Contingent categorization in speech perception

This is an Accepted Manuscript of an article published by Taylor & Francis in Language Cognition and Neuroscience in 2014, available online: http://www.tandfonline.com/10.1080/01690965.2013.824995.The speech signal is notoriously variable, with the same phoneme realized differently depending on factors like talker and phonetic context. Variance in the speech signal has led to a proliferation of theories of how listeners recognize speech. A promising approach, supported by computational modeling studies, is contingent categorization, wherein incoming acoustic cues are computed relative to expectations. We tested contingent encoding empirically. Listeners were asked to categorize fricatives in CV syllables constructed by splicing the fricative from one CV syllable with the vowel from another CV syllable. The two spliced syllables always contained the same fricative, providing consistent bottom-up cues; however on some trials, the vowel and/or talker mismatched between these syllables, giving conflicting contextual information. Listeners were less accurate and slower at identifying the fricatives in mismatching splices. This suggests that listeners rely on context information beyond bottom-up acoustic cues during speech perception, providing support for contingent categorization

The slow development of real-time processing: Spoken Word Recognition as a crucible for new thinking about language acquisition and disorders

Words are fundamental to language, linking sound, articulation and spelling to meaning and syntax; and lexical deficits are core to communicative disorders. Work in language acquisition commonly asks how lexical knowledge – the sound pattern and meaning of words – is acquired. This is insufficient to account for skilled behavior. Sophisticated real-time processes must decode the sound pattern of words and interpret them appropriately. This paper reviews work that overcome this gap by using sensitive real-time measures of language processing (eye-tracking in the Visual World Paradigm) along with highly familiar words with school age children. This work reveals that the development of word recognition skills can be characterized by differences in the rate by which decisions unfold in the lexical system (the activation rate) and that this develops extremely slowly – through adolescence. In contrast language disorders can be linked to differences in the ultimate degree to which competing interpretations are suppressed (competition resolution), and this can be mechanistically linked to deficits in inhibition. This has implications for real-world problems such as reading and second language acquisition. It suggests that developing accurate, flexible, and efficient processing is just an important goal of language acquisition, as acquiring language knowledge

The Role of Single Talker Acoustic Variation in Early Word Learning

Overall view front from left side; In 1959, in works such as Standing Women (bronze; Mexico City, Mus. A. Mod.), he moved from the non-academic naturalism of his early style, which was still linked to the 19th century, to a more realistic idiom, taking as his models the indigenous women of south-eastern Mexico, whom he represented standing or seated, singly, in pairs or in a group. They are women with large bodies, both heavily built and scrawny, all seemingly caught in a violent transition from youth to old age. They inhabit a dramatic silence in which there is no communication, and occasionally they appear with the ancestral dignity of their race, as in Woman from Yalalag (bronze, 1975; Monclova, Bib. Pape). Source: Grove Art Online; http://www.oxfordartonline.com/ (accessed 7/13/2010

Understanding language processing in variable populations on their own terms: towards a functionalist psycholinguistics of individual differences, development and disorders.

Classical psycholinguistics seeks a universal set of language processing mechanisms for all people. This relies on the “modal” listener: hearing, neurotypical, monolingual, young adults. Applied psycholinguistics then characterizes differences in terms of their deviation from modal. This approach mirrors naturalist philosophies of health which presume a normal function, and ill health as a deviation. In contrast, functionalist positions argue that ill health is in part culturally derived and occurs when a person cannot meet socio-culturally defined goals. This separates differences in underlying biology (disease) from socio-cultural function (illness). Functionalism offers a needed alternative for psycholinguistics, given that few people fit the modal definition. In contrast to psychometric measures—which are culturally defined—a process-based approach can yield more insight. We illustrate that with work examining word recognition across multiple domains: cochlear implant users, children, language disorders, L2 learners, and aging. This work seeks to understand each group’s solutions to the problem of word recognition as interesting in its own right. Variation in process is value-neutral, even as psychometric measures assess fit with cultural expectations (e.g., disease vs. illness). By examining variation in processing across people with a variety of skills and goals, we arrive at deeper insight into fundamental principles

Don’t Force It! Gradient Speech Categorization Calls for Continuous Categorization Tasks

Research on speech categorization and phoneme recognition has relied heavily on tasks in which participants listen to stimuli from a speech continuum, and are asked to either classify each stimulus (identification) or discriminate between them (discrimination). Such tasks rest on assumptions about how perception maps onto discrete responses – assumptions that have not been thoroughly investigated. Here we identify critical challenges in the link between these tasks and theories of speech perception. In particular, we show that patterns that have traditionally been linked to categorical perception could arise despite continuous underlying perception; and that patterns that run counter to categorical perception could arise despite underlying categorical perception. We describe an alternative measure of speech perception using a Visual Analogue Scale that better differentiates between processes at play in speech perception, and review some recent findings that show how this task can be used to better inform our theories

The development of lexical competition in written- and spoken-word competition

Efficient word recognition depends on the ability to overcome competition from overlapping words. The nature of the overlap depends on the input modality: spoken words have temporal overlap from other words that share phonemes in the same positions, whereas written words have spatial overlap from other words with letters in the same places. It is unclear how these differences in input format affect the ability to recognize a word and the types of competitors that become active while doing so. This study investigates word recognition in both modalities in children between 7 and 15. Children complete a visual-world paradigm eye-tracking task that measures competition from words with several types of overlap, using identical word lists between modalities. Results showed correlated developmental changes in the speed of target recognition in both modalities. Additionally, developmental changes were seen in the efficiency of competitor suppression for some competitor types in the spoken modality. These data reveal some developmental continuity in the process of word recognition independent of modality, but also some instances of independence in how competitors are activated. Stimuli, data and analyses from this project are available at: https://osf.io/eav7

The Development of Lexical Processing: Real-Time Phonological Competition and Semantic Activation in School Age Children

Prior research suggests that real-time word recognition processes are stabilized in early childhood (Fernald et al., 2006). However, recent work suggests that development of these processes continues throughout adolescence (Huang & Snedeker, 2011; Rigler et al., 2015). This study aimed to investigate whether these developmental changes are based solely within the lexical system, or are due to domain general changes. This study also aimed to investigate the development of real-time lexical-semantic activation. We captured semantic activation phonological competition and non-linguistic domain general processing skills using two Visual World Paradigm experiments in 43 7-9-year-olds, 42 10-13-year-olds, and 30 16-17 year-olds. Older children were quicker to fixate the target word and exhibited earlier onset and offset of fixations to both semantic and phonological competitors. Visual/cognitive skills explained significant, but not all, variance in the development of these effects. Developmental changes in semantic activation were largely attributable to changes in phonological processing. These results suggest that the concurrent development of linguistic processes and broader visual/cognitive skills lead to developmental changes in real-time word recognition, while semantic activation is stable across these ages

Don’t force it! Gradient speech categorization calls for continuous categorization tasks

Published Online: 20 December 2022Research on speech categorization and phoneme recognition has relied heavily on tasks in which participants listen to stimuli from a speech continuum and are asked to either classify each stimulus (identification) or discriminate between them (discrimination). Such tasks rest on assumptions about how perception maps onto discrete responses that have not been thoroughly investigated. Here, we identify critical challenges in the link between these tasks and theories of speech categorization. In particular, we show that patterns that have traditionally been linked to categorical perception could arise despite continuous underlying perception and that patterns that run counter to categorical perception could arise despite underlying categorical perception. We describe an alternative measure of speech perception using a visual analog scale that better differentiates between processes at play in speech categorization, and we review some recent findings that show how this task can be used to better inform our theories.This project was supported by National Institutes of Health (NIH) Grant No. DC008089 awarded to B.M. This work was supported by the Basque Government through the Basque Excellence Research Center (BERC) 2018–2021 and BERC 2022–2025 programs, by the Spanish State Research Agency through BCBL Severo Ochoa Excellence Accreditation Nos. SEV-2015-0490 and CEX2020-001010- S, and by the Spanish Ministry of Science and Innovation through Grant No. PID2020-113348GB-I00, awarded to E.C.K. This project has received funding from the European Union’s Horizon 2020 research and innovation program, under Marie Skłodowska-Curie Grant Agreement No. 793919, awarded to E.C.K