Browsing by Author "Wilbur, Ronnie B."

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    Age of acquisition effects differ across linguistic domains in sign language: EEG evidence
    (Elsevier, 2020) Malaia, Evie A.; Krebs, Julia; Roehm, Dietmar; Wilbur, Ronnie B.; University of Alabama Tuscaloosa; Salzburg University; Purdue University West Lafayette Campus; Purdue University
    One of the key questions in the study of human language acquisition is the extent to which the development of neural processing networks for different components of language are modulated by exposure to linguistic stimuli. Sign languages offer a unique perspective on this issue, because prelingually Deaf children who receive access to complex linguistic input later in life provide a window into brain maturation in the absence of language, and subsequent neuroplasticity of neurolinguistic networks during late language learning. While the duration of sensitive periods of acquisition of linguistic subsystems (sound, vocabulary, and syntactic structure) is well established on the basis of L2 acquisition in spoken language, for sign languages, the relative timelines for development of neural processing networks for linguistic sub-domains are unknown. We examined neural responses of a group of Deaf signers who received access to signed input at varying ages to three linguistic phenomena at the levels of classifier signs, syntactic structure, and information structure. The amplitude of the N400 response to the marked word order condition negatively correlated with the age of acquisition for syntax and information structure, indicating increased cognitive load in these conditions. Additionally, the combination of behavioral and neural data suggested that late learners preferentially relied on classifiers over word order for meaning extraction. This suggests that late acquisition of sign language significantly increases cognitive load during analysis of syntax and information structure, but not word-level meaning.
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    Age of sign language acquisition has lifelong effect on syntactic preferences in sign language users
    (Sage, 2021) Krebs, Julia; Roehm, Dietmar; Wilbur, Ronnie B.; Malaia, Evie A.; Salzburg University; Purdue University; Purdue University West Lafayette Campus; University of Alabama Tuscaloosa
    Acquisition of natural language has been shown to fundamentally impact both one's ability to use the first language and the ability to learn subsequent languages later in life. Sign languages offer a unique perspective on this issue because Deaf signers receive access to signed input at varying ages. The majority acquires sign language in (early) childhood, but some learn sign language later-a situation that is drastically different from that of spoken language acquisition. To investigate the effect of age of sign language acquisition and its potential interplay with age in signers, we examined grammatical acceptability ratings and reaction time measures in a group of Deaf signers (age range = 28-58 years) with early (0-3 years) or later (4-7 years) acquisition of sign language in childhood. Behavioral responses to grammatical word order variations (subject-object-verb [SOV] vs. object-subject-verb [OSV]) were examined in sentences that included (1) simple sentences, (2) topicalized sentences, and (3) sentences involving manual classifier constructions, uniquely characteristic of sign languages. Overall, older participants responded more slowly. Age of acquisition had subtle effects on acceptability ratings, whereby the direction of the effect depended on the specific linguistic structure.
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    Interaction between topic marking and subject preference strategy in sign language processing
    (Routledge, 2019) Krebs, Julia; Malaia, Evie; Wilbur, Ronnie B.; Roehm, Dietmar; Salzburg University; University of Alabama Tuscaloosa; Purdue University System; Purdue University; Purdue University West Lafayette Campus
    The preference of the human parser for interpreting syntactically ambiguous sentence-initial arguments as the subject of a clause (i.e. subject preference) has been documented for spoken and sign languages. Recent research (He, Y. [2016]. Interactive processing within and beyond sentence-level: An ERP investigation of simple and complex Chinese sentences (Unpublished doctoral dissertation). University of Mainz, Mainz) suggests that the subject preference can be eliminated by manipulating information structure (topicalisation). To investigate the effects of interaction between syntax and information structure on language processing, we tested the role of topic marking in sentence processing in Austrian Sign Language (oGS). We examined whether non-manual topic marking on the sentence-initial argument eliminates the subject preference using event-related brain potentials. We replicated the finding of the subject preference in oGS by identifying an N400-family response to object-first sentences. Further, topic marking in oGS influenced the processing of the topic argument itself and later processing stages. This suggests that interpretation of topic marking imposes additional processing costs, relative to syntactic reanalysis.
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    Psycholinguistic Mechanisms of Classifier Processing in Sign Language
    (American Psychological Association, 2021) Krebs, Julia; Malaia, Evie; Wilbur, Ronnie B.; Roehm, Dietmar; Salzburg University; University of Alabama Tuscaloosa; Purdue University West Lafayette Campus; Purdue University
    Nonsigners viewing sign language are sometimes able to guess the meaning of signs by relying on the overt connection between form and meaning, or iconicity (cf. Ortega, Ozyurek, & Peeters, 2020; Strickland et al.. 2015). One word class in sign languages that appears to be highly iconic is classifiers: verb-like signs that can refer to location change or handling. Classifier use and meaning are governed by linguistic rules, yet in comparison with lexical verb signs, classifiers are highly variable in their morpho-phonology (variety of potential handshapes and motion direction within the sign). These open-class linguistic items in sign languages prompt a question about the mechanisms of their processing: Are they part of a gestural-semiotic system (processed like the gestures of nonsigners), or are they processed as linguistic verbs? To examine the psychological mechanisms of classifier comprehension. we recorded the electroencephalogram (EEG) activity of signers who watched videos of signed sentences with classifiers. We manipulated the sentence word order of the stimuli (subject-object-verb [SOV] vs. object-subject-verb [OSV]), contrasting the two conditions, which, according to different processing hypotheses, should incur increased processing costs for OSV orders. As previously reported for lexical signs, we observed an N400 effect for OSV compared with SOV, reflecting increased cognitive load for linguistic processing. These findings support the hypothesis that classifiers are a linguistic part of speech in sign language, extending the current understanding of processing mechanisms at the interface of linguistic form and meaning.
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    Visual form of ASL verb signs predicts non- signer judgment of transitivity
    (PLOS, 2022) Bradley, Chuck; Malaia, Evie A.; Siskind, Jeffrey Mark; Wilbur, Ronnie B.; Purdue University West Lafayette Campus; Purdue University; University of Alabama Tuscaloosa
    Longstanding cross-linguistic work on event representations in spoken languages have argued for a robust mapping between an event's underlying representation and its syntactic encoding, such that-for example-the agent of an event is most frequently mapped to subject position. In the same vein, sign languages have long been claimed to construct signs that visually represent their meaning, i.e., signs that are iconic. Experimental research on linguistic parameters such as plurality and aspect has recently shown some of them to be visually universal in sign, i.e. recognized by non-signers as well as signers, and have identified specific visual cues that achieve this mapping. However, little is known about what makes action representations in sign language iconic, or whether and how the mapping of underlying event representations to syntactic encoding is visually apparent in the form of a verb sign. To this end, we asked what visual cues non-signers may use in evaluating transitivity (i.e., the number of entities involved in an action). To do this, we correlated non-signer judgments about transitivity of verb signs from American Sign Language (ASL) with phonological characteristics of these signs. We found that non-signers did not accurately guess the transitivity of the signs, but that non-signer transitivity judgments can nevertheless be predicted from the signs' visual characteristics. Further, non-signers cue in on just those features that code event representations across sign languages, despite interpreting them differently. This suggests the existence of visual biases that underlie detection of linguistic categories, such as transitivity, which may uncouple from underlying conceptual representations over time in mature sign languages due to lexicalization processes.