Strategic Focus Areas
SFA 1: Visual & Cognitive Plasticity
The goal of this SFA is to determine the effects of variation in sensory and linguistic experience on the development of visual and higher cognitive systems. (Rain Bosworth, Leader)
Using multiple methods and grains of analyses, spanning VL2’s psychophysical and neurophysiological studies, VL2 researchers have made significant contributions to Theme 1, regarding our understanding of the impact that early visual sensory and visual language experiences can have on neural systems and higher cognitive processes following differences in early sensory experience. Recent VL2 brain and behavioral studies have provided evidence for the flexibility of visual-cognitive neural systems in adapting to a different sensory language modality (that is, visual as opposed to auditory language). Behaviorally, deaf signers show enhanced low-level perceptual and attentional abilities, in ways that allow them to function efficiently, learn from their environment, and succeed academically in the classroom. This key evidence raises the possibility that such low-level visual and attention adaptations may provide positive “upstream” advantages to higher cognitive processes, mental language representation, and reading. It also suggests that there may be adaptations for higher-level perception of language input, and these adaptations might also mean a different linguistic representation of phonology that is visually based and not sound-based.
That visual processing is enhanced in deaf children and adults with early life visual language exposure raises the question as to why. Enhancement of visual abilities may come about because the language places heavy demands on visual processing, for example, the processing of visual phonological cues (e.g., sign-phonetic and sign syllabic, fingerspelling, and other rhythmic-temporal patterning) as well as other grammatical features of visual language structure. For example, Dye et al. (2009) demonstrated peripheral visual attention is enhanced in deaf adults (see also Bavelier et al. 2006). Bosworth and colleagues found that early sign language exposure enhances low-level form sensitivity as seen by better performance on an orientation discrimination task by both children and adults, suggesting that the beneficial effects of early exposure to ASL on form processing (specifically, orientation discrimination) begins in early childhood and continues through the lifespan. Hauser, Dye, & Bavelier (2009) found that early exposure to ASL has beneficial effects on selective attention. Deaf early-exposed bilinguals were faster on a peripheral attention allocation task than deaf late bilinguals. Further, Bélanger, Slattery, Mayberry, and Rayner (2012) showed that peripheral visual enhancement benefitted reading. Here, skilled deaf readers showed a wider perceptual span than hearing readers and less skilled deaf readers.
In Years 8-9, and beyond, we use our foundational findings as a springboard to ask next-step questions, which is how do such visual affordances impact higher cognitive processes underlying healthy language processing and reading—indeed, higher cognitive processes that are central to achieving lifelong academic and societal success. SFA1 (Lead by Bosworth) studies 1-3 (PIs, Bosworth, Petitto, and Rayner, respectively) share a scientific goal of studying visual perception of language input, including the visual cues that make possible the young infant’s capacity to differentiate visual language from gesture (where both reside in the same modality), and the behavioral and/or neural processes underlying ASL vocabulary, fingerspelling, orthographic decoding, and reading. All three studies in SFA1 are united by their advancement of the Center’s scientific themes. They address the impact of differences in early visual sensory experience (Theme 1), the impact of ASL exposure when it is early versus late (critical/sensitive period hypothesis, Theme 2), and are united by their goal to understand the different learning mechanisms that make possible the child's capacities underlying visual sign phonology, and their relation to successful reading acquisition (Theme 3).