From Behavioral Facilitation to Inhibition: The Neuronal Correlates of the Orienting and Reorienting of Auditory Attention

The effects of attention in auditory-visual integration revealed by time-varying networks

Attention and audiovisual integration are crucial subjects in the field of brain information processing. A large number of previous studies have sought to determine the relationship between them through specific experiments, but failed to reach a unified conclusion. The reported studies explored the relationship through the frameworks of early, late, and parallel integration, though network analysis has been employed sparingly. In this study, we employed time-varying network analysis, which offers a comprehensive and dynamic insight into cognitive processing, to explore the relationship between attention and auditory-visual integration. The combination of high spatial resolution functional magnetic resonance imaging (fMRI) and high temporal resolution electroencephalography (EEG) was used. Firstly, a generalized linear model (GLM) was employed to find the task-related fMRI activations, which was selected as regions of interesting (ROIs) for nodes of time-varying network. Then the electrical activity of the auditory-visual cortex was estimated via the normalized minimum norm estimation (MNE) source localization method. Finally, the time-varying network was constructed using the adaptive directed transfer function (ADTF) technology. Notably, Task-related fMRI activations were mainly observed in the bilateral temporoparietal junction (TPJ), superior temporal gyrus (STG), primary visual and auditory areas. And the time-varying network analysis revealed that V1/A1↔STG occurred before TPJ↔STG. Therefore, the results supported the theory that auditory-visual integration occurred before attention, aligning with the early integration framework.

Neural correlates of the attention training technique as used in metacognitive therapy – A randomized sham-controlled fMRI study in healthy volunteers

Introduction

The Attention Training Technique (ATT) developed as part of metacognitive therapy is a psychotherapeutic treatment method used to enhance top-down attentional flexibility and control. This study investigated potential neurocognitive changes due to ATT and its underlying neural mechanisms using pre-to-post functional magnetic resonance imaging (fMRI).

Materials and methods

Fifty-four healthy participants were subjected to a randomized, sham-controlled attention training and evaluated using a neurocognitive test battery that partly took place in an fMRI environment. Participants received two doses ATT or sham ATT daily for 1 week. On day eight, all subjects completed the neurocognitive test battery again.

Results

After the training, the ATT group showed a significant improvement in reaction times regarding attentional disengagement compared to the sham ATT group. fMRI data showed decreased levels of activation in the anterior cingulate cortex (ACC) when comparing the ATT group to the sham ATT group during attentional disengagement post intervention. No ATT > sham ATT effects were found regarding selective auditory attention, working memory performance and inhibitory control.

Discussion

These findings putatively indicate that ATT facilitates faster attention allocation and increased attentional flexibility in healthy subjects. The fMRI results suggest this ATT-dependent improvement is accompanied by reduced ACC activity, indicating a more flexible attentional state.

Different Roles of the Left and Right Ventrolateral Prefrontal Cortex in Cognitive Reappraisal: An Online Transcranial Magnetic Stimulation Study

The ventrolateral prefrontal cortex (VLPFC) plays a pivotal role in cognitive reappraisal. Previous studies suggested a functional asymmetry of the bilateral VLPFC, but the evidence is still insufficient during cognitive reappraisal. In this study, we conducted an online single-pulse transcranial magnetic stimulation (spTMS) to investigate the causal and distinct roles of the left and right VLPFC in reappraisal. Participants were instructed to reappraise (down-regulate) or attend to pictures depicting social exclusion scenarios while the spTMS was applied over the left or right VLPFC of the participants’ brains. The results showed that spTMS of either the left or the right VLPFC would increase reappraisal difficulty. Meanwhile, the outcome of reappraisal (measured by self-reported negative feelings) significantly deteriorated when the right (but not the left) VLPFC was temporally interrupted by spTMS, while the verbal fluency during oral reporting of the reappraisal strategy was significantly reduced when the left VLPFC was interrupted by spTMS. Taken together, these findings provide causal evidence for the involvement of left and right VLPFC with distinct roles: while the left VLPFC is responsible for the linguistic especially semantic process of generating and selecting appraisals according to the goal of emotion regulation, the right VLPFC plays a critical role in inhibiting inappropriate negative emotions and thoughts generated by the effective scenarios. These findings deepen our understanding of the neurocognitive mechanism of emotion regulation.

ERP-study on the time course of disgust-motivated spatial avoidance

Recently, we showed that disgusting sound cues direct spatial attention away from the location of their origin to the opposite location indicating spatial disgust avoidance (Zimmer et al., 2015, Psychophysiology; 2016, Neuroimage). However, in these studies, we had solely used an inter-stimulus interval (ISI) of 200-300 ms, leaving unclear how disgust avoidance develops over time. Studies have shown that spatial attraction due to anger persists longer when induced by auditory rather than visual stimuli. In the present ERP-study, one of two laterally presented sounds (neutral/disgust) cued a laterally presented visual target. ISIs varied from short (50-150 ms) over middle (350-450 ms) to long (650-750 ms). For disgust stimuli, response times were longer for invalidly cued targets compared to validly cued targets, reflecting disgust avoidance. There was an increased P3 amplitude for validly versus invalidly cued targets consistent with disgust avoidance. In contrast, in the neutral condition, we found evidence of inhibition of return (IOR), as we observed a reversal of the usual validity effect from short to long ISI in the behavioral data and on the P1-component. These results indicate that spatial avoidance motivated by auditory disgust persists over time, presumably enforced by emotional rather than general attentional processes.

Neurophysiological correlates of the attention training technique: A component study

In the current study, we investigate the neuronal correlates of the Attention Training Technique (ATT), a psychotherapeutic intervention used in metacognitive therapy to enhance flexible cognitive control and ameliorate rumination.

We adapted the ATT in a neuroscientific attention paradigm in order to investigate the effects of its components: selective attention, attention switching and divided attention in comparison to a control task. Functional near-infrared spectroscopy was used to measure changes in blood oxygenation of fronto-lateral and parietal cortical areas. Furthermore, subjects rated their task performance, effort and attention drifts in each task condition.

We observed increased blood oxygenation in the right inferior frontal gyrus, right dorsolateral prefrontal cortex and superior parietal lobule during the ATT conditions in comparison to the control condition. Additionally, subjective effort was associated with blood oxygenation in the right inferior prefrontal cortex.

Our results are consistent with the theoretical underpinnings of the ATT suggesting that the ATT's mechanism of change lies in the training of areas of the cognitive control network and dorsal attention network. Aberrant functioning of both networks has been shown to be related to depression and rumination.

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The neurophysiological underpinnings of the Attention Training Technique (ATT) were investigated in an experimental design.

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The ATT requires activation of brain areas in the cognitive control network (CCN) and dorsal attention network (DAN).

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We observed increased blood oxygenation in the right IFG, dlPFC and superior parietal lobule during the ATT.

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Subjective effort during the ATT was associated with blood oxygenation in the IFG.

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The ATT might influence depressive rumination through the training of the CCN and DAN.