Biomedical subjects

M Gareth Gaskell

Publications and source records attributed to M Gareth Gaskell.

6 recordsLinked to original sources

PubMed2006

Reading spoken words: orthographic effects in auditory priming.

Three experiments examined the involvement of orthography in spoken word processing using a task - unimodal auditory priming with offset overlap - taken to reflect activation of prelexical representations. Two types of prime-target relationship were compared; both involved phonological overlap, but only one had a strong orthographic overlap (e.g., dream-gleam vs. scheme-gleam). In Experiment 1, which used lexical decision, phonological overlap facilitated target responses in comparison with an unrelated condition (e.g., stove-gleam). More importantly, facilitation was modulated by degree of orthographic overlap. Experiment 2 employed the same design as Experiment 1, but with a modified procedure aimed at eliciting swifter responses. Again, the phonological priming effect was sensitive to the degree of orthographic overlap between prime and target. Finally, to test whether this orthographic boost was caused by congruency between response type and valence of the prime-target overlap, Experiment 3 used a pseudoword detection task, in which participants responded "yes" to novel words and "no" to known words. Once again phonological priming was observed, with a significant boost in the orthographic overlap condition. These results indicate a surprising level of orthographic involvement in speech perception, and provide clear evidence for mandatory orthographic activation during spoken word recognition.

Analysis of Variance↗

PubMed2006

Frequency effects in spoken and visual word recognition: evidence from dual-task methodologies.

The authors report 3 dual-task experiments concerning the locus of frequency effects in word recognition. In all experiments, Task 1 entailed a simple perceptual choice and Task 2 involved lexical decision. In Experiment 1, an underadditive effect of word frequency arose for spoken words. Experiment 2 also showed underadditivity for visual lexical decision. It was concluded that word frequency exerts an influence prior to any dual-task bottleneck. A related finding in similar dual-task experiments is Task 2 response postponement at short stimulus onset asynchronies. This was explored in Experiment 3, and it was shown that response postponement was equivalent for both spoken and visual word recognition. These results imply that frequency-sensitive processes operate early and automatically.

Adolescent↗

PubMed2003

Lexical competition and the acquisition of novel words.

Three experiments examined the involvement of newly learnt words in lexical competition. Adult participants were familiarized with novel nonsense sequences that overlapped strongly with existing words (e.g. cathedruke, derived from cathedral) through repeated presentation in a phoneme-monitoring task. Experiment 1 looked at the immediate effects of exposure to these sequences, with participants showing familiarity with the form of the novel sequences in a two-alternative forced choice task. The effect of this exposure on lexical competition was examined by presenting the existing words (e.g. cathedral) in a lexical decision task. The immediate effect of the exposure was facilitatory, suggesting that the novel words had activated the representation of the closest real word rather than developing their own lexical representations. In Experiment 2, inhibitory lexical competition effects emerged over the course of 5 days for offset-diverging (e.g. cathedruke-cathedral) but not onset-diverging (e.g. yothedral-cathedral) novel words. Experiment 3 disentangled the roles of time and level-of-exposure in the lexicalization process and assessed the generality of the observed lexical inhibition using pause detection. A single, concentrated exposure session was used, which resulted in good recognition performance soon after. Lexicalization effects were absent immediately after exposure but emerged 1 week later, despite no intervening exposure to the novel items. These results suggest that integrating a novel word into the mental lexicon can be an extended process: phonological information is learnt swiftly, but full integration with existing items develops at a slower rate.

Adolescent↗

PubMed2003

Constraints on definite article alternation in speech production: to "thee" or not to "thee"?

A recent study showed that the pronunciation of the definite article in English (as either a reduced "thuh" or an unreduced "thee") depends on a number of different factors, including the pronunciation, spelling, and stress assignment of the following word (Raymond, Fisher, & Healy, 2002). However, it is not clear from previous research whether these factors influenced performance implicitly in normal speech production or whether explicit knowledge of the object of the experiment was relied on. In Experiment 1, we examined implicit performance on pronunciation of the definite article and found more systematic behavior than had previously been observed but, again, an influence of the pronunciation, spelling, and stress assignment of the following word. In Experiment 2, we tested the influence of the following word on definite article production during language development for two groups of children 8 and 10 years of age. This experiment showed increasing use of the unreduced form during development and a further influence of orthography. We interpret these results in terms of an interaction between perception and production in which the production system makes use of generalizations on the basis of both phonological and orthographic representations generated in perception.

Adolescent↗

PubMed2002

Representation and competition in the perception of spoken words.

We present data from four experiments using cross-modal priming to examine the effects of competitor environment on lexical activation during the time course of the perception of a spoken word. The research is conducted from the perspective of a distributed model of speech perception and lexical representation, which focuses on activation at the level of lexical content. In this model, the strength of competition between simultaneously active lexical items depends on the degree of coherence between their distributed semantic and phonological representations. Consistent with this model, interference effects are more complete when the purely semantic aspects of these coactive representations are probed (using semantic priming) than when phonological aspects are probed as well (using repetition priming).

Adolescent↗

PubMed2002

Perception of resyllabification in French.

In three experiments, we examined the effects of phonological resyllabification processes on the perception of French speech. Enchainment involves the resyllabification of a word-final consonant across a syllable boundary (e.g., in chaque avion, the /k/ crosses the syllable boundary to become syllable initial). Liaison involves a further process of realization of a latent consonant, alongside resyllabification (e.g., the /t/ in petit avion). If the syllable is a dominant unit of perception in French (Mehler, Dommergues, Frauenfelder, & Segui, 1981), these processes should cause problems for recognition of the following word. A cross-modal priming experiment showed no cost attached to either type of resyllabification in terms of reduced activation of the following word. Furthermore, word- and sequence-monitoring experiments again showed no cost and suggested that the recognition of vowel-initial words may be facilitated when they are preceded by a word that had undergone resyllabification through enchainment or liaison. We examine the sources of information that could underpin facilitation and propose a refinement of the syllable's role in the perception of French speech.

Adult↗