Differential Functional Connectivity of Rostral Anterior Cingulate Cortex During Emotional Interference

The rostral-ventral subdivision of the anterior cingulate cortex (rACC) plays a key role in the regulation of emotional processing. Although rACC has strong anatomical connections with anterior insular cortex (AIC), amygdala, prefrontal cortex and striatal brain regions, it is unclear whether the functional connectivity of rACC with these regions changes when regulating emotional processing. Furthermore, it is not known whether this connectivity changes with deficits in emotion regulation seen in different kinds of anxiety and depression. To address these questions regarding rACC functional connectivity, non-patients high in self-reported anxious apprehension (AP), anxious arousal (AR), anhedonic depression (AD) or none (CON) indicated the ink color of pleasant, neutral and unpleasant words during functional magnetic resonance imaging. While ignoring task-irrelevant unpleasant words, AD and CON showed an increase in the functional connectivity of rACC with AIC, putamen, caudate and ventral pallidum. There was a decrease in this connectivity in AP and AR, with AP showing greater reduction than AR. These findings provide support for the role of rACC in integrating interoceptive, emotional and cognitive functions via interactions with insula and striatal regions during effective emotion regulation in healthy individuals and a failure of this integration that may be specific to anxiety, particularly AP

Differential engagement of anterior cingulate corte subdivisions for cognitive and emotional function.

Abstract Functional differentiation of dorsal (dACC) and rostral (rACC) anterior cingulate cortex for cognitive and emotional function has received considerable indirect support. Using fMRI, parallel tasks, and within-subject analysis, the present study directly tested the proposed specialization of ACC subdivisions. A Task  Region interaction confirmed more dACC activation during color-word distractors and more rACC activation during emotion-word distractors. Activity in ACC subdivisions differentially predicted behavioral performance. Connectivity with prefrontal and limbic regions also supported distinct dACC and rACC roles. Findings provide direct evidence for differential engagement of ACC subdivisions in cognitive and emotional processing and for differential functional connectivity in the implementation of cognitive control and emotion regulation. Results point to an anatomical and functional continuum rather than segregated operations

Neural Mechanisms Involved in Emotion /Attention Interactions

157 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.Although it is well-established that emotional context modulates attention and that this modulation varies across different types of clinical groups, the exact mechanisms involved remain unclear. Dorsolateral prefrontal cortex (DLPFC), amygdala, dorsal (dACC), and rostral (rACC) anterior cingulate cortex (ACC) have been shown to play a critical role in the interaction of emotion and attention processes. The present project proposes a model of brain connectivity that involves these brain regions and functional connections between them as well as how these connections vary in non-clinical control, depression and anxiety groups. Two critical aspects of this model of brain connectivity were examined. Firstly, although functional differentiation of dACC and rACC for aspects of cognitive and emotional function has received considerable indirect support, no direct statistical test of this specialization has been published. Using fMRI, parallel tasks, and within-subject analysis, the present study directly tested the proposed specialization of ACC subdivisions. A Task x Region interaction confirmed more dACC activation during color-word distractors and more rACC activation during emotion-word distractors. Activity in ACC subdivisions differentially predicted behavioral performance. Connectivity with prefrontal and limbic regions also supported distinct dACC and rACC roles. Findings provide direct evidence for differential engagement of ACC subdivisions in cognitive and emotional processing and for differential functional connectivity in the implementation of cognitive control and emotion regulation. Secondly, context-dependent interactions between DLPFC, amygdala, dACC, and rACC were explored in clinical and non-clinical groups performing the emotional Stroop task. Compared to depression and control groups, anxiety groups showed greater interference from negative stimuli. Control and depression participants showed a stronger positive dACC-DLPFC relationship for negative versus neutral words, indicating greater dACC-DLPFC implemented control in the presence of negative distractors. In contrast, individuals with anxiety showed a less positive dACC-DLPFC relationship for negative versus neutral words, indicating a weakening of this relationship in the presence of emotionally aversive stimuli, thereby resulting in poorer behavioral performance. The rACC-amygdala relationship showed a similar pattern of relationships. Findings provide important insight into mechanisms involved in disruption of cognitive function in the presence of affective stimuli as well as how this relationship manifests in clinical conditions.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Glucose-Induced Enhancement of Spatial Memory in Humans

Glucose has repeatedly been shown to enhance learning and memory processes for a variety of tasks in humans and non-human animals. This study examined the effect of glucose on human spatial memory. Thirty-two young adults were randomly assigned to one of three treatment conditions (l00mg/kg or 50g glucose or saccharine). Subjects consumed a lemon-flavored beverage containing the appropriate sweetener and were subsequently presented with 16 pictures arranged on a 4 x 4 grid. Following a 20-second study period the pictures were removed, shuffled and handed to the subject who attempted to place them in their appropriate location on the grid. Subjects received three consecutive trials and on recall trial 24-hrs later. Results indicated that subjects receiving l00mg/kg of glucose performed significantly better than controls. These finding are consistent with results from both human and non-human studies examining the effects of glucose on other forms of memory