Poster B31, Tuesday, August 20, 2019, 3:15 – 5:00 pm, Restaurant Hall
Say What You Mean: Contrasting BOLD responses of the ventral anterior temporal lobe during visual recognition of iconic and arbitrary word forms
Richard J. Binney1, Baihan Lu2, Mairead Healy1, Gabriella Vigliocco2;1School of Psychology, Bangor University, 2Division of Psychology and Language Sciences, University College London
It is a traditionally held view that the relationship between a word’s form (i.e., its phonology and orthography) and its meaning (i.e., semantics) is arbitrary. Indeed, there is evidence from within both classical and contemporary literatures to suggest that arbitrariness creates learning advantages and greater flexibility in language use, including the acquisition of larger and abstract vocabularies. Conversely, there is a growing body of evidence for an important function of iconicity in language, that is, of a direct mapping from word form on to aspects of its meaning. This includes a role in early language learning, where direct mappings facilitate a child’s appreciation of the relationship between words and their sensorimotor experience. Further, there is evidence that iconicity can afford greater resilience of word knowledge to neurological damage. The present study contrasted, for the very first time, neural responses to iconic and arbitrary words during a visual lexical decision task presented in the English language. The aim was to determine whether there may be alternative neural mechanisms to achieving recognition of these two types of words. We hypothesized that this would be realized in differential engagement of semantic and phonologic cortical systems. The study focused upon a familiar form of iconicity in English, known as onomatopoeia, in which the phonology of a word imitates the sound to which it refers (e.g., quack, boom and sizzle). Iconic and arbitrary words were identified via ratings performed by an independent participant sample, and then matched a priori on a number of other psycholinguistic variables including but not limited to lexical frequency, imageability, age of acquisition, and number of phonemes. An additional set of words that were similar to the iconic words by way of strong associations with auditory events (e.g, choir, radio, drums) were also used to ascertain whether any differences can be explained by semantic properties of words rather than iconicity per se. Thirty participants at Bangor University underwent fMRI which was acquired in a rapid event-related design and using a dual-echo EPI sequence that is optimized to reduce magnetic-susceptibility associated signal loss in key parts of the ventral language pathway (e.g., the visual word form area and the basal language area). No differences were observed in behavioural responses (as measured by accuracy and decision times) to each of the word categories. A univariate analysis of the neuroimaging data revealed that during recognition of iconic words, as contrasted to each of the two sets of non-iconic words, there was decreased activation in the ventral anterior temporal lobe, an area associated with integration of multimodal semantic features. This suggests that recognition of these iconic words can be achieved without accessing such higher-level semantic information. Increased activation for iconic words was also observed in the precuneus, an area associated with mental imagery. We discuss the results of an ongoing multivariate pattern-based analysis, and the implications of these novel data for models of word recognition, comprehension and language development.
Themes: Meaning: Lexical Semantics, Morphology
Method: Functional Imaging