Neuropsychologia
March 17, 2018
Tali R. Marron, Yulia Lerner, Ety Berant et al.
128 citations
Chain free association tasks, in which participants produce a series of related words, can isolate spontaneous associative thinking during creativity. Using fMRI, the default mode network—a brain system linked to internally directed thought—was more active during chain free association than during tasks requiring more controlled thinking, while the left inferior frontal gyrus, part of the executive control network, showed reduced activation. Higher scores on associative fluency, flexibility, and semantic remoteness from the chain free association task correlated with greater default mode network activity and lower left inferior frontal gyrus activity, as well as with better creative performance, but not with intelligence. This suggests chain free association measures may capture unconstrained associative thinking relevant to creativity.
Molecular Psychiatry
April 26, 2025
Rebecca Harding, Neomi Singer, Talma Hendler et al.
4 citations
Psilocybin therapy reduces anhedonia more than the SSRI escitalopram in major depressive disorder, yet escitalopram dampens emotional responses to musical surprises while psilocybin therapy preserves them. Escitalopram increases brain activity in memory and emotion regions during musical surprises, whereas psilocybin therapy decreases activity in the ventromedial prefrontal cortex and angular gyrus and increases sensory region activation. These contrasting neural and behavioral effects suggest fundamentally different treatment mechanisms: psilocybin may maintain subjective responses by reducing the salience of prediction errors or strengthening hedonic expectations, while escitalopram may weaken hedonic priors.
Biological psychiatry global open science
March 1, 2026
Noam Goldway, Taly Markovits, Naomi Fine et al.
1 citation
Dissociation—feeling detached from one's body, environment, or self—often accompanies posttraumatic stress disorder (PTSD), but its neural basis is poorly understood. Using network control theory on resting-state functional MRI data, researchers examined brain dynamics during dissociative states in healthy volunteers given ketamine (n=30) and in PTSD patients (n=78) before and after treatment. Ketamine induced brain dynamics similar to those in untreated PTSD patients: increased dominance of the default mode network (DMN) meta-state and decreased dominance of the somatomotor network (SOM) meta-state. After treatment, reduced DMN meta-state dominance correlated with fewer dissociative symptoms. Treated patients also showed more organized, less entropic brain states, though ketamine did not significantly alter entropy indices. Dissociative states, whether drug-induced or clinical, involve increased DMN and reduced SOM dominance.
Mol Psychiatry
July 1, 2025
Rebecca Harding, Neomi Singer, Matthew B. Wall et al.
correction
In a study comparing psilocybin therapy (PT) to escitalopram for depression, brain responses to unexpected musical notes were measured. After PT, there was decreased activation in the ventromedial prefrontal cortex and angular gyrus, and greater activation in sensory regions. This suggests PT alters brain processing of unexpected events differently than escitalopram, potentially contributing to its therapeutic effects.
Noam Goldway, Taly Markovits, Naomi Fine et al.
preprint
Dissociation—feeling detached from one's body, surroundings, or self—is common in PTSD but its neural basis is poorly understood. Using network control theory, researchers examined brain dynamics during dissociative states in two contexts: ketamine-induced dissociation in 30 healthy volunteers and therapeutic interventions in 78 PTSD patients. Ketamine produced brain dynamics similar to those seen in PTSD patients before treatment, with increased dominance of a default mode network meta-state and decreased dominance of a somatomotor meta-state. Ketamine did not significantly alter the brain's energetic landscape, but transition energies increased after PTSD treatment, suggesting more organized, less entropic brain dynamics.