Transcranial focused ultrasound selectively increases perfusion and modulates functional connectivity of deep brain regions in humans.

Background: Low intensity, transcranial focused ultrasound (tFUS) is a re-emerging brain stimulation technique with the unique capability of reaching deep brain structures non-invasively. Objective/Hypothesis: We sought to demonstrate that tFUS can selectively and accurately target and modulate deep brain structures in humans important for emotional functioning as well as learning and memory. We hypothesized that tFUS would result in significant longitudinal changes in perfusion in the targeted brain region as well as selective modulation of BOLD activity and BOLD-based functional connectivity of the target region. Methods: In this study, we collected MRI before, simultaneously during, and after tFUS of two deep brain structures on different days in sixteen healthy adults each serving as their own control. Using longitudinal arterial spin labeling (ASL) MRI and simultaneous blood oxygen level dependent (BOLD) functional MRI, we found changes in cerebral perfusion, regional brain activity and functional connectivity specific to the targeted regions of the amygdala and entorhinal cortex (ErC). Results: tFUS selectively increased perfusion in the targeted brain region and not in the contralateral homolog or either bilateral control region. Additionally, tFUS directly affected BOLD activity in a target specific fashion without engaging auditory cortex in any analysis. Finally, tFUS resulted in selective modulation of the targeted functional network connectivity. Conclusion: We demonstrate that tFUS can selectively modulate perfusion, neural activity and connectivity in deep brain structures and connected networks. Lack of auditory cortex findings suggests that the mechanism of tFUS action is not due to auditory or acoustic startle response but rather a direct neuromodulatory process. Our findings suggest that tFUS has the potential for future application as a novel therapy in a wide range of neurological and psychiatric disorders associated with subcortical pathology.

Attachment, affective temperament, and personality disorders: a study of their relationships in psychiatric outpatients.

BACKGROUND: As the result of extensive translational and cross-disciplinary research, attachment theory is now a construct with significant neuropsychiatric traction. The correlation of attachment with other influential conceptual models (i.e. temperament and personality) is therefore of interest. Consequently, we explored how two attachment dimensions (attachment anxiety and attachment avoidance) correlated with measures of temperament and personality in 357 psychiatric outpatients. METHODS: We performed a retrospective review of four questionnaires (the Experiences in Close Relationship scale (ECR-R), Temperament and Character inventory (TCI), Temperament Evaluation of the Memphis, Pisa, Paris and San Diego questionnaire (TEMPS-A), and Personality Self-Portrait Questionnaire (PSQ)). Frequency measures and correlations were examined, as was the predictive value of attachment security for a personality disorder (PD). RESULTS: Significant, robust correlations were found between attachment anxiety and (1) several negative affective temperaments (dysthymic and cyclothymic); (2) several indices of personality pathology (low self-directedness (TCI), DSM-IV paranoid, borderline, histrionic, avoidant and dependent personality traits). Attachment avoidance had fewer large correlations. In an exploratory model, the negative predictive value of attachment security for a PD was 86%. LIMITATIONS: Subjects were a relatively homogeneous subset of ambulatory psychiatric outpatients. PD diagnoses were via self-report. CONCLUSIONS: Clinically, these findings highlight the significant overlap between attachment, affective temperament, and personality and support the value of attachment as a screen for PDs. More broadly, given our growing understanding of the neurobiology of attachment (i.e. links with the oxytocin system), these results raise interesting questions about underlying biological systems and psychiatric treatment.

Heart rate variability as a marker of self-regulation.

Self-regulation is central to many of the most important individual and societal problems today. We sought to determine whether the relationship between self-regulation and heart rate variability (HRV) could be replicated and extended. We hypothesized that baseline HRV would predict persistence on an anagram task, and that under conditions requiring greater self-control, HRV would increase. Two groups were given the same set of difficult and unsolvable anagrams. To induce self-regulatory fatigue, the suppression group was asked to try to not think of a white bear while the expression group was asked to try to think of a white bear. Baseline HRV predicted persistence on the unsolvable anagram. Both groups demonstrated changes in HRV relative to baseline, although we were unable to replicate findings that HRV was elevated during high self-regulatory effort. We were, however, able to replicate findings that the expression group persisted longer on the anagram task compared to the suppression group but only when accounting for physical activity scores. The present study advances our knowledge of the relationship between HRV and self-regulation, so that we can more successfully treat those with seriously impaired self-control.