Infants perceive speech and acquire language amidst noisy and complex auditory environments. Thus, elucidation of the cognitive mechanisms governing speech perception under noisy conditions is crucial. Cortical encoding of the speech envelope has been one approach used to study speech-in-noise perception in adults. For infants, research shows that Infant Directed Speech (IDS) facilitates cortical encoding of the speech envelope in quiet conditions more than adult direct speech. However, it is unclear whether infants are able to track the IDS speech envelope amidst competing speech. To investigate this, we recorded the neural responses from 40 typically-hearing infants (20 seven-month-olds, 20 eleven-month-olds) to continuous IDS using electroencephalography (EEG) in three conditions: Quiet, Co-located Noise, and Separated Noise. The target stimuli consisted of naturally recorded IDS produced by two female English speakers. The noise stimuli consisted of a four-person babble constructed from audiobooks read by 2 male and 2 female English speakers. We presented stimuli at an overall level of 70 dB SPL via speakers placed at 0°, +90°, and -90° azimuth to infants sitting on a caregiver’s lap in a sound-attenuated booth. Our team analyzed EEG signals using the Multivariate Temporal Response Function (mTRF) toolbox in MATLAB. This backward modeling approach assesses whether the stimulus envelope can be reconstructed based on the recorded neural responses. Reconstruction accuracies greater than chance were observed in all three conditions for the majority of infants, suggesting that we were able to decode the speech envelope in both quiet and noise. Participants demonstrated the capacity to process speech, even amidst competing auditory stimuli, emphasizing speech perception competencies from an early developmental stage. These results support using the envelope model and mTRF method as a feasible method for investigating the development of speech-in-noise perception in infants and young children.

Currently, over 6.6 million Americans use walking canes, rollators, and forearm crutches. However, little work has been done to improve the practicality of mobility aids for users. Prior work on modifying these mobility devices has centered around sensing and monitoring user interactions with their mobility device, without changes to the core structure of the devices. Our project aims to explore a set of mobility aid modifications including aesthetics, comfort, and ergonomics. We conducted over 15 qualitative interviews with mobility aid users using phenomenological interviewing strategies to understand user preferences and experiences better and gain feedback on possible adjustments to mobility devices. After qualitative analysis and creating codes based on patterns observed in the interviews analyzed, we identified and compiled unique experiences amongst mobility aid users into a codebook. We then sought to address these observations using fabrication methods such as 3D printing, laser-cutting, and soldering to modify existing mobility devices and develop prototyping materials. Subsequently, we conducted a follow-up design workshop to have users develop modifications and accessory ideas using the tools and templates we provided. Some modifications considered included interactivity stickers, physical feedback mechanisms, and improved mobility aid tip designs. Ultimately, we gained feedback for modifications in future mobility aids research and produced guidelines from our experiences working with mobility devices that can improve community input in accessibility aid research. This work also contributed valuable insights into approaching mobility aid improvements from a Human-Computer Interaction perspective.

Multiple Sclerosis (MS) is a chronic central nervous system (CNS) disease in which the immune system attacks the myelin surrounding nerve cells, resulting in decreased communication between the brain and the rest of the body, and severe physical and neurological defects. Gut metabolites produced by gut microbiota play a significant role in maintaining host immune homeostasis, and research has shown that short-chain fatty acids (SCFAs) have therapeutic potential. When tested in the mouse model of MS, experimental autoimmune encephalomyelitis (EAE), delivering butyrate-conjugated block copolymer micelles to the distal gut ameliorated EAE progression by increasing the amount of regulatory T cells and cytokines, and strengthening intestinal barrier functions. For prolonged SCFA delivery to the distal gut, a SCFA-conjugated hybrid lipid-polymer nanopolymer carrier is required. A nanoparticle is required because butyrate has a strong odor/taste and requires many pills per day to have significant suspension. To synthesize this nanoparticle, we optimized the nanogenerator to determine its effects on size and charge. This included modulating the total flow rate, flow rate ratio, input concentration ratio (lipid:polymer). We hypothesize that larger size, smaller surface area-to-volume ratio, and anionic surface charge will prolong retention and time in the distal GI. Once the nanoparticle is optimized, the potential of SCFA-conjugated nanocarriers to ameliorate EAE progression will be measured by comparing EAE mice and healthy controls, using the same outcome measures. This will allow us to select which polymer-conjugated SCFAs to incorporate into the optimized nanocarriers. We believe the SCFAs will inhibit proinflammatory macrophage activation, induce anti-inflammatory Treg cells, and promote demyelination and axonal degeneration to reduce the effects of MS in mice. In humans, delivering these nanoparticles as a drug will serve as a much more efficient means of treating MS when compared to the current treatment procedures.