Portable Psychophysics: A novel approach to evaluate temporal processing in basic research and clinical settings

To perceive and interact with the environment functionally, our brain must simultaneously encode and decode various temporal cues and efficiently combine them across different senses. Nonetheless, not all sensory modalities exhibit equally valuable temporal resolutions, being auditory the primary sensory modality through which time is precisely experienced. Consequently, such a combination is not a linear process, and temporal information perceived across individual sensory streams shows several grades of relevance when performing duration estimations. To date, however, it is still unclear how temporal processing occurs within the brain, along with how auditory impairments during development might determine plastic changes that negatively affect time perception. Powerful insights can be obtained by investigating temporal processing in individuals whose auditory perception was impaired during critical developmental stages, when the brain experienced the most plastic properties. Interestingly, both the absence of hearing experience during development, such as in congenital and early deafness, and its deterioration, such as in Developmental Dyslexia, seem to determine a generalized reduction of temporal sensitivity across the lifespan. Even though there is solid evidence suggesting that abnormal auditory experience might affect temporal processing, there is a surprising lack of behavioral evidence aiming at bridging temporal impairment in deafness and Developmental Dyslexia. I thereby first investigated temporal processing in these populations using classing psychophysical techniques. I thus developed two different tasks directly designed to evaluate visual temporal abilities, with a specific focus on the magnocellular properties of temporal perception. Being particularly prone to be shaped by abnormal sensory experience during development, magnocellular cells should in fact reflect different temporal encoding according to the nature of the auditory impairment. Then, due to the COVID-19 pandemic and the consequent, inevitable difficulties emerged in data collection, I decided to foster a remote and safe approach to psychophysical testing. I therefore conceptualized, designed, and validated PsySuite, an Android App aimed at providing a reliable and easy-to-use tool to assess perceptual measurements while respecting social distancing restrictions. PsySuite’s feasibility in performing remote data collection was evaluated through extensive hardware and behavioral testing, allowing to determine the reliability of the produced stimuli and the generalizability of the results obtained with the App. After establishing PsySuite’s effectiveness and stability, I developed a portable version of a psychophysical task specifically designed to gauge and enhance temporal perceptual skills in typical adults. With this newfound, novel approach, I then investigated temporal processing in deaf and dyslexic participants.