No Right to Speak? The Relationship between Object Naming and Semantic Impairment:Neuropsychological Evidence and a Computational Model

The processes required for object naming were addressed in a study of patients with semantic dementia (a selective decline of semantic memory resulting from progressive temporal lobe atrophy) and in a computational model of single-word production. Although all patients with semantic dementia are impaired in both single-word production and comprehension, previous reports had indicated two different patterns: (a) a parallel decline in accuracy of naming and comprehension, with frequent semantic naming errors, suggesting a purely semantic basis for the anomia and (b) a dramatic progressive anomia. Longitudinal data for 16 patients with semantic dementia reflected these two profiles, but with the following additional important specifications: (1)despite a few relatively extreme versions of one or other profile, the full set of cases formed a continuum in the extent of anomia for a given degree of degraded comprehension; (2) the degree of disparity between these two abilities was associated with relative asymmetry in laterality of atrophy: a parallel decline in the two measures characterized patients with greater right-than left-temporal atrophy, while disproportionate anomia occurred with a predominance of atrophy in the left-temporal lobe. In an implemented computational model of naming, semantic representations were distributed across simulated left-and right-temporal regions, but the semantic units on the left were more strongly connected to left-lateralized phonological representations. Asymmetric damage to semantic units reproduced the longitudinal patient profiles of naming relative to comprehension, plus additional characteristics of the patients' naming performance. On the basis of both the neuropsychological and computational evidence, we propose that semantic impairment alone can account for the full range of word production deficits described here.

Download Full-text

Word form retrieval in language production

The Oxford Handbook of Psycholinguistics ◽

10.1093/oxfordhb/9780198568971.013.0028 ◽

2007 ◽

pp. 470-488 ◽

Cited By ~ 2

Author(s):

Antje S. Meyer ◽

Eva Belke

Keyword(s):

Language Production ◽

Knowledge Building ◽

Word Production ◽

Word Form ◽

Lexical Selection ◽

Single Word ◽

Phonological Representations ◽

Phonological Knowledge ◽

Phonetic Code ◽

Selection Of

Current models of word form retrieval converge on central assumptions. They all distinguish between morphological, phonological, and phonetic representations and processes; they all assume morphological and phonological decomposition, and agree on the main processing units at these levels. In addition, all current models of word form postulate the same basic retrieval mechanisms: activation and selection of units. Models of word production often distinguish between processes concerning the selection of a single word unit from the mental lexicon and the retrieval of the associated word form. This article explores lexical selection and word form retrieval in language production. Following the distinctions in linguistic theory, it discusses morphological encoding, phonological encoding, and phonetic encoding. The article also considers the representation of phonological knowledge, building of phonological representations, segmental retrieval, retrieval of metrical information, generating the phonetic code of words, and a model of word form retrieval.

Download Full-text

Distinctions between two phonological output deficits

Applied Psycholinguistics ◽

10.1017/s0142716400006986 ◽

1994 ◽

Vol 15 (1) ◽

pp. 75-95 ◽

Cited By ~ 40

Author(s):

Susan E. Kohn ◽

Katherine L. Smith

Keyword(s):

Behavioral Pattern ◽

Word Production ◽

Phonological Encoding ◽

Single Word ◽

Phonological Representations ◽

Behavioral Features ◽

Phonemic Representations ◽

Two Stages ◽

Phonological Activation ◽

Phonological System

ABSTRACTTwo aphasics with a similar level of phonological production difficulty are compared to distinguish the properties of disruption to two stages in the phonological system for producing single words: activation of stored lexical-phonological representations versus construction of phonemic representations. A set of distinguishing behavioral features for breakdown at each stage is generated on the basis of a model of single word production. Important variables for analyzing output include: (a) the unit of phonological encoding (morpheme versus syllable), (b) the phonemic relationship between targets and responses, (c) the effects of target consonant-vowel (CV) structure, and (d) the level of pseudoword production. On a set of production tests, the expected behavioral pattern for impaired lexical-phonological activation was displayed by LW, while the expected behavioral pattern for impaired phonemic planning was displayed by CM.

Download Full-text

Dual Task Interference in Single Word Production

PsycEXTRA Dataset ◽

10.1037/e501882009-499 ◽

2000 ◽

Author(s):

Victor S. Ferreira ◽

Harold Pashler

Keyword(s):

Dual Task ◽

Word Production ◽

Single Word ◽

Task Interference ◽

Dual Task Interference

Download Full-text

Defective production and recognition of actions in Pick's disease with temporal lobe atrophy (semantic dementia)

Higher Brain Function Research ◽

10.2496/hbfr.29.268 ◽

2009 ◽

Vol 29 (2) ◽

pp. 268-276 ◽

Cited By ~ 1

Author(s):

Masaki Kondo ◽

Satoshi Mochizuki ◽

Mutsutaka Kobayakawa ◽

Natsuko Tsuruya ◽

Mitsuru Kawamura

Keyword(s):

Temporal Lobe ◽

Semantic Dementia ◽

Pick's Disease ◽

Pick’S Disease ◽

Lobe Atrophy

Download Full-text

Anhedonia in Semantic Dementia—Exploring Right Hemispheric Contributions to the Loss of Pleasure

Brain Sciences ◽

10.3390/brainsci11080998 ◽

2021 ◽

Vol 11 (8) ◽

pp. 998

Author(s):

Siobhán R. Shaw ◽

Hashim El-Omar ◽

Siddharth Ramanan ◽

Olivier Piguet ◽

Rebekah M. Ahmed ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Temporal Lobe ◽

Rating Scale ◽

Right Hemisphere ◽

Semantic Knowledge ◽

Semantic Dementia ◽

Anterior Cingulate ◽

Functional Impairments ◽

Lobe Atrophy

Semantic dementia (SD) is a younger-onset neurodegenerative disease characterised by progressive deterioration of the semantic knowledge base in the context of predominantly left-lateralised anterior temporal lobe (ATL) atrophy. Mounting evidence indicates the emergence of florid socioemotional changes in SD as atrophy encroaches into right temporal regions. How lateralisation of temporal lobe pathology impacts the hedonic experience in SD remains largely unknown yet has important implications for understanding socioemotional and functional impairments in this syndrome. Here, we explored how lateralisation of temporal lobe atrophy impacts anhedonia severity on the Snaith–Hamilton Pleasure Scale in 28 SD patients presenting with variable right- (SD-R) and left-predominant (SD-L) profiles of temporal lobe atrophy compared to that of 30 participants with Alzheimer’s disease and 30 healthy older Control participants. Relative to Controls, SD-R but not SD-L or Alzheimer’s patients showed clinically significant anhedonia, representing a clear departure from premorbid levels. Overall, anhedonia was more strongly associated with functional impairment on the Frontotemporal Dementia Functional Rating Scale and motivational changes on the Cambridge Behavioural Inventory in SD than in Alzheimer’s disease patients. Voxel-based morphometry analyses revealed that anhedonia severity correlated with reduced grey matter intensity in a restricted set of regions centred on right orbitofrontal and temporopolar cortices, bilateral posterior temporal cortices, as well as the anterior cingulate gyrus and parahippocampal gyrus, bilaterally. Finally, regression and mediation analysis indicated a unique role for right temporal lobe structures in modulating anhedonia in SD. Our findings suggest that degeneration of predominantly right-hemisphere structures deleteriously impacts the capacity to experience pleasure in SD. These findings offer important insights into hemispheric lateralisation of motivational disturbances in dementia and suggest that anhedonia may emerge at different timescales in the SD disease trajectory depending on the integrity of the right hemisphere.

Download Full-text

Computational model of medial temporal lobe epilepsy

BMC Neuroscience ◽

10.1186/1471-2202-16-s1-p144 ◽

2015 ◽

Vol 16 (Suppl 1) ◽

pp. P144

Author(s):

Sora Ahn ◽

Sangbeom Jun ◽

Hyang Lee ◽

Seungjun Lee

Keyword(s):

Temporal Lobe Epilepsy ◽

Computational Model ◽

Temporal Lobe ◽

Medial Temporal Lobe ◽

Medial Temporal Lobe Epilepsy

Download Full-text

Left posterior temporal cortex is sensitive to syntax within conceptually matched Arabic expressions

Scientific Reports ◽

10.1038/s41598-021-86474-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Suhail Matar ◽

Julien Dirani ◽

Alec Marantz ◽

Liina Pylkkänen

Keyword(s):

Temporal Lobe ◽

Temporal Cortex ◽

Syntactic Complexity ◽

Conceptual Combination ◽

Single Word ◽

Grammatical Structure ◽

Neural Basis ◽

Word Meanings ◽

Left Posterior ◽

Vary Structure

AbstractDuring language comprehension, the brain processes not only word meanings, but also the grammatical structure—the “syntax”—that strings words into phrases and sentences. Yet the neural basis of syntax remains contentious, partly due to the elusiveness of experimental designs that vary structure independently of meaning-related variables. Here, we exploit Arabic’s grammatical properties, which enable such a design. We collected magnetoencephalography (MEG) data while participants read the same noun-adjective expressions with zero, one, or two contiguously-written definite articles (e.g., ‘chair purple’; ‘the-chair purple’; ‘the-chair the-purple’), representing equivalent concepts, but with different levels of syntactic complexity (respectively, indefinite phrases: ‘a purple chair’; sentences: ‘The chair is purple.’; definite phrases: ‘the purple chair’). We expected regions processing syntax to respond differently to simple versus complex structures. Single-word controls (‘chair’/‘purple’) addressed definiteness-based accounts. In noun-adjective expressions, syntactic complexity only modulated activity in the left posterior temporal lobe (LPTL), ~ 300 ms after each word’s onset: indefinite phrases induced more MEG-measured positive activity. The effects disappeared in single-word tokens, ruling out non-syntactic interpretations. In contrast, left anterior temporal lobe (LATL) activation was driven by meaning. Overall, the results support models implicating the LPTL in structure building and the LATL in early stages of conceptual combination.

Download Full-text

Word comprehension in temporal cortex and Wernicke area

Neurology ◽

10.1212/wnl.0000000000006788 ◽

2018 ◽

Vol 92 (3) ◽

pp. e224-e233 ◽

Cited By ~ 6

Author(s):

M.-Marsel Mesulam ◽

Benjamin M. Rader ◽

Jaiashre Sridhar ◽

Matthew J. Nelson ◽

Jungmoon Hyun ◽

...

Keyword(s):

Temporal Lobe ◽

Sentence Comprehension ◽

Single Case ◽

Temporal Cortex ◽

Primary Progressive Aphasia ◽

Single Word ◽

Word Comprehension ◽

Cerebrovascular Lesions ◽

Core Components

ObjectiveTo explore atrophy–deficit correlations of word comprehension and repetition in temporoparietal cortices encompassing the Wernicke area, based on patients with primary progressive aphasia (PPA).MethodsCortical thickness in regions within and outside the classical Wernicke area, measured by FreeSurfer, was correlated with repetition and single word comprehension scores in 73 right-handed patients at mild to moderate stages of PPA.ResultsAtrophy in the Wernicke area was correlated with repetition (r = 0.42, p = 0.001) but not single word comprehension (r = −0.072, p = 0.553). Correlations with word comprehension were confined to more anterior parts of the temporal lobe, especially its anterior third (r = 0.60, p < 0.001). A single case with postmortem autopsy illustrated preservation of word comprehension but not repetition 6 months prior to death despite nearly 50% loss of cortical volume and severe neurofibrillary degeneration in core components of the Wernicke area.ConclusionsTemporoparietal cortices containing the Wernicke area are critical for language repetition. Contrary to the formulations of classic aphasiology, their role in word and sentence comprehension is ancillary rather than critical. Thus, the Wernicke area is not sufficient to sustain word comprehension if the anterior temporal lobe is damaged. Traditional models of the role of the Wernicke area in comprehension are based almost entirely on patients with cerebrovascular lesions. Such lesions also cause deep white matter destruction and acute network diaschisis, whereas progressive neurodegenerative diseases associated with PPA do not. Conceptualizations of the Wernicke area that appear to conflict, therefore, can be reconciled by considering the hodologic and physiologic differences of the underlying lesions.

Download Full-text