The relationship of cortical activity induced by pain stimulation with clinical and cognitive features of somatic symptom disorder: A controlled functional near infrared spectroscopy study

OBJECTIVE

The neurobiological correlates of Somatic Symptom Disorder (SSD) introduced in the DSM-5 has been the focus of a limited investigation. We aimed to examine the cortical response to painful stimuli and its relationship to symptom severity as well as cognitive and psychological characteristics in proposed models of somatoform disorders.

METHODS

We measured hemodynamic responses by 52-channel functional near-infrared spectroscopy. We compared the cortical response to painful stimuli in index patients with SSD (N = 21) versus age, and gender matched healthy control subjects (N = 21). We used brush stimulation as the control condition. We analyzed the relationship of cortical activity with SSD symptom severity as well as somatosensory amplification (SSA), alexithymia, dysfunctional illness behaviour, worry, and neuroticism.

RESULTS

Patients with SSD had higher somatic symptom severity, SSA, alexithymia, neuroticism, illness-related worry, and behaviour. Somatic symptom severity was predicted by a model including SSA and subjective feeling of pain in the index patients. Activity in the left-angular and right-middle temporal gyri was higher in the SSD subjects than the controls during pain stimulation. Positive correlations were detected between mean pain threshold levels and left middle occipital gyrus activity, as well as between SSA-scores and right-angular gyrus activity during pain condition in the index patients with SSD.

CONCLUSION

We present the first evidence that representation of pain in terms of cortical activity is different in subjects with SSD than healthy controls. SSA has functional neuroanatomic correlates and predicts symptom severity in SSD and therefore is involved as a valid intermediate phenotype in SSD pathophysiology.

Attachment Security and Cortical Activity Measured by Functional Near-Infrared Spectroscopy During a Working Memory Task in Healthy Young Adults

Introduction

Attachment style has been associated with socio-emotional outcomes, however little evidence suggests a possible association with executive functioning. Few studies have demonstrated that attachment style mediates working memory and learning relationships. We hypothesized that attachment style affects performance and cortical activity patterns of working memory.

Methods

We compared working memory performance and cortical activity in securely and insecurely attached first-year college students (N=49) using three n-back task conditions. Cortical activity was recorded by functional near-infrared spectroscopy during these three conditions of the n-back task. Attachment style was assessed using the Relationship Scale Questionnaire, categorized into four groups.

Results

Both study groups showed similar working memory performance. The cortical representation of working memory was different between the two groups. The securely attached group demonstrated higher activity in the right superior frontal and superior-medial frontal areas across all n-back conditions as well as in the right superior frontal cortex during the two-back and three-back conditions. The insecurely attached group displayed higher activity in the bilateral supplementary motor area and the left premotor area only during the three-back condition.

Conclusion

These findings emphasize the potential influence of attachment style on the cortical representation of working memory. Different activity maps between the two groups may reflect varying cognitive strategies employed to achieve a comparable working memory performance. Moreover, these results suggest that each style may have a distinct strategy to achieve attachment-relevant and irrelevant neurocognitive tasks.