Exploring the impact of community-based choral participation on cognitive function and well-being for persons with dementia: evidence from the Voices in Motion project.

OBJECTIVES: Music-based interventions are postulated to mitigate cognitive decline in individuals with dementia. However, the mechanisms underlying why music-based interventions facilitate cognitive benefits remain unknown. The present study examines whether a choral intervention can modulate patterns of cognitive change in persons with dementia and whether within-person variation in affect is associated with this change. METHODS: Thirty-three older adults with dementia engaged weekly in the Voices in Motion (ViM) study consisting of 3 choral seasons spanning 18-months. Performance on the Mini-Mental State Examination (MMSE) and the Positive and Negative Affect Schedule was assessed monthly within each choral season using a longitudinal intensive repeated-measures design. Three-level multilevel models were employed to disaggregate between- and within-person effects across short- (month-to-month) and long-term (season-to-season) intervals. RESULTS: ViM participants exhibited an annual MMSE decline of 1.8 units, notably less than the clinically meaningful 3.3 units indicated by non-intervention literature. Further, variability in negative affect shared a within-person time-varying association with MMSE performance; decreases in negative affect, relative to one's personal average, were linked to corresponding improvements in cognitive function. CONCLUSION: Engagement in the ViM choral intervention may attenuate cognitive decline for persons with dementia via a reduction of psychological comorbidities such as elevated negative affect.

A direct replication and extension of Popp and Serra (2016, experiment 1): better free recall and worse cued recall of animal names than object names, accounting for semantic similarity.

Introduction: Free recall tends to be better for names of animate concepts such as animals than for names of inanimate objects. In Popp and Serra's 2016 article, the authors replicated this "animacy effect" in free recall but when participants studied words in pairs (animate-animate pairs intermixed with inanimate-inanimate pairs) and were tested with cued recall, performance was better for inanimate-inanimate pairs than for animate-animate pairs ("reverse animacy"). We tested the replicability of this surprising effect and one possible explanation for the effect (semantic similarity). Methods: Our Experiment 1 was a preregistered direct replication (N = 101) of Popp and Serra's Experiment 1 (mixed-lists condition). In a second preregistered experiment conducted in four different samples (undergraduate N = 153, undergraduate N = 143, online Prolific N = 101, online Prolific/English-as-a-first-language N = 150), we manipulated the within-category semantic similarity of animal and object wordlists. Results: AIn Experiment 1, just as in Popp and Serra, we observed an animacy effect for free recall and a reverse animacy effect for cued recall. Unlike Popp and Serra, we found that controlling for interference effects rendered the reverse animacy effect non-significant. We took this as evidence that characteristics of the stimulus sets (e.g., category structure, within-category similarity) may play a role in animacy and reverse animacy effects. In Experiment 2, in three out of our four samples, we observed reverse animacy effects when within-category similarity was higher for animals and when within-category similarity was equated for animals and objects. Discussion: Our results suggest that the reverse animacy effect observed in Popp and Serra's 2016 article is a robust and replicable effect, but that semantic similarity alone cannot explain the effect.

Parameterizing Practice in a Longitudinal Measurement Burst Design to Dissociate Retest Effects From Developmental Change: Implications for Aging Neuroscience.

Background: In longitudinal designs, the extraneous influence of retest effects can confound and obscure estimates of developmental change. The current study provides a novel approach to independently parameterize short-term retest effects and long-term developmental change estimates by leveraging a measurement burst design and three-level multilevel modeling. We further employ these short- and long-term slopes as predictors of cognitive status at long-term follow-up assessments. Methods: Participants included 304 older adults from Project MIND: a longitudinal measurement burst study assessing cognitive performance across both biweekly sessions and annual retests. Participants were classified as either Healthy controls (HC) or Cognitively Impaired, not Demented (CIND) at baseline, the final burst assessment (Year 4), and at an additional four-year follow-up (Year 8). Response time inconsistencies (RTI) were computed at each burst occasion for a simple choice response time (CRT) task and a one-back response time (BRT) task. Three-level multilevel models were employed to simultaneously examine change in RTI for both CRT and BRT across weeks within years, as well as across years, in order to dissociate within-individual retest effects (short-term) from developmental (long-term) change slopes. Individual slopes were then extracted and utilized in a series of multinomial logistic regression equations to contrast short- vs. long-term RTI change as predictors of cognitive status. Results: Separately parameterizing short- and long-term change estimates yielded distinct patterns of variation. CRT RTI remained stable across short-term weekly assessments, while significantly increasing across years. In contrast, BRT RTI decreased significantly across short-term assessments but showed no change across long-term assessments. After dissociating change estimates, short-term BRT as well as long-term CRT and BRT estimates predicted cognitive status at long-term follow-ups; increases in RTI, suggesting either an inability to benefit from retest or process-based developmental decline, were associated with an increased likelihood of being classified as CIND. Conclusions: We showcase an innovative approach to dissociate retest effects from developmental change across and within individuals. Accurately parameterizing these distinct change estimates can both reduce systematic bias in longitudinal trend estimates as well as provide a clinically useful tool by utilizing retest effects to predict cognitive health and impairment.