Is visual lexical decision a dynamic and competitive process? No, if we look at reaction times. Yes, if we study how it unfolds in time

Pezzulo Giovanni

doi:10.3389/conf.fnins.2012.86.00001

Abstract

Event Abstract Back to Event Is visual lexical decision a dynamic and competitive process? No, if we look at reaction times. Yes, if we study how it unfolds in time Laura Barca1* and Giovanni Pezzulo2 1 ISTC-CNR, Institute of Cognitive Sciences and Technologies, Italy 2 ILC-CNR, Istituto di Linguistica Computazionale “Antonio Zampolli”, Italy Visual lexical decision is a classical paradigm in Psycholinguistic, and numerous studies have assessed a so-called "lexicality effect" (i.e., better performance with lexical over non-lexical stimuli). Far less is know relative to the dynamics of choice, as many studies measure overal reaction times which are not informative of the underlying processes. To unfold visual lexical decision in time, we measured participants' hand movements toward one of two items alternatives by recording the streaming x,y coordinates of the computer mouse. Participants categorized as 'lexical' or 'non-lexical' four kinds of stimuli: high and low frequency words, pseudowords, and letter strings. Spatial attraction toward the opposite category was present for low frequency words and pseudowords. Increasing stimuli ambiguity lead to enhcanced movements' complexity and trajectories' attraction to competitors, as no such effect was present for high frequency words and letter strings. Results fit well with dynamic models of perceptual decision-making describing the process as a competition between alternatives guided by the continuous accumulation of evidence, as well as with a recent neural model of visual word recognition that highlights the role of top-down influences and predictions on perceptual processes. More broadly, our results point to a key role of statistical decision theory to study linguistic processing in terms of dynamic and non-modular mechanisms. Finally, we discuss two aspects that make our set-up challenging for current dynamical models of decision-making: 1) not all information (e.g. ortographic, phonological and semantic) is available at the same time, therefore the accumulation process is nonstationary; 2) the choice is not completed at the action onset, but can be revised at any time during the movement. Keywords: computational neuroscience, psycholinguistic, statistical decision theory Conference: Neural Coding, Decision-Making & Integration in Time, Rauischholzhausen, Germany, 26 Apr - 29 Apr, 2012. Presentation Type: Poster Presentation Topic: Neural Coding, Decision-Making & Integration in Time Citation: Barca L and Pezzulo G (2012). Is visual lexical decision a dynamic and competitive process? No, if we look at reaction times. Yes, if we study how it unfolds in time . Front. Neurosci. Conference Abstract: Neural Coding, Decision-Making & Integration in Time. doi: 10.3389/conf.fnins.2012.86.00001 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 12 Jan 2012; Published Online: 16 Jan 2012. * Correspondence: Dr. Laura Barca, ISTC-CNR, Institute of Cognitive Sciences and Technologies, Rome-Italy, Italy, laura.barca@istc.cnr.it Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Laura Barca Giovanni Pezzulo Google Laura Barca Giovanni Pezzulo Google Scholar Laura Barca Giovanni Pezzulo PubMed Laura Barca Giovanni Pezzulo Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Highlights

We measured participants' hand movements toward one of two item alternatives by recording the streaming x,y coordinates of the computer mouse
Linguistic and pseudo-linguistic stimuli could be ordered along a lexicality dimension or a "lexical dimension line", which functions as a continuum between highly lexical items, weak lexical items, weak nonlexical items and highly nonlexical items
Using the MouseTracker apparatus [1], we tracked continuous hand movement responses during a visual-lexical decision task to observe the graded effects of competing items attracting the trajectory of the mouse during trials in which the categorization was correctly executed

Summary

Introduction

We measured participants' hand movements toward one of two item alternatives by recording the streaming x,y coordinates of the computer mouse. Linguistic and pseudo-linguistic stimuli could be ordered along a lexicality dimension or a "lexical dimension line", which functions as a continuum between highly lexical items (i.e. words with high frequency values), weak lexical items (i.e. words with low frequency values), weak nonlexical items (i.e. legal pseudowords) and highly nonlexical items (i.e., strings of letters). Using the MouseTracker apparatus [1], we tracked continuous hand movement responses during a visual-lexical decision task to observe the graded effects of competing items attracting the trajectory of the mouse during trials in which the categorization was correctly executed.

Results

Conclusion