Greater Blood Oxygen Level-dependent Signal Research Articles

Anterior Insula Activation During Cardiac Interoception Relates to Depressive Symptom Severity in HIV-Positive and HIV-Negative Postmenopausal Women.

ABSTRACTObjectiveThis study aimed to determine whether subclinical symptoms of depression in postmenopausal women are associated with blood oxygen level–dependent (BOLD) activity within the anterior insula during cardiac interoceptive awareness and whether this association differs for persons living with the human immunodeficiency virus (PWH).MethodTwenty-three postmenopausal (mean [standard deviation] age = 56.5 [4.8] years) and 27 HIV-negative women (mean [standard deviation] age = 56.4 [8.0]) underwent functional magnetic resonance imaging while performing a heartbeat detection task. BOLD activation within the bilateral anterior insula based on the contrast of a heartbeat detection condition with and without a distracting tone was entered along with age, HIV status, and psychological stress into two multivariate regression models with self-reported depressive symptom severity as the outcome.ResultsDepressive symptoms did not vary by HIV status, nor was there a main effect or interaction for PWH on insula BOLD activation. Depressive symptoms were positively associated with psychological stress for the left (β = 0.310, t(49) = 2.352, p = .023) and right brain models (β = 0.296, t(49) = 2.265, p = .028) as well as the magnitude of BOLD activation in the left insula (β = 0.290, t(49) = 2.218, p = .032) and right insula (β = 0.318, t(49) = 2.453, p = .018), respectively. Exploratory analyses revealed that greater magnitude of BOLD activation attributed to exteroceptive noise (tone) was also correlated with self-reported distrust and preoccupation with interoceptive sensations.ConclusionsResults support an active interference model for interoceptive awareness wherein greater BOLD signal in the anterior insula in the presence of distracting exteroceptive stimuli may reflect greater prediction error, a feature of depression.

Neuroimaging of executive function in survivors of pediatric brain tumors and healthy controls.

Research on the long-term sequelae of treatment for pediatric brain tumors has identified significant neurocognitive deficits experienced by many survivors. Despite indications of deficits based on cognitive assessment, the identification of specific neurobiological mechanisms of these deficits using neuroimaging techniques has yet to be considered. This study used norm-referenced standardized assessment and functional MRI (fMRI) to examine attention and executive functioning deficits of survivors of pediatric brain tumors, as compared with healthy children. Survivors of pediatric brain tumors performed more poorly than healthy children on measures of overall cognitive ability, attention, and executive function during testing, as well as on a working memory task during fMRI. Survivors showed lower blood-oxygen level dependent (BOLD) signal in bilateral frontal regions associated with sustained attention (BA6/8) and greater BOLD signal in left cingulate regions associated with complex problem-solving and performance monitoring (BA32) during working memory task completion. Both group and brain activation accounted for significant variance in neurocognitive functioning. Survivors of pediatric brain tumor and healthy children differed in brain activation during completion of a working memory task, and brain activation was associated with deficits noted in testing. These findings may improve understanding of mechanisms of cognitive deficits and avenues for intervention for children with brain tumors.

Impact of Cognitive Behavioral Therapy for Social Anxiety Disorder on the Neural Dynamics of Cognitive Reappraisal of Negative Self-beliefs

Cognitive behavioral therapy (CBT) for social anxiety disorder (SAD) is thought to enhance cognitive reappraisal in patients with SAD. Such improvements should be evident in cognitive reappraisal-related prefrontal cortex responses. To determine whether CBT for SAD modifies cognitive reappraisal-related prefrontal cortex neural signal magnitude and timing when implementing cognitive reappraisal with negative self-beliefs. DESIGN Randomized clinical trial of CBT for SAD vs wait-list control group during a study that enrolled patients from 2007 to 2010. University psychology department. Seventy-five patients with generalized SAD randomly assigned to CBT or wait list. Sixteen sessions of individual CBT for SAD. Negative emotion ratings and functional magnetic resonance imaging blood oxygen-level dependent signal when reacting to and cognitively reappraising negative self-beliefs embedded in autobiographical social anxiety situations. RESULTS During reactivity trials, compared with wait list, CBT produced (1) greater reduction in negative emotion ratings and (2) greater blood oxygen-level dependent signal magnitude in the medial prefrontal cortex. During cognitive reappraisal trials, compared with wait list, CBT produced (3) greater reduction in negative emotion ratings, (4) greater blood oxygen level-dependent signal magnitude in the dorsolateral and dorsomedial prefrontal cortex, (5) earlier temporal onset of dorsomedial prefrontal cortex activity, and (6) greater dorsomedial prefrontal cortex-amygdala inverse functional connectivity. Modulation of cognitive reappraisal-related brain responses, timing, and functional connectivity may be important brain changes that contribute to the effectiveness of CBT for social anxiety. This study demonstrates that clinically applied neuroscience investigations can elucidate neurobiological mechanisms of change in psychiatric conditions. clinicaltrials.gov Identifier: NCT00380731.

Rostral Prefrontal Cortex and the Focus of Attention in Prospective Memory

Prospective memory (PM) denotes the function to realize intentions after a delay while being immersed in distracting ongoing (OG) activity. Here, we scrutinize the often-reported involvement of rostral prefrontal cortex (rPFC; approximating Brodmann area 10) in such situations: This region might mediate attention between external stimuli and the internally maintained intention, that is, between stimulus-oriented (SO) and stimulus-independent (SI) processing. Using functional magnetic resonance imaging (fMRI) we orthogonally crossed 1) PM versus OG activity only, with 2) SO versus SI attention. In support of the hypothesis, common regions of medial rPFC exhibited greater blood oxygen level–dependent (BOLD) signal for the contrasts of both OG task only versus PM and SO versus SI attending. However, activation related to the former contrast extended more superiorly, suggesting a functional gradient along a dorsal–ventral axis within this region. Moreover, region-of-interest analyses revealed that PM versus OG task only was associated with greater BOLD signal in left lateral rPFC, reflecting the requirement to maintain delayed intentions. Distinct aspects of this region were also transiently engaged at transitions between SO and SI conditions. These results are consistent with the hypothesis that some of the rostral prefrontal signal changes associated with PM performance reflect relative differences in SO versus SI processing.

Brain–behavior correlates of optimizing learning through interleaved practice

Understanding how to make learning more efficient and effective is an important goal in behavioral neuroscience. The notion of “desirable difficulties” asserts that challenges for learners during study result in superior learning. One “desirable difficulty” that has a robust benefit on learning is contextual interference (CI), in which different tasks are practiced in an interleaved order rather than in a repetitive order. This study is the first to combine functional imaging and paired-pulse transcranial magnetic stimulation to analyze the neural basis of the CI effect in skill learning. Difficulty during practice of a serial reaction time task was manipulated by presenting sequences of response locations in a repetitive or an interleaved order. Participants practiced 3 sequences for 2days and were tested on day 5 to examine sequence-specific learning. During practice, slower response times (RT), greater frontal–parietal blood-oxygen-level-dependent (BOLD) signal, and higher motor cortex (M1) excitability were found in the interleaved condition compared to the repetitive condition. Consistent with the CI effect, we found faster RT, decreased BOLD signal in frontal–parietal regions, and greater M1 excitability during the day 5 retention task when subjects had practiced interleaved sequences. Correlation analyses indicated that greater BOLD signal in contralateral sensorimotor region and M1 excitability during interleaved practice were interrelated. Furthermore, greater BOLD signal in prefrontal, premotor and parietal areas and greater M1 excitability during interleaved practice correlated with the benefit of interleaved practice on retention. This demonstrates that interleaved practice induces interrelated changes in both cortical hemodynamic responses and M1 excitability, which likely index the formation of enhanced memory traces and efficient long-term retrieval.