Naturalistic joint action usually requires both motor coordination and strategic cooperation. However, these two fundamental processes have systematically been studied independently. We devised a ...novel collaborative task, combining different levels of motor noise with different levels of strategic noise, to determine whether sense of agency (the experience of control over an action) reflects the interplay between these low-level (motor) and high-level (strategic) processes. We also examined how dominance in motor control could influence prosocial behaviours. We found that self-agency was particularly dependent on motor cues while joint agency was particularly dependent on strategic cues. We suggest that the prime importance of strategic cues for joint agency reflects the co-representation of co-agents’ interests during the task. Furthermore, we observed a reduction of prosocial strategies in agents who exerted a dominant motor control over the joint action, showing that the strategic dimension of human interactions is also reliant on low-level motor features.
Cortical activity and walking speed are known to decline with age and can lead to an increased risk of falls in the elderly. Despite age being a known contributor to this decline, individuals age at ...different rates. This study aimed to analyse left and right cortical activity changes in elderly adults regarding their walking speed. Cortical activation and gait data were obtained from 50 healthy older individuals. Participants were then grouped into a cluster based on their preferred walking speed (slow or fast). Analyses on the differences of cortical activation and gait parameters between groups were carried out. Within-subject analyses on left and right–hemispheric activation were also performed. Results showed that individuals with a slower preferred walking speed required a higher increase in cortical activity. Individuals in the fast cluster presented greater changes in cortical activation in the right hemisphere. This work demonstrates that categorizing older adults by age is not necessarily the most relevant method, and that cortical activity can be a good indicator of performance with respect to walking speed (linked to fall risk and frailty in the elderly). Future work may wish to explore how physical activity training influences cortical activation over time in the elderly.
The present study investigated transposed-word effects in a post-cued word-in-sequence identification experiment. Five horizontally aligned words were simultaneously presented for a brief duration ...and followed by a backward mask and cue for the position of the word to be identified within the sequence. The five-word sequences could form a grammatically correct sentence (e.g., The boy can run fast), an ungrammatical transposed-word sequence (e.g., The can boy run fast) or an ungrammatical control sequence (e.g., The can get run fast), and the same target word at the same position (e.g., the word ‘run’) was tested in the three conditions. Consistent with previous studies using a grammatical decision task and a same-different matching task, a transposed-word effect was observed, with word identification being more accurate in transposed-word sequences than in control sequences. Furthermore, here we could show for the first time that word identification was more accurate in correct sentences compared with transposed-word sequences. We suggest that the word identification advantage found for transposed-word sequences compared with ungrammatical control sequences is due to facilitatory feedback to word identities from sentence-level representations, albeit with less strength compared to the feedback provided by correct sentences.
We develop two improvements over our previously-proposed joint enhancement and separation (JES) framework for child speech extraction in real-world multilingual scenarios. First, we introduce an ...iterative adaptation based separation (IAS) technique to iteratively fine-tune our pre-trained separation model in JES using data from real scenes to adapt the model. Second, to purify the training data, we propose a dynamic mask separation (DMS) technique with variable lengths in movable windows to locate meaningful speech segments using a scale-invariant signal-to-noise ratio (SI-SNR) objective. With DMS on top of IAS, called DMS+IAS, the combined technique can remove a large number of noise backgrounds and correctly locate speech regions in utterances recorded under real-world scenarios. Evaluated on the BabyTrain corpus, our proposed IAS system achieves consistent extraction performance improvements when compared to our previously-proposed JES framework. Moreover, experimental results also show that the proposed DMS+IAS technique can further improve the quality of separated child speech in real-world scenarios and obtain a relatively good extraction performance in difficult situations where adult speech is mixed with child speech.
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