Mismatches in resident and stranger serotonin transporter genotypes lead to escalated aggression, and the target for aggression is mediated by sex differences in male and female rhesus monkeys (Macaca mulatta).

A variety of studies show that the s-allele of the serotonin transporter genotype (5-HTT) is related to aggression. However, influences of sex and 5-HTT genotype of both subject and opponent have not received as much attention in aggression research. Using a nonhuman primate model, the present study explores differences in rates of aggression exhibited by 201 group-housed male and female rhesus monkeys (Macaca mulatta; 122 females; 79 males) exposed to an unfamiliar age- and sex-matched stranger while in the presence of other same-sex members of their social group. The study also assesses whether the rates of aggression increase when the home-cage resident, the unfamiliar stimulus animal, or both possess the short (s) allele of the 5-HTT. Results showed that, when compared to females, males exhibited higher rates of physical aggression toward the stranger, and when both the male resident and the male stranger possessed the s-allele, rates of physical aggression toward the stranger increased five-fold. Resident females also engaged in higher rates of physical aggression when they possessed the s-allele, although unlike the males, their physical aggression was directed toward familiar same-sex members of their social group. The findings of this study indicate that rates of physical aggression are modulated by 5-HTT resident and stranger suggest a role of sexual competition in the phenotype of the 5-HTT genotype. Importantly, when two males with impulse deficits, as a function of the s-allele, are placed together, rates of violence exhibited by the dyad escalate substantially.

Reconsidering outdoor temperature and cognition in multiple sclerosis.

BACKGROUND: Research in multiple sclerosis (MS) suggests warmer weather plays a role in disease manifestation. OBJECTIVE: This work sought to replicate the finding that warmer outdoor temperatures are significantly associated with poorer cognition in MS. METHODS: Associations between outdoor temperature and cognition were examined in three studies with a total of 263 patients with MS. RESULTS: Contrary to previous research, no significant relationship was found between cognitive performance and outdoor temperature in MS. CONCLUSIONS: The results of the current work underscore the need to better understand if, when, and how cognitive performance may be influenced by seasonal variables in MS.

Performance Comparisons on the Saint Louis University Mental Status Examination Between Black and White Veterans and Education Classification in a Large Outpatient Sample from the Southern United States.

OBJECTIVE: An increasing scientific literature recognizes that traditional cut-off scores for cognitive screeners may not be optimal for use in patients who differ in race/ethnicity from the screeners' normative/reference group. There is also literature on how racial/ethnic contextual factors, such as stereotype threat or perceived discrimination, may influence performance on cognitive testing. The current study examined the characteristics of SLUMS (a cognitive screening measure) performance in a large (n = 602) sample of Black (n = 229) and White (n = 373) veterans in a VA hospital located in the Southern United States. METHOD: SLUMS data were gathered from retrospective electronic chart review between January 2013 and February 2020. Race/ethnicity of veterans was gathered by chart review and race of hospital providers who administered the SLUMS by personal communication. RESULTS: Black veterans were 1.99 times more likely to be classified by total SLUMS score as being within the dementia range compared with White veterans. Differences in item level performance were only found between Black and White veterans with ≥ high school education. Race of clinical provider (i.e., Black or White) administering the SLUMS did not significantly impact veteran performance on the SLUMS. CONCLUSION: This is the first large sample study of differences in SLUMS performance between Black and White veterans. Findings replicate earlier research on Black and White performance differences on individual SLUMS items and provide an analysis of examiner-examinee racial discordance. This study underscores the importance of researching cognitive measures in groups who differ from the original normative/references samples.

Speedy eye movements in multiple sclerosis: association with performance on visual and nonvisual cognitive tests.

OBJECTIVE: Eye movement difficulties in multiple sclerosis (MS) are common and may influence performance on cognitive tests. The following studies examined associations between a new measure of speedy eye movement speed and visual/nonvisual cognitive tests. METHOD: In Experiment 1, MS patients (N = 71) were administered cognitive tests and the Speedy Eyes Test (SET) as a measure of purposeful speedy eye movements under timed conditions. Experiment 2 was composed of MS patients (n = 60) and a neurologically healthy comparison group (n = 31) and examined group differences in an abbreviated version of the SET. RESULTS: In both studies, slower eye movements were significantly associated with poorer performance on cognitive tests with a large effect size in Experiment 1 and a medium effect size in Experiment 2. Analyses in Experiment 2 also revealed significant group differences in an abbreviated measure of the SET, where MS patients had slower eye movements than the comparison group. CONCLUSIONS: Pending further research, the SET, a brief, inexpensive, and nontechnical measure of speedy eye movement, may serve as a visual/oculomotor indicator of cognitive impairment in multiple sclerosis.

How patients with multiple sclerosis perceive cognitive slowing.

Slowed processing speed is the primary cognitive deficit in multiple sclerosis (MS). However, no studies have examined how patients perceive this deficit. The purpose of this paper is to examine perceived processing speed difficulties in clinical and community samples of MS patients. As expected, MS patients reported more processing speed difficulties than controls. Perceived processing speed difficulties were significantly associated with impulsivity, slowed motor speed, greater anxiety, and increased introversion. In contrast, perceived processing speed did not correlate well with objective measures of processing speed. Findings showed that MS patients perceive their thinking to be significantly slowed. Perceived cognitive slowing was most related to performance on motor tasks and elevated anxiety. Evaluation of anxiety and patient education about objective measures versus subjective perceptions of slowed processing speed may be helpful to MS patients who report significant cognitive slowing.