Discover the most talked about and latest scientific content & concepts.

Journal: Brain sciences


The current review highlights the evidence supporting the use of ketogenic diet therapies in the management of adult epilepsy, adult malignant glioma and Alzheimer’s disease. An overview of the scientific literature, both preclinical and clinical, in each area is presented and management strategies for addressing adverse effects and compliance are discussed.


A mild traumatic brain injury (mTBI) is a complex pathophysiologic process that has a systemic effect on the body aside from solely an impairment in cognitive function. Dysfunction of the autonomic nervous system (ANS) has been found to induce abnormalities in organ systems throughout the body, and may contribute to cardiovascular dysregulation and increased mortality. Autonomic dysfunction, also known as dysautonomia, has been studied in moderate and severe TBI, and has emerged as a major contributing factor in the symptomatology in mTBI as well. Analysis of the ANS has been studied through changes in heart rate variability (HRV), pupillary dynamics, eye pressure, and arterial pulse wave in those with mild TBI. Graded exercise testing has been studied as both a method of diagnosis and as a means of recovery in those with mild TBI, especially in those with persistent symptoms. Given the studies showing persistence of autonomic dysfunction after symptomatic resolution of concussions, further research is needed to establish return to play protocols.

Concepts: Psychology, Brain, Heart, Traumatic brain injury, Axon, Autonomic nervous system, Post-concussion syndrome, Concussion


Hallucinogen Persisting Perception Disorder (HPPD) is a rare, and therefore, poorly understood condition linked to hallucinogenic drugs consumption. The prevalence of this disorder is low; the condition is more often diagnosed in individuals with a history of previous psychological issues or substance misuse, but it can arise in anyone, even after a single exposure to triggering drugs. The aims of the present study are to review all the original studies about HPPD in order to evaluate the following: (1) the possible suggested etiologies; (2) the possible hallucinogens involved in HPPD induction; (3) the clinical features of both HPPD I and II; (4) the possible psychiatric comorbidities; and (5) the available and potential therapeutic strategies. We searched PubMed to identify original studies about psychedelics and Hallucinogen Persisting Perception Disorder (HPPD). Our research yielded a total of 45 papers, which have been analyzed and tabled to provide readers with the most updated and comprehensive literature review about the clinical features and treatment options for HPPD.

Concepts: Psychology, Psychedelic drug, Salvinorin A, Psychedelics, dissociatives and deliriants, Dimethyltryptamine, Psychedelic, Hallucinogen persisting perception disorder


We examined how well typical adult listeners remember the speech of a person with a voice disorder (relative to that of a person without a voice disorder). Participants (n = 40) listened to two lists of words (one list uttered in a disordered voice and the other list uttered in a normal voice). After each list, participants completed a free recall test, in which they tried to remember as many words as they could. While the total number of words recalled did not differ between the disordered voice condition and the normal voice condition, an investigation of the serial-position curve revealed a difference. In the normal voice condition, a parabolic (i.e., u-shaped) serial-position curve was observed, with a significant primacy effect (i.e., the beginning of the list was remembered better than the middle) and a significant recency effect (i.e., the end of the list was remembered better than the middle). In contrast, in the disordered voice condition, while there was a significant recency effect, no primacy effect was present. Thus, the increased ability to remember the first words uttered by a speaker (relative to subsequent words) may disappear when the speaker has a voice disorder. Explanations and implications of this finding are discussed.

Concepts: English-language films, The Normal, Memory processes, List, Lists, Oral communication, Serial position effect, Free recall


Awareness of mild traumatic brain injury (mTBI) and persisting post-concussive syndrome (PCS) has increased substantially in the past few decades, with a corresponding increase in research on diagnosis, management, and treatment of patients with mTBI. The purpose of this article is to provide a narrative review of the current literature on behavioral assessment and management of patients presenting with mTBI/PCS, and to detail the potential role of neuropsychologists and rehabilitation psychologists in interdisciplinary care for this population during the acute, subacute, and chronic phases of recovery.

Concepts: Psychology, Medical terms, Traumatic brain injury, Chronic, Neuropsychology, Post-concussion syndrome, Acute, Concussion


Recent research has shown smaller health effects of socioeconomic status (SES) indicators such as education attainment for African Americans as compared to whites. However, less is known about diminished returns based on gender within African Americans.


Background: Most of the literature on the association between socioeconomic status (SES) and health is focused on the protective effects of SES. However, a growing literature suggests that high SES may also operate as a vulnerability factor. Aims: Using a national sample of African American youth, this study compared the effects of perceived discrimination on major depressive disorder (MDD) based on SES. Methods: The current cross-sectional study included 810 African American youth who participated in the National Survey of American Life-Adolescent supplement. The independent variable was perceived discrimination. Lifetime, 12-month, and 30-day MDD were the dependent variables. Age and gender were covariates. Three SES indicators (subjective SES, income, and poverty index) were moderators. We used logistic regressions for data analysis. Results: Perceived discrimination was associated with higher risk of lifetime, 12-month, and 30-day MDD. Interactions were found between subjective SES and perceived discrimination on lifetime, 12-month, and 30-day MDD, suggesting a stronger effect of perceived discrimination in youth with high subjective SES. Objective measures of SES (income and poverty index) did not interact with perceived discrimination on MDD. Conclusion: While perceived discrimination is a universally harmful risk factor for MDD, its effect may depend on the SES of the individual. Findings suggest that high subjective SES may operate as a vulnerability factor for African American youth.

Concepts: Risk, Socioeconomic status, Major depressive disorder, Seasonal affective disorder, Dysthymia, Depression, Southern United States, Types of psychological depression


Language and face processing develop in similar ways during the first year of life. Early in the first year of life, infants demonstrate broad abilities for discriminating among faces and speech. These discrimination abilities then become tuned to frequently experienced groups of people or languages. This process of perceptual development occurs between approximately 6 and 12 months of age and is largely shaped by experience. However, the mechanisms underlying perceptual development during this time, and whether they are shared across domains, remain largely unknown. Here, we highlight research findings across domains and propose a top-down/bottom-up processing approach as a guide for future research. It is hypothesized that perceptual narrowing and tuning in development is the result of a shift from primarily bottom-up processing to a combination of bottom-up and top-down influences. In addition, we propose word learning as an important top-down factor that shapes tuning in both the speech and face domains, leading to similar observed developmental trajectories across modalities. Importantly, we suggest that perceptual narrowing/tuning is the result of multiple interacting factors and not explained by the development of a single mechanism.

Concepts: Scientific method, Language, Developmental psychology, Mechanism, Human development, Discrimination, Multiplication


Background: Minorities' Diminished Return (MDR) can be defined as smaller health gains from socioeconomic status (SES) indicators, such as education attainment among ethnic minorities compared to the majority group. The current study tested whether income explains why Black and White adults differ in the association between education attainment and self-rated health (SRH). Methods: With a cross-sectional design, this study used data from Cycle 5 of the Health Information National Trends Survey (HINTS), 2017. With a nationally representative sample, the HINTS study generates results that are generalizable to US adults. This study included 2277 adults who were either non-Hispanic White (n = 1868; 82%) or non-Hispanic Black (n = 409; 18%). The independent variable was education attainment. The dependent variable was SRH, measured using a standard single item. Age, gender, and health insurance status were covariates. Ethnicity was the focal moderator. Income was the mediator. A structural equation model (SEM) was applied for data analysis. Results: Overall, higher education attainment was associated with better SRH, net of covariates. However, a significant interaction between ethnicity and education attainment suggested a smaller SRH gain from education for Blacks compared to Whites. This interaction could be explained by Black⁻White differences in income. Conclusion: Our study results suggests that labor market preferences may explain smaller effects of education attainment on SRH for Blacks relative to Whites. Given this finding and other studies documenting MDR, policies should reduce labor market discrimination, increasing job opportunities and reducing the racial pay gap for Blacks. Programs should help Blacks compete for prestigious and high-paying jobs.


Although perceived discrimination in Black youth is a risk factor for a wide range of negative mental health outcomes, recent research has suggested some gender differences in these associations. Gender differences in vulnerability to perceived discrimination among Caribbean Black youth is, however, still unknown. The current cross-sectional study investigated gender variations in the association between perceived discrimination and substance use (SU) in a national sample of Caribbean Black youth. Data came from the National Survey of American Life-Adolescents (NSAL-A), 2003⁻2004. This analysis included 360 Caribbean Black youth (165 males and 195 females) who were between 13 and 17 years old. Sociodemographic factors, perceived discrimination, and SU were measured. Logistic regressions were used for data analysis. Among Caribbean Black youth, a positive association was found between perceived discrimination and SU (odds ratio (OR) = 1.15 (95% confidence interval (CI) = 1.02⁻1.29)). A significant interaction was found between gender and perceived discrimination on smoking (OR = 1.23 (95% CI = 1.07⁻1.41)) suggesting that the association between perceived discrimination and smoking is larger for male than female Caribbean Black youth. The interaction between gender and perceived discrimination on SU was not statistically significant (OR = 1.32 (95% CI = 0.94⁻1.86)). While perceived discrimination increases SU in Caribbean Black youth, this effect is stronger for males than females, especially for smoking. While discrimination should be reduced at all levels and for all populations, clinicians may specifically address discrimination for SU prevention and treatment among male Caribbean Black youth.