Probability and surprisal in auditory comprehension of morphologically complex words

Abstract

Two auditory lexical decision experiments document for morphologically complex words two points at which the probability of a target word given the evidence shifts dramatically. The first point is reached when morphologically unrelated competitors are no longer compatible with the evidence. Adapting terminology from Marslen-Wilson (1984), we refer to this as the word's initial uniqueness point (UP1). The second point is the complex uniqueness point (CUP) introduced by Balling and Baayen (2008), at which morphologically related competitors become incompatible with the input. Later initial as well as complex uniqueness points predict longer response latencies. We argue that the effects of these uniqueness points arise due to the large surprisal (Levy, 2008) carried by the phonemes at these uniqueness points, and provide independent evidence that how cumulative surprisal builds up in the course of the word co-determines response latencies. The presence of effects of surprisal, both at the initial uniqueness point of complex words, and cumulatively throughout the word, challenges the Shortlist B model of Norris and McQueen (2008), and suggests that a Bayesian approach to auditory comprehension requires complementation from information theory in order to do justice to the cognitive cost of updating probability distributions over lexical candidates.Keywords: spoken word recognition; Shortlist B; morphological processing; uniqueness points; neighbourhood measures; (cumulative) surprisal; Kullback-Leibler divergence; morphological family size. The Shortlist B model proposed by Norris and McQueen (2008) is the most comprehensive computational theory of auditory comprehension available to date. The model computes that sequence of words that is most likely to represent the lexical parse of the utterance heard, given the input, a stream of phonemes coming in over time. For instance, given the Dutch sequence of spoken words kar personen, the final state of the model is one in which kar ('cart') and personen ('persons') have probability 1, whereas competitors such as karper ('carp') and persoon ('persons') have probability 0.

Non-linear processing of a linear speech stream: The influence of morphological structure on the recognition of spoken Arabic words

“…Recently, morphologically sensitive measures of UP have also been defined and positively assessed as predictors of lexical processing. For example, Balling and Baayen (2012) define the complex uniqueness point (CUP) as the point at which a suffixed word becomes uniquely distinguishable from all words that share the same stem, therefore considering derived morphological continuations as (morphological) competitors during recognition. Wurm (1997) focuses on the importance of prefixes to spoken word recognition and formulates the conditional root uniqueness point (CRUP) as the uniqueness point of the root given a particular prefix.…”

The cave of shadows: Addressing the human factor with generalized additive mixed models

“…There are indications that males and females may be differentially sensitive to word frequency (Ullman et al, 2002;Balling and Baayen, 2008), but a gender by frequency interaction is not always found (Balling and Baayen, 2012;Tabak et al, 2005Tabak et al, , 2010. As the baldey data set combines a perfectly balanced set of subjects (10 males and 10 females) with a large number of items (2780 Dutch words), it provides a testing ground for differential effects of the two genders in lexical processing.…”

BALDEY: A database of auditory lexical decisions

“…We computed the positions of two different identification points. We refer to the first one as the lemma identification point (LIP); it is similar to the uniqueness point defined by Marslen-Wilson (1980), being the phoneme after which the only remaining lexical candidates are morphological continuation forms of the (prefix plus) stem (see also Balling & Baayen, 2012). An example in our corpus is bananen, "bananas", with the LIP at the second [n], at which point either the plural form of the stimulus or its singular banaan, "banana", is possible, but the competitor banaal, "banal", is no longer possible (note that this example also works for English).…”