Implicit racial bias is a systematic societal issue that can lead individuals to make harmful, ethnically- or racially-biased choices. Prior research shows that awareness of such bias can engage control mechanisms in the brain that mitigate its expression. A key neural correlate for regulating racial bias is the dorsolateral prefrontal cortex (DLPFC), identified in prior neuroimaging work as part of a more extensive executive functioning network (Mattan et al., 2018). In the present study, we causally investigate the role of the right DLPFC (rDLPFC) in controlling racial bias using a non-invasive form of brain stimulation, transcranial magnetic stimulation (TMS). Forty participants received inhibitory TMS to downregulate activity in the right DLPFC or a control site (right middle temporal area; V5/MT). Following TMS, participants completed the Dictator Game (DG), a behavioral measure of generosity involving monetary donations. Results showed no significant difference in behavioral outcomes based on TMS site: participants who received rDLPFC stimulation performed similarly to those who received control site stimulation. Our study increases understanding of the neural circuits involved in racial bias and suggests a more complex neural circuitry involved in controlling racial bias.

Age-related neurodegenerative conditions, such as Alzheimer’s Disease (AD) and Multiple Sclerosis (MS), present significant societal challenges. The thalamus, a key network hub implicated in cognitive and motor functions, is among the earliest gray matter regions affected, with alterations linked to clinical dysfunction. Although sex differences in microglia during aging have been reported, the combined effects of age and sex on microglia subpopulations, reactive astrocytes, and synaptic integrity in the thalamus remain poorly understood. Addressing this gap is crucial given the dual role of microglia in inflammation and neurodegeneration. In this study, we examined how healthy aging impacts thalamic neuropathology in males and females using four groups of sex-matched young and midlife C57BL/6J mice. We performed immunohistochemical staining and imaging to assess markers for activated microglia (IBA1 with MHC II), phagocytic microglia (IBA1 with CD68 and APOE), disease-associated microglia (IBA1 with CLEC7A), reactive astrocytes (GFAP with LCN2), and synaptic elements (VGLUT2 and PSD95), followed by statistical analysis. Compared to young subjects, midlife mice exhibited significant increases in activated, disease-associated, phagocytic microglia and reactive astrocytes, accompanied by synaptic loss. Notably, these age-dependent changes were consistent in both sexes. Our findings provide critical insights into the complex interplay underlying thalamic neuropathology, advancing our understanding of biological aging.

Post-stroke epilepsy is a dangerous and debilitating condition in which seizures appear after a diagnosed stroke. Currently, there is no way to predict the likelihood of developing this condition after the occurrence of an acute ischemic stroke. Patient medical record numbers were provided and electronic health records from University of California, Los Angeles (UCLA) teaching hospitals were reviewed. Patients with acute ischemic stroke diagnoses at UCLA and imaging data (ADC scores, mismatch volume, Tmax > 6 seconds, and mismatch ratio) available were considered for the study. 10 cases and 7 controls were found. The age range for cases was 42 to 83 years, with a median of 71.5 years, and for controls, the age range was 76-94 years with a median of 81 years. No associations were found between development of epilepsy and acute imaging changes, particularly in diffusion restriction and as denoted by ADC scores (p = 0.35), diffusion-perfusion mismatch volume (p = 0.35), perfusion delay of 6 seconds Tmax > 6 seconds (p = 0.15), and mismatch ratio (p = 0.3885), respectively. Further, more expansive analysis is required to determine the relationship between imaging mismatch data and post-stroke epilepsy status and outcomes.

The study of human reaction times across various sensory modalities offers valuable insights into the structure of humans’ spatial awareness. This research specifically explores auditory and tactile sensory modalities to evaluate the hypothesis that tactile reactions are faster than auditory responses and both are faster than visual responses, based on the biological evolution order of the senses. The MePMoS theory suggests that subconscious reactions to single stimuli will occur within 200 ms, while conscious reactions to dual and triple stimuli will occur within 400 ms. Participants were subjected to experimental protocols involving single, dual, and triple stimuli conditions across the two sensory modalities. The protocol setup is centered around an Arduino Uno, programmed to control a headphone and three vibration motors and receive button input. Auditory stimuli consist of three distinct pitches (C4, C5, C6), and tactile stimuli utilize vibration motors strategically positioned at different locations on the fingers and limbs. Each experimental condition incorporated standardized 25 practice trials with correction signaling, followed by data collection phases (100 trials), where the stimuli are presented to the participant and a randomized wait time (between 500 - 1500 ms) follows. The tactile modality tests have aligned with expectations of superior tactile reaction speeds.

We examined the relationship between orofacial behavior and task variables operating at multiple timescales in mice engaged in a Two-Alternative-Choice Task (2-AFC) set-shifting task. Head-fixed mice were trained to discriminate between visual gratings (45° vs. 135°) and auditory tones (high vs. low) in a compound audiovisual task that required adapting to covert switches in stimulus relevance. To quantify orofacial behavior, we used two overhead cameras and a standardized DeepLabCut labeling protocol to track key points on the pupils, nose, ears, and paws. Manual annotations from randomly sampled frames were used to train the model for full-session tracking, yielding motion energy metrics and heat maps aligned to task performance. We studied orofacial motion and pupil dynamics in different timescales defined within (stimulus onset, response time, etc.) and across (audio vs. visual blocks) trials. We found systematic patterns of dynamics for all regions of interest defined by multiple time scales, particularly during transitions between modality blocks. These findings reveal that facial movements encode both within- and across-trial dynamics and provide valuable insights into how behavior may shape neural activity during flexible sensorimotor decision-making.