Helen J. Chenery

Language disorders in dementia of the Alzheimer type

The language profile of a group of 18 Alzheimer patients is documented and their performance on a standard aphasia test battery compared to a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. The Alzheimer patients scored significantly lower than the controls in the areas of verbal expression, auditory comprehension, repetition, reading, and writing. Articulation abilities were the same in each group. A language deficit was evident in all Alzheimer patients. The language disorder exhibited resembled a transcortical sensory aphasia. Syntax and phonology remained relatively intact but semantic abilities were impaired. The results support the inclusion of a language deficit as a diagnostic criterion of Alzheimers disease.

Conversations Between Carers and People With Schizophrenia: A Qualitative Analysis Using Leximancer

We examined conversations between people with schizophrenia (PwS) and family or professional carers with whom they interacted frequently. We allocated PwS to one of two communication profiles: Low-activity communicators talked much less than their conversational partners, whereas high-activity communicators talked much more. We used Leximancer text analytics software to analyze the conversations. We found that carers used different strategies to accommodate to the PwS’s behavior, depending on the PwS’s communication profile and their relationship. These findings indicate that optimal communication strategies depend on the PwS’s conversational tendencies and the relationship context. They also suggest new opportunities for qualitative assessment via intelligent text analytics technologies.

Language impairment in Parkinson's disease

Abstract Increasingly, researchers and clinicians are beginning to unveil both cognitive and linguistic impairments in Parkinsons disease (PD), a condition characterized in the past primarily by impairment of the motoric aspects of ambulation and speech. This study describes subtle language impairment in 20 subjects with PD on a battery of measures selected to be sensitive to frontal lobe language function. Comparative performances of the PD subjects with an age, gender, and education-matched control group revealed significant performance level differences across several language variables. The PD subject group as a whole, presented with impaired naming and definitional abilities, and difficulties in interpreting ambiguity and figurative language. When the PD subjects were divided on the basis of their score on a cognitive rating scale, PD subjects with below normal cognitive status presented with deficits in naming, definition, and multi-definition abilities, as well as problems in interpreting ambiguit...

Automatic auditory processing of English words as indexed by the mismatch negativity, using a multiple deviant paradigm

Objective: The aim of this study was to investigate mismatch negativity (MMN) responses to a variety of speech stimuli (/de:/, /ge:/, /deI/ “day”, and /geI/ “gay”) in a multiple deviant paradigm. It was hypothesized that all speech stimulus contrasts in the multiple deviant paradigm, including the fine acoustic speech contrast [d/g], would elicit robust MMN responses and that consonant vowel (CV) real word deviants (e.g., “day” and “gay”) would elicit larger MMN responses than CV nonword deviants (e.g., “de” and “ge”) within and across experimental contrasts. Design: Ten healthy, right-handed, native English–speaking adults (23.4 ± 2.27 yr) with normal hearing were presented with 12 blocks of stimuli, using a multiple deviant oddball paradigm. Each of the four speech stimuli were presented as standards (p = 0.7) in three blocks, with the remaining stimuli acting as deviants (p = 0.1 each). Subjects were also presented with the same stimuli in a behavioral discrimination task. Results: MMN responses to the fine acoustic speech contrast [d/g] (e.g., “de” versus “ge”, “day” versus “gay”) did not reach significance. However, a significant and larger MMN response was obtained at an earlier latency to the real word deviants among nonword standards with the same initial consonant (i.e., de→day, ge→gay) when compared with the responses to nonword deviants among word standards (day→de, gay→ge). Conclusions: The results showed that MMN responses could be elicited by speech stimuli with large, single acoustic deviances, within a multiple deviant paradigm design. This result has positive clinical implications for the testing of subjects who may only tolerate short testing sessions (e.g., pathological populations) in that responses to a wider range of speech stimuli may be recorded without necessarily having to increase session length. The results also demonstrated that MMN responses were elicited by large, single acoustic deviances but not fine acoustic deviances within the speech stimuli. The poor results for the fine acoustic deviances support previous studies that have used single contrast paradigms and found that when carefully controlled methodological designs and strict methods of analysis are applied, robust responses to fine-grained CV syllable contrasts may be difficult to obtain. The enhanced MMN observed in response to the real word deviants among nonword standards may provide further evidence for the presence of long-term neural traces for words in the brain, however possible contextual effects limit the interpretation of these data. Further research is needed to investigate the ability of the MMN response to accurately reflect speech sounds with fine acoustic contrasts, as well as the ability of the MMN to reflect neural traces for words in the brain, before it can be reliably used as a clinical tool in the investigation of spoken word processing in pathological populations.

Semantic priming in Parkinson's disease : Evidence for delayed spreading activation

Nineteen persons with Parkinsons disease (PD) and 19 matched control participants completed a battery of online lexical decision tasks designed to isolate the automatic and attentional aspects of semantic activation within the semantic priming paradigm. Results highlighted key processing abnormalities in PD. Specifically, persons with PD exhibited a delayed time course of semantic activation. In addition, results suggest that experimental participants were unable to implicitly process prime information and, therefore, failed to engage strategic processing mechanisms in response to manipulations of the relatedness proportion. Results are discussed in terms of the Gain/Decay hypothesis (Milberg, McGlinchey-Berroth, Duncan, Higgins, 1999) and the dopaminergic modulation of signal to noise ratios in semantic networks.

Perceptual speech characteristics of dysarthric speakers following severe closed head injury

The perceptual speech characteristics of a group of 20 severely closed head-injured (CHI) subjects were compared with those of a normal non-neurologically impaired control group matched for age and sex. The CHI subjects were found to be significantly less intelligible than the controls, and exhibited deficits in the prosodic, resonatory, articulatory, respiratory and phonatory aspects of speech production. The most frequently occurring deviant speech dimensions related to disturbances of prosody, resonance, articulation and respiration, with those deviant speech dimensions pertaining to phonation being less apparent in the speech of the CHI subjects. The findings are discussed in relation to the heterogeneity of the CHI population and the effects of CHI on neuromuscular function. The study highlights the need for accurate, instrumental physiological evaluation of the motor subsystems involved in speech production.

Hemispheric contributions to lexical ambiguity resolution: evidence from individuals with complex language impairment following left-hemisphere lesions.

Nine individuals with complex language deficits following left-hemisphere cortical lesions and a matched control group (n = 9) performed speeded lexical decisions on the third word of auditory word triplets containing a lexical ambiguity. The critical conditions were concordant (e.g., coin-bank-money), discordant (e.g., river-bank-money), neutral (e.g., day-bank-money), and unrelated (e.g., river-day-money). Triplets were presented with an interstimulus interval (ISI) of 100 and 1250 ms. Overall, the left-hemisphere-damaged subjects appeared able to exhaustively access meanings for lexical ambiguities rapidly, but were unable to reduce the level of activation for contextually inappropriate meanings at both short and long ISIs, unlike control subjects. These findings are consistent with a disruption of the proposed role of the left hemisphere in selecting and suppressing meanings via contextual integration and a sparing of the right-hemisphere mechanisms responsible for maintaining alternative meanings.

Dopamine and semantic activation: An investigation of masked direct and indirect priming

To investigate the effects of dopamine on the dynamics of semantic activation, 39 healthy volunteers were randomly assigned to ingest either a placebo (n = 24) or a levodopa (n = 16) capsule. Participants then performed a lexical decision task that implemented a masked priming paradigm. Direct and indirect semantic priming was measured across stimulus onset asynchronies (SOAs) of 250, 500 and 1200 ms. The results revealed significant direct and indirect semantic priming effects for the placebo group at SOAs of 250 ms and 500 ms, but no significant direct or indirect priming effects at the 1200 ms SOA. In contrast, the levodopa group showed significant direct and indirect semantic priming effects at the 250 ms SOA, while no significant direct or indirect priming effects were evident at the SOAs of 500 ms or 1200 ms. These results suggest that dopamine has a role in modulating both automatic and attentional aspects of semantic activation according to a specific time course. The implications of these results for current theories of dopaminergic modulation of semantic activation are discussed.

UNDERSTANDING AMBIGUOUS WORDS IN BIASED SENTENCES: EVIDENCE OF TRANSIENT CONTEXTUAL EFFECTS IN INDIVIDUALS WITH NONTHALAMIC SUBCORTICAL LESIONS AND PARKINSON'S DISEASE*

A cross-modal priming experiment was used to investigate lexical ambiguity resolution during sentence processing in individuals with nonthalamic subcortical lesions (NSL) (n = 10), compared to matched normal controls (n = 10), and individuals with cortical lesions (CL) (n = 10) and Parkinsons disease (PD) (n = 10). Critical sentences biased towards the dominant or subordinate meaning of a sentence-final lexical ambiguity were presented auditorily, followed after a short interstimulus-interval (ISI) (0 msec) or a long ISI (1000 msec), by the presentation of a visual target which was related to the dominant or subordinate meaning, or was an unrelated control word. Subjects made speeded lexical decisions on the targets. At the short ISI, lexical activation for the neurological patient groups appeared influenced by contextual information to a greater extent than in normal controls, which may indicate delayed lexical decision making or disturbed automatic lexical activation. At the long ISI, only the PD and NSL individuals failed to selectively activate the contextually appropriate meaning, suggesting a breakdown in the attention-based control of semantic activation through contextual integration. This finding may implicate disruptions to proposed frontal-striatal mechanisms which mediate attentional allocation and strategy formation.

Assessment in speech-language pathology

This seventh special issue of Language Testingis devoted to a field in which the assessment of linguistic and communicative abilities is a regular and integral activity, but one which to date has not figured highly in the pages of this journal: that of speech–language pathology. Although a small number of articles concerned with speech and language disorders have appeared in Language Testingover the years (see, for example, Fletcher and Peters, 1984; Baker, 1993), this special issue provides the first opportunity to offer readers a set of papers on this theme. There are, of course, central concerns which are common to all areas of assessment, whether this be for purposes of education, professional certification, medical diagnosis or rehabilitation. Readers will thus recognize in these papers the overriding concern with validity, i.e., that the assessment procedures yield information from which speech–language pathologists can make correct inferences regarding the existence, nature and severity of speech and language disturbances in their clients. Further, in speech–language pathology, as in other settings, the uses to which assessment results are put can have important personal, social and vocational consequences. Indeed, the design and provision of appropriate and effective therapy depends, in large part, on the quality of the information obtained from formal or informal assessments, in combination with case-history data. A second set of concerns unites all those who work on the development or investigation of language-assessment procedures in particular. In this category we include such issues as the principled sampling of language content for inclusion in a test, the availability or collection