EEG source activity during processing of neutral stimuli in subjects with anxiety disorders

Abstract

Anxiety disorders are a social problem due to their prevalence and consequences. It is crucial to explore the influence of anxiety on cognitive processes. In this study we recorded EEG activity from 73 subjects (35 patients, 38 controls, matched for age and education) during performance of the Continuous Attention Task. We used low resolution electromagnetic tomography (LORETA) for evaluation of mechanisms of impaired cognitive performance in anxiety disorders. Analysis showed that patients with anxiety disorders committed more errors than the controls, had a short latency of P300 and higher amplitude of ERPs at all steps of stimulus processing. Furthermore, we showed that there was a relationship between the scores of Hamilton Anxiety Scale and Beck Depression Inventory, and amplitudes and latencies of ERPs. The results of LORETA analysis showed that enhanced neural responses were found within circuits mediating visual information processing, sustained attention and anxiety. Also, we found higher current density within areas playing an important role in the brain fear network -anterior cingulate and anterior part of insula. Electrophysiological neuroimaging showed greater recruitment of cognitive resources in anxiety disorders, evidenced by higher current density and activation of greater number of brain areas. Despite the strategy employed to compensate for cognitive problems, the anxiety patients did not achieve the same performance as controls. Present study demonstrates that anxiety disorders influence processing of neutral stimuli and this influence is observable at both behavioral and electrophysiological level. The data suggests instability of neural systems responsible for information selection, working memory, engagement and focusing of attention.

The influence of mood on visual perception of neutral material

“…To our knowledge, this is the first study to show that a preceding mood manipulation impacts the processing of low-motivational (i.e., NEU) stimuli in healthy subjects. Based on results of a previous study examining processing of neutral stimuli in a group of anxious patients, we would expect an increase in processing of neutral stimuli (Gmaj et al 2016). Here, we observed a less intense processing of neutral stimuli in negative mood comparing to positive mood in healthy subjects.…”

“…The apparent lack of neuroimaging data concerning mood-related changes in perceptual processes can be only partially supplemented by clinical research, in which involved subjects are characterized by permanent shifts in their baseline emotional state. The issue of processing of neutral stimuli has been investigated by Gmaj et al (2016). In the study, patients with anxiety disorders exhibited increased activation in perceptual and attentional areas when viewing non-arousing content; this was reflected in higher event-related potential (ERP) components and Low Resolution Electromagnetic Tomography (LORETA) derived activation.…”

Top-down and bottom-up competition in visual stimuli processing

“…P3 is a heterogeneous component (250-500 ms, midline fronto-central or centro-parietal) that is thought to reflect the informational content of stimulus, memory operations, and decisive processes of selection and preparation of the correct behavioral response. It is also modulated by frequency of stimuli presentation and probability of its appearance (Gmaj et al 2016, Verleger et al 2005, Wronka et al 2012. Additionally, the level of actual processing depth for motivationally-arousing stimuli (emotional slides in our case) can be inferred from the late positive potential (LPP).…”

Working memory, impulsivity and emotional regulation correlates with frontal asymmetry of healthy young subjects during auditory session

“…In healthy Austrian individuals, attention orientation was found to be systematically related to specific oscillatory brain responses [5] while approach motivation was linked to frontal asymmetry in healthy Finnish subjects [28]. In patients with psychiatric disorders, substantial differences in oscillatory frequencies were observed [9,22].…”

“…Measurement of scalp electrical impulses through electroencephalogram (EEG) has already become an important field in neurophysiological research in different parts of the world [5,9,22,28]. In healthy Austrian individuals, attention orientation was found to be systematically related to specific oscillatory brain responses [5] while approach motivation was linked to frontal asymmetry in healthy Finnish subjects [28].…”