Hyper-Frequency Network Topology Changes During Choral Singing

Choral singing requires the coordination of physiological subsystems within and across individuals. Previously, we suggested that the choir functions as a superordinate system that imposes boundary conditions on the dynamic features of the individual singers and found reliable differences in the network topography by analyzing within- and cross-frequency couplings (WFC and CFC, respectively). Here, we further refine our analyses to investigate hyper-frequency network (HFN) topology structures (i.e., the layout or arrangement of connections) using a graph-theoretical approach. In a sample of eleven singers and one conductor engaged in choral singing (aged between 23 and 56 years, and including five men and seven women), we calculated phase coupling (WFC and CFC) between respiratory, cardiac, and vocalizing subsystems across ten frequencies of interest. All these couplings were used for construction of HFN with nodes being a combination of frequency components and subsystems across choir participants. With regard to the network topology measures, we found that clustering coefficients (CCs) as well as local and global efficiency were highest and characteristic path lengths, correspondingly, were shortest when the choir sang a canon in parts as compared to singing it in unison. Furthermore, these metrics revealed a significant relationship to individual heart rate, as an indicator of arousal, and to an index of heart rate variability indicated by the LF/HF ratio (low and high frequency, respectively), and reflecting the balance between sympathetic and parasympathetic activity. In addition, we found that the CC and local efficiency for groups singing the same canon part were higher than for groups of singers constructed randomly post hoc, indicating stronger neighbor–neighbor connections in the former. We conclude that network topology dynamics are a crucial determinant of group behavior and may represent a potent biomarker for social interaction

Feature Integration Across the Lifespan: Stickier Stimulus–Response Bindings in Children and Older Adults

Humans integrate the features of perceived events and of action plans into episodic event files. Here we investigated whether children (9–10 years), younger adults (20–31 years), and older adults (64–76 years) differ in the flexibility of managing (updating) event files. Relative to young adults, performance in children and older adults was more hampered by partial mismatches between present and previous stimulus–response relations, suggesting less efficient updating of episodic stimulus–response representations in childhood and old age. Results are discussed in relation to changes in cortical neurochemistry during maturation and senescence

Assistive Technology for Successful Aging: Perspectives from Developmental Behavioral and Neuroscience

Growing into old age is a personal privilege and a societal achievement. However, it is also a challenge for both the individuals and societies. The impressive gains in extending average physical longevity to 75 years and beyond is not necessary accompanied by high-levels of physical, psychological, and brain "fitness". Thus, it is important to seek ways to help older adults maintaining functions in these domains in order to maintain life quality in old age. Adaptive assistive devices and environments are promising technological advancements for promoting successful aging. Sufficient plasticity in the aging psychological and neurocognitive systems are necessary for technologies to engender desired effects. Designs and evaluations of assistive technologies need to consider dynamic changes in developmental resources across the lifespan. This paper reviews evidence of behavioral and neurocognitive plasticity in old age and highlights psychological principles for successful aging technologies

Neural activation patterns during retrieval of schema-related memories: Differences and commonalities between children and adults

Schemas represent stable properties of individuals’ experiences, and allow to classify new events as being congruent or incongruent with existing knowledge. Research with adults indicates that the prefrontal cortex (PFC) is involved in memory retrieval of schema-related information. However, developmental differences between children and adults in the neural correlates of schema-related memories are not well understood. One reason for this is the inherent confound between schema-relevant experience and maturation, as both are related to time. To overcome this limitation, we used a novel paradigm that experimentally induces, and then probes for task-relevant knowledge during encoding of new information. Thirty-one children aged 8–12 years and 26 young adults participated in the experiment. While successfully retrieving schema-congruent events, children showed less medial PFC activity than adults. In addition, medial PFC activity during successful retrieval correlated positively with children’s age. While successfully retrieving schema-incongruent events, children showed stronger hippocampus (HC) activation as well as weaker connectivity between the striatum and the dorsolateral PFC than adults. These findings were corroborated by an exploratory full-factorial analysis investigating age differences in the retrieval of schemacongruent versus schema-incongruent events, comparing the two conditions directly. Consistent with the findings of the separate analyses, two clusters, one in the medial PFC, one in the HC, were identified that exhibited a memory x congruency x age group interaction. In line with the two-component model of episodic memory development, the present findings point to an age-related shift from a more HC-bound processing to an increasing recruitment of prefrontal brain regions in the retrieval of schema-related events