Anhedonia and rumination, a form of repetitive negative thinking (RNT), are key features of depression associated with poor treatment outcomes, chronic disease progression, and an increased risk of suicidality. Although their interaction is thought to sustain depressive states, the state-level mechanisms linking these symptoms remain poorly understood.

In this multilevel, randomized within-subjects study, 62 individuals (n = 38 females) with varying levels of depressive symptoms completed the Probabilistic Reward Task (PRT) under two conditions: experimentally induced RNT and an active control. Concurrent electroencephalography was employed to assess electroencephalographic markers of reward functioning.

RNT significantly attenuated both reward response bias and feedback-related positivity (FRP) amplitudes, with the most pronounced effects in individuals with more severe depressive symptoms. These effects were not attributable to differences in task difficulty or perceptual cortical processing of PRT stimuli, supporting the specificity of RNT’s impact on reward-related processes.

RNT may transiently disrupt behavioral and neural indicators of reward functioning. These findings suggest that cognitive states such as RNT can exacerbate or reveal the latent reward-processing deficits typically observed in individuals with anhedonia. This state-dependent sensitivity highlights the potential utility of targeting RNT to restore reward processing in depression.

Growing studies have reported an elevated risk of violence in patients with depression, yet the neurobiological underpinnings remain poorly understood. The present study explored the resting-state electroencephalogram (EEG) features in major depressive disorder (MDD) patients with violent offenses to identify potential neurological markers for violence prediction and intervention.

Twenty-nine MDD patients who committed violent offenses (violent depression [VD] group), 27 MDD patients without violent behaviors (nonviolent depression [NVD] group), and 25 healthy controls (HCs) were included. Resting-state EEGs were recorded for at least 5 min. EEG microstates, functional connectivity (FC), and graph theory metrics were analyzed and compared between groups.

First, the VD group had increased microstate A, more microstates A-B transition, but lower microstates B-D and C-D transition. Second, the VD group exhibited two enhanced functional brain networks compared to NVD and HCs, and three weakened functional brain networks compared to HCs, which were primarily distributed in the frontal and frontoparietal networks. Third, the VD group specifically exhibited reduced nodal efficiency (aNe) in the superior parietal lobe and increased aNe in the middle occipital gyrus.

MDD patients with violent offenses exhibited alterations in EEG microstates, FCs in the frontal lobe and frontoparietal network, and disrupted aNe in specific parietal and occipital lobes. These alternations are closely associated with deficits in emotional regulation, executive function, and inhibitory control, which may subserve as potential neurobiomarkers for violence risk assessment in patients with depression.

Bilateral sensory stimulation (BLS), such as eye movements or alternating tactile stimulation, is a key component of Eye Movement Desensitisation and Reprocessing (EMDR), a recommended treatment for post-traumatic stress disorder (PTSD). However, the neurophysiological mechanisms underlying BLS remain poorly understood.

This study examined the physiological effects of visual and tactile BLS on frontal electroencephalography (EEG) activity and autonomic arousal in patients with PTSD and healthy controls, by varying the type of stimulation in different emotional stimuli.

Twenty female PTSD patients and twenty matched healthy controls participated in a counterbalanced, within-subjects design. Participants recalled a subjectively stressful or neutral event while receiving visual or tactile BLS. Frontal EEG and peripheral psychophysiological measures were recorded before and after stimulation. Data were analysed using mixed model analysis to examine the effects of stimulation type, memory condition and group.

Both visual and tactile BLS significantly increased the total power of frontal EEG and decreased spectral edge frequency and peripheral physiological activation. These effects were consistent between the groups and memory conditions.

BLS, regardless of visual or tactile modality or emotional memory content, is associated with increased frontal EEG activity and reduced autonomic arousal. These findings support the hypothesis that BLS facilitates top-down cortical regulation, potentially aiding emotional processing in EMDR by using an inherent mechanism to promote psychological recovery. More research is needed to clarify the neural mechanisms and clinical implications.

Insomnia disorder, characterized by chronic sleep disruption, often co-occurs with maladaptive emotional memory processing. However, much remains unknown regarding the evolution of emotional memories and their neural representations over time among individuals with insomnia disorder.

We examined the electroencephalographic (EEG) activities during emotional memory encoding, post-encoding sleep, and multiple retrieval phases – including immediate post-encoding, post-sleep, and a 7-day delayed retrieval – among 34 participants with insomnia disorder and 35 healthy control participants.

Healthy controls exhibited adaptive dissipation of emotional memory: memory declined over time, accompanied by reduced subjective feelings toward negative memories. In contrast, participants with insomnia exhibited impaired dissipation: they retained both the emotional content and affective tone of the memories, with diminished time-dependent declines in memory and affect. Beyond behavioral performance, only participants with insomnia maintained stable neural representations of emotion over time, a pattern absent in healthy controls. Additionally, during the post-encoding sleep, slow-wave sleep (SWS), and rapid eye movement (REM) sleep durations predicted the adaptive dissipation of emotional memory over time, but only among healthy participants.

These findings highlight abnormalities in emotional memory processing among individuals with insomnia disorder and underscore the important function of SWS and REM sleep in facilitating adaptive emotional memory processing.

Lingual seizures are rare hyperkinetic tongue movements with significant clinical implications due to their epileptogenic origin. Despite their diagnostic value, these seizures are often underrecognized, particularly when electroencephalographic (EEG) findings are inconclusive. This study aims to characterize their clinical features, EEG patterns, imaging findings and underlying causes, emphasizing the need for increased awareness and improved diagnosis.

A retrospective review identified patients with isolated lingual seizures or those with additional motor involvement. Data on demographics, seizure characteristics, EEG findings, imaging results and underlying causes were collected and analyzed. Seizures were classified based on the International League Against Epilepsy (ILAE) 2017 framework to refine their clinical and diagnostic profiles.

Thirteen patients were identified: 11 with focal-aware and 1 with focal-unaware seizures. Seven had epilepsia partialis continua, and five experienced frequent seizures. Seizure involvement was limited to the tongue in four cases, extended to cranial muscles in seven and affected the tongue, cranial and extremity muscles in two. Significant ictal EEG findings were noted in only three patients with extensive motor involvement. However, nine patients had acute cerebral lesions, associated with glial tumors, encephalitis, chronic gliosis or cortical hemorrhage.

This study provides a detailed characterization of lingual seizures, highlighting their clinical, electrophysiological and imaging features. Given their rarity and underdiagnosis, our findings offer valuable guidance for clinicians, underscoring the importance of improved recognition and diagnostic strategies for this distinct seizure type.