ABSTRACT
The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation. While providing many insights into brain functions, the block design adds more manipulation in functional network analysis that may reduce the purity of the blood oxygenation level-dependent signal. Recent studies utilized one single long run for task trials of the same condition, the so-called continuous design, to investigate functional connectivity based on task functional magnetic resonance imaging. Continuous brain activities associated with the single-task condition can be directly utilized for task-related functional connectivity assessment, which has been examined for working memory, sensory, motor, and semantic task experiments in previous research. But it remains unclear how the block and continuous design influence the assessment of task-related functional connectivity networks. This study aimed to disentangle the separable effects of block/continuous design and working memory load on task-related functional connectivity networks, by using repeated-measures analysis of variance. Across 50 young healthy adults, behavioral results of accuracy and reaction time showed a significant main effect of design as well as interaction between design and load. Imaging results revealed that the cingulo-opercular, fronto-parietal, and default model networks were associated with not only task activation, but significant main effects of design and load as well as their interaction on intra- and inter-network functional connectivity and global network topology. Moreover, a significant behavior-brain association was identified for the continuous design. This work has extended the evidence that continuous design can be used to study task-related functional connectivity and subtle brain-behavioral relationships.
ABSTRACT
Objective:To study the influence of age-related functional hearing loss on memory ability. Methods:From January to October, 2018, 30 patients aged 52 to 76 years visiting otolaryngology were screened hearing using a computer aided platform, and then were divided into two groups according to the results. Those with good speech recognition in noise (SIN < -2.63 dB) were in L group (n = 15) and those with poor speech recognition in noise (SIN > -2.63 db) were in H group (n = 15). They were assessed with Paired Associates Learning (PAL) and Spatial Working Memory (SWM) of Cambridge Neuropsychological Test Automated Battery in loading of four, six and eight models. Results:The amount of errors of both PAL and SWM increased with the loading in both groups (χ2 > 28.182, P < 0.001). The amount of errors of PAL was less in L group than in H group under any loading (U < 53.5, P < 0.05), while the amount of errors of SWM only less under loading of six models (U = 55.0, P < 0.05). There was no significant interaction between hearing and loading (F < 1.680, P > 0.05). Conclusion:Age-related functional hearing loss tend to impair episodic memory rather than working memory, whatever the impacts of memory load.