Evaluating the Effectiveness of Standardized and Personally Relevant Stimuli in Two Mood Induction Procedures

The experience of emotion is a critical component of behavior, cognition, and general human functioning. In order to better understand emotional experience, researchers have utilized mood induction procedures (MIPs) to elicit specific emotional responses. Previous studies have reviewed the effectiveness of various MIPs; however, these studies do not account for more recently developed picture datasets and are limited in their examination of the impact that personal relevance has on MIP effectiveness. The present study examined changes in emotion using four different MIPs that varied based on stimuli type (either Picture or Vignette) and relevance to the participant (Personally Relevant or Standardized). Additionally, factors related to social desirability, emotion regulation and expression, emotional functioning, and personality were evaluated to determine possible influences of MIP effectiveness. Seventy-eight undergraduates participated in the study. Results indicated no differences in the effectiveness of Picture and Vignette MIPs. However, MIPs based on personally relevant stimuli were more effective that those based on standardized stimuli. Only the Personally Relevant Positive Vignette MIP was significantly correlated with social desirability, emotional functioning, and personality variables. Generally, these results suggest that researchers may benefit from tapping into the personally relevant emotional experiences of their participants. However, given small effect sizes for the direct comparison of MIPs, researchers may also want to consider other factors (e.g., constraints of the experimental environment) when choosing which MIPs to use

A Behavioral and Neural Investigation of the Impact of Age and Genetic Risk for Alzheimer’s Disease on Inhibitory Control

Significant advances have been made in understanding Alzheimer’s disease (AD), but our ability to accurately predict who will develop AD remains limited. Executive functioning has been neglected as a preclinical marker of AD, despite the vital role of these abilities (e.g., planning, set shifting, inhibition) in everyday functioning. Inhibitory deficits in particular have been found to predict impairment in activities of daily living, an important criterion in the diagnosis of AD. This study examined differences in behavioral task performance and underlying neural processing based on event related potentials (ERPs) during an inhibition task as a function of age and genetic risk for AD based on apolipoprotein-E (APOE) ε4 status. Participants included 49 healthy, cognitively intact older adults and 42 young adult college students. Genetic testing was conducted for older adults, 24 of whom were APOE ε4 carriers. Participants completed the Parametric Go/NoGo/Stop (PGNGS) task while EEG data was collected for later extraction of ERPs. Significant ERP differences by genetic risk emerged such that APOE ε4+ participants exhibited significantly more negative amplitudes than APOE ε4- participants at midline electrodes in response to Stop trials (Fz: p\u3c.001, FCz: p=.002, Cz: p=.012). These neural differences were seen in the absence of genetic risk differences in behavioral task performance, suggesting that psychophysiological measures may be more sensitive to early disease stage differences than neuropsychological testing alone. Expected age differences also emerged, with older adults exhibiting slower response times and longer ERP latencies in most task conditions and at most electrode sites. In conclusion, this study revealed significant ERP differences across genetic risk groups in cognitive intact older adults, revealing a new early marker of AD risk. Moreover, these findings underscore the importance of considering executive abilities, such as inhibition, as preclinical markers of risk for AD

Executive Functioning and Risk for Alzheimer\u27s Disease in The Cognitively Intact: Family History Predicts Wisconsin Card Sorting Test Performance

Alzheimer’s disease (AD) research typically focuses on memory. However, executive functioning (EF) deficits are also common among AD patients; these deficits are associated with decreased functioning in activities of daily living, an important criterion in diagnosing AD. A classic test of EF ability, the Wisconsin Card Sort Test (WCST), has demonstrated sensitivity to differentiating individuals with AD from healthy controls, discriminating AD groups based on disease severity, and distinguishing AD from other types of dementia. Such sensitivity to AD raises the possibility that the WCST is also sensitive to very early, preclinical differences between those who have heightened risk for AD and those with lower risks. Method: The current study, therefore, examined WCST performance in healthy, cognitively intact older adults with a first-degree (i.e., sibling or parent) family history (FH) of AD (n _ 18) and those with no such FH of AD (n _ 24). Results: Results revealed significant group differences for Categories Achieved, Percent Conceptual Level Responses, Total Errors, Perseverative Errors, and Non-Perseverative Errors, with the FH_ group consistently exhibiting poorer performance. Moreover, hierarchical regression analyses indicated that after accounting for age, sex, and education, FH significantly predicted all 5 of these variables. Conclusions: These results speak to the potential role of EF in bolstering the current understanding of early cognitive markers of future decline. Furthering what is known about the relationship between AD and nonmemory specific domains of cognition such as executive functioning may allow for better prediction of cognitive decline and potential progression to AD

Physical Activity Reduces Hippocampal Atrophy in Elders at Genetic Risk for Alzheimer\u27s Disease

We examined the impact of physical activity (PA) on longitudinal change in hippocampal volume in cognitively intact older adults at varying genetic risk for the sporadic form of Alzheimer\u27s disease (AD). Hippocampal volume was measured from structural magnetic resonance imaging (MRI) scans administered at baseline and at an 18-month follow-up in 97 healthy, cognitively intact older adults. Participants were classified as High or Low PA based on a self-report questionnaire of frequency and intensity of exercise. Risk status was defined by the presence or absence of the apolipoprotein E-epsilon 4 (APOE-ε4) allele. Four subgroups were studied: Low Risk/High PA (n = 24), Low Risk/Low PA (n = 34), High Risk/High PA (n = 22), and High Risk/Low PA (n = 17). Over the 18 month follow-up interval, hippocampal volume decreased by 3% in the High Risk/Low PA group, but remained stable in the three remaining groups. No main effects or interactions between genetic risk and PA were observed in control brain regions, including the caudate, amygdala, thalamus, pre-central gyrus, caudal middle frontal gyrus, cortical white matter (WM), and total gray matter (GM). These findings suggest that PA may help to preserve hippocampal volume in individuals at increased genetic risk for AD. The protective effects of PA on hippocampal atrophy were not observed in individuals at low risk for AD. These data suggest that individuals at genetic risk for AD should be targeted for increased levels of PA as a means of reducing atrophy in a brain region critical for the formation of episodic memories

Recommendations for accelerating open preprint peer review to improve the culture of science

Peer review is an important part of the scientific process, but traditional peer review at journals is coming under increased scrutiny for its inefficiency and lack of transparency. As preprints become more widely used and accepted, they raise the possibility of rethinking the peer-review process. Preprints are enabling new forms of peer review that have the potential to be more thorough, inclusive, and collegial than traditional journal peer review, and to thus fundamentally shift the culture of peer review toward constructive collaboration. In this Consensus View, we make a call to action to stakeholders in the community to accelerate the growing momentum of preprint sharing and provide recommendations to empower researchers to provide open and constructive peer review for preprints

Event-Related Potentials, Inhibition, and Risk for Alzheimer’s Disease Among Cognitively Intact Elders

Background: Despite advances in understanding Alzheimer’s disease (AD), prediction of AD prior to symptom onset remains severely limited, even when primary risk factors such as the apolipoprotein E (APOE) ɛ4 allele are known. Objective: Although executive dysfunction is highly prevalent and is a primary contributor to loss of independence in those with AD, few studies have examined neural differences underlying executive functioning as indicators of risk for AD prior to symptom onset, when intervention might be effective. Methods: This study examined event-related potential (ERP) differences during inhibitory control in 44 cognitively intact older adults (20 ɛ4+, 24 ɛ4-), relative to 41 young adults. All participants completed go/no-go and stop-signal tasks. Results: Overall, both older adult groups exhibited slower reaction times and longer ERP latencies compared to young adults. Older adults also had generally smaller N200 and P300 amplitudes, except at frontal electrodes and for N200 stop-signal amplitudes, which were larger in older adults. Considered with intact task accuracy, these findings suggest age-related neural compensation. Although ɛ4 did not distinguish elders during go or no-go tasks, this study uniquely showed that the more demanding stop-signal task was sensitive to ɛ4 differences, despite comparable task and neuropsychological performance with non-carriers. Specifically, ɛ4+ elders had slower frontal N200 latency and larger N200 amplitude, which was most robust at frontal sites, compared with ɛ4-. Conclusion: N200 during a stop-signal task is sensitive to AD risk, prior to any evidence of cognitive dysfunction, suggesting that stop-signal ERPs may be an important protocol addition to neuropsychological testing

Evidence that Accumulation of Mutants in a Biofilm Reflects Natural Selection Rather than Stress-Induced Adaptive Mutation

The accumulation of mutant genotypes within a biofilm evokes the controversy over whether the biofilm environment induces adaptive mutation or whether the accumulation can be explained by natural selection. A comparison of the virulence of two strains of the dental pathogen Streptococcus mutans showed that rats infected with one of the strains accumulated a high proportion (average, 22%) of organisms that had undergone a deletion between two contiguous and highly homologous genes. To determine if the accumulation of deletion mutants was due to selection or to an increased mutation rate, accumulations of deletion mutants within in vitro planktonic and biofilm cultures and within rats inoculated with various proportions of deletion organisms were quantified. We report here that natural selection was the primary force behind the accumulation of the deletion mutants

Outpatient Upper Respiratory Tract Viral Infections in Children with Malaria Symptoms in Western Kenya

A cross-sectional study was performed in children 5 through 10 years of age presenting to outpatient clinics in Nyanza Province, Kenya, in which nasal swab and blood specimens were collected during the high malaria transmission season. Patients presenting with malaria-like symptoms within 4 days of fever onset were enrolled in the study. Plasmodium parasitemia was determined by blood smear microscopy. Nasal swabs were screened for a panel of respiratory viruses by polymerase chain reaction. Influenza A, rhinoviruses, and other respiratory viruses were detected in 18%, 26%, and 12% of 197 specimens, respectively. Four of 36 patients with influenza A had a positive malaria blood slide, compared with 20 of 52 patients with rhinovirus. A significant burden of disease caused by influenza A in febrile children during the study period was observed, highlighting the need for further research into the burden of influenza disease in regions where malaria is holoendemic