BACKGROUND Obesity and cigarette smoking are two leading preventable causes of death. Previous re... more BACKGROUND Obesity and cigarette smoking are two leading preventable causes of death. Previous research suggests that comorbid smoking and obesity likely share neurobehavioral underpinnings; however, the influence of body mass index (BMI) on resting-state functional connectivity (rsFC) in smokers remains unknown. In this study, we explore how BMI affects rsFC and associations between rsFC and smoking-related behavior. METHODS Treatment-seeking cigarette smokers (N = 87; 54 % men) completed a BOLD resting-state fMRI scan session. We grouped smokers into BMI groups (N = 23 with obesity, N = 33 with overweight, N = 31 lean) and used independent components analysis (ICA) to identify the resting state networks commonly associated with cigarette smoking: salience network (SN), right and left executive control networks (ECN) and default mode network (DMN). Average rsFC values were extracted (p < 0.001, k = 100) to determine group differences in rsFC and relationship to self-reported smoking and dependence. RESULTS Analyses revealed a significant relationship between BMI and connectivity in the SN and a significant quadratic effect of BMI on DMN connectivity. Heavier smoking was related to greater rsFC in the SN among lean and obese groups but reduced rsFC in the overweight group. CONCLUSIONS Findings build on research suggesting an influence of BMI on the neurobiology of smokers. In particular, dysfunction of SN-DMN-ECN circuitry in smokers with overweight may lead to a failure to modulate attention and behavior and subsequent difficulty quitting smoking. Future research is needed to elucidate the mechanism underlying the interaction of BMI and smoking and its impact on treatment.
Preserved cognitive performance is one of the key contributors to successful aging. The processin... more Preserved cognitive performance is one of the key contributors to successful aging. The processing speed theory and prefrontal executive theory – are competing theories regarding the general causes of cognitive aging. Here, we used a theoretically-driven framework to investigate the neural correlates of older adults with preserved processing speed. Older adults with youth-like processing speed (SuperAgers) were compared with normal aged adults (TypicalAgers) using neuroimaging methods. Global cerebral blood flow (CBF) accounted for approximately 45% of the variance in processing speed, while neither regional CBF nor other structural measures predicted additional variance. In addition, despite having significantly cortical thinning, SuperAgers still shown comparable global CBF levels with young adults. These results support the global mechanism suggested by processing speed theory and indicate that global CBF may serve as a biomarker of cognitive aging.
Sleep deprivation significantly reduces the ability to maintain a consistent alertness level and ... more Sleep deprivation significantly reduces the ability to maintain a consistent alertness level and impairs vigilant attention. Previous studies have shown that longer inter-stimulus intervals (ISI) are associated with faster reaction times (RT) on the Psychomotor Vigilance Test (PVT). However, whether and how sleep deprivation interacts with this ISI effect remains unclear. N=70 healthy adults (age range 20-50 yrs, 41 males) participated in a 5-day and 4-night in-laboratory controlled sleep deprivation study, including N=54 in the experimental group with one night of total sleep deprivation and N=16 in the control group without sleep loss. All participants completed a neurobehavioral test battery every 2 hours while awake, including a 10-min standard PVT (PVT-S, N=1626) and a 3-min brief PVT (PVT-B, N=1622). The linear approach to threshold with ergodic rate (LATER) model was used to fit the RT data. RT decreased significantly with longer ISI on the PVT-S and PVT-B. Increased ISI effe...
The American journal of hospice & palliative care, 2018
Patients with cancer frequently experience physical and psychological distress that can worsen th... more Patients with cancer frequently experience physical and psychological distress that can worsen their quality of life. We assessed the outcomes of an 8-week mindfulness-based art therapy (MBAT) intervention, Walkabout: Looking In, Looking Out, on symptoms, sleep quality, health-related quality of life, sense of coherence (SOC), and spirituality in outpatients with cancer. A 1-group, pre-post intervention design with repeated measures at baseline, week 4, and week 8. Despite a small pilot sample (n = 18), we found large effect sizes and statistically significant improvements from week 1 to week 8 in depression, the comprehensibility subscale of the SOC, and each subscale of spirituality, that is, peace, meaning, and faith. There were no significant changes in physical functioning, pain, sleep, tiredness, drowsiness, nausea, and appetite. The MBAT intervention, Walkabout, seems to meet key palliative care goals including improvement in emotional well-being, comprehensibility, and meani...
The mechanism of sacral neuromodulation is poorly understood. We compared brain activity during u... more The mechanism of sacral neuromodulation is poorly understood. We compared brain activity during urgency before and after sacral neuromodulation in women with overactive bladder and according to response to treatment. Women with refractory overactive bladder who elected for sacral neuromodulation were invited to undergo a functional magnetic resonance imaging exam before and after treatment. During the imaging exams, the bladder was filled until urgency was experienced. Regions of interest were identified a priori, and brain activity in these regions of interest was compared before and after treatment as well as according to treatment response. A whole brain exploratory analysis with an uncorrected voxel level threshold of p<0.001 was also conducted to identify additional brain regions that changed after sacral neuromodulation. Among 12 women who underwent a pretreatment functional magnetic resonance imaging exam, seven were successfully treated with sacral neuromodulation and und...
Research indicates that overnight nicotine abstinence disrupts neural activity in the mesocortico... more Research indicates that overnight nicotine abstinence disrupts neural activity in the mesocorticolimbic reward network; however, less is known about the time course of abstinence-induced brain changes. To examine the potential neural effects of early abstinence, we used arterial spin labeling perfusion fMRI, to measure regional cerebral blood flow (rCBF) changes in the resting brain induced by 4h of nicotine abstinence. In a repeated measures design, 5min of resting perfusion fMRI data were acquired in awake nicotine-dependent individuals (eyes open) during 'smoking as usual' (SMK) and following 4h of monitored nicotine abstinence (ABS) conditions (N=20). Conditions were compared using a paired t test in SPM8. Craving was assessed prior to each condition. Compared to SMK, ABS significantly increased craving and reduced rCBF in select regions, including the hippocampus and ventral striatum (cluster corr, α=0.01, 943 contiguous voxels). The magnitude of the abstinence-induced ...
To provide a quantitative meta-analysis of the antidepressant effects of sleep deprivation to com... more To provide a quantitative meta-analysis of the antidepressant effects of sleep deprivation to complement qualitative reviews addressing response rates. English-language studies from 1974 to 2016 using the keywords sleep deprivation and depression searched through PubMed and PsycINFO databases. A total of 66 independent studies met criteria for inclusion: conducted experimental sleep deprivation, reported the percentage of the sample that responded to sleep deprivation, provided a priori definition of antidepressant response, and did not seamlessly combine sleep deprivation with other therapies (eg, chronotherapeutics, repetitive transcranial magnetic stimulation). Data extracted included percentage of responders, type of sample (eg, bipolar, unipolar), type of sleep deprivation (eg, total, partial), demographics, medication use, type of outcome measure used, and definition of response (eg, 30% reduction in depression ratings). Data were analyzed with meta-analysis of proportions and a Poisson mixed-effects regression model. The overall response rate to sleep deprivation was 45% among studies that utilized a randomized control group and 50% among studies that did not. The response to sleep deprivation was not affected significantly by the type of sleep deprivation performed, the nature of the clinical sample, medication status, the definition of response used, or age and gender of the sample. These findings support a significant effect of sleep deprivation and suggest the need for future studies on the phenotypic nature of the antidepressant response to sleep deprivation, on the neurobiological mechanisms of action, and on moderators of the sleep deprivation treatment response in depression.
Purpose. To quantitatively measure changes in cerebral perfusion in select regions of interest in... more Purpose. To quantitatively measure changes in cerebral perfusion in select regions of interest in the brain during urinary urgency in women with overactive bladder (OAB) using arterial spin labeling (ASL). Methods. Twelve women with OAB and 10 controls underwent bladder filling and rated urinary urgency (scale 0–10). ASL fMRI scans were performed (1) in the low urgency state after voiding and (2) high urgency state after drinking oral fluids. Absolute regional cerebral blood flow (rCBF) in select regions of interest was compared between the low and high urgency states. Results. There were no significant differences in rCBF between the low and high urgency states in the control group. In the OAB group, rCBF (mean ± SE, ml/100 g/min) increased by 10–14% from the low to the high urgency state in the right anterior cingulate cortex (ACC) (44.56±0.59 versus 49.52±1.49,…
Stress is a strong risk factor for major depressive disorder, while sensitization to stress in re... more Stress is a strong risk factor for major depressive disorder, while sensitization to stress in remitted individuals plays a key role in depression recurrence. The present study explored the state-independent (trait) and dependent (state) neural responses to psychosocial stress in major depressive disorder. Thirty-six patients with medication-naive first-episode current depression, 33 patients with remitted depression, and 36 demographically matched healthy control participants were administered the Montreal Imaging Stress Task during functional MRI. One-way analyses of variance were used to assess differences in stress responses in the three groups. Both currently depressed and remitted patients exhibited higher stress levels and cortisol responses than control subjects. Compared with control subjects, both depressed and remitted patients exhibited reduced activation in the ventromedial prefrontal cortex and increased activation in the precuneus. The stress-induced ventromedial pref...
Some studies show that the medial frontal cortex is associated with more skilled action anticipat... more Some studies show that the medial frontal cortex is associated with more skilled action anticipation, while similar findings are not observed in some other studies, possibly due to the stimuli employed and the participants used as the control group. In addition, no studies have investigated whether there is any functional connectivity between the medial frontal cortex and other brain regions in more skilled action anticipation. Therefore, the present study aimed to re-investigate how the medial frontal cortex is involved in more skilled action anticipation by circumventing the limitations of previous research and to investigate that the medial frontal cortex functionally connected with other brain regions involved in action processing in more skilled action anticipation. To this end, professional badminton players and novices were asked to anticipate the landing position of the shuttlecock while watching badminton match videos or to judge the gender of the players in the matches. Th...
BACKGROUND Obesity and cigarette smoking are two leading preventable causes of death. Previous re... more BACKGROUND Obesity and cigarette smoking are two leading preventable causes of death. Previous research suggests that comorbid smoking and obesity likely share neurobehavioral underpinnings; however, the influence of body mass index (BMI) on resting-state functional connectivity (rsFC) in smokers remains unknown. In this study, we explore how BMI affects rsFC and associations between rsFC and smoking-related behavior. METHODS Treatment-seeking cigarette smokers (N = 87; 54 % men) completed a BOLD resting-state fMRI scan session. We grouped smokers into BMI groups (N = 23 with obesity, N = 33 with overweight, N = 31 lean) and used independent components analysis (ICA) to identify the resting state networks commonly associated with cigarette smoking: salience network (SN), right and left executive control networks (ECN) and default mode network (DMN). Average rsFC values were extracted (p < 0.001, k = 100) to determine group differences in rsFC and relationship to self-reported smoking and dependence. RESULTS Analyses revealed a significant relationship between BMI and connectivity in the SN and a significant quadratic effect of BMI on DMN connectivity. Heavier smoking was related to greater rsFC in the SN among lean and obese groups but reduced rsFC in the overweight group. CONCLUSIONS Findings build on research suggesting an influence of BMI on the neurobiology of smokers. In particular, dysfunction of SN-DMN-ECN circuitry in smokers with overweight may lead to a failure to modulate attention and behavior and subsequent difficulty quitting smoking. Future research is needed to elucidate the mechanism underlying the interaction of BMI and smoking and its impact on treatment.
Preserved cognitive performance is one of the key contributors to successful aging. The processin... more Preserved cognitive performance is one of the key contributors to successful aging. The processing speed theory and prefrontal executive theory – are competing theories regarding the general causes of cognitive aging. Here, we used a theoretically-driven framework to investigate the neural correlates of older adults with preserved processing speed. Older adults with youth-like processing speed (SuperAgers) were compared with normal aged adults (TypicalAgers) using neuroimaging methods. Global cerebral blood flow (CBF) accounted for approximately 45% of the variance in processing speed, while neither regional CBF nor other structural measures predicted additional variance. In addition, despite having significantly cortical thinning, SuperAgers still shown comparable global CBF levels with young adults. These results support the global mechanism suggested by processing speed theory and indicate that global CBF may serve as a biomarker of cognitive aging.
Sleep deprivation significantly reduces the ability to maintain a consistent alertness level and ... more Sleep deprivation significantly reduces the ability to maintain a consistent alertness level and impairs vigilant attention. Previous studies have shown that longer inter-stimulus intervals (ISI) are associated with faster reaction times (RT) on the Psychomotor Vigilance Test (PVT). However, whether and how sleep deprivation interacts with this ISI effect remains unclear. N=70 healthy adults (age range 20-50 yrs, 41 males) participated in a 5-day and 4-night in-laboratory controlled sleep deprivation study, including N=54 in the experimental group with one night of total sleep deprivation and N=16 in the control group without sleep loss. All participants completed a neurobehavioral test battery every 2 hours while awake, including a 10-min standard PVT (PVT-S, N=1626) and a 3-min brief PVT (PVT-B, N=1622). The linear approach to threshold with ergodic rate (LATER) model was used to fit the RT data. RT decreased significantly with longer ISI on the PVT-S and PVT-B. Increased ISI effe...
The American journal of hospice & palliative care, 2018
Patients with cancer frequently experience physical and psychological distress that can worsen th... more Patients with cancer frequently experience physical and psychological distress that can worsen their quality of life. We assessed the outcomes of an 8-week mindfulness-based art therapy (MBAT) intervention, Walkabout: Looking In, Looking Out, on symptoms, sleep quality, health-related quality of life, sense of coherence (SOC), and spirituality in outpatients with cancer. A 1-group, pre-post intervention design with repeated measures at baseline, week 4, and week 8. Despite a small pilot sample (n = 18), we found large effect sizes and statistically significant improvements from week 1 to week 8 in depression, the comprehensibility subscale of the SOC, and each subscale of spirituality, that is, peace, meaning, and faith. There were no significant changes in physical functioning, pain, sleep, tiredness, drowsiness, nausea, and appetite. The MBAT intervention, Walkabout, seems to meet key palliative care goals including improvement in emotional well-being, comprehensibility, and meani...
The mechanism of sacral neuromodulation is poorly understood. We compared brain activity during u... more The mechanism of sacral neuromodulation is poorly understood. We compared brain activity during urgency before and after sacral neuromodulation in women with overactive bladder and according to response to treatment. Women with refractory overactive bladder who elected for sacral neuromodulation were invited to undergo a functional magnetic resonance imaging exam before and after treatment. During the imaging exams, the bladder was filled until urgency was experienced. Regions of interest were identified a priori, and brain activity in these regions of interest was compared before and after treatment as well as according to treatment response. A whole brain exploratory analysis with an uncorrected voxel level threshold of p<0.001 was also conducted to identify additional brain regions that changed after sacral neuromodulation. Among 12 women who underwent a pretreatment functional magnetic resonance imaging exam, seven were successfully treated with sacral neuromodulation and und...
Research indicates that overnight nicotine abstinence disrupts neural activity in the mesocortico... more Research indicates that overnight nicotine abstinence disrupts neural activity in the mesocorticolimbic reward network; however, less is known about the time course of abstinence-induced brain changes. To examine the potential neural effects of early abstinence, we used arterial spin labeling perfusion fMRI, to measure regional cerebral blood flow (rCBF) changes in the resting brain induced by 4h of nicotine abstinence. In a repeated measures design, 5min of resting perfusion fMRI data were acquired in awake nicotine-dependent individuals (eyes open) during 'smoking as usual' (SMK) and following 4h of monitored nicotine abstinence (ABS) conditions (N=20). Conditions were compared using a paired t test in SPM8. Craving was assessed prior to each condition. Compared to SMK, ABS significantly increased craving and reduced rCBF in select regions, including the hippocampus and ventral striatum (cluster corr, α=0.01, 943 contiguous voxels). The magnitude of the abstinence-induced ...
To provide a quantitative meta-analysis of the antidepressant effects of sleep deprivation to com... more To provide a quantitative meta-analysis of the antidepressant effects of sleep deprivation to complement qualitative reviews addressing response rates. English-language studies from 1974 to 2016 using the keywords sleep deprivation and depression searched through PubMed and PsycINFO databases. A total of 66 independent studies met criteria for inclusion: conducted experimental sleep deprivation, reported the percentage of the sample that responded to sleep deprivation, provided a priori definition of antidepressant response, and did not seamlessly combine sleep deprivation with other therapies (eg, chronotherapeutics, repetitive transcranial magnetic stimulation). Data extracted included percentage of responders, type of sample (eg, bipolar, unipolar), type of sleep deprivation (eg, total, partial), demographics, medication use, type of outcome measure used, and definition of response (eg, 30% reduction in depression ratings). Data were analyzed with meta-analysis of proportions and a Poisson mixed-effects regression model. The overall response rate to sleep deprivation was 45% among studies that utilized a randomized control group and 50% among studies that did not. The response to sleep deprivation was not affected significantly by the type of sleep deprivation performed, the nature of the clinical sample, medication status, the definition of response used, or age and gender of the sample. These findings support a significant effect of sleep deprivation and suggest the need for future studies on the phenotypic nature of the antidepressant response to sleep deprivation, on the neurobiological mechanisms of action, and on moderators of the sleep deprivation treatment response in depression.
Purpose. To quantitatively measure changes in cerebral perfusion in select regions of interest in... more Purpose. To quantitatively measure changes in cerebral perfusion in select regions of interest in the brain during urinary urgency in women with overactive bladder (OAB) using arterial spin labeling (ASL). Methods. Twelve women with OAB and 10 controls underwent bladder filling and rated urinary urgency (scale 0–10). ASL fMRI scans were performed (1) in the low urgency state after voiding and (2) high urgency state after drinking oral fluids. Absolute regional cerebral blood flow (rCBF) in select regions of interest was compared between the low and high urgency states. Results. There were no significant differences in rCBF between the low and high urgency states in the control group. In the OAB group, rCBF (mean ± SE, ml/100 g/min) increased by 10–14% from the low to the high urgency state in the right anterior cingulate cortex (ACC) (44.56±0.59 versus 49.52±1.49,…
Stress is a strong risk factor for major depressive disorder, while sensitization to stress in re... more Stress is a strong risk factor for major depressive disorder, while sensitization to stress in remitted individuals plays a key role in depression recurrence. The present study explored the state-independent (trait) and dependent (state) neural responses to psychosocial stress in major depressive disorder. Thirty-six patients with medication-naive first-episode current depression, 33 patients with remitted depression, and 36 demographically matched healthy control participants were administered the Montreal Imaging Stress Task during functional MRI. One-way analyses of variance were used to assess differences in stress responses in the three groups. Both currently depressed and remitted patients exhibited higher stress levels and cortisol responses than control subjects. Compared with control subjects, both depressed and remitted patients exhibited reduced activation in the ventromedial prefrontal cortex and increased activation in the precuneus. The stress-induced ventromedial pref...
Some studies show that the medial frontal cortex is associated with more skilled action anticipat... more Some studies show that the medial frontal cortex is associated with more skilled action anticipation, while similar findings are not observed in some other studies, possibly due to the stimuli employed and the participants used as the control group. In addition, no studies have investigated whether there is any functional connectivity between the medial frontal cortex and other brain regions in more skilled action anticipation. Therefore, the present study aimed to re-investigate how the medial frontal cortex is involved in more skilled action anticipation by circumventing the limitations of previous research and to investigate that the medial frontal cortex functionally connected with other brain regions involved in action processing in more skilled action anticipation. To this end, professional badminton players and novices were asked to anticipate the landing position of the shuttlecock while watching badminton match videos or to judge the gender of the players in the matches. Th...
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