A cortical information bottleneck during decision-making.

Decision-making emerges from distributed computations across multiple brain areas, but it is unclear why the brain distributes the computation. In deep learning, artificial neural networks use multiple areas (or layers) to form optimal representations of task inputs. These optimal representations are sufficient to perform the task well, but minimal so they are invariant to other irrelevant variables. We recorded single neurons and multiunits in dorsolateral prefrontal cortex (DLPFC) and dorsal premotor cortex (PMd) in monkeys during a perceptual decision-making task. We found that while DLPFC represents task-related inputs required to compute the choice, the downstream PMd contains a minimal sufficient, or optimal, representation of the choice. To identify a mechanism for how cortex may form these optimal representations, we trained a multi-area recurrent neural network (RNN) to perform the task. Remarkably, DLPFC and PMd resembling representations emerged in the early and late areas of the multi-area RNN, respectively. The DLPFC-resembling area partially orthogonalized choice information and task inputs and this choice information was preferentially propagated to downstream areas through selective alignment with inter-area connections, while remaining task information was not. Our results suggest that cortex uses multi-area computation to form minimal sufficient representations by preferential propagation of relevant information between areas.

WaveMAP for identifying putative cell types from in vivo electrophysiology.

Action potential spike widths are used to classify cell types as either excitatory or inhibitory; however, this approach obscures other differences in waveform shape useful for identifying more fine-grained cell types. Here, we present a protocol for using WaveMAP to generate nuanced average waveform clusters more closely linked to underlying cell types. We describe steps for installing WaveMAP, preprocessing data, and clustering waveform into putative cell types. We also detail cluster evaluation for functional differences and interpretation of WaveMAP output. For complete details on the use and execution of this protocol, please refer to Lee et al. (2021).1.

Fixing the GAP: The role of RhoGAPs in cancer.

Cancer progression and metastasis are processes that involve significant cellular changes. Many of these changes include alterations in the activity of the Rho GTPase family of proteins. Rho GTPases are signaling proteins that function as molecular switches and are involved in the regulation of most major cellular processes. Cancer development is often associated with abnormalities in Rho GTPase signaling. Rho GTPase signaling is regulated by two families of proteins, guanine nucleotide-exchange factors (RhoGEFs) and GTPase activating proteins (RhoGAPs), that function upstream of the Rho proteins to regulate their activation and inactivation, respectively. While initial work has focused on the role of RhoGEFs in cancer, the RhoGAP family members are rapidly being established as key regulators of cancer development and progression. The aim of this review is to summarize our advances in understanding the role of RhoGAPs in cancer and to discuss their significance in the development of therapeutics.

Sleep Challenges and Interventions in Children With Visual Impairment.

PURPOSE: To examine sleep patterns in a large and heterogeneous group of children with visual impairment. METHODS: A cross-sectional survey of parents of children with visual impairment was offered via the National Federation of the Blind and the National Organization for Albinism and Hypopigmentation. RESULTS: Complete survey results were available for 72 participants, aged 1 to 16 years. Parents of 52 (72%) children reported that their child had cycles of good sleep and bad sleep, and 50 (69%) reported that their child's sleep patterns caused significant stress for them or their family. Scores on the Childhood Sleep Habits Questionnaire (CSHQ) increased (> 41) in 64 (89%) children, indicating a likely clinically significant sleep problem. When compared to normative data from children aged 4 to 10 years, children in the current sample scored higher (more sleep problems) on all eight subscales on the CSHQ. The presence of comorbid developmental delay was most strongly associated with sleep problems. Supplemental melatonin and improving daytime and nighttime schedules or routines were reported as the most helpful for sleep. Many families reported a need for further information regarding melatonin use as a supplement. CONCLUSIONS: A high proportion of children with visual impairment experience clinically meaningful sleep problems, regardless of degree of light perception or visual acuity. There is a strong need for increased awareness and screening for sleep problems in this population. Potential treatment modalities, including supplemental melatonin, should be discussed with families. [J Pediatr Ophthalmol & Strabismus. 2022;59(2):77-86.].

The Diagnostic Yield of Cone-Beam Computed Tomography for Degenerative Changes of the Temporomandibular Joint in Dogs.

Degenerative changes of the temporomandibular joint (DTMJ) may be diagnosed via cone - beam computed tomography (CBCT). However, despite advancement in CBCT imaging, correlation of DTMJ features identified on CBCT with gross and histological findings is currently limited. This study aimed to correlate CBCT findings of DTMJ of dogs with gross and histopathologic changes. Temporomandibular joints (TMJ) (n = 38) from fresh cadaver heads of asymptomatic dogs (n = 19) were examined radiologically, macroscopically, and microscopically. Association of CBCT - detected DTMJ changes with gross and histological findings were statistically evaluated via kappa statistics and ordinal logistic mixed-effects models. The radiological changes observed on CBCT included joint space narrowing, subchondral/cortical bone changes (i.e., erosions or lysis), osteophytes, and subchondral bone sclerosis. Upon macroscopic evaluation, the majority of examined specimens had mild changes with cartilage defects and osteophytes affecting <10% of the total articular surface area. Histopathologic changes comprised splitting and degeneration of the fibrous cartilage layers, subchondral bone exposure, subchondral bone sclerosis, focal subchondral bone lysis, and occasional cell death. Subchondral sclerosis was the most prevalent finding radiologically and histologically with a fair to excellent agreement. Importantly, the more severe the TMJ degenerative changes, the higher the agreement between CBCT and histology. Based on the correlative results of statistical analysis, CBCT was found to be a suitable modality to evaluate DTMJ.

Revisiting the paradox of hope: The role of discrimination among first-year Black college students.

The psychology of hope is used to conceptualize how college students successfully meet their personal and professional goals and ultimately persist to graduation. However, limited evidence has suggested that high levels of hope might have a paradoxical effect for Black college students when faced with experiences of discrimination. The present study examined the moderation effects of hope on the associations between experiences of discrimination and perceptions of stress and academic integration among a sample of 1st-year U.S. Black college students (N = 203) partly derived from secondary data. Structural equation modeling revealed inverse associations between hope and stress, as well as positive associations between hope and academic integration. However, latent variable moderation revealed that students with high levels of hope had the strongest positive associations between discrimination and stress, thus supporting a paradoxical effect. By contrast, the negative association between discrimination and academic integration emerged for only students with low levels of hope. Results suggest the psychological and academic benefits of hope are complex. Specifically, in the context of discrimination experiences, hope may have a paradoxical effect for Black students' mental health while still retaining a positive and buffering effect for their academic integration. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Psychometric properties of a suicide screen for adjudicated youth in residential care.

There is a need to efficiently and effectively screen adjudicated youth residing within the juvenile justice system for suicide proneness. Accordingly, in the current study, the psychometric properties of the Life Attitude Schedule: Short Form (LAS:S), a 24-item risk assessment for suicide proneness, were assessed using data from adjudicated youth residing in an alternative sentencing facility (n = 130). As predicted, statistically significant correlations were obtained between total LAS:S suicide proneness scores and reports of recent suicide ideation and hopelessness. Contrary to expectation, the previously reported 2-factor model for the LAS:S, with Factor 1 representing physical unhealthiness and Factor 2 representing psychological death, poorly fit the data. In adjudicated youth, we found that a single factor model derived from the 4 LAS:S subscales produced a better fit to the data than the 2-factor model. The death-related, self-related, injury-related, and negative health-related behaviors contained on the LAS:S shared common variance in these youth. A clinical implication is that practitioners can effectively use the total LAS:S score when screening adjudicated youth for suicide proneness.