Biomedical subjects

W Marslen-Wilson

Publications and source records attributed to W Marslen-Wilson.

14 recordsLinked to original sources

PubMed2001

Does the medial temporal lobe bind phonological memories?

The medial temporal lobes play a central role in the consolidation of new memories. Medial temporal lesions impair episodic learning in amnesia, and disrupt vocabulary acquisition. To investigate the role of consolidation processes in phonological memory and to understand where and how, in amnesia, these processes begin to fail, we reexamined phonological memory in the amnesic patient HM. While HM's word span performance was normal, his supraspan recall was shown to be markedly impaired, with his recall characterized by a distinctive pattern of phonological errors, where he recombined phonemes from the original list to form new response words. These were similar to errors observed earlier for patients with specifically semantic deficits. Amnesic Korsakoff's patients showed a similar, though much less marked, pattern. We interpret the data in terms of a model of lexical representation where temporal lobe damage disrupts the processes that normally bind semantic and phonological representations.

Aged↗

PubMed2000

The relative time course of semantic and phonological activation in reading Chinese.

The relative time course of semantic and phonological activation was investigated in the context of whether phonology mediates access to lexical representations in reading Chinese. Compound words (Experiment 1) and single-character words (Experiments 2 and 3) were preceded by semantic and phonological primes. Strong semantic priming effects were found at both short (57 ms) and long (200 ms) stimulus onset asynchrony (SOA), but phonological effects were either absent in lexical decision (Experiment 1), were present only at the longer SOA in character decision (Experiment 2) or were equally strong as semantic effects in naming (Experiment 3). Experiment 4 revealed facilitatory or inhibitory effects, depending on SOA, in phonological judgments to character pairs that were not phonologically but semantically related. It was concluded that, in reading Chinese, semantic information in the lexicon is activated at least as early and just as strongly as phonological information.

Adult↗

PubMed2000

Morphological priming: dissociation of phonological, semantic, and morphological factors.

Previous experiments based on a masked-priming paradigm revealed robust morphological priming effects induced by two derivational morphemes in Hebrew: the root and the verbal pattern. However, considering the special characteristics of the masked-priming paradigm, the possible contributions of phonological and/or semantic factors to these morphological effects could not be firmly assessed. In the present study, the role of these factors in morphological priming was examined, using cross-modal presentation. Experiment 1 revealed that priming between morphologically related words in Hebrew is determined by higher level linguistic characteristics and cannot be reduced to phonological overlap. Experiment 2 confirmed that morphological priming occurs in Hebrew even when primes and targets are not semantically related but, nevertheless, increases with semantic similarity. The results support the claim that morphological priming cannot be accounted for by considering semantic and phonological factors alone, and they exemplify the potential of using both masked and cross-modal priming to examine morphological processing.

Adult↗

PubMed1996

Perceptual distance and competition in lexical access.

Two experiments use rhyme priming techniques to explore the decision space for lexical access. The 1st experiment, using intramodal (auditory-auditory) priming, covaried the phonological distance of a spoken rhyme prime (e.g., pomato) from its source word (e.g., tomato) with the presence or absence of close lexical competitors. The results showed strong effects of phonological distance and no significant effects of competitor environment. The 2nd experiment, using ambiguous rhyme primes in a cross-modal (auditory-visual) priming task, showed that phonetically ambiguous primes could fully match their source words, but only in the appropriate lexical environment. The results support a view of lexical access in which the listener's perceptual experience is based on strict requirements for a bottom-up match with the speech input, and in which competitor environment does not directly modulate the on-line goodness-of-fit computation.

Decision Making↗

PubMed1994

Levels of perceptual representation and process in lexical access: words, phonemes, and features.

Three experiments and a simulation study investigate competing featural and phonemic views of the representation of the speech input in access to the mental lexicon. Auditory lexical decision and gating tasks show that the processing consequences of subcategorical mismatches (conflicts between phonetic cues to speech segment identity) depend on the lexical status of the conflicting cues, such that conflicts that only involve nonwords do not disrupt performance. A further study, using a phonetic-decision task with the same stimuli, found the same pattern. A simulation study shows that the interactive activation model TRACE, with top-down feedback to a prelexical phonemic level, does not model these effects successfully. The authors argue instead for a direct access featural model, based on a distributed computational substrate, where featural information is mapped directly onto lexical representations.

Adult↗

PubMed1991

The mental representation of lexical form: a phonological approach to the recognition lexicon.

We propose a psycholinguistic model of lexical processing which incorporates both process and representation. The view of lexical access and selection that we advocate claims that these processes are conducted with respect to abstract underspecified phonological representations of lexical form. The abstract form of a given item in the recognition lexicon is an integrated segmental-featural representation, where all predictable and non-distinctive information is withheld. This means that listeners do not have available to them, as they process the speech input, a representation of the surface phonetic realisation of a given word-form. What determines performance is the abstract, underspecified representation with respect to which this surface string is being interpreted. These claims were tested by studying the interpretation of the same phonological feature, vowel nasality, in two languages, English and Bengali. The underlying status of this feature differs in the two languages; nasality is distinctive only in consonants in English, while both vowels and consonants contrast in nasality in Bengali. Both languages have an assimilation process which spreads nasality from a nasal consonant to the preceding vowel. A cross-linguistic gating study was conducted to investigate whether listeners would interpret nasal and oral vowels differently in two languages. The results show that surface phonetic nasality in the vowel in VN sequences is used by English listeners to anticipate the upcoming nasal consonant. In Bengali, however, nasality is initially interpreted as an underlying nasal vowel. Bengali listeners respond to CVN stimuli with words containing a nasal vowel, until they get information about the nasal consonant. In contrast, oral vowels in both languages are unspecified for nasality and are interpreted accordingly. Listeners in both languages respond with CVN words (which have phonetic nasality on the surface) as well as with CVC words while hearing an oral vowel. The results of this cross-linguistic study support, in detail, the hypothesis that the listener's interpretation of the speech input is in terms of an abstract underspecified representation of lexical form.

Concept Formation↗

PubMed1990

Processing distinctions between stems and affixes: evidence from a non-fluent aphasic patient.

In this paper, we study the ability of a non-fluent aphasic patient, BN, to comprehend morphologically complex words when they appear in utterance contexts. We first establish that he is insensitive to the contextual appropriateness of both derived and inflected words. In a further experiment we show that he has no difficulty processing the stems of complex words and conclude that his problem is with the bound morphemes themselves. We then ask whether this problem is due to his inability to access either the phonological form of a morphologically complex word or its semantic and/or syntactic content. We find that only the access of semantic and syntactic content is impaired. We conclude from these six studies that: (a) BN presents a counter-example to the claim that non-fluent patients have particular difficulty with those aspects of morphology which have a syntactic function; (b) BN processes both derived and inflected words by mapping the sensory input onto the entire full-form of a complex word, but the semantic and syntactic content of the stem alone is accessed and integrated into the context. The semantic and syntactic implications of the suffix are never evaluated. This implies separate representation of the stems and suffixes of some types of morphologically complex words.

Adult↗

PubMed1988