Modulation of vocal pitch control through high-definition transcranial direct current stimulation of the left ventral motor cortex.

Neural interactions between sensorimotor integration mechanisms play critical roles in voice motor control. We investigated how high-definition transcranial direct current stimulation (HD-tDCS) of the left ventral motor cortex modulates neural mechanisms of sensorimotor integration during voice motor control. HD-tDCS was performed during speech vowel production in an altered auditory feedback (AAF) paradigm in response to upward and downward pitch-shift stimuli. In one experiment, two groups received either anodal or cathodal 2 milliamp (mA) HD-tDCS to the left ventral motor cortex while a third group received sham (placebo) stimulation. In a second experiment, two groups received either 1 mA or 2 mA cathodal HD-tDCS to the left ventral motor cortex. Results of the first experiment indicated that the magnitude of vocal compensation was significantly reduced following anodal and cathodal HD-tDCS only in responses to downward pitch-shift AAF stimuli, with stronger effects associated with cathodal HD-tDCS. However, no such effect was observed following sham stimulation. Results of the second experiment indicate that there is not a differential effect of modulation from 1 mA versus 2 mA. Further, these results replicate the directional finding of the first experiment for vocal compensation in response to downward pitch-shift only. These findings suggest that neurostimulation of the left ventral motor cortex modulates sensorimotor mechanisms underlying voice motor control. We speculate that this effect is associated with the increased contribution of feedforward motor mechanisms, leading to reduced compensatory speech responses to AAF.

Toward a "smart" nightstand prototype: an examination of nightstand table contents and preferences.

OBJECTIVE: Two studies were conducted to obtain an understanding of the types of items seniors keep in their nightstands and to understand how users feel about the possibility of "smart" furniture. BACKGROUND: To enable aging in place and universal design, it is vital to understand the needs of a broad range of aging individuals, especially since there is little research on nightstand usage and design. METHODS: Study 1 allowed for the development of a structured inventory of nightstand use today in assisted living and rehabilitation facilities. Study 1 led to Study 2, demonstrating the need to conceptualize new ideas for smart nightstands. Feedback was obtained from intergenerational participants who could discuss their needs and preferences for a smart nightstand. RESULTS: In Study 1, more than 150 items were recorded and categorized into 25 different groups. The authors found that participants utilized the top portion of their nightstand as opposed to the lower sections; most items were found on top of the nightstand or in the top drawer. In Study 2, the authors found that the vast majority of participants are willing to consider the use of a smart nightstand. Participants discussed key functions and design preferences, which included carefully designed storage, the ability to move the nightstand up and down, contemporary design, and interaction through voice activation. CONCLUSION: Existing nightstands do not meet the needs of current users. This research provides greater understanding of the existing limitations associated with nightstands. Study 2 confirmed that user-centered design and the use of technology can be used to enhance daily living. Smart furniture may play a role in promoting the health and independence of diverse user groups.