Lexical Discrimination Research Articles

A - 66 Non-Fluent/Agrammatic Variant of Primary Progressive Aphasia (Nappa) in a Bilingual Chinese Speaker: a Single-Case Study.

The non-fluent/agrammatic variant of primary progressive aphasia (naPPA) is a neurodegenerative syndrome associated with agrammatism in language production and effortful speech (Gorno-Tempini et al., 2011). There is limited literature on PPA in non-English speakers and few clinical cases of bilingual naPPA have been described (Tee et al., 2022; Zanini et al., 2011). Characteristics of symptoms in orthographic languages, such as Chinese, are not well understood (Ting et al., 2017). This case describes the assessment of naPPA in a bilingual Mandarin Chinese speaker. A 66-year-old Asian male with 16years of education complained of worsening aphasia in both languages over two years with initial preferential sparing of Chinese. A comprehensive neuropsychological battery was administered mostly in Chinese with select subtests in English. Language functioning was assessed with the Bilingual Aphasia Screening Test (Paradis & Libben, 1987). Agrammatism and apraxia of speech was present in both languages. Single-word comprehension and object knowledge was preserved, while comprehension of complex commands was impaired. Lexical discrimination of real and nonsense words was preserved. Delayed memory was impaired with relative improvement upon recognition. Attention, processing speed, visuospatial skills, and motor functioning were preserved. Mood was euthymic. This case revealed deficits in both languages with slower decline of the dominant language, suggesting that the less proficient language in bilinguals is more vulnerable to degeneration in naPPA.

Semantic Versus Orthographic Preferences in Aphasia: Behavioral Evidence.

In this study, we compared the orthographic and semantic preferences of healthy adults and age and gender matched adults with aphasia, an acquired language disorder. Previous research in word retrieval and word associations has addressed semantic and phonological connections, but it has not as often included analyses of orthographic skills. We matched (on age and gender) 10 neurotypical adults and 11 older adults with aphasia and administered to both groups a lexical discrimination task requiring them to select, from 18 choices, those words that were most different from three words (daughter, laughter, son). Among the choices were foil words (e.g., daughter), orthographic similarities (laughter) and semantic similarities (son). Results revealed that individuals with aphasia focused on orthographic differences, while healthy adults chose semantic differences. Further studies should further explore this orthographic focus to develop treatment strategies, using behavioral and objective measures, for word-finding deficits in aphasia.

Language as a proxy for cultural change. A contrastive analysis for French and Italian lexicon on male homosexuality

Discrimination against LGBT people represents a significant and long-standing societal problem that occurs in several forms, including lexical discrimination, which consists in frequent usage of discriminatory epithets. Lexical discrimination produces a vicious circle where speakers grow subconsciously accustomed to abusive language and marginalisation becomes institutionalised. A vast literature has tackled lexical discrimination, providing several country-level studies. The cases of France and Italy are described as very different: while the French experience is centred around grassroot mobilisation, Italy features a traditional strategy of silence. This work aims to verify such difference empirically. Using a rich and detailed dataset, we apply time series analysis on the frequencies of usage of the terms that characterise male homosexuality. Our results highlight some similarities and some differences between the French and the Italian case, stressing the importance of lexical resemantisation that occurred in France but not in Italy.

A Processing-Oriented Investigation of Inflectional Complexity

Due to the typological diversity of their inflectional processes, \textcolor{red}{some languages are intuitively more difficult than other languages. Yet, finding a single measure to quantitatively assess the comparative complexity of an inflectional system proves an exceedingly difficult endeavour. In this paper we propose to investigate the issue from a processing-oriented standpoint, using data processed by a type of recurrent neural network to quantitatively model the dynamic of word processing and learning in different input conditions. We evaluate the relative complexity of a set of typologically different inflectional systems (Greek, Italian, Spanish, German, English and Standard Modern Arabic) by training a Temporal Self-Organizing Map (TSOM), a recurrent variant of Kohonen's Self-Organizing Maps, on a fixed set of verb forms from top-frequency verb paradigms, with no information about the morphosemantic and morphosyntactic content conveyed by the forms. After training, the behavior of each language-specific TSOM is assessed on different tasks, looking at self-organizing patterns of temporal connectivity and functional responses. Our simulations show that word processing is facilitated by maximally contrastive inflectional systems, where verb forms exhibit the earliest possible point of lexical discrimination. Conversely, word learning is favored by a maximally generalizable system, where forms are inferred from the smallest possible number of their paradigm companions. Based on evidence from the literature and our own data, we conjecture that the resulting balance is the outcome of the interaction between form frequency and morphological regularity. Big families of stem-sharing, regularly inflected forms are the productive core of an inflectional system. Such a core is easier to learn but slower to discriminate. In contrast, less predictable verb forms, based on alternating and possibly suppletive stems, are easier to process but are learned by rote. Inflection systems thus strike a balance between these conflicting processing and communicative requirements, while staying within tight learnability bounds, in line with Ackermann and Malouf's Low Conditional Entropy Conjecture. Our quantitative investigation supports a discriminative view of morphological inflection as a collective, emergent system, whose global self-organization rests on a surprisingly small handful of language-independent principles of word coactivation and competition.

Looking up improves performance in verbal tasks

ABSTRACTEarlier research suggested that gaze direction has an impact on cognitive processing. It is likely that horizontal gaze direction increases activation in specific areas of the contralateral cerebral hemisphere. Consistent with the lateralization of memory functions, we previously showed that shifting gaze to the left improves visuo-spatial short-term memory. In the current study, we investigated the effect of unilateral gaze on verbal processing. We expected better performance with gaze directed to the right because language is lateralized in the left hemisphere. Also, an advantage of gaze directed upward was expected because local processing and object recognition are facilitated in the upper visual field. Observers directed their gaze at one of the corners of the computer screen while they performed lexical decision, grammatical gender and semantic discrimination tasks. Contrary to expectations, we did not observe performance differences between gaze directed to the left or right, which is consistent with the inconsistent literature on horizontal asymmetries with verbal tasks. However, RTs were shorter when observers looked at words in the upper compared to the lower part of the screen, suggesting that looking upwards enhances verbal processing.

Corrigendum to “Learning transforms functional organization for Mandarin lexical tone discrimination in the brain: Evidence from a MEG experiment on second language learning” [J. Neurolinguistics, 42 (2017) 124–139

Corrigendum to “Learning transforms functional organization for Mandarin lexical tone discrimination in the brain: Evidence from a MEG experiment on second language learning” [J. Neurolinguistics, 42 (2017) 124–139

Lexical tonal discrimination in Zapotec children. A study of the theta rhythm

Lexical tonal discrimination in Zapotec children. A study of the theta rhythm

Lexical tonal discrimination in Zapotec children. A study of the theta rhythm

BackgroundZapotec is a language used mainly in the state of Oaxaca in Mexico of tonal characteristic; homophone words with difference in fundamental frequency with different meanings. Our objective was to analyze changes in the electroencephalographic (EEG) theta rhythm during word discrimination of lexical tonal bi-syllabic homophone word samples of Zapotec. MethodsWe employed electroencephalography analysis during lexical tonal discrimination in 12 healthy subjects 9-16 years of age. ResultsWe observed an increase in theta relative power between lexical discrimination and at rest eyes-open state in right temporal site. We also observed several significant intra- and inter-hemispheric correlations in several scalp sites, mainly in left fronto-temporal and right temporal areas when subjects were performing lexical discrimination. ConclusionsOur data suggest more engagement of neural networks of the right hemisphere are involved in Zapotec language discrimination.

Neural distance amplification of lexical tone in human auditory cortex.

In tonal languages, like Chinese, lexical tone serves as a key feature to provide contrast in word meaning. Behavior studies suggest that Mandarin Chinese tone is categorically perceived. However, the neural mechanism underlying Mandarin tone perception is still poorly understood. In this study, an Oddball paradigm was designed by selecting two standard-deviant stimulus pairs with same physical distance but different category labels, among the synthesized tones with continuously varying pitch contours. Using electrocorticography (ECoG) recording over human auditory cortex, high temporal and spatial resolution cortical neural signals were used for the first time to investigate the cortical processing of lexical tone. Here, we found different neural responses to the two standard-deviant tone pairs, and the difference increased from low to high level along the hierarchy of human auditory cortex. In the two dimensional neural space, cross-category neural distance of lexical tones is selectively amplified on those high level electrodes. These findings support a hierarchical and categorical model of Mandarin tone perception, and favor the using of high-level electrodes for a better performance of lexical tone discrimination in speech brain computer interface.

Cue weight in the perception of Trique glottal consonants.

This paper examines the perceptual weight of cues to the coda glottal consonant contrast in Trique (Oto-Manguean) with native listeners. The language contrasts words with no coda (/Vː/) from words with a coda glottal stop (/VɁ/) or breathy coda (/Vɦ/). The results from a speeded AX (same-different) lexical discrimination task show high accuracy in lexical identification for the /Vː/-/Vɦ/ contrast, but lower accuracy for the other contrasts. The second experiment consists of a labeling task where the three acoustic dimensions that distinguished the glottal consonant codas in production [duration, the amplitude difference between the first two harmonics (H1-H2), and F0] were modified orthogonally using step-wise resynthesis. This task determines the relative weight of each dimension in phonological categorization. The results show that duration was the strongest cue. Listeners were only sensitive to changes in H1-H2 for the /Vː/-/Vɦ/ and /Vː/-/VɁ/ contrasts when duration was ambiguous. Listeners were only sensitive to changes in F0 for the /Vː/-/Vɦ/ contrast when both duration and H1-H2 were ambiguous. The perceptual cue weighting for each contrast closely matches existing production data [DiCanio (2012 a). J. Phon. 40, 162-176] Cue weight differences in speech perception are explained by differences in step-interval size and the notion of adaptive plasticity [Francis et al. (2008). J. Acoust. Soc. Am. 124, 1234-1251; Holt and Lotto (2006). J. Acoust. Soc. Am. 119, 3059-3071].

Assessing spoken word recognition in children who are deaf or hard of hearing: a translational approach.

Under natural conditions, listeners use both auditory and visual speech cues to extract meaning from speech signals containing many sources of variability. However, traditional clinical tests of spoken word recognition routinely employ isolated words or sentences produced by a single talker in an auditory-only presentation format. The more central cognitive processes used during multimodal integration, perceptual normalization, and lexical discrimination that may contribute to individual variation in spoken word recognition performance are not assessed in conventional tests of this kind. In this article, we review our past and current research activities aimed at developing a series of new assessment tools designed to evaluate spoken word recognition in children who are deaf or hard of hearing. These measures are theoretically motivated by a current model of spoken word recognition and also incorporate "real-world" stimulus variability in the form of multiple talkers and presentation formats. The goal of this research is to enhance our ability to estimate real-world listening skills and to predict benefit from sensory aid use in children with varying degrees of hearing loss.

Using a maze task to track lexical and sentence processing

A word maze consists of a sequence of frames, each containing two alternatives. Subjects are required to select one of those alternatives according to some criterion defined by the experimenter. This simple technique can be used to investigate a wide range of issues. For example, if one alternative is a word and the other is a nonword, the subject may be required to press a key to indicate where the word is. This provides an interesting variant of the lexical decision task, since the difficulty of the lexical discrimination can be manipulated on a trial-by-trial basis by varying the properties of the nonword alternative. On the other hand, a version of a self-paced reading task is created if each successive frame contains a word that can continue a sentence, and the subject is required to identify which word that is. Once again, by manipulating the properties of the incorrect alternative one may be able to control the mode of processing adopted by the subject. Although this is a highly artificial form of reading, it does allow one to study the sentence processing under more tightly controlled conditions.

Evidence of deficient central speech processing in children with specific language impairment: The T-complex

Objective This paper examined neurophysiological correlates of speech in children with language impairment (LI) and typical language development (TLD) across four experiments using different speech stimuli and tasks. Methods The T-complex event-related potential (ERP) components and other ERP components (e.g., mismatch negativity [MMN]; N400) were examined. A subset of the children participated in more than one of the experiments. Results 73% of the children with LI had poor T-complex measures compared to only 13% of children with TLD. The T-complex measures were more comparable, in terms of indicating typical versus deviant processing, to neurophysiological measures of language processing, such as lexical discrimination, than to other measures of auditory and speech processing, such as the MMN. Only one LI child showed no poor measures and 64% showed three or more poor neurophyisological measures. However, 50% of children with TLD showed no poor neurophysiological measures, and 82% of the TLD children showed no more than two poor measures. Conclusions These results suggest that poor auditory processing, as measured by the T-complex, is a marker for LI and that multiple deficits serve to mark LI. Significance The T-complex measures, indexing secondary auditory cortex, reflect an important aspect of processing in speech and language development.

Lexical Neighborhood Density Effects on Spoken Word Recognition and Production in Healthy Aging

We examined the effects of lexical competition and word frequency on spoken word recognition and production in healthy aging. Older (n = 16) and younger adults (n = 21) heard and repeated meaningful English sentences presented in the presence of multitalker babble at two signal-to-noise ratios, +10 and -3 dB. Each sentence contained three keywords of high or low word frequency and phonological neighborhood density (ND). Both participant groups responded less accurately to high- than low-ND stimuli; response latencies (from stimulus offset to response onset) were longer for high- than low-ND sentences, whereas response durations-time from response onset to response offset-were longer for low- than high-ND stimuli. ND effects were strongest for older adults in the most difficult conditions, and ND effects in accuracy were related to inhibitory function. The results suggest that the sentence repetition task described here taps the effects of lexical competition in both perception and production and that these effects are similar across the life span, but that accuracy in the lexical discrimination process is affected by declining inhibitory function in older adults.

FMRI study of language activation in schizophrenia, schizoaffective disorder and in individuals genetically at high risk

Background Structural and functional abnormalities have been found in language-related brain regions in patients with schizophrenia. We previously reported findings pointing to differences in word processing between people with schizophrenia and individuals who are at high-risk for schizophrenia using a voxel-based (whole brain) fMRI approach. We now extend this finding to specifically examine functional activity in three language related cortical regions using a larger cohort of individuals. Method A visual lexical discrimination task was performed by 36 controls, 21 subjects at high genetic-risk for schizophrenia, and 20 patients with schizophrenia during blood oxygenation level dependent (BOLD) fMRI scanning. Activation in bilateral inferior frontal gyri (Brodmann's area 44–45), bilateral inferior parietal lobe (Brodmann's area 39–40), and bilateral superior temporal gyri (Brodmann's area 22) was investigated. For all subjects, two-tailed Pearson correlations were calculated between the computed laterality index and a series of cognitive test scores determining language functioning. Results Regional activation in Brodmann's area 44–45 was left lateralized in normal controls, while high-risk subjects and patients with schizophrenia or schizoaffective disorder showed more bilateral activation. No significant differences among the three diagnostic groups in the other two regions of interest (Brodmann's area 22 or areas 39–40) were found. Furthermore, the apparent reasons for loss of leftward language lateralization differed between groups. In high-risk subjects, the loss of lateralization was based on reduced left hemisphere activation, while in the patient group, it was due to increased right side activation. Language ability related cognitive scores were positively correlations with the laterality indices obtained from Brodmann's areas 44–45 in the high-risk group, and with the laterality indices from Brodmann's areas 22 and 44–45 in the patient group. Conclusions This study reinforces previous language related imaging studies in high-risk subjects and patients with schizophrenia suggesting that reduced functional lateralization in language related frontal cortex may be a vulnerability marker for schizophrenia. Future studies will determine whether it is predictive of who develops illness.

Lexical semantics' discrimination between ‘登’ and ‘上’ of raising movement verbs

Lexical semantics' discrimination between ‘登’ and ‘上’ of raising movement verbs

Isolating Rule- versus Evidence-Based Prefrontal Activity during Episodic and Lexical Discrimination: a Functional Magnetic Resonance Imaging Investigation of Detection Theory Distinctions

Dorsolateral and frontopolar prefrontal cortices (PFCs) are often implicated in neuroimaging studies of memory retrieval, with this activity ascribed to controlled monitoring processes indicative of difficult or demanding retrieval. Difficulty, however, is multiply determined, with success rates governed both by the available evidence and by the nature of decision rules applied to that evidence. Using event-related functional magnetic resonance imaging, we isolated these factors by 1) contrasting different decision rules across matched evidence and 2) manipulating the level of evidence within a fixed decision rule. For identically constructed retrieval probes (1 old and 1 new item), same-different (are these different?) compared with forced-choice (which one is old?) decision rules yielded bilateral dorsolateral and right frontopolar PFC increases. However, these regions were unaffected when the available evidence was greatly lowered within forced-choice decisions. Thus, the regions were simultaneously sensitive to the type of decision rule and yet insensitive to the level of evidence supporting those decisions. Analogous lexical tasks yielded similar patterns, demonstrating that the PFC responses were not episodic memory specific. We discuss the mechanistic differences between same-different versus forced-choice decisions and the implications of these data for current theories of PFC activity during episodic remembering and executive control.

Representational specificity of within-category phonetic variation in the mental lexicon

This study examines whether within-category variation in voice onset time (VOT) is encoded in long-term memory and affects subsequent word recognition, and whether these effects are modulated by the degree of lexical discriminability. Four long-term repetition-priming experiments were conducted using words containing word-initial voiceless stops varying in VOT. The magnitude of priming was compared between same and different VOT conditions in words with voiced counterparts (pat/bat) and words without voiced counterparts (cow/*gow), and in words with high-frequency counterparts (clue/glue) and words with low-frequency counterparts (cab/gab). If veridical representations of each episode are preserved in memory, variation in VOT should have demonstrable effects on the magnitude of priming. However, if within-category variation is discarded and form-based representations are abstract, variation in VOT should not mediate priming. Further, if lexical discriminability modulates the degree of encoding of within-category variation, words with counterparts and words with high-frequency counterparts should show larger specificity effects than words without counterparts and words with low-frequency counterparts. Implications of these results for the specificity and abstractness of phonetic representations in long-term memory will be discussed.

Representational specificity of within-category phonetic variation in the mental lexicon

This study examines (1) whether within-category phonetic variation in voice onset time (VOT) is encoded in long-term memory and has consequences for subsequent word recognition and, if so, (2) whether such effects are greater in words with voiced counterparts (pat/bat) than those without (cow/*gow), given that VOT information is more critical for lexical discrimination in the former. Two long-term repetition priming experiments were conducted using words containing word-initial voiceless stops varying in VOT. Reaction times to a lexical decision were compared between the same and different VOT conditions in words with or without voiced counterparts. If veridical representations of each episode are preserved in memory, variation in VOT should have demonstrable effects on the magnitude of priming. However, if within-category variation is discarded and form-based representations are abstract, the variation in VOT should not mediate priming. The implications of these results for the specificity and abstractness of phonetic representations in long-term memory will be discussed.

Intrasubject variability of cognitive and word retrieval performance across six sessions

Florida State University, Tallahassee, FL 32306, USAA burgeoning interest appears to be developing in understandingthe nature and interactions between aphasia and nonlinguistic cogni-tive factors such as attention and working memory (Caspari, Parkin-son, LaPointe, & Katz, 1998; Erickson, Goldfinger, & LaPointe, 1996;Helm-Estabrooks, 2002; LaPointe & Erickson, 1991; Murray, 1999).Others (Hoffmann, 2001; Hochstenbach, Mulder, van Limbeek,Donders, & Schoonderwaldt, 1998) have noted the strong presence ofcognitive decline after stroke and commented on how marked slownessof information processing could impact linguistic performance.Some researchers (McNeil et al., 1991) have integrated disturbancesof cognitive processing into cognitive resource allocation models ofaphasia and suggested that the intrasubject variability of languageperformance seen in aphasia might be explained by fluctuating cog-nitive performance. Disturbances in word retrieval and lexical-se-mantic processing remains one of the hallmarks of aphasia andexplanations of variability across these domains also have been enig-matic (Moreno, Buchanan, & Van Orden, 2002; Nespoulous, Villiard,& Lecours, 1989). Despite the growing archive of research on cogni-tive-linguistic interactions, the sources of variability in aphasia remainelusive and unclearly understood. More elementally, the nature andrelationship of intrasubject variability on cognitive and word retrievaltasks across repeatedsessions of assessmentis relatively unstudied. Thepurpose of this study is twofold:1. To describe the variability of four individuals with aphasia on in-depth tasks of word retrieval and cognitive processing performanceacross six sessions of assessment.2. To explore the pattern of correlation and variability among wordretrieval and cognitive processing tasks across six sessions to deter-mine if changes in word retrieval across test sessions can be pre-dicted by changes in cognitive processing performance.MethodsParticipantsFour individuals with aphasia were recruited for this study andvolunteered to participate in six assessment sessions each. Our parti-cipants all suffered a single, left hemisphere thromboembolic CVA andwere mildly to moderately impaired in language as measured by theWestern Aphasia Battery and other standardized measures of languageimpairment. Participants were classified as having non-fluent, Broca’s-type aphasia. They ranged in age from 34 to 66 with a mean of 58.6.All were right handed pre-morbidly, were judged to be neurologicallystable beyond the acute epoch, and ranged in time post onset from 3months to several years. All participants were male.MeasuresSerialperformanceontheprinciplemeasuresincludedthefollowing:Cognitive measure: A computerized assessment protocol was se-lectedthatmeasuresthefollowingcognitiveskillsinthevisualmodality:• simple reaction time• choice reaction time• serial pattern matching• lexical discrimination• visual selective attention• response reversal with rapid visual scanning• abstract form discriminationThis measure has been standardized on a large group of non-braindamaged subjects and a variety of clinical populations (Miller, 1990;1995). The battery measures and records reaction times in millisecondsas well as accuracy across the 10 subtests of the full battery. Signaldetection analysis and accuracy corrected for false positives is alsorecorded and summarized.Word retrieval measure: The Test of Adolescent/Adult WordFinding (TAWF) (German, 1990). The complete TAWF batterymeasures naming nouns, verbs, sentence completion, naming to de-scription, and naming categories. Accuracy as well as latency of re-sponses is recorded.The measures were administered in counterbalanced order. The sixsessions for each participant were accomplished with approximatelyweekly sessions over a six-week period.ResultsFig. 1 presents the group means for the word retrieval scores (totalperformance for all TAWF subtests) as well as the group means for allof the CalCap cognitive processing subtests across the six sessions ofadministration. Description and analysis of performance across theindividual subtests and for individual subjects also will be presented.Spearman’s coefficient of correlation for word retrieval (groupTAWF total scores) and group CalCap reaction times was ).886(p = .028). Spearman’s r value for word retrieval and CalCap accuracywas ).08 (n.s.).