 (DDRG, BWG) or USD70 (CG). Submaximal cycle ergometer testing was completed using the YMCA protocol (Golding et al. 1989), a submaximal, 3-stage branching program dependent on heart rate responses to given workloads. A steady-state heart rate must be achieved before progressing to the next stage. Steady-state heart rates for each stage were matched against workload and VO2. A regression equation was used to estimate VO2max. This test procedure was employed for both the pretest and posttest. Flanker task
a Lycra electrode cap, and impedances and EEG signal quality were checked. At the beginning of the experiment, participants were given a detailed description of the flanker task and asked to respond as quickly and accurately as possible. The flanker task started after a block of 20 practice trials. Participants completed a total of 220 trials that were divided into five blocks, with breaks lasting 2.5 min between blocks. Each participant was tested individually in a sound-attenuated cubicle with a computer screen at a viewing distance of 60 cm. During the intervention phase, DDRG and BWG participants received a total of three sessions of 30 min of PE each week for 12 weeks. Each session was conducted at the same time on different days in a week. The resting and exercise heart rates were recorded by a Polar watch (Johnson-POLAR RS800CX, sampling rate of 1,000), which has been validated as a reliable measure of heart rate (Jonckheer-Sheehy et al. 2012; Weippert et al. 2010). Taking the age and sedentary lifestyle of participants into account, the target heart rate range was large. That is, although the preferred exercise intensity was 50 % of maximal heart rate (HRmax) during both exercises, the range was set from 40 to 60 % of HRmax so that the participant could progressively adapt to the intensity of exercise and maintain the exercise intensity at 50 % HRmax. In order to monitor and maintain exercise intensity within the target heart rate, heart rate and perceived exertion were reported every 5 min during exercise for the adjustment of exercise intensity. In doing so, the possible confounding effect of exercise intensity on cognition was controlled. CG participants were instructed to maintain their original lifestyle and received a weekly telephone interview to provide social support and ascertain their compliance. The posttest was conducted 1 day after the last intervention session, and the procedure and requests were the same as those of the pretest. During their final visit, participants were given their oral and written report on information related to their blood pressure, PE, and cognitive performance and were compensated local
The flanker task is a selective attention paradigm, often employed to examine interference control, one aspect of executive control (Eriksen and Eriksen 1974). This task requires individuals to respond as quickly as possible to the direction of a central target arrow in an array of arrows presented on a screen. Stimuli were presented in white against a black background and consisted of a horizontal array of five arrows, which were equally likely to point to the left (). Further, the flanking stimuli (i.e., the four arrows surrounding the centrally placed target stimulus) were equally likely to be congruent (>>>>>) or incongruent (>>>) with the target arrow. One response box (Neuroscan STIM response pad) containing a left and a right button were placed in front of the participant. Participants were instructed to respond to the central target arrow by pressing a left button with left index finger if the center target arrow was pointing to left and a right button with right index finger if the center target arrow was pointing to right. Each block consisted of 22 congruent and 22 incongruent trials with left and right target arrows occurring with equal probability. The stimuli were 3-cm-tall white arrows, which were presented focally for 120 ms with a response window of 1,000 ms. The intertrial interval (ITI) were 1,100, 1,300, and 1,500 ms and randomly distributed throughout the task for preventing participants from expecting a specific frequency of responding. Total task duration of one block was approximately 2 min. Electroencephalogram recording EEGs were recorded by NeuroScan NuAmps acquisition amplifiers (Neuroscan, Charlotte, NC, USA). An electrode cap was placed on the subject according to the 10–20 International System (Jasper 1958). The signals were referenced to linked earlobes, and Fpz served as the ground. In addition, vertical and horizontal eye movement artifacts (VEOG and HEOG, respectively) were assessed through collection of bipolar electro-oculographic activity (EOG). A 60-Hz notch filter was also employed during the data collection.
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Exp Brain Res (2015) 233:1181–1188
The band pass filter was between 1 and 100 Hz. Scalp electrode impedances were below 10 KΩ. Data were acquired at a sampling rate of 500 Hz using Neuroscan software that was installed on an IBM computer. Data analysis Behavioral data Reaction time (RT) and accuracy were used to evaluate performance. All error trials or trials with responses faster than 200 ms or slower than 1,000 ms ( .30). There were no significant age differences among the three groups [F(2, 23) = 1.306, p = .290, partial η2 = .102]. The analysis for VO2max revealed a significant interaction of Time × Group [F(2, 23) = 10.252, p = .001, partial η2 = .471]. The follow-up analyses demonstrated no difference between groups in the pretest, but a difference was observed in the posttest [F(2, 23) = 3.646, p = .048, partial η2 = .231]. DDRG participants exhibited a greater
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Exp Brain Res (2015) 233:1181–1188
1185
Table 2 Mean RT (ms) and response accuracy rate (%) across groups and conditions Accuracy rate (%)
RT-congruent (ms)
RT-incongruent (ms)
DDRG (N = 7) Pretest Posttest
96.16 ± 3.82 97.26 ± 2.21
478.71 ± 45.63 429.14 ± 25.33
520.14 ± 59.26 466.86 ± 51.39
BWG (N = 11) Pretest Posttest
96.10 ± 5.33 97.92 ± 1.99
435.31 ± 51.41 411.46 ± 43.62
462.77 ± 66.93 440.08 ± 58.20
CG (N = 8) Pretest Posttest
97.49 ± 4.21 97.82 ± 1.23
421.88 ± 25.00 460.13 ± 45.94
477.50 ± 60.46 515.13 ± 78.15
Total (N = 26) Pretest
96.51 ± 4.21
442.32 ± 47.86
481.32 ± 65.42
97.73 ± 1.82
429.79 ± 44.38
468.21 ± 68.62
Posttest
VO2max than CG participants [p = .016, d = 1.16, 95 % CI (1.54, 13.61)], while the difference between BWG and CG participants was only marginally significant [p = .102, d = .86, 95 % CI (−.96, 9.87)] (see Table 1). Behavioral measurement The ANOVA showed neither interaction, F(2,23) = .32, p = . 727, partial η2 = .03, nor main effects (Group: F(1,23) = .51, p = .610, partial η2 = .04; Time: F(1,23) = 4.00, p = .057, partial η2 = .15) in response accuracy. Although ANOVA for the RTs failed to show significant three way interaction effect, F(2,23) = .56, p = .579, partial η2 = .05, a significant Time × Group interaction was found, F(2,23) = 30.43, p
