Individuals exhibit a natural bias to approach positive social cues (e.g., smiling face) and to avoid negative ones, which may be altered in psychiatric conditions. Computerized approach/avoidance ...training to promote affectively congruent behavior has proven useful in modulating such biases. Here, we investigate how exposure to a higher rate of congruency impacts neural processing of social-affective cues.
While undergoing functional magnetic resonance imaging (fMRI), twenty-four individuals completed two versions of the approach-avoidance task (AAT), in which they had to approach or avoid dynamic facial expressions of either happiness or disgust. In the high congruency condition, congruent responses (i.e. approaching happy faces, avoiding disgusted faces) were more frequent. The balanced condition had equal amounts of congruent and incongruent responses.
Processing of congruent approach-avoidance actions towards social cues was associated with lower recruitment of the right anterior insula in the congruency-intensive relative to the balanced condition. Differential activation between the high congruency and balanced condition in the right hippocampus was negatively related to individuals’ trait avoidance tendency. These findings are consistent with reduced affective neural processing of social cues when being exposed to congruent AAT contexts. These neural foci could be important targets when assessing the effectiveness of affective congruency training protocols.
•Approach-avoidance action tendencies may be altered in psychiatric conditions.•Congruency-focused AAT may improve neural processing of social-affective cues.•High congruency AAT was associated with lower right anterior insula recruitment.•A high congruency AAT condition may help reduce affective processing of social cues.
This study prospectively examines the influence of alcohol on neuropsychological functioning in boys and girls characterized prior to initiating drinking (
N
= 76, ages 12-14). Adolescents who ...transitioned into heavy (
n
= 25; 11 girls, 14 boys) or moderate (
n
= 11; 2 girls, 9 boys) drinking were compared with matched controls who remained nonusers throughout the ~3-year follow-up period (
N
= 40; 16 girls, 24 boys). For girls, more past year drinking days predicted a greater reduction in visuospatial task performance from baseline to follow-up, above and beyond performance on equivalent measures at baseline (
R
2
Δ = 10%,
p
< .05), particularly on tests of visuospatial memory (
R
2
Δ = 8%,
p
< .05). For boys, a tendency was seen for more past year hangover symptoms to predict worsened sustained attention (
R
2
Δ = 7%,
p
< .05). These preliminary longitudinal findings suggest that initiating moderately heavy alcohol use and incurring hangover during adolescence may adversely influence neurocognitive functioning. Neurocognitive deficits linked to heavy drinking during this critical developmental period may lead to direct and indirect changes in neuromaturational course, with effects that would extend into adulthood.
Rationale
Alcohol dependence is associated with high rates of recidivism. Stress has been shown to increase alcohol craving in alcohol-dependent individuals, but the association between ...stress-induced craving and alcoholism treatment outcome is not well understood.
Objective
The aim of the present study was to examine the relationship between strength of stress-induced alcohol craving in the human laboratory and subsequent drinking in a cohort of treatment-seeking, alcohol-dependent adults.
Materials and methods
This is a prospective study assessing stress-induced craving in the lab and subsequent treatment outcomes in alcohol-dependent subjects enrolled in a 12-week outpatient study. Stress was induced using a previously developed, individualized, audio recorded stress script and validated with objective (salivary cortisol) and subjective measures of distress. In vivo craving for alcohol was measured pre- and post-challenge using VAS.
Results
Subjects were 28 (16 male, 12 female) alcohol-dependent outpatients. Greater stress-induced craving was associated with a blunted salivary cortisol response, significantly shorter time to alcohol relapse, higher mean drinks per week, fewer percent days abstinent, and lower rates of complete abstinence over the study duration (all
p
's < 0.05). Conversely, no demographic or baseline variables were significant predictors of any outcome variable.
Conclusions
These results suggest that greater stress-related increases in alcohol craving are associated with poorer alcohol treatment outcomes. The findings support the use of stress-induced craving as a predictor of alcohol relapse propensity. Furthermore, treatments that address high stress levels and the associated high levels of alcohol craving are likely to improve treatment outcomes in alcohol dependence.
Trauma and posttraumatic stress are highly comorbid with chronic pain and are often antecedents to developing chronic pain conditions. Pain and trauma are associated with greater utilization of ...medical services, greater use of psychiatric medication, and increased total cost of treatment. Despite the high overlap in the clinic, the neural mechanisms of pain and trauma are often studied separately. In this study, resting-state functional magnetic resonance imaging (rs-fMRI) scans were completed among a diagnostically heterogeneous sample of veterans with a range of back pain and trauma symptoms. Using Group Iterative Multiple Model Estimation (GIMME), an effective functional connectivity analysis, we explored an unsupervised model deriving subgroups based on path similarity in
defined regions of interest (ROIs) from brain regions implicated in the experience of pain and trauma. Three subgroups were identified by patterns in functional connection and differed significantly on several psychological measures despite similar demographic and diagnostic characteristics. The first subgroup was highly connected overall, was characterized by functional connectivity from the nucleus accumbens (NAc), the anterior cingulate cortex (ACC), and the posterior cingulate cortex (PCC) to the insula and scored low on pain and trauma symptoms. The second subgroup did not significantly differ from the first subgroup on pain and trauma measures but was characterized by functional connectivity from the ACC and NAc to the thalamus and from ACC to PCC. The third subgroup was characterized by functional connectivity from the thalamus and PCC to NAc and scored high on pain and trauma symptoms. Our results suggest that, despite demographic and diagnostic similarities, there may be neurobiologically dissociable biotypes with different mechanisms for managing pain and trauma. These findings may have implications for the determination of appropriate biotype-specific interventions that target these neurological systems.
Suicide is a significant public health problem. Suicidal ideation (SI) increases the risk for completed suicide. However, the brain basis of SI is unknown. The objective of this study was to examine ...the neural correlates of self-monitoring in individuals at risk for suicide. We hypothesized that combat veterans with a history of SI relative to those without such a history would show altered activation in the anterior cingulate cortex and related circuitry during self-monitoring.
Two groups of combat-exposed war veterans (13 men with and 13 men without history of SI) were studied. Both the SI and non-SI participants had two or more of the following: a) current major depressive disorder, b) current posttraumatic stress disorder, and c) history of mild traumatic brain injury, and each subject performed a validated stop task during functional magnetic resonance imaging. Error-related activation was compared between the SI and non-SI groups.
The SI group demonstrated more error-related activation of the anterior cingulate (8256 mm(3), t = 2.51) and prefrontal cortex (i.e., clusters >2048 mm(3), voxelwise p < .05). The SI and non-SI participants showed similar behavioral task performance (i.e., mean error rate, F values < 0.63, p values > .43; and mean reaction times, F = 0.27, p = .61).
These findings suggest neural correlates of altered self-monitoring in individuals with a history of SI and may further suggest that functional magnetic resonance imaging could be used to identify individuals at risk for suicide before they engage in suicidal behavior.
The aim of this study was to examine the effect of Posttraumatic Stress Disorder (PTSD) and childhood adversity on brain structure. We assessed hippocampal and amygdala shape in veterans with varying ...levels of PTSD symptom severity and exposure to early life stressors (ELS).
A total of 70 male veterans, who were deployed to a combat area during OIF/OEF/OND and who had been exposed to trauma during deployment, were included in the study. We applied a vertex-wise shape analysis of 3T MRI scans to measure indentation or expansion in hippocampal and amygdala shape.
Analyses showed a positive correlation between number of ELS and vertices in the right amygdala and the right hippocampus, as well as a positive correlation between PTSD symptom severity and right hippocampal vertices. There were no significant interactions between PTSD symptoms, ELS, and brain shape.
Results indicate a relationship between exposure to more childhood adversity and expansion in amygdala and hippocampal shape as well as between more severe PTSD symptoms and expansion in hippocampal shape. These findings may have important implications for the pathophysiology of trauma-related disorders.
•More severe PTSD symptoms is linked to expansion in hippocampal shape.•Exposure to more childhood adversity is linked to expansion in amygdala shape.•Exposure to more childhood adversity is linked to expansion in hippocampal shape.
Norepinephrine (NE) driven noninvasive vagus nerve stimulation (nVNS), which improves attention and reduces reaction time, augments learning. Equally important, endogenous NE mediated arousal is ...highly dependent on the valence (positive or negative) of the exogenous stimulus. But to date, no study has measured valence specific effects of nVNS on both functional magnetic resonance imaging (fMRI) anticipation task response and reaction time in healthy individuals. Therefore, the aim of this pilot study was to assess whether nVNS vs sham modulates valence cortical anticipation task response and reaction time in a normative sample.
Participants received right sided transcutaneous cervical nVNS (N = 12) or sham (N = 12) stimulation during a 3T fMRI scan. Subjects first performed a continuous performance task (CPT) and then a cued anticipation task to images of positively and negatively valenced events during fMRI. Reaction times to cues and Blood oxygen level dependent (BOLD) response were examined over phase to identify effects of nVNS/sham over time.
nVNS reduced reaction time for all valenced image anticipation trials. With the fMRI anticipation task, we observed a valence-specific effect; nVNS increased responsivity to images with negative valence and decreased responsivity to images with positive valence, whereas sham showed an inverse valence response.
nVNS was linked to reduced reaction time during the anticipation task. In tandem, nVNS consistently enhanced responsivity to negatively valenced images and diminished responsivity to positively valenced images, suggesting specific nVNS driven endogenous neurotransmitter signaling may contribute.
•nVNS effects, (increase in arousal and reduction in reaction time) is in part ascribed to (LC-NE) cortical signaling.•In this study, nVNS (in contrast to sham) reduced reaction time across all valenced anticipation tasks.•In contrast to sham, nVNS: 1) increased responsivity to images with negative valence and 2) decreased responsivity to images with positive valence.•nVNS additive response during the negatively valenced (arousing) image anticipation tasks may reduce reaction time.
Neuroimaging and fetal alcohol spectrum disorders Spadoni, Andrea D.; McGee, Christie L.; Fryer, Susanna L. ...
Neuroscience and biobehavioral reviews,
01/2007, Letnik:
31, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Heavy prenatal alcohol exposure causes permanent structural alterations to the brain and can lead to numerous cognitive and behavioral outcomes. Consistent with many of the neuropsychological and ...behavioral deficits that have been reported, neuroimaging studies reveal a pattern of structural abnormalities associated with prenatal alcohol exposure. This chapter systematically reviews structural anomalies by brain region, identifying cognitive and behavioral correlates when relevant. The consensus shows that in addition to the overall reduction of brain size, prominent brain shape abnormalities have been observed, with narrowing in the parietal region and reduced brain growth in portions of the frontal lobe. Commensurating with these anomalies, volumetric and tissue density findings cite disproportionate reductions in the parietal lobe, cerebellar vermis, corpus callosum, and the caudate nucleus, suggesting that certain areas of the brain may be especially vulnerable to prenatal alcohol exposure. In sum, neuroimaging techniques have greatly advanced our understanding of brain–behavior relationships in fetal alcohol spectrum disorders (FASD), and hopefully will lead to improved diagnosis and treatment options for those affected by prenatal exposure to alcohol.
Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are highly comorbid conditions that often co-occur with chronic pain. We have shown that women with PTSD subsequent to ...intimate partner violence show attenuated brain response to repeated experimental pain that was related to symptoms of avoidance. The aim of this study was to extend our past findings to males with combat trauma and to examine brain response to experimental pain in men with and without PTSD who sustained mTBI during combat. Seventy male veterans performed an experimental pain paradigm during functional magnetic resonance imaging fMRI. Of the 70 total subjects, 46 self-reported a history of mTBI during combat (46 of 70). Of those with mTBI, 26 also met criteria for PTSD (26 of 46). As in our previous study, we examined change in brain activity to repeated heat pain with linear mixed-effects modeling for group by administration interaction effects. We observed a significant group by administration interaction to repeated heat pain within insular, frontal, and parietal cortices, such that the control group showed increased activation over time, whereas mTBI groups (mTBI-only, mTBI + PTSD) showed decreased activation within bilateral anterior insulas (AIs) between administrations. Importantly, change in the right AI response was inversely correlated with avoidance symptoms, but only in those with comorbid mTBI + PTSD. Further, in the comorbid group, greater AI attenuation was associated with decreased connectivity with anterior cingulate (ACC). The current study provides further evidence that repeated exposure to brief painful stimuli results in attenuation of insula activation over time in traumatized individuals. Further, in PTSD, AI shows greatest attenuation in those with the highest level of avoidance-a finding that was replicated across diverse samples. Thus, this mechanism may be a generalized mechanism of maladaptive response to experimental pain in those with significant trauma.
Background: Prolonged exposure (PE) therapy is the first-line treatment for posttraumatic stress disorder (PTSD) in combat veterans. The underlying brain changes of treatment effect in PTSD are ...currently unknown. Methods: A total of 31 veterans with PTSD completed an fMRI scan performing an affective anticipation task at baseline and were enrolled in PE therapy. Of these, 7 prematurely terminated therapy, while 24 individuals completed PE therapy and an identical follow-up fMRI scan. At follow-up, 15 of the 24 completers still had diagnosable PTSD (NR-PTSD) and 9 of the 24 completers showed complete remission from PTSD (R-PTSD), i.e. they did not meet diagnostic criteria for PTSD. Results: The left anterior insula showed a significant group by scan session interaction. Specifically, the R-PTSD group showed decreased activation during anticipation of negative images from pre- to posttreatment scans, while the NR-PTSD group showed increased activation during anticipation of positive images in this region. Furthermore, the change in functional activation in the insula co-occurred with increased connectivity between this insular region and the right cingulate and right mid-posterior insular region in R-PTSD. Conclusions: These findings suggest that the capacity to effectively remit from PTSD symptoms after PE treatment requires the ability to connect with physiological signals and moderate the discomfort of anticipatory anxiety of exposure therapy. These processes appear to be controlled by a network where the anterior insula is connected with the cingulate and the mid-posterior insula.
PDF
