Power spectrum scale invariance identifies prefrontal dysregulation in paranoid schizophrenia

Abstract

Theory and experimental evidence suggest that complex living systems function close to the boundary of chaos, with erroneous organization to an improper dynamical range (too stiff or chaotic) underlying system-wide dysregulation and disease. We hypothesized that erroneous organization might therefore also characterize paranoid schizophrenia, via optimization abnormalities in the prefrontal-limbic circuit regulating emotion. To test this, we acquired fMRI scans from 35 subjects (N = 9 patients with paranoid schizophrenia and N = 26 healthy controls), while they viewed affect-valent stimuli. To quantify dynamic regulation, we analyzed the power spectrum scale invariance (PSSI) of fMRI time-courses and computed the geometry of time-delay (Poincaré) maps, a measure of variability. Patients and controls showed distinct PSSI in two clusters (k(1) : Z = 4.3215, P = 0.00002 and k(2) : Z = 3.9441, P = 0.00008), localized to the orbitofrontal/medial prefrontal cortex (Brodmann Area 10), represented by β close to white noise in patients (β ≈ 0) and in the pink noise range in controls (β ≈ -1). Interpreting the meaning of PSSI differences, the Poincaré maps indicated less variability in patients than controls (Z = -1.9437, P = 0.05 for k(1) ; Z = -2.5099, P = 0.01 for k(2) ). That the dynamics identified Brodmann Area 10 is consistent with previous schizophrenia research, which implicates this area in deficits of working memory, executive functioning, emotional regulation and underlying biological abnormalities in synaptic (glutamatergic) transmission. Our results additionally cohere with a large body of work finding pink noise to be the normal range of central function at the synaptic, cellular, and small network levels, and suggest that patients show less supple responsivity of this region.

Schizophrenia and the Efficacy of qEEG-Guided Neurofeedback Treatment

“…Brodmann Area 10 is consistent with the previous schizophrenia research, which implicates this area in deficits of working memory, executive functioning, emotional regulation, and underlying biological abnormalities in synaptic (glutamatergic) transmission. 82 Sites which are helpful in attention, motivation, and inhibition of emotions, are: Fp1-Fp2: inhibit beta, delta, and theta bipolar montage.…”

“…82,83 The corresponding NF training lead was found to be helpful in paranoia: F7-T3: inhibit alpha, theta, and beta bipolar montage.…”

Neurobiological and behavioural studies of affective instability in clinical populations: A systematic review

“…This study again emphasises the role of the salience network -with connectivity between this area and the right fronto-parietal cortex increased in those with BPD, and its connection with the ventromedial PFC decreased in those with BP. For schizophrenia, BA 10 (orbitofrontal and prefrontal cortex) may have a role in the emotional dysregulation seen in the disorder (Radulescu et al, 2012) and the amydala and anterior cingulate cortex in processing threat and safety cues in ADHD (Maier et al, 2014). Please see Figure 2.…”

“…Radulescu et al, (Radulescu et al, 2012) investigated the dynamic features of patterns of neural regulation in response to emotional stimuli, that may underlie emotional dysregulation in schizophrenia.…”

Treating Thought Disorders

“…78,79 Paranoid schizophrenia tends to be related to differences in Brodmann areas (BA) 10 and 46 and the prefrontal-limbic circuit. 80,81 Although a large body of publications suggests a prefrontal deficit in schizophrenia, newer findings suggest an imbalance, or dysregulation, between the two primary components of a prefrontal-limbic negative feedback loop. 82,83 This may be related to the excitatory component of the amygdala 84,85 and the inhibitory component provided primarily by the prefrontal regions.…”