Low Cost MR Compatible Haptic Stimulation with Application to fMRI Neurofeedback.

The most common feedback displays in the fMRI environment are visual, e.g., in which participants try to increase or decrease the level of a thermometer. However, haptic feedback is increasingly valued in computer interaction tasks, particularly for real-time fMRI feedback. fMRI-neurofeedback is a clinical intervention that has not yet taken advantage of this trend. Here we describe a low-cost, user-friendly, MR-compatible system that can provide graded haptic vibrotactile stimulation in an initial application to fMRI neurofeedback. We also present a feasibility demonstration showing that we could successfully set up the system and obtain data in the context of a neurofeedback paradigm. We conclude that vibrotactile stimulation using this low-cost system is a viable method of feedback presentation, and encourage neurofeedback researchers to incorporate this type of feedback into their studies.

Time course of pupillary response to threat words before and after attention bias modification for transdiagnostic anxiety disorders: A randomized controlled trial.

INTRODUCTION: Altered attention to threatening stimuli at initial and sustained stages of processing may be dissociable dimensions that influence the development and maintenance of transdiagnostic symptoms of anxiety, such as vigilance, and possibly require distinct intervention. Attention bias modification (ABM) interventions were created to implicitly train attention away from threatening stimuli and have shown efficacy in treating anxiety. ABM alters neurocognitive functioning during initial stages of threat processing, but less is known regarding effects of ABM on neural indices of threat processing at sustained (i.e., intermediate and late) stages, or if ABM-related neural changes relate to symptom response. The current study utilized pupillary response as a temporally sensitive and cost-effective peripheral marker of neurocognitive response to ABM. MATERIALS AND METHODS: In a randomized controlled trial, 79 patients with transdiagnostic anxiety provided baseline data, 70 were randomized to receive eight sessions of twice-weekly ABM (n = 49) or sham training (n = 21), and 65 completed their assigned treatment condition and returned for post-training assessment. RESULTS: Among ABM, but not sham, patients, pupillary response to threat words during initial and intermediate stages decreased from pre- to post-training. Pre- to post-training reductions in intermediate and late pupillary response to threat were positively correlated with reductions in patient-reported vigilance among ABM, but not sham, patients. CONCLUSIONS: All measured stages of threat processing had relevance in understanding the neural mechanisms of ABM, with overlapping yet dissociable roles exhibited within a single neurophysiological marker across an initial-intermediate-late time continuum. Pupillometry may be well suited to measure both target engagement and treatment outcome following ABM.

Emotional reactivity and regulation in anxious and nonanxious youth: a cell-phone ecological momentary assessment study.

BACKGROUND: Reviews have highlighted anxious youths' affective disturbances, specifically, elevated negative emotions and reliance on ineffective emotion regulation strategies. However, no study has examined anxious youth's emotional reactivity and regulation in real-world contexts. METHODS: This study utilized an ecological momentary assessment approach to compare real-world emotional experiences of 65 youth with generalized anxiety disorder, social anxiety disorder, or social phobia (ANX) and 65 age-matched healthy controls (CON), ages 9-13 years. RESULTS: Hierarchical linear models revealed that ANX reported higher levels of average past-hour peak intensity of nervous, sad and upset emotions than CON youth but similar levels during momentary reports of current emotion. As expected, ANX youth reported more frequent physiological reactions in response to a negative event; however, there were no group differences in how frequently they used cognitive-behavioral strategies. Avoidance, distraction and problem solving were associated with the down-regulation of all negative emotions except nervousness for both ANX and CON youth; however, group differences emerged for acceptance, rumination and physiological responding. CONCLUSIONS: In real-world contexts, ANX youth do not report higher levels of momentary negative emotions but do report heightened negative emotions in response to challenging events. Moreover, ANX youth report no differences in how frequently they use adaptive regulatory strategies but are more likely to have physiological responses to challenging events. They are also less effective at using some strategies to down-regulate negative emotion than CON youth.

Pupillary assessment and computational modeling of the Stroop task in depression.

Depressed individuals frequently display disruptions in selective attention, but the time course and specificity of these difficulties are not well-understood. To better understand the nature of attentional disruptions in depression, 28 healthy adults and 23 unmedicated depressed adults completed a Stroop color-naming task using a long inter-stimulus interval and pupil dilation was recorded as a measure of cognitive load. Both groups took longer to name the color for incongruent than congruent trials. Pupil dilation was also larger for incongruent trials than for congruent trials across groups, which suggested that pupil dilation reflected cognitive load on the task. Though the groups did not differ in the magnitude of Stroop effect in pupil dilation, depressed individuals displayed decreased pupil dilation in the seconds following stimuli relative to controls. Computational neural network modeling further suggested that observed effects were consistent with decreased prefrontal cortex activity, associated with decreased cognitive control.

Use of concurrent pupil dilation assessment to inform interpretation and analysis of fMRI data.

Potential contributions of concurrently acquired pupil dilation data to functional magnetic resonance imaging (fMRI) experiments were examined. Sixteen healthy participants completed a working memory task (digit sorting) during measurement of pupil dilation outside the fMRI environment and during concurrent 3T fMRI assessment. Pupil dilation increased parametrically with task difficulty inside and outside the scanner, on a similar time course, suggesting that task demand was similar in both environments. The time course of pupil dilation during digit sorting was similar to the time course of the fMRI signal in the middle frontal gyrus, suggesting that middle-frontal gyrus activity indexed the engagement working memory processes. Incorporating individual differences in pupil dilation improved the sensitivity and specificity of general linear modeling analyses of activity in the middle frontal gyrus, above and beyond standard analytic techniques. Results suggest concurrent pupil dilation during fMRI assessment can help to (1) specify whether task demand is the same inside and outside the fMRI environment, (2) resolve the extent to which fMRI signals reflect different aspects of event-related designs, and (3) explain variation in fMRI data due to individual differences in information processing.

Using connectionist models to guide assessment of psychological disorder.

Connectionist models are introduced as promising tools for understanding the nature of psychological disorders and guiding their assessment. Specifically, ways in which connectionist models can guide the following aspects of the assessment process are described: understanding what constructs are relevant to assess, designing approaches to assessing these constructs, and understanding individual differences in data from assessments. Two extended examples are given based on the authors' research on cognitive aspects of depression and Alzheimer's disease.

Can't shake that feeling: event-related fMRI assessment of sustained amygdala activity in response to emotional information in depressed individuals.

BACKGROUND: Previous research suggests that depressed individuals engage in prolonged elaborative processing of emotional information. A computational neural network model of emotional information processing suggests this process involves sustained amygdala activity in response to processing negative features of information. This study examined whether brain activity in response to emotional stimuli was sustained in depressed individuals, even following subsequent distracting stimuli. METHODS: Seven depressed and 10 never-depressed individuals were studied using event-related functional magnetic resonance imaging during alternating 15-sec emotional processing (valence identification) and non-emotional processing (Sternberg memory) trials. Amygdala regions were traced on high-resolution structural scans and co-registered to the functional data. The time course of activity in these areas during emotional and non-emotional processing trials was examined. RESULTS: During emotional processing trials, never-depressed individuals displayed amygdalar responses to all stimuli, which decayed within 10 sec. In contrast, depressed individuals displayed sustained amygdala responses to negative words that lasted throughout the following non-emotional processing trials (25 sec later). The difference in sustained amygdala activity to negative and positive words was moderately related to self-reported rumination. CONCLUSIONS: Results suggest that depression is associated with sustained activity in brain areas responsible for coding emotional features.