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Robert M Post - One of the best experts on this subject based on the ideXlab platform.
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interregional cerebral metabolic associativity during a Continuous Performance Task part i healthy adults
Psychiatry Research-neuroimaging, 2008Co-Authors: Mark W Willis, Tim A Kimbrell, Terence A Ketter, Mark S George, Brenda E Benson, Peter Herscovitch, Robert M Post, Andrew M SpeerAbstract:One emerging hypothesis regarding psychiatric illnesses is that they arise from the dysregulation of normal circuits or neuroanatomical patterns. In order to study mood disorders within this framework, we explored normal metabolic associativity patterns in healthy volunteers as a prelude to examining the same relationships in affectively ill patients (Part II). We applied correlational analyses to regional brain activity as measured with FDG-PET during an auditory Continuous Performance Task (CPT) in 66 healthy volunteers. This simple attention Task controlled for brain activity that otherwise might vary amongst affective and cognitive states. There were highly significant positive correlations between homologous regions in the two hemispheres in thalamic, extrapyramidal, orbital frontal, medial temporal and cerebellar areas. Dorsal frontal, lateral temporal, cingulate, and especially insula, and inferior parietal areas showed less significant homologous associativity, suggesting more specific lateralized function. The medulla and bilateral thalami exhibited the most diverse interregional associations. A general pattern emerged of cortical regions covarying inversely with subcortical structures, particularly the frontal cortex with cerebellum, amygdala and thalamus. These analytical data may help to confirm known functional and neuroanatomical relationships, elucidate others as yet unreported, and serve as a basis for comparison to patients with psychiatric illness.
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interregional cerebral metabolic associativity during a Continuous Performance Task part ii differential alterations in bipolar and unipolar disorders
Psychiatry Research-neuroimaging, 2008Co-Authors: Brenda E Benson, Tim A Kimbrell, Terence A Ketter, Mark S George, Mark W Willis, Peter Herscovitch, Andrew M Speer, Robert M PostAbstract:Unipolar and bipolar disorders have often been reported to exhibit abnormal regional brain activity in prefrontal cortex and paralimbic structures compared with healthy controls. We sought to ascertain how regions postulated to be abnormal in bipolar and unipolar disorders were functionally connected to the rest of the brain, and how this associativity differed from healthy controls. Thirty patients with bipolar disorder (BPs), 34 patients with unipolar disorder (UPs), and 66 healthy volunteers (Willis, M.W., Benson, B.E., Ketter, T.A., Kimbrell, T.A., George, M.S., Speer, A.M., Herscovitch, P., Post, R.M., 2008. Interregional cerebral metabolic associativity during a Continuous Performance Task in healthy adults. Psychiatry Research: Neuroimaging 164 (1)) were imaged using F-18-fluorodeoxyglucose and positron emission tomography (FDG-PET) while performing an auditory Continuous Performance Task (CPT). Five bilateral regions of interest (ROIs), namely dorsolateral prefrontal cortex (DLPFC), insula, inferior parietal cortex (INFP), thalamus and cerebellum, were correlated with normalized cerebral metabolism in the rest of the brain while covarying out Hamilton Depression Rating Scale Scores. In bipolar patients compared with controls, metabolism in the left DLPFC and INFP, and bilateral thalamus and insula had more positive and fewer negative metabolic correlations with other brain regions. In contrast, compared with controls, unipolar patients had fewer significant correlative relationships, either positive or negative. In common, bipolar and unipolar patients lacked the normal inverse relationships between the DLPFC and cerebellum, as well as relationships between the primary ROIs and other limbic regions (medial prefrontal cortex, anterior cingulate, and temporal lobes) compared with controls. Associations of DLPFC and INFP with other brain areas were different in each hemisphere in patients and controls. Bipolar patients exhibited exaggerated positive coherence of activity throughout the brain, while unipolar patients showed a paucity of normal interrelationships compared with controls. These abnormal patterns of metabolic associativity suggest marked interregional neuronal dysregulation in bipolar and unipolar illness exists beyond that of mere absolute regional differences from control levels, and provides rationale for using acute and long-term therapies that may re-establish and maintain normal associativity in these devastating illnesses.
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regional cerebral glucose utilization in patients with a range of severities of unipolar depression
Biological Psychiatry, 2002Co-Authors: Tim A Kimbrell, Terence A Ketter, Mark S George, John T Little, Brenda E Benson, Mark W Willis, Peter Herscovitch, Robert M PostAbstract:Abstract Background: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. Methods: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory Continuous Performance Task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this Task. Results: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). Conclusions: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.
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regional cerebral glucose utilization in patients with a range of severities of unipolar depression
Biological Psychiatry, 2002Co-Authors: Tim A Kimbrell, Terence A Ketter, Mark S George, John T Little, Brenda E Benson, Mark W Willis, Peter Herscovitch, Robert M PostAbstract:Abstract Background: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. Methods: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory Continuous Performance Task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this Task. Results: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). Conclusions: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.
Joseph Degutis - One of the best experts on this subject based on the ideXlab platform.
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childhood adversity and dimensional variations in adult sustained attention
Frontiers in Psychology, 2020Co-Authors: Sarah C Vogel, Michael Esterman, Joseph Degutis, Jeremy Wilmer, Kerry J Ressler, Laura GermineAbstract:Background & Objective Sustained attention is a transdiagnostic phenotype linked with most forms of psychopathology. We sought to understand factors that influence the development of sustained attention, by looking at the relationship between childhood adversity and adult sustained attention. Participants, Setting, and Methods Participants were 5,973 TestMyBrain.org visitors from English-speaking countries who completed a Continuous Performance Task (gradCPT) of sustained attention and a childhood adversity questionnaire. We analyzed gradCPT Performance using a signal detection approach. Results Discrimination ability (the main metric of Performance on the gradCPT) was associated with total childhood adversity load, even when controlling for covariates related to age, gender, parental education, race, country of origin, and relative socioeconomic status (=-0.079, b=-0.032, 95% CI [-0.043, -0.021], p<0.001 ). Conclusions Our results demonstrate that attention differences related to childhood adversity exposure can (1) be measured using brief, Performance-based measures of sustained attention, (2) persist into adulthood, and (3) be detected at the population level. These results, paired with the well-documented associations between sustained attention and psychopathology, indicate that sustained attention may be an important mechanism for understanding early influences on mental health.
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individual differences in sustained attention are associated with cortical thickness
Human Brain Mapping, 2019Co-Authors: Alex Mitko, Joseph Degutis, David Rothlein, Victoria N Poole, Meghan E Robinson, Regina E Mcglinchey, David H Salat, Michael EstermanAbstract:Several studies have examined how individual differences in sustained attention relate to functional brain measures (e.g., functional connectivity), but far fewer studies relate sustained attention ability, or cognition in general, to individual differences in cortical structure. Functional magnetic resonance imaging meta-analyses and patient work have highlighted that frontoparietal regions, lateralized to the right hemisphere, are critical for sustained attention, though recent work implicates a broader expanse of brain regions. The current study sought to determine if and where variation in cortical thickness is significantly associated with sustained attention Performance. Sustained attention was measured using the gradual onset Continuous Performance Task and the Test of Variables of Attention in 125 adult Veteran participants after acquiring two high-resolution structural MRI scans. Whole-brain vertex-wise analyses of the cortex demonstrated that better sustained attention was associated with increased thickness in visual, somatomotor, frontal, and parietal cortices, especially in the right hemisphere. Network-based analyses revealed relationships between sustained attention and cortical thickness in the dorsal attention, ventral attention, somatomotor, and visual networks. These results indicate cortical thickness in multiple regions and networks is associated with sustained attention, and add to the growing knowledge of how structural MRI can help explain individual differences in cognition.
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Modulating Reward Induces Differential Neurocognitive Approaches to Sustained Attention.
Cerebral cortex (New York N.Y. : 1991), 2017Co-Authors: Michael Esterman, Guanyu Liu, Victoria N Poole, Joseph DegutisAbstract:Reward and motivation have powerful effects on cognition and brain activity, yet it remains unclear how they affect sustained cognitive Performance. We have recently shown that a variety of motivators improve accuracy and reduce variability during sustained attention. In the current study, we investigate how neural activity in Task-positive networks supports these sustained attention improvements. Participants performed the gradual-onset Continuous Performance Task with alternating motivated (rewarded) and unmotivated (unrewarded) blocks. During motivated blocks, we observed increased sustained neural recruitment of Task-positive regions, which interacted with fluctuations in Task Performance. Specifically, during motivated blocks, participants recruited these regions in preparation for upcoming targets, and this activation predicted accuracy. In contrast, during unmotivated blocks, no such advanced preparation was observed. Furthermore, during motivated blocks, participants had similar activation levels during both optimal (in-the-zone) and suboptimal (out-of-the-zone) epochs of Performance. In contrast, during unmotivated blocks, Task-positive regions were only engaged to a similar degree as motivated blocks during suboptimal (out-of-the-zone) periods. These data support a framework in which motivated individuals act as "cognitive investors," engaging Task-positive resources proactively and consistently during sustaining attention. When unmotivated, however, the same individuals act as "cognitive misers," engaging maximal Task-positive resources only during periods of struggle.
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frontal eye field involvement in sustaining visual attention evidence from transcranial magnetic stimulation
NeuroImage, 2015Co-Authors: Michael Esterman, Guanyu Liu, Hidefusa Okabe, Andrew J Reagan, Michelle Thai, Joseph DegutisAbstract:Abstract The frontal eye field (FEF), particularly the right FEF, is broadly implicated in top–down control of transient acts of attention, but less is known about its involvement in sustained attention. Although neuroimaging studies of sustained attention Tasks commonly find FEF activation, it is unclear how this region contributes to moment-to-moment fluctuations in sustained Performance. We sought to determine if the FEF plays a critical role in sustained attention, and if that role differs between periods of worse Performance (out-of-the-zone) and periods of better Performance (in-the-zone). We used offline 1 Hz repetitive transcranial magnetic stimulation (TMS) to temporarily attenuate either right or left FEF excitability while participants performed a go/no-go sustained attention Task (the gradual onset Continuous Performance Task). The results demonstrate that following TMS to the right FEF, sustained attention during in-the-zone periods significantly worsened both in terms of lower accuracy and increased reaction time variability. In contrast, applying TMS to the left FEF did not significantly affect accuracy or variability. These results demonstrate that the right FEF plays a crucial role in supporting optimal sustained attention.
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in the zone or zoning out tracking behavioral and neural fluctuations during sustained attention
Cerebral Cortex, 2013Co-Authors: Michael Esterman, Joseph Degutis, Monica D. Rosenberg, Sarah NoonanAbstract:Despite growing recognition that attention fluctuates from moment-to-moment during sustained Performance, prevailing analysis strategies involve averaging data across multiple trials or time points, treating these fluctuations as noise. Here, using alternative approaches, we clarify the relationship between ongoing brain activity and Performance fluctuations during sustained attention. We introduce a novel Task (the gradual onset Continuous Performance Task), along with innovative analysis procedures that probe the relationships between reaction time (RT) variability, attention lapses, and intrinsic brain activity. Our results highlight 2 attentional states-a stable, less error-prone state ("in the zone"), characterized by higher default mode network (DMN) activity but during which subjects are at risk of erring if DMN activity rises beyond intermediate levels, and a more effortful mode of processing ("out of the zone"), that is less optimal for sustained Performance and relies on activity in dorsal attention network (DAN) regions. These findings motivate a new view of DMN and DAN functioning capable of integrating seemingly disparate reports of their role in goal-directed behavior. Further, they hold potential to reconcile conflicting theories of sustained attention, and represent an important step forward in linking intrinsic brain activity to behavioral phenomena.
Brenda E Benson - One of the best experts on this subject based on the ideXlab platform.
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interregional cerebral metabolic associativity during a Continuous Performance Task part i healthy adults
Psychiatry Research-neuroimaging, 2008Co-Authors: Mark W Willis, Tim A Kimbrell, Terence A Ketter, Mark S George, Brenda E Benson, Peter Herscovitch, Robert M Post, Andrew M SpeerAbstract:One emerging hypothesis regarding psychiatric illnesses is that they arise from the dysregulation of normal circuits or neuroanatomical patterns. In order to study mood disorders within this framework, we explored normal metabolic associativity patterns in healthy volunteers as a prelude to examining the same relationships in affectively ill patients (Part II). We applied correlational analyses to regional brain activity as measured with FDG-PET during an auditory Continuous Performance Task (CPT) in 66 healthy volunteers. This simple attention Task controlled for brain activity that otherwise might vary amongst affective and cognitive states. There were highly significant positive correlations between homologous regions in the two hemispheres in thalamic, extrapyramidal, orbital frontal, medial temporal and cerebellar areas. Dorsal frontal, lateral temporal, cingulate, and especially insula, and inferior parietal areas showed less significant homologous associativity, suggesting more specific lateralized function. The medulla and bilateral thalami exhibited the most diverse interregional associations. A general pattern emerged of cortical regions covarying inversely with subcortical structures, particularly the frontal cortex with cerebellum, amygdala and thalamus. These analytical data may help to confirm known functional and neuroanatomical relationships, elucidate others as yet unreported, and serve as a basis for comparison to patients with psychiatric illness.
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interregional cerebral metabolic associativity during a Continuous Performance Task part ii differential alterations in bipolar and unipolar disorders
Psychiatry Research-neuroimaging, 2008Co-Authors: Brenda E Benson, Tim A Kimbrell, Terence A Ketter, Mark S George, Mark W Willis, Peter Herscovitch, Andrew M Speer, Robert M PostAbstract:Unipolar and bipolar disorders have often been reported to exhibit abnormal regional brain activity in prefrontal cortex and paralimbic structures compared with healthy controls. We sought to ascertain how regions postulated to be abnormal in bipolar and unipolar disorders were functionally connected to the rest of the brain, and how this associativity differed from healthy controls. Thirty patients with bipolar disorder (BPs), 34 patients with unipolar disorder (UPs), and 66 healthy volunteers (Willis, M.W., Benson, B.E., Ketter, T.A., Kimbrell, T.A., George, M.S., Speer, A.M., Herscovitch, P., Post, R.M., 2008. Interregional cerebral metabolic associativity during a Continuous Performance Task in healthy adults. Psychiatry Research: Neuroimaging 164 (1)) were imaged using F-18-fluorodeoxyglucose and positron emission tomography (FDG-PET) while performing an auditory Continuous Performance Task (CPT). Five bilateral regions of interest (ROIs), namely dorsolateral prefrontal cortex (DLPFC), insula, inferior parietal cortex (INFP), thalamus and cerebellum, were correlated with normalized cerebral metabolism in the rest of the brain while covarying out Hamilton Depression Rating Scale Scores. In bipolar patients compared with controls, metabolism in the left DLPFC and INFP, and bilateral thalamus and insula had more positive and fewer negative metabolic correlations with other brain regions. In contrast, compared with controls, unipolar patients had fewer significant correlative relationships, either positive or negative. In common, bipolar and unipolar patients lacked the normal inverse relationships between the DLPFC and cerebellum, as well as relationships between the primary ROIs and other limbic regions (medial prefrontal cortex, anterior cingulate, and temporal lobes) compared with controls. Associations of DLPFC and INFP with other brain areas were different in each hemisphere in patients and controls. Bipolar patients exhibited exaggerated positive coherence of activity throughout the brain, while unipolar patients showed a paucity of normal interrelationships compared with controls. These abnormal patterns of metabolic associativity suggest marked interregional neuronal dysregulation in bipolar and unipolar illness exists beyond that of mere absolute regional differences from control levels, and provides rationale for using acute and long-term therapies that may re-establish and maintain normal associativity in these devastating illnesses.
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regional cerebral glucose utilization in patients with a range of severities of unipolar depression
Biological Psychiatry, 2002Co-Authors: Tim A Kimbrell, Terence A Ketter, Mark S George, John T Little, Brenda E Benson, Mark W Willis, Peter Herscovitch, Robert M PostAbstract:Abstract Background: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. Methods: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory Continuous Performance Task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this Task. Results: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). Conclusions: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.
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regional cerebral glucose utilization in patients with a range of severities of unipolar depression
Biological Psychiatry, 2002Co-Authors: Tim A Kimbrell, Terence A Ketter, Mark S George, John T Little, Brenda E Benson, Mark W Willis, Peter Herscovitch, Robert M PostAbstract:Abstract Background: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. Methods: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory Continuous Performance Task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this Task. Results: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). Conclusions: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.
Tim A Kimbrell - One of the best experts on this subject based on the ideXlab platform.
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interregional cerebral metabolic associativity during a Continuous Performance Task part i healthy adults
Psychiatry Research-neuroimaging, 2008Co-Authors: Mark W Willis, Tim A Kimbrell, Terence A Ketter, Mark S George, Brenda E Benson, Peter Herscovitch, Robert M Post, Andrew M SpeerAbstract:One emerging hypothesis regarding psychiatric illnesses is that they arise from the dysregulation of normal circuits or neuroanatomical patterns. In order to study mood disorders within this framework, we explored normal metabolic associativity patterns in healthy volunteers as a prelude to examining the same relationships in affectively ill patients (Part II). We applied correlational analyses to regional brain activity as measured with FDG-PET during an auditory Continuous Performance Task (CPT) in 66 healthy volunteers. This simple attention Task controlled for brain activity that otherwise might vary amongst affective and cognitive states. There were highly significant positive correlations between homologous regions in the two hemispheres in thalamic, extrapyramidal, orbital frontal, medial temporal and cerebellar areas. Dorsal frontal, lateral temporal, cingulate, and especially insula, and inferior parietal areas showed less significant homologous associativity, suggesting more specific lateralized function. The medulla and bilateral thalami exhibited the most diverse interregional associations. A general pattern emerged of cortical regions covarying inversely with subcortical structures, particularly the frontal cortex with cerebellum, amygdala and thalamus. These analytical data may help to confirm known functional and neuroanatomical relationships, elucidate others as yet unreported, and serve as a basis for comparison to patients with psychiatric illness.
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interregional cerebral metabolic associativity during a Continuous Performance Task part ii differential alterations in bipolar and unipolar disorders
Psychiatry Research-neuroimaging, 2008Co-Authors: Brenda E Benson, Tim A Kimbrell, Terence A Ketter, Mark S George, Mark W Willis, Peter Herscovitch, Andrew M Speer, Robert M PostAbstract:Unipolar and bipolar disorders have often been reported to exhibit abnormal regional brain activity in prefrontal cortex and paralimbic structures compared with healthy controls. We sought to ascertain how regions postulated to be abnormal in bipolar and unipolar disorders were functionally connected to the rest of the brain, and how this associativity differed from healthy controls. Thirty patients with bipolar disorder (BPs), 34 patients with unipolar disorder (UPs), and 66 healthy volunteers (Willis, M.W., Benson, B.E., Ketter, T.A., Kimbrell, T.A., George, M.S., Speer, A.M., Herscovitch, P., Post, R.M., 2008. Interregional cerebral metabolic associativity during a Continuous Performance Task in healthy adults. Psychiatry Research: Neuroimaging 164 (1)) were imaged using F-18-fluorodeoxyglucose and positron emission tomography (FDG-PET) while performing an auditory Continuous Performance Task (CPT). Five bilateral regions of interest (ROIs), namely dorsolateral prefrontal cortex (DLPFC), insula, inferior parietal cortex (INFP), thalamus and cerebellum, were correlated with normalized cerebral metabolism in the rest of the brain while covarying out Hamilton Depression Rating Scale Scores. In bipolar patients compared with controls, metabolism in the left DLPFC and INFP, and bilateral thalamus and insula had more positive and fewer negative metabolic correlations with other brain regions. In contrast, compared with controls, unipolar patients had fewer significant correlative relationships, either positive or negative. In common, bipolar and unipolar patients lacked the normal inverse relationships between the DLPFC and cerebellum, as well as relationships between the primary ROIs and other limbic regions (medial prefrontal cortex, anterior cingulate, and temporal lobes) compared with controls. Associations of DLPFC and INFP with other brain areas were different in each hemisphere in patients and controls. Bipolar patients exhibited exaggerated positive coherence of activity throughout the brain, while unipolar patients showed a paucity of normal interrelationships compared with controls. These abnormal patterns of metabolic associativity suggest marked interregional neuronal dysregulation in bipolar and unipolar illness exists beyond that of mere absolute regional differences from control levels, and provides rationale for using acute and long-term therapies that may re-establish and maintain normal associativity in these devastating illnesses.
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regional cerebral glucose utilization in patients with a range of severities of unipolar depression
Biological Psychiatry, 2002Co-Authors: Tim A Kimbrell, Terence A Ketter, Mark S George, John T Little, Brenda E Benson, Mark W Willis, Peter Herscovitch, Robert M PostAbstract:Abstract Background: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. Methods: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory Continuous Performance Task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this Task. Results: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). Conclusions: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.
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regional cerebral glucose utilization in patients with a range of severities of unipolar depression
Biological Psychiatry, 2002Co-Authors: Tim A Kimbrell, Terence A Ketter, Mark S George, John T Little, Brenda E Benson, Mark W Willis, Peter Herscovitch, Robert M PostAbstract:Abstract Background: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. Methods: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory Continuous Performance Task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this Task. Results: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). Conclusions: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.
Mark W Willis - One of the best experts on this subject based on the ideXlab platform.
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interregional cerebral metabolic associativity during a Continuous Performance Task part i healthy adults
Psychiatry Research-neuroimaging, 2008Co-Authors: Mark W Willis, Tim A Kimbrell, Terence A Ketter, Mark S George, Brenda E Benson, Peter Herscovitch, Robert M Post, Andrew M SpeerAbstract:One emerging hypothesis regarding psychiatric illnesses is that they arise from the dysregulation of normal circuits or neuroanatomical patterns. In order to study mood disorders within this framework, we explored normal metabolic associativity patterns in healthy volunteers as a prelude to examining the same relationships in affectively ill patients (Part II). We applied correlational analyses to regional brain activity as measured with FDG-PET during an auditory Continuous Performance Task (CPT) in 66 healthy volunteers. This simple attention Task controlled for brain activity that otherwise might vary amongst affective and cognitive states. There were highly significant positive correlations between homologous regions in the two hemispheres in thalamic, extrapyramidal, orbital frontal, medial temporal and cerebellar areas. Dorsal frontal, lateral temporal, cingulate, and especially insula, and inferior parietal areas showed less significant homologous associativity, suggesting more specific lateralized function. The medulla and bilateral thalami exhibited the most diverse interregional associations. A general pattern emerged of cortical regions covarying inversely with subcortical structures, particularly the frontal cortex with cerebellum, amygdala and thalamus. These analytical data may help to confirm known functional and neuroanatomical relationships, elucidate others as yet unreported, and serve as a basis for comparison to patients with psychiatric illness.
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interregional cerebral metabolic associativity during a Continuous Performance Task part ii differential alterations in bipolar and unipolar disorders
Psychiatry Research-neuroimaging, 2008Co-Authors: Brenda E Benson, Tim A Kimbrell, Terence A Ketter, Mark S George, Mark W Willis, Peter Herscovitch, Andrew M Speer, Robert M PostAbstract:Unipolar and bipolar disorders have often been reported to exhibit abnormal regional brain activity in prefrontal cortex and paralimbic structures compared with healthy controls. We sought to ascertain how regions postulated to be abnormal in bipolar and unipolar disorders were functionally connected to the rest of the brain, and how this associativity differed from healthy controls. Thirty patients with bipolar disorder (BPs), 34 patients with unipolar disorder (UPs), and 66 healthy volunteers (Willis, M.W., Benson, B.E., Ketter, T.A., Kimbrell, T.A., George, M.S., Speer, A.M., Herscovitch, P., Post, R.M., 2008. Interregional cerebral metabolic associativity during a Continuous Performance Task in healthy adults. Psychiatry Research: Neuroimaging 164 (1)) were imaged using F-18-fluorodeoxyglucose and positron emission tomography (FDG-PET) while performing an auditory Continuous Performance Task (CPT). Five bilateral regions of interest (ROIs), namely dorsolateral prefrontal cortex (DLPFC), insula, inferior parietal cortex (INFP), thalamus and cerebellum, were correlated with normalized cerebral metabolism in the rest of the brain while covarying out Hamilton Depression Rating Scale Scores. In bipolar patients compared with controls, metabolism in the left DLPFC and INFP, and bilateral thalamus and insula had more positive and fewer negative metabolic correlations with other brain regions. In contrast, compared with controls, unipolar patients had fewer significant correlative relationships, either positive or negative. In common, bipolar and unipolar patients lacked the normal inverse relationships between the DLPFC and cerebellum, as well as relationships between the primary ROIs and other limbic regions (medial prefrontal cortex, anterior cingulate, and temporal lobes) compared with controls. Associations of DLPFC and INFP with other brain areas were different in each hemisphere in patients and controls. Bipolar patients exhibited exaggerated positive coherence of activity throughout the brain, while unipolar patients showed a paucity of normal interrelationships compared with controls. These abnormal patterns of metabolic associativity suggest marked interregional neuronal dysregulation in bipolar and unipolar illness exists beyond that of mere absolute regional differences from control levels, and provides rationale for using acute and long-term therapies that may re-establish and maintain normal associativity in these devastating illnesses.
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regional cerebral glucose utilization in patients with a range of severities of unipolar depression
Biological Psychiatry, 2002Co-Authors: Tim A Kimbrell, Terence A Ketter, Mark S George, John T Little, Brenda E Benson, Mark W Willis, Peter Herscovitch, Robert M PostAbstract:Abstract Background: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. Methods: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory Continuous Performance Task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this Task. Results: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). Conclusions: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.
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regional cerebral glucose utilization in patients with a range of severities of unipolar depression
Biological Psychiatry, 2002Co-Authors: Tim A Kimbrell, Terence A Ketter, Mark S George, John T Little, Brenda E Benson, Mark W Willis, Peter Herscovitch, Robert M PostAbstract:Abstract Background: Patients with unipolar depression are most often reported to have decreased regional cerebral glucose metabolism (rCMRglu) in dorsal prefrontal and anterior cingulate cortices compared with healthy control subjects, often correlating inversely with severity of depression. Methods: We measured rCMRglu with fluorine-18 deoxyglucose positron emission tomography (PET) in 38 medication-free patients with unipolar depression and 37 healthy control subjects performing an auditory Continuous Performance Task to further investigate potential prefrontal and anterior paralimbic rCMRglu abnormalities in patients attending to this Task. Results: Compared with control subjects, the subgroup of patients with Hamilton depression scores of 22 or greater demonstrated decreased absolute rCMRglu in right prefrontal cortex and paralimbic/amygdala regions as well as bilaterally in the insula and temporoparietal cortex (right > left); they also exhibited increased normalized metabolic activity bilaterally in the cerebellum, lingula/cuneus, and brain stem. Severity of depression negatively correlated with absolute rCMRglu in almost the entire extent of the right cingulate cortex as well as bilaterally in prefrontal cortex, insula, basal ganglia, and temporoparietal cortex (right > left). Conclusions: Areas of frontal, cingulate, insula, and temporal cortex appear hypometabolic in association with different components of the severity and course of illness in treatment-resistant unipolar depression.