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The field of 3-dimensional (3D) bioprinting has significantly expanded capabilities in producing precision-engineered hydrogel constructs, and recent years have seen the development of various stimuli-responsive bio- and photoinks. There is, however, a distinct lack of digital light processing (DLP)-compatible photoinks with thermoresponsivity. To remedy this, this work focuses on formulating and optimizing a versatile ink for DLP printing of thermoresponsive hydrogels, with numerous potential applications in tissue engineering, drug delivery, and adjacent biomedical fields. Photoink optimization was carried out using a multifactorial study design. The optimized photoink yielded crosslinked hydrogels with strong variations in hydrophobicity (contact angles of 44.4° LCST), indicating marked thermoresponsivity. Mechanical- and rheological characterization of the printed hydrogels showed significant changes above the LCST: storage- and loss moduli both increased and loss tangent and compressive modulus decreased above this temperature (P ≤ 0.01). The highly cytocompatible hydrogel microwell arrays yielded both single- and multilayer spheroids with human dermal fibroblasts (HDFs) and HeLa cells successfully. Evaluation of the release of encapsulated model macro- (bovine serum albumin, BSA) and small molecule (rhodamine B) drugs in a buffer solution showed an interestingly inverted thermoresponsive release profile with >80% release at room temperature and about 50-60% release above the gels' LCST. All told, the optimized ink holds great promise for multiple biomedical applications including precise and high-resolution fabrication of complex tissue structures, development of smart drug delivery systems and 3D cell culture.

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The implicit learning account of syntactic priming proposes that the same mechanism underlies syntactic priming and language development, providing a link between a child and adult language processing. The present experiment tested predictions of this account by comparing the persistence of syntactic priming effects in children and adults. Four-year-olds and adults first described transitive events after hearing transitive primes, constituting an exposure phase that established priming effects for passives. The persistence of this priming effect was measured in a test phase as participants described further transitive events but no longer heard primes. Their production of passives was compared to a baseline group who described the same pictures without any exposure to primes. Neither immediate nor long-term priming effects differed between children and adults but both children and adults showed significant immediate and persistent effects of the priming when the test phase occurred immediately after the exposure phase and when a short delay separated the exposure and test phase. The implications of these results for an implicit learning account of syntactic priming are discussed.

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By about age three, English-learning children begin to understand passive sentences with familiar verbs. We probed the nature of children's linguistic representations by asking whether 3-year-olds promptly extend their emerging knowledge of the passive structure to novel verbs. In three preferential-looking experiments, 3-year-olds (N = 124) interpreted novel verbs presented in short passives (Experiment 1, "She's getting snedded!") as transitive verbs, referring to causal-action rather than solo-action events, and used word-order in full passives, (Experiments 2 and 3, e.g., "She's getting snedded by the boy!"), to select a target event in which the subject was the patient, not the agent of action. Comprehension accuracy in Experiments 1 and 2 varied with vocabulary, but this vocabulary effect disappeared when children were given more time and more repetitions of the test sentences (Experiment 3). These findings support early-abstraction accounts of acquisition: 3-year-olds represent passive syntax in abstract terms, permitting extension to novel verbs. This, in turn, allows them to use passive sentences to identify the grammatical subcategory and meaning of an unknown verb.

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Young adults can be primed to reuse a syntactic structure across otherwise unrelated utterances but it is not known whether this phenomenon exists in older adults. In a dialogue task, young and older adults described transitive verb target pictures after hearing active or passive sentences. Both groups were more likely to produce a passive sentence following a passive prime than following an active prime (indicating syntactic priming), and this effect increased when the prime and target involved the same verb (indicating lexical boost). These effects were statistically equivalent in young and older adults, suggesting that the syntactic representations underlying sentence production are unaffected by normal aging. (PsycINFO Database Record

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Error-based implicit learning models (e.g., Chang, Dell, & Bock, 2006) propose that a single learning mechanism underlies immediate and long-term effects of experience on children's syntax. We test two key predictions of these models: That individual experiences of infrequent structures should yield both immediate and long-term facilitation, and that such learning should be consistent in individual speakers across time. Children (and adults) described transitive events in two picture-matching games, held a week apart. In both sessions, the experimenter's immediately preceding syntax (active vs. passive) dynamically influenced children's (and adults') syntactic choices in an individually consistent manner. Moreover, children showed long-term facilitation, through an increased likelihood to produce passives in Session 2, with speakers who were most likely to immediately repeat passives in Session 1 being most likely to produce passives in Session 2. Our results are consistent with an error-based syntactic learning mechanism that operates across the lifespan.

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Children recruit verb syntax to guide verb interpretation. We asked whether 22-month-olds spontaneously encode information about a particular novel verb's syntactic properties through listening to sentences, retain this information in long-term memory over a filled delay, and retrieve it to guide interpretation upon hearing the same novel verb again. Children watched dialogues in which interlocutors discussed unseen events using a novel verb in transitive (e.g., "Anna blicked the baby") or intransitive sentences ("Anna blicked"). Children later heard the verb in isolation ("Find blicking!") while viewing a two-participant causal action and a one-participant action event. Children who had heard transitive dialogues looked longer at the two-participant event than did those who heard intransitive dialogues. This effect disappeared if children heard a different novel verb at test ("Find kradding!"). These findings implicate a role for distributional learning in early verb learning: Syntactic-combinatorial information about otherwise unknown words may pervade the toddler's lexicon, guiding later word interpretation.

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We report a syntactic priming experiment that examined whether children's acquisition of the passive is a staged process, with acquisition of constituent structure preceding acquisition of thematic role mappings. Six-year-olds and nine-year-olds described transitive actions after hearing active and passive prime descriptions involving the same or different thematic roles. Both groups showed a strong tendency to reuse in their own description the syntactic structure they had just heard, including well-formed passives after passive primes, irrespective of whether thematic roles were repeated between prime and target. However, following passive primes, six-year-olds but not nine-year-olds also produced reversed passives, with well-formed constituent structure but incorrect thematic role mappings. These results suggest that by six, children have mastered the constituent structure of the passive; however, they have not yet mastered the non-canonical thematic role mapping. By nine, children have mastered both the syntactic and thematic dimensions of this structure.

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In a syntactic priming paradigm, three- and four-year-old children and adults described transitive events after hearing thematically and lexically unrelated active and short passive prime descriptions. Both groups were more likely to produce full passive descriptions (the king is being scratched by the tiger) following short passive primes (the girls are being shocked) than active primes (the sheep is shocking the girl). These results suggest that by four, children have (shared) abstract syntactic representations for both short and full passives, contrary to previous proposals (e.g., Horgan, 1978).

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