John Ingram

Automatic and volitional semantic processing in aphasia

The present study investigated the status of semantic information in aphasia by comparing the performances of aphasic and nonaphasic subjects on two tasks: an automatic semantic facilitation task and a volitional task of relatedness judgment. Both the aphasic and nonaphasic groups evidenced a semantic facilitation effect, in an on-line task of semantic processing. However, those aphasics with severe comprehension and naming disturbances (termed low comprehension aphasics) demonstrated considerable difficulty in judging the relatedness between a pictured object and members of that objects semantic field, the severity of the impairment being greater for those pictures that the low comprehension aphasics were unable to name. The pattern of results can best be explained by supposing the structural integrity of the store of semantic information in aphasia, and in particular in low comprehension aphasia: information that is retrieved and manipulated in judgment-mediated tasks with considerable difficulty.

An investigation of confrontation naming performance in Alzheimer's dementia as a function of disease severity

Abstract The confrontation naming performance of persons with dementia of the Alzheimers type (DAT) is a widely investigated area, yet considerable confusion remains as to the precise nature of the breakdown, in particular whether the deficit is related to either a procedural or structural semantic deficit that remains uniform over the course of the disease. The present study undertook a detailed error analysis of the naming responses of 23 subjects with DAT, grouped on the basis of their dementia severity into three groups of mild (n = 8), moderate (n = 7), and moderately severe (n = 8), to investigate the pattern of progression of anomia in DAT. The results provided strong support for the proposal that anomia in DAT changes both quantitatively and qualitatively over the course of the disease, with the naming responses of subjects severely affected by the disease reflecting increased compromise of core semantic structures and processes. In the milder stages of DAT, however, the anomia is characterized b...

Accuracy of perception and production of compound and phrasal stress by Vietnamese-Australians

This study considered the accuracy of perception and production of the compound-phrasal contrast by Vietnamese-Australians learning English and examined phonological, demographic, and speaker normalization factors that might influence acquisition of the contrast. In the study, 32 Vietnamese subjects took part; their performance on the perception part of the study was compared to that of 32 native English-speaking Australians. Complexity of phonological environment, in terms of number of syllables and consonant clusters alien to Vietnamese phonology, and length of residence in Australia were found to be the major factors influencing both the perception and production of the contrast. Accuracy of perception and production were highly correlated. Australian subjects, while performing significantly better than Vietnamese subjects on the perception task, nevertheless demonstrated the same pattern of accuracy across different levels of phonological complexity as had the latter.

Strategy-based semantic priming in Alzheimer's dementia

The ability to engage semantic search strategies was assessed in a group of patients with dementia of the Alzheimers type (DAT) (n = 11) and a group of age-matched control subjects (n = 13). The subjects performed a semantic priming task in which attentional priming was induced by manipulating the expected relationship between the primes and targets. Older control subjects were able to predict target words on the basis of expectancy, regardless of the semantic relationship between the prime and target. The DAT patients were also able to predict targets on the basis of expectancy, but only when the prime and target were semantically related. These results suggest that the structure of semantic memory remains intact in DAT, and that semantic memory retrieval may be facilitated by providing DAT patients with appropriate search strategies.

Learning to Predict the Phonological Structure of English Loanwords in Japanese

Loanword formation seems to provide a good test bed for the growing field of computational phonology, since it occurs in a more tightly controlled environment than other language processing tasks. We show how feedforward neural networks and decision trees can be trained to predict the phonological structure of English loanwords in Japanese, and compare the performance of the two paradigms. In each case the system produces a phonemic representation of the Japanese form, after receiving as input the phonological feature matrix of the current and surrounding phonemes. The performance is improved with the inclusion of information about the stress pattern, orthography of reduced vowels and location of word boundaries.

The resolution of lexical ambiguity with reference to context in dementia of the Alzheimer's type

The present study investigated how a dementing illness such as Alzheimers disease, might affect an individuals recourse to higher order contextual information in the access and integration of lexical material in on-line discourse comprehension. More specifically, the experiment investigated the priming of homophones in a discourse context, by use of a cross-modal lexical decision task, and compared the performances of a group of six subjects with mild to moderate dementia of the Alzheimers type (DAT) with those of a matched control group. The subjects listened to 2-sentence paragraphs and performed a lexical decision on visually presented targets that followed ambiguous prime words (or homophones) at two inter-stimulus intervals (ISIs): 330 and 1000 msec. When the target was a word, it was either an associate of the prime word, a probable inference suggested by the discourse, or an unrelated word. The control subjects primed both the discourse-appropriate and discourse-inappropriate associate of the homophone at short (330 msec) ISIs (but not an appropriate inference word), a finding which supports the exhaustive access model of ambiguity resolution. As the ISI was lengthened to 1000 msec, however, the discourse-appropriate inference word was primed, and reflects the operation of attention-dependent integrative strategies. The subjects with DAT primed both appropriate associates and inference words at the short ISI. At ISI of 1000 msec, the DAT subjects primed the appropriate associate and showed substantial inhibition priming of the inappropriate associate. These results point to disturbances in the selective automatic activation of lexical material, and in the conscious integration and elaboration of lexical material in ongoing discourse comprehension in persons with DAT.

Well-formedness judgment: A comparison of offline and online performance in Broca's aphasics

Thc oen itninteureasc ttioo nb eo fa pcreangtmraal tiiscs uaen di ns ymnotadcetlisc ocfo nsestnrtaeinnctse processing. It is well established that object relatives (1) are harder to process than subject relatives (2). Passivization, other things being equal, increases sentence complexity. However, one of the functions of the passive construction is to promote an NP into the role of subject so that it can be more easily bound to the head NP in a higher clause. Thus, (3) is predicted to be marginally preferred over (1). Passiviazation in this instance may be seen as a way of avoiding the object relative construction. 1. The pipe that the traveller smoked annoyed the passengers. 2. The traveller that smoked the pipe annoyed the passengers. 3.The pipe that was smoked by the traveller annoyed the 4.The traveller that the pipe was smoked by annoyed the 5.The traveller that the lady was assaulted by annoyed the In (4) we have relativization of an NP which has been demoted by passivization to the status of a by-phrase. Such relative clauses may only be obtained under quite restrictive pragmatic conditions. Many languages do not permit relativization of a constituent as low as a by-phrase on the NP accessibility hierarchy (Comrie, 1984). The factors which determine the acceptability of demoted NP relatives like (4-5) reflect the ease with which the NP promoted to subject position can be taken as a discourse topic. We explored the acceptability of sentences such as (1-5) using pair-wise judgements of samddifferent meaning, accompanied by ratings of easeof understanding. Results are discussed with reference to Gibsons DLT model of linguistic complexity and sentence processing (Gibson, 2000)0na eg rcarmitimcaal tfieca tcuorem opfr ethhee nospieornat iodneafli cdietf i(nAitiCoDn )o ft hthaet frequently co-occurs with Broca’s aphasia is above-chance performance on well-formedness judgment tasks for many syntactic constructions, but impaired performance where syntactic binding of traces to their antecedents occurs. However, the methodologies used to establish this aspect of the performance profile of the ACD have been predominantly offline. Offline well-formedness tasks entail extralinguistic processing (e.g. perception, attention, short-term memory, conscious reflection) in varying amounts and the influence of such processes on parsing mechanisms is yet to be fully established. In order to (a) further understand the role of extra-linguistic processing on parsing, and (b) gain a more direct insight into the online nature of parsing in Broca’s aphasia, 8 subjects underwent a series of wellformedness judgment investigations using both offline and online test batteries. The sentence types and error types used were motivated by three current theories about the nature of the ACD, namely, the Trace-Based Account (Grodzinsky, 2000), the Mapping Hypothesis (Linebarger et al., 1983) and Capacity proposals (e.g. Frazier & Friederici, 1991). The results from the present investigation speak directly to the three aforementioned theories and also demonstrate the important role that extralinguistic processing plays during offline assessment. The clinical implications of the different outcomes from the offline vs. online tasks are also discussed.

Prosodic boundaries and syntactic branching in Japanese and English

This paper explores communalities and differences in prosodic boundary marking in English and Japanese. Kubozono (1989) observed an interesting asymmetry in Japanese: that the onset of a right branching syntactic constituent is characterized by sudden pitch rise, not observed at the onset of a left‐branching constituent, which he attributed to the phonetic realization rule of a metrical boost. Left‐branching constitutes the unmarked direction of embedding in Japanese phrase structure. English is overwhelmingly right branching in its syntactic structures. The metrical boost proposed by Kubozono is similar to the mechanism of f0 baseline resetting often proposed to explain juncture marking at major phrase boundaries. English has a prosodic asymmetry, parallel to the Japanese case, whereby prosodic boundary marking is required, at the boundary of certain left‐branching constituents. The paper seeks to replicate Kubozono’s observations and to compare the phonetic realization of juncture in Japanese and Englis...

Studies in cross-language speech perception

AbstractThree cross-language experiments are reported investigating aspects of the functional separation of phonetic and phonological levels of processing in speech perception. The first experiment presents additional evidence from French to supplement findings from Bengali, Hindi and English (Lahiri & Marslen-Wilson, 1991; Ohala and Ohala, 1995), on the perception of vowel nasal resonance and its implications for abstract lexical representations and processing strategies in speech perception. The second and third experiments compare Korean and Japanese learners of English on the perception of consonant and vowel contrasts in Australian English, investigating how phonological transfer effects interact with the phonetic discriminability of speech sounds and the normalisation strategies that listeners use to separate linguistic and non-linguistic sources of phonetic variability. These cross-linguistic studies provide new evidence on the relationship between phonetic and phonological levels of processing in ...