Effect of subconscious changes in bodily response on thought shifting in people with accurate interoception.

Our thought states shift from one state to another from moment to moment. The relationship between the thought shifting and bodily responses is yet to be directly examined. This exploratory study examined the influence of cardiovascular reactivity and interoception-sensing an internal bodily state-on the shifting of thought states. Participants (N = 100, 70 women) completed two tasks: the heartbeat counting task (HCT) and the vigilance task (VT). We assessed their interoceptive accuracy through their performance on the HCT. The VT was a simple sustained attention task in which participants pressed a key when the target stimulus appeared and were asked to report their thoughts. We presented subliminal vibration stimuli to induce alterations in heart rate (i.e., vibration block). Results showed that participants with higher interoceptive accuracy reported more continuation of self-referential thought (about past episodes and future plans regarding themselves) during the vibration block than did those with lower interoceptive accuracy. These results suggest that individuals with higher interoceptive accuracy are more likely to be influenced by their subliminal bodily response, resulting in divergent attention from the task and intermittent self-referential thought.

Functional connectivity changes between frontopolar cortex and nucleus accumbens following cognitive behavioral therapy in major depression: A randomized clinical trial.

Cognitive behavioral therapy (CBT) is a psychotherapy that challenges distorted cognitions; however, the neural mechanisms that underpin CBT remain unclear. Hence, we aimed to assess the treatment-related resting-state functional connectivity (rsFC) changes in the brain regions associated with future thinking and the associations between rsFC changes and clinical improvements. Thirty-eight adult patients with MDD were randomly assigned with equal likelihood to receive 16-week individual CBT or talking control with a 12-month follow-up period. We evaluated the rsFC changes in the frontal regions, nucleus accumbens, amygdala, and limbic structures key to the depression pathophysiology and future thinking with 2 ×  2 mixed ANOVA interaction analysis. Pearson's correlation analysis with Bonferroni's correction was also performed to examine the associations with clinical symptoms, such as depression severity and automatic thoughts in follow-up evaluations. Treatment-specific changes include enhancement in frontopolar connectivity with the nucleus accumbens. An increased rsFC was associated with lower negative automatic thoughts postoperatively, together with lower depressive symptoms and higher positive automatic thoughts at follow-up. Conclusively, rsFC changes in the fronto-limbic neural control circuit after CBT, particularly between the frontal pole and nucleus accumbens, may be clinically meaningful functional changes related to the depression recovery process.

Coexistence of thought types as an attentional state during a sustained attention task.

Some studies have asked participants about attentional state on a scale from on-task to off-task, which set the middle option as attention focused on both, including the possibility of the coexistence of thoughts. In addition, studies using multidimensional probes explicitly assumed coexistence within spontaneous thoughts and task-focus dimensions. Although several studies have assumed the coexistence of some thought dimensions, none has explored whether these are different types of thoughts (task-focus, mind-wandering, task-related, external stimuli-related). To examine whether this coexistence of thought types occurred, we used thought probes to determine the degree of immersion in each. The participants responded to probes presented at random during a sustained attention task. The results revealed a mixture of thought types in many self-reports. In addition, the state of attentional allocation behind self-reports was estimated using the hidden Markov model. We observed the following attentional states: task-focused, task-unrelated, task-related, external stimuli-focused, and task-focused-but also focused on other thoughts. These results suggest that individuals can simultaneously allocate attention to thought types and discriminate between reporting. In some cases, probe options should also be considered for this coexistence. We also examined the relationship between self-reports and behavioral indexes, and discussed the necessity of separately measuring the degree of immersion for each thought type.

[Dynamic Functional Connectivity in Resting-State fMRI and Its Clinical Applications].

The conventional analysis assumes a constant mental state during scanning and assesses the strength of functional connectivity as the average of the entire fMRI data. However, it is suggested that even at rest, functional connectivity may change with time, and the conventional analysis has not been able to fully evaluate its properties. To overcome this limitation, many studies propose an index called dynamic functional connectivity (dFC) or time-varying functional connectivity (TVFC) or the chronnectome. This article reviews the significance and methods of dFC, examples of its application in clinical studies, and its limitations. Finally, we discuss its potential for clinical application.

ß-Lactolin Enhances Neural Activity, Indicated by Event-Related P300 Amplitude, in Healthy Adults: A Randomized Controlled Trial.

BACKGROUND: Epidemiological studies have shown that dairy product consumption is beneficial for cognitive function in elderly individuals. ß-lactolin is a Gly-Thr-Trp-Tyr lacto-tetrapeptide rich in fermented dairy products that improves memory retrieval, attention, and executive function in older adults with subjective cognitive decline and prevents the pathology of Alzheimer's disease in rodents. There has been no study on the effects of ß-lactolin on neural activity in humans. OBJECTIVE: We investigated the effects of ß-lactolin on neural activity and cognitive function in healthy adults. METHODS: In this randomized, double-blind, placebo-controlled study, 30 participants (45-64 years old) consumed ß-lactolin or placebo for 6 weeks. Neural activity during auditory and language tasks was measured through 64-channel electroencephalography. Moreover, verbal fluency tests were performed at baseline and after 6 weeks. RESULTS: The ß-lactolin group had a significantly higher P300 amplitude at the Cp2 site (a part of the parietal lobe near the center of brain, p = 0.011), and C4 site (the area between the frontal and parietal lobe, p = 0.02) during the auditory tasks after 6 weeks than the placebo group. Thus, ß-lactolin supplementation promoted neural activity in the parietal area, which increases concentration and attention during auditory cognitive tasks. Compared with the placebo group, the ß-lactolin group also showed significant changes in the scores of verbal fluency test after 6 weeks (p = 0.033). CONCLUSION: Our findings provide insight into the mechanisms underlying the effects of ß-lactolin on attention in healthy adults.