Michael Cerullo - Academia.edu (original) (raw)
Papers by Michael Cerullo
American Journal of Ophthalmology, 2002
Molecular Psychiatry, 2010
We examined sustained attention deficits in bipolar disorder and associated changes in brain acti... more We examined sustained attention deficits in bipolar disorder and associated changes in brain activation assessed by functional magnetic resonance imaging (fMRI). We hypothesized that relative to healthy participants, those with mania or mixed mania would (1) exhibit incremental decrements in sustained attention over time, (2) overactivate brain regions required for emotional processing and (3) progressively underactivate attentional regions of prefrontal cortex. Fifty participants with manic/mixed bipolar disorder (BP group) and 34 healthy comparison subjects (HC group) received an fMRI scan while performing a 15-min continuous performance task (CPT). The data were divided into three consecutive 5-min vigilance periods to analyze sustained attention. Composite brain activation maps indicated that both groups activated dorsal and ventral regions of an anterior-limbic network, but the BP group exhibited less activation over time relative to baseline. Consistent with hypotheses 1 and 2, the BP group showed a marginally greater behavioral CPT sustained attention decrement and more bilateral amygdala activation than the HC group, respectively. Instead of differential activation in prefrontal cortex over time, as predicted in hypothesis 3, the BP group progressively decreased activation in subcortical regions of striatum and thalamus relative to the HC group. These results suggest that regional activation decrements in dorsolateral prefrontal cortex accompany sustained attention decrements in both bipolar and healthy individuals. Stable amygdala overactivation across prolonged vigils may interfere with sustained attention and exacerbate attentional deficits in bipolar disorder. Differential striatal and thalamic deactivation in bipolar disorder is interpreted as a loss of amygdala (emotional brain) modulation by the ventrolateral prefrontal-subcortical circuit, which interferes with attentional maintenance.
Bipolar Disorders, 2009
To determine whether specific aspects of impulsivity (response disinhibition, inability to delay ... more To determine whether specific aspects of impulsivity (response disinhibition, inability to delay gratification, inattention) differ between healthy and bipolar manic subjects, and whether these aspects of impulsivity were associated with each other and severity of affective symptoms. Performance of 70 bipolar I manic or mixed patients was compared to that of 34 healthy subjects on three tasks specifically designed to study response inhibition, ability to delay gratification, and attention; namely, a stop signal task, a delayed reward task, and a continuous performance task, respectively. Correlations among tasks and with symptom ratings were also performed. Bipolar subjects demonstrated significant deficits on all three tasks as compared to healthy subjects. Performance on the three tasks was largely independent. Task performance was not significantly associated with the severity of affective symptom ratings. However, measures of response inhibition and attention were sensitive to medication effects. Differences in the delayed reward task were independent of medication effects or symptom ratings. During the delayed reward task, although bipolar patients made their choices more slowly than healthy subjects, they were significantly more likely to choose a smaller, but more quickly obtained reward. Moreover, performance on this task was not associated with performance on the other impulsivity measures. Manic patients showed more impulsive responding than mixed patients. Bipolar I manic patients demonstrate deficits on tests of various aspects of impulsivity as compared to healthy subjects. Some of these differences between groups may be mediated by medication effects. Findings suggested that inability to delay gratification (i.e., delayed reward task) was not simply a result of the speed of decision making or inattention, but rather that it reflected differences between bipolar and healthy subjects in the valuation of reward relative to delay.
Minds and Machines, 2014
If a brain is uploaded into a computer, will consciousness continue in digital form or will it en... more If a brain is uploaded into a computer, will consciousness continue in digital form or will it end forever when the brain is destroyed? Philosophers have long debated such dilemmas and classify them as questions about personal identity. There are currently three main theories of personal identity: biological, psychological, and closest continuer theories. None of these theories can successfully address the questions posed by the possibility of uploading. I will argue that uploading requires us to adopt a new theory of identity, psychological branching identity. Psychological branching identity states that consciousness will continue as long as there is continuity in psychological structure. What differentiates this from psychological identity is that it allows identity to continue in multiple selves. According to branching identity, continuity of consciousness will continue in both the original brain and the upload after nondestructive uploading. Branching identity can also resolve long standing questions about split-brain syndrome and can provide clear predictions about identity in even the most difficult cases imagined by philosophers.
Current Psychosis & Therapeutics Reports, 2006
Substance Abuse Treatment, Prevention, and Policy, 2007
International Review of Psychiatry, 2009
American Journal of Psychiatry, 2008
Perspectives in Biology and Medicine, 2006
Biological Psychiatry, 2011
Background-Bipolar I disorder is defined by the occurrence of mania. The presence of mania, coupl... more Background-Bipolar I disorder is defined by the occurrence of mania. The presence of mania, coupled with a course of illness characterized by waxing and waning of affective symptoms, suggests that bipolar disorder arises from dysfunction of neural systems that maintain emotional arousal and homeostasis. We used functional magnetic resonance imaging (fMRI) to study manic bipolar subjects as they performed a cognitive task designed to examine the ventrolateral prefrontal emotional arousal network. Methods-We used fMRI to study regional brain activation in 40 DSM-IV manic bipolar I patients and 36 healthy subjects while they performed a continuous performance task with emotional and neutral distracters. Event-related region-of-interest analyses were performed to test the primary hypothesis. Voxelwise analyses were also completed. Results-Compared with healthy subjects, the manic subjects exhibited blunted activation to emotional and neutral images, but not targets, across most of the predefined regions of interest. Several additional brain regions identified in the voxelwise analysis also exhibited similar differences between groups, including right parahippocampus, right lingual gyrus, and medial thalamus. In addition to these primary findings, the manic subjects also exhibited increased activation in response to targets in number of brain regions that were primarily associated with managing affective stimuli. Group differences did not appear to be secondary to medication exposure or other confounds.
PLOS Computational Biology, 2015
In the last decade, Guilio Tononi has developed the Integrated Information Theory (IIT) of consci... more In the last decade, Guilio Tononi has developed the Integrated Information Theory (IIT) of consciousness. IIT postulates that consciousness is equal to integrated information (F). The goal of this paper is to show that IIT fails in its stated goal of quantifying consciousness. The paper will challenge the theoretical and empirical arguments in support of IIT. The main theoretical argument for the relevance of integrated information to consciousness is the principle of information exclusion. Yet, no justification is given to support this principle. Tononi claims there is significant empirical support for IIT, but this is called into question by the creation of a trivial theory of consciousness with equal explanatory power. After examining the theoretical and empirical evidence for IIT, arguments from philosophy of mind and epistemology will be examined. Since IIT is not a form of computational functionalism, it is vulnerable to fading/ dancing qualia arguments. Finally, the limitations of the phenomenological approach to studying consciousness are examined, and it will be shown that IIT is a theory of protoconsciousness rather than a theory of consciousness.
Journal of clinical and experimental neuropsychology, Jan 10, 2015
Previous research has shown that performance on cognitive tasks administered in the scanner can b... more Previous research has shown that performance on cognitive tasks administered in the scanner can be altered by the scanner environment. There are no previous studies that have investigated the impact of scanner noise using a well-validated measure of affective change. The goal of this study was to determine whether performance on an affective attentional task or emotional response to the task would change in the presence of distracting acoustic noise, such as that encountered in a magnetic resonance imaging (MRI) environment. Thirty-four young adults with no self-reported history of neurologic disorder or mental illness completed three blocks of the affective Posner task outside of the scanner. The task was meant to induce frustration through monetary contingencies and rigged feedback. Participants completed a Self-Assessment Manikin at the end of each block to rate their mood, arousal level, and sense of dominance. During the task, half of the participants heard noise (recorded from...
Topics in magnetic resonance imaging : TMRI, 2008
Although advances in the clinical criteria of various axis I psychiatric disorders are continuall... more Although advances in the clinical criteria of various axis I psychiatric disorders are continually being made, there is still considerable overlap in the clinical features, and diagnosis is often challenging. As a result, there has been substantial interest in using morphometric magnetic resonance imaging to better characterize these diseases and inform diagnosis. Region of interest and voxel-based morphometry studies are reviewed herein to examine the extent to which these goals are being met across various psychiatric disorders. It is concluded based on the studies reviewed that specific patterns of regional loss, although present in certain axis I disorders, are not, as yet, diagnostically useful. However, advances in outcome and treatment monitoring show considerably more promise for rapid application in psychiatry.
Geriatrics, 2008
Psychiatric side effects including mania, depression, psychosis, and delirium, are extremely comm... more Psychiatric side effects including mania, depression, psychosis, and delirium, are extremely common in patients treated with corticosteroids. The elderly and those with previous psychiatric diagnoses are not at increased risk for these side effects, but females and those with prior corticosteroid-induced psychiatric side effects are. Depression and mania are the most frequent behavioral side effects, followed by psychosis and delirium. In the geriatric population, there is a long list of medical etiologies of psychosis, delirium, mania, and depression. These must be distinguished from corticosteroid side effects. Treatment involves stopping the corticosteroids, if possible, and targeting the specific psychiatric symptoms that develop.
Journal of cancer education : the official journal of the American Association for Cancer Education, 2002
Spiritual and religious issues (SRI) in medical school curricula may promote psychosocial and spi... more Spiritual and religious issues (SRI) in medical school curricula may promote psychosocial and spiritual sensitivity, but few data exist on this relationship. A questionnaire was administered to third-year medical students (response rate = 69.2%). Students indicated exposure to SRI and read a vignette about a hypothetical cancer patient. SRI exposure through lectures, small-group discussions, and physician modeling predicted, respectively, likelihood of extra attention toward the patient, conversing with the patient about dying, and praying with the patient. Exposure to SRI in medical school may sensitize students to the psychosocial and spiritual needs of dying patients.
Journal of Affective Disorders, 2015
Background: Depressive and anxiety disorders are among the most frequently occurring psychiatric ... more Background: Depressive and anxiety disorders are among the most frequently occurring psychiatric conditions in children and adolescents and commonly present occur together. Co-occurring depression and anxiety is associated with increased functional impairment and suicidality compared to depression alone. Despite this, little is known regarding the neurostructural differences between anxiety disorders and major depressive disorder (MDD). Moreover, the neurophysiologic impact of the presence of anxiety in adolescents with MDD is unknown. Methods: Using voxel-based morphometry, gray matter volumes were compared among adolescents with MDD (and no co-morbid anxiety disorders, n ¼ 14), adolescents with MDD and co-morbid anxiety ("anxious depression," n ¼12), and healthy comparison subjects (n ¼41). Results: Patients with anxious depression exhibited decreased gray matter volumes in the dorsolateral prefrontal cortex (DLPFC) compared to patients with MDD alone. Compared to healthy subjects, adolescents with anxious depression had increased gray matter volumes in the pre-and post-central gyri. Limitations: The current sample size was small and precluded an analysis of multiple covariates which may influence GMV. Conclusions: Gray matter deficits in the DLPFC in youth with anxious depression compared to patients with MDD and no co-occurring anxiety may reflect the more severe psychopathology in these patients. Additionally, the distinct gray matter fingerprints of MDD and anxious depression (compared to healthy subjects) suggest differing neurophysiologic substrates for these conditions, though the etiology and longitudinal trajectory of the differences remain to be determined.
Bipolar Disorders, 2014
Objectives-Despite different treatments and course of illness, depressive symptoms appear similar... more Objectives-Despite different treatments and course of illness, depressive symptoms appear similar in major depressive disorder (MDD) and bipolar I disorder (BP-I). This similarity of depressive symptoms suggests significant overlap in brain pathways underlying neurovegetative, mood, and cognitive symptoms of depression. These shared brain regions might be expected to exhibit similar activation in individuals with MDD and BP-I during functional magnetic resonance imaging (fMRI). Methods-fMRI was used to compare regional brain activation in participants with BP-I (n = 25) and MDD (n = 25) during a depressive episode as well as 25 healthy comparison (HC) participants. During the scans, participants performed an attentional task that incorporated emotional pictures. Results-During the viewing of emotional images, subjects with BP-I showed decreased activation in the middle occipital gyrus, lingual gyrus, and middle temporal gyrus compared to both subjects with MDD and HC participants. During attentional processing, participants with MDD had increased activation in the parahippocampus, parietal lobe, and postcentral gyrus. However, among these regions, only the postcentral gyrus also showed differences between MDD and HC participants. Conclusions-No differences in cortico-limbic regions were found between participants with BP-I and MDD during depression. Instead, the major differences occurred in primary and secondary visual processing regions with decreased activation in these regions in BP-I compared
The Handbook of Neuropsychiatric Biomarkers, Endophenotypes and Genes, 2009
Page 1. Abstract Bipolar disorder, characterized by recurrent episodes of mania and commonly depr... more Page 1. Abstract Bipolar disorder, characterized by recurrent episodes of mania and commonly depression, is a debil-itating mental illness that affects millions of children, adolescents, and adults worldwide. Individuals with ...
NeuroImage, 2006
The present study used functional magnetic resonance imaging to examine cortical specialization f... more The present study used functional magnetic resonance imaging to examine cortical specialization for letter processing. We assessed whether brain regions that were involved in letter processing exhibited domain-specific and/or mandatory responses, following Fodor's definition of properties of modular systems (Fodor, J.A., 1983. The Modularity of Mind. The MIT Press, Cambridge, MA.). Domainspecificity was operationalized as selective, or exclusive, activation for letters relative to object and visual noise processing and a baseline fixation task. Mandatory processing was operationalized as selective activation for letters during both a silent naming and a perceptual matching task. In addition to these operational definitions, other operational definitions of selectivity for letter processing discussed by [Pernet, C., Celsis, P., Demonet, J., 2005. Selective response to letter categorization within the left fusiform gyrus. NeuroImage 28, 738-744] were applied to the data. Although the left fusiform gyrus showed a specialized response to letters using the definition of selectivity put forth by [Pernet, C., Celsis, P., Demonet, J., 2005. Selective response to letter categorization within the left fusiform gyrus. NeuroImage 28, 738-744], this region did not exhibit specialization for letters according to our more conservative definition of selectivity. Instead, this region showed equivalent activation by letters and objects in both the naming and matching tasks. Hence, the left fusiform gyrus does not exhibit domain-specific or mandatory processing but may reflect a shared input system for both stimulus types. The left insula and some portions of the left inferior parietal lobule, however, did show a domain-specific response for letter naming but not for letter matching. These regions likely subserve some linguistically oriented cognitive process that is unique to letters, such as grapheme-to-phoneme translation or retrieval of phonological codes for letter names. Hence, cortical specialization for letters emerged in the naming task in some peri-sylvian language related cortices, but not in occipito-temporal cortex. Given that the domain-specific response for letters in left peri-sylvian regions was only present in the naming task, these regions do not process letters in a mandatory fashion, but are instead modulated by the linguistic nature of the task.
American Journal of Ophthalmology, 2002
Molecular Psychiatry, 2010
We examined sustained attention deficits in bipolar disorder and associated changes in brain acti... more We examined sustained attention deficits in bipolar disorder and associated changes in brain activation assessed by functional magnetic resonance imaging (fMRI). We hypothesized that relative to healthy participants, those with mania or mixed mania would (1) exhibit incremental decrements in sustained attention over time, (2) overactivate brain regions required for emotional processing and (3) progressively underactivate attentional regions of prefrontal cortex. Fifty participants with manic/mixed bipolar disorder (BP group) and 34 healthy comparison subjects (HC group) received an fMRI scan while performing a 15-min continuous performance task (CPT). The data were divided into three consecutive 5-min vigilance periods to analyze sustained attention. Composite brain activation maps indicated that both groups activated dorsal and ventral regions of an anterior-limbic network, but the BP group exhibited less activation over time relative to baseline. Consistent with hypotheses 1 and 2, the BP group showed a marginally greater behavioral CPT sustained attention decrement and more bilateral amygdala activation than the HC group, respectively. Instead of differential activation in prefrontal cortex over time, as predicted in hypothesis 3, the BP group progressively decreased activation in subcortical regions of striatum and thalamus relative to the HC group. These results suggest that regional activation decrements in dorsolateral prefrontal cortex accompany sustained attention decrements in both bipolar and healthy individuals. Stable amygdala overactivation across prolonged vigils may interfere with sustained attention and exacerbate attentional deficits in bipolar disorder. Differential striatal and thalamic deactivation in bipolar disorder is interpreted as a loss of amygdala (emotional brain) modulation by the ventrolateral prefrontal-subcortical circuit, which interferes with attentional maintenance.
Bipolar Disorders, 2009
To determine whether specific aspects of impulsivity (response disinhibition, inability to delay ... more To determine whether specific aspects of impulsivity (response disinhibition, inability to delay gratification, inattention) differ between healthy and bipolar manic subjects, and whether these aspects of impulsivity were associated with each other and severity of affective symptoms. Performance of 70 bipolar I manic or mixed patients was compared to that of 34 healthy subjects on three tasks specifically designed to study response inhibition, ability to delay gratification, and attention; namely, a stop signal task, a delayed reward task, and a continuous performance task, respectively. Correlations among tasks and with symptom ratings were also performed. Bipolar subjects demonstrated significant deficits on all three tasks as compared to healthy subjects. Performance on the three tasks was largely independent. Task performance was not significantly associated with the severity of affective symptom ratings. However, measures of response inhibition and attention were sensitive to medication effects. Differences in the delayed reward task were independent of medication effects or symptom ratings. During the delayed reward task, although bipolar patients made their choices more slowly than healthy subjects, they were significantly more likely to choose a smaller, but more quickly obtained reward. Moreover, performance on this task was not associated with performance on the other impulsivity measures. Manic patients showed more impulsive responding than mixed patients. Bipolar I manic patients demonstrate deficits on tests of various aspects of impulsivity as compared to healthy subjects. Some of these differences between groups may be mediated by medication effects. Findings suggested that inability to delay gratification (i.e., delayed reward task) was not simply a result of the speed of decision making or inattention, but rather that it reflected differences between bipolar and healthy subjects in the valuation of reward relative to delay.
Minds and Machines, 2014
If a brain is uploaded into a computer, will consciousness continue in digital form or will it en... more If a brain is uploaded into a computer, will consciousness continue in digital form or will it end forever when the brain is destroyed? Philosophers have long debated such dilemmas and classify them as questions about personal identity. There are currently three main theories of personal identity: biological, psychological, and closest continuer theories. None of these theories can successfully address the questions posed by the possibility of uploading. I will argue that uploading requires us to adopt a new theory of identity, psychological branching identity. Psychological branching identity states that consciousness will continue as long as there is continuity in psychological structure. What differentiates this from psychological identity is that it allows identity to continue in multiple selves. According to branching identity, continuity of consciousness will continue in both the original brain and the upload after nondestructive uploading. Branching identity can also resolve long standing questions about split-brain syndrome and can provide clear predictions about identity in even the most difficult cases imagined by philosophers.
Current Psychosis & Therapeutics Reports, 2006
Substance Abuse Treatment, Prevention, and Policy, 2007
International Review of Psychiatry, 2009
American Journal of Psychiatry, 2008
Perspectives in Biology and Medicine, 2006
Biological Psychiatry, 2011
Background-Bipolar I disorder is defined by the occurrence of mania. The presence of mania, coupl... more Background-Bipolar I disorder is defined by the occurrence of mania. The presence of mania, coupled with a course of illness characterized by waxing and waning of affective symptoms, suggests that bipolar disorder arises from dysfunction of neural systems that maintain emotional arousal and homeostasis. We used functional magnetic resonance imaging (fMRI) to study manic bipolar subjects as they performed a cognitive task designed to examine the ventrolateral prefrontal emotional arousal network. Methods-We used fMRI to study regional brain activation in 40 DSM-IV manic bipolar I patients and 36 healthy subjects while they performed a continuous performance task with emotional and neutral distracters. Event-related region-of-interest analyses were performed to test the primary hypothesis. Voxelwise analyses were also completed. Results-Compared with healthy subjects, the manic subjects exhibited blunted activation to emotional and neutral images, but not targets, across most of the predefined regions of interest. Several additional brain regions identified in the voxelwise analysis also exhibited similar differences between groups, including right parahippocampus, right lingual gyrus, and medial thalamus. In addition to these primary findings, the manic subjects also exhibited increased activation in response to targets in number of brain regions that were primarily associated with managing affective stimuli. Group differences did not appear to be secondary to medication exposure or other confounds.
PLOS Computational Biology, 2015
In the last decade, Guilio Tononi has developed the Integrated Information Theory (IIT) of consci... more In the last decade, Guilio Tononi has developed the Integrated Information Theory (IIT) of consciousness. IIT postulates that consciousness is equal to integrated information (F). The goal of this paper is to show that IIT fails in its stated goal of quantifying consciousness. The paper will challenge the theoretical and empirical arguments in support of IIT. The main theoretical argument for the relevance of integrated information to consciousness is the principle of information exclusion. Yet, no justification is given to support this principle. Tononi claims there is significant empirical support for IIT, but this is called into question by the creation of a trivial theory of consciousness with equal explanatory power. After examining the theoretical and empirical evidence for IIT, arguments from philosophy of mind and epistemology will be examined. Since IIT is not a form of computational functionalism, it is vulnerable to fading/ dancing qualia arguments. Finally, the limitations of the phenomenological approach to studying consciousness are examined, and it will be shown that IIT is a theory of protoconsciousness rather than a theory of consciousness.
Journal of clinical and experimental neuropsychology, Jan 10, 2015
Previous research has shown that performance on cognitive tasks administered in the scanner can b... more Previous research has shown that performance on cognitive tasks administered in the scanner can be altered by the scanner environment. There are no previous studies that have investigated the impact of scanner noise using a well-validated measure of affective change. The goal of this study was to determine whether performance on an affective attentional task or emotional response to the task would change in the presence of distracting acoustic noise, such as that encountered in a magnetic resonance imaging (MRI) environment. Thirty-four young adults with no self-reported history of neurologic disorder or mental illness completed three blocks of the affective Posner task outside of the scanner. The task was meant to induce frustration through monetary contingencies and rigged feedback. Participants completed a Self-Assessment Manikin at the end of each block to rate their mood, arousal level, and sense of dominance. During the task, half of the participants heard noise (recorded from...
Topics in magnetic resonance imaging : TMRI, 2008
Although advances in the clinical criteria of various axis I psychiatric disorders are continuall... more Although advances in the clinical criteria of various axis I psychiatric disorders are continually being made, there is still considerable overlap in the clinical features, and diagnosis is often challenging. As a result, there has been substantial interest in using morphometric magnetic resonance imaging to better characterize these diseases and inform diagnosis. Region of interest and voxel-based morphometry studies are reviewed herein to examine the extent to which these goals are being met across various psychiatric disorders. It is concluded based on the studies reviewed that specific patterns of regional loss, although present in certain axis I disorders, are not, as yet, diagnostically useful. However, advances in outcome and treatment monitoring show considerably more promise for rapid application in psychiatry.
Geriatrics, 2008
Psychiatric side effects including mania, depression, psychosis, and delirium, are extremely comm... more Psychiatric side effects including mania, depression, psychosis, and delirium, are extremely common in patients treated with corticosteroids. The elderly and those with previous psychiatric diagnoses are not at increased risk for these side effects, but females and those with prior corticosteroid-induced psychiatric side effects are. Depression and mania are the most frequent behavioral side effects, followed by psychosis and delirium. In the geriatric population, there is a long list of medical etiologies of psychosis, delirium, mania, and depression. These must be distinguished from corticosteroid side effects. Treatment involves stopping the corticosteroids, if possible, and targeting the specific psychiatric symptoms that develop.
Journal of cancer education : the official journal of the American Association for Cancer Education, 2002
Spiritual and religious issues (SRI) in medical school curricula may promote psychosocial and spi... more Spiritual and religious issues (SRI) in medical school curricula may promote psychosocial and spiritual sensitivity, but few data exist on this relationship. A questionnaire was administered to third-year medical students (response rate = 69.2%). Students indicated exposure to SRI and read a vignette about a hypothetical cancer patient. SRI exposure through lectures, small-group discussions, and physician modeling predicted, respectively, likelihood of extra attention toward the patient, conversing with the patient about dying, and praying with the patient. Exposure to SRI in medical school may sensitize students to the psychosocial and spiritual needs of dying patients.
Journal of Affective Disorders, 2015
Background: Depressive and anxiety disorders are among the most frequently occurring psychiatric ... more Background: Depressive and anxiety disorders are among the most frequently occurring psychiatric conditions in children and adolescents and commonly present occur together. Co-occurring depression and anxiety is associated with increased functional impairment and suicidality compared to depression alone. Despite this, little is known regarding the neurostructural differences between anxiety disorders and major depressive disorder (MDD). Moreover, the neurophysiologic impact of the presence of anxiety in adolescents with MDD is unknown. Methods: Using voxel-based morphometry, gray matter volumes were compared among adolescents with MDD (and no co-morbid anxiety disorders, n ¼ 14), adolescents with MDD and co-morbid anxiety ("anxious depression," n ¼12), and healthy comparison subjects (n ¼41). Results: Patients with anxious depression exhibited decreased gray matter volumes in the dorsolateral prefrontal cortex (DLPFC) compared to patients with MDD alone. Compared to healthy subjects, adolescents with anxious depression had increased gray matter volumes in the pre-and post-central gyri. Limitations: The current sample size was small and precluded an analysis of multiple covariates which may influence GMV. Conclusions: Gray matter deficits in the DLPFC in youth with anxious depression compared to patients with MDD and no co-occurring anxiety may reflect the more severe psychopathology in these patients. Additionally, the distinct gray matter fingerprints of MDD and anxious depression (compared to healthy subjects) suggest differing neurophysiologic substrates for these conditions, though the etiology and longitudinal trajectory of the differences remain to be determined.
Bipolar Disorders, 2014
Objectives-Despite different treatments and course of illness, depressive symptoms appear similar... more Objectives-Despite different treatments and course of illness, depressive symptoms appear similar in major depressive disorder (MDD) and bipolar I disorder (BP-I). This similarity of depressive symptoms suggests significant overlap in brain pathways underlying neurovegetative, mood, and cognitive symptoms of depression. These shared brain regions might be expected to exhibit similar activation in individuals with MDD and BP-I during functional magnetic resonance imaging (fMRI). Methods-fMRI was used to compare regional brain activation in participants with BP-I (n = 25) and MDD (n = 25) during a depressive episode as well as 25 healthy comparison (HC) participants. During the scans, participants performed an attentional task that incorporated emotional pictures. Results-During the viewing of emotional images, subjects with BP-I showed decreased activation in the middle occipital gyrus, lingual gyrus, and middle temporal gyrus compared to both subjects with MDD and HC participants. During attentional processing, participants with MDD had increased activation in the parahippocampus, parietal lobe, and postcentral gyrus. However, among these regions, only the postcentral gyrus also showed differences between MDD and HC participants. Conclusions-No differences in cortico-limbic regions were found between participants with BP-I and MDD during depression. Instead, the major differences occurred in primary and secondary visual processing regions with decreased activation in these regions in BP-I compared
The Handbook of Neuropsychiatric Biomarkers, Endophenotypes and Genes, 2009
Page 1. Abstract Bipolar disorder, characterized by recurrent episodes of mania and commonly depr... more Page 1. Abstract Bipolar disorder, characterized by recurrent episodes of mania and commonly depression, is a debil-itating mental illness that affects millions of children, adolescents, and adults worldwide. Individuals with ...
NeuroImage, 2006
The present study used functional magnetic resonance imaging to examine cortical specialization f... more The present study used functional magnetic resonance imaging to examine cortical specialization for letter processing. We assessed whether brain regions that were involved in letter processing exhibited domain-specific and/or mandatory responses, following Fodor's definition of properties of modular systems (Fodor, J.A., 1983. The Modularity of Mind. The MIT Press, Cambridge, MA.). Domainspecificity was operationalized as selective, or exclusive, activation for letters relative to object and visual noise processing and a baseline fixation task. Mandatory processing was operationalized as selective activation for letters during both a silent naming and a perceptual matching task. In addition to these operational definitions, other operational definitions of selectivity for letter processing discussed by [Pernet, C., Celsis, P., Demonet, J., 2005. Selective response to letter categorization within the left fusiform gyrus. NeuroImage 28, 738-744] were applied to the data. Although the left fusiform gyrus showed a specialized response to letters using the definition of selectivity put forth by [Pernet, C., Celsis, P., Demonet, J., 2005. Selective response to letter categorization within the left fusiform gyrus. NeuroImage 28, 738-744], this region did not exhibit specialization for letters according to our more conservative definition of selectivity. Instead, this region showed equivalent activation by letters and objects in both the naming and matching tasks. Hence, the left fusiform gyrus does not exhibit domain-specific or mandatory processing but may reflect a shared input system for both stimulus types. The left insula and some portions of the left inferior parietal lobule, however, did show a domain-specific response for letter naming but not for letter matching. These regions likely subserve some linguistically oriented cognitive process that is unique to letters, such as grapheme-to-phoneme translation or retrieval of phonological codes for letter names. Hence, cortical specialization for letters emerged in the naming task in some peri-sylvian language related cortices, but not in occipito-temporal cortex. Given that the domain-specific response for letters in left peri-sylvian regions was only present in the naming task, these regions do not process letters in a mandatory fashion, but are instead modulated by the linguistic nature of the task.