The fast pace and relative ease at which individuals with typical language acquire and use words belie the complexity and vulnerability of lexical representation development (i.e., word learning) and lexical-semantic processing. Lexical-semantic processing impairments are common in both developmental and acquired communication disorders and, even…

Background: Humans often use co-speech gestures to promote effective communication. Attention has been paid to the cortical areas engaged in the processing of co-speech gestures. Aims: To investigate the neural network underpinned in the processing of co-speech gestures and to observe whether there is a relationship between areas involved in…

Primary progressive aphasia (PPA) is an acquired neurodegenerative syndrome that has specific and devastating effects on an individual's speech and language ability. Based on a detailed assessment of behavior and cognition, combined with structural neuroimaging data and pathological evidence, PPA is typically classified into three variants: the…

Purpose: Recovery from aphasia is thought to depend on neural plasticity, that is, functional reorganization of surviving brain regions such that they take on new or expanded roles in language processing. To make progress in characterizing the nature of this process, we need feasible, reliable, and valid methods for identifying language regions of…

Purpose: Brain imaging has provided puzzle pieces in the understanding of language. In neurologically healthy populations, the structure of certain brain regions is associated with particular language functions (e.g., semantics, phonology). In studies on focal brain damage, certain brain regions or connections are considered sufficient or…

Investigating instances where lexical selection fails can lead to deeper insights into the cognitive machinery and architecture supporting successful word retrieval and speech production. In this paper, we used a multiplex lexical network approach that combines semantic and phonological similarities among words to model the structure of the mental…

Background: The ability to generate words that follow certain constraints, or verbal fluency, is a sensitive indicator of neurocognitive impairment, and is impacted by a variety of variables. Aims: To investigate the effect of post-stroke aphasia, elicitation category and linguistic variables on verbal fluency performance. Methods &…

This study examined the time course of object naming in 21 individuals with primary progressive aphasia (PPA) (8 agrammatic (PPA-G); 13 logopenic (PPA-L)) and healthy age-matched speakers (n=17) using a semantic interference paradigm with related and unrelated interfering stimuli presented at stimulus onset asynchronies (SOAs) of -1000, -500, -100…

Previous research on participants with aphasia has mainly been based on standard functional neuroimaging analysis. Recent studies have shown that functional connectivity analysis can detect compensatory activity, not revealed by standard analysis. Little is known, however, about the default-mode network in aphasia. In the current study, we studied…

Current accounts of spoken language assume the existence of a lexicon where wordforms are stored and interact during spoken language perception, understanding and production. Despite the theoretical importance of the wordform lexicon, the exact localization and function of the lexicon in the broader context of language use is not well understood.…

We present a neural network model of learning and processing the English past tense that is based on the notion that experience-dependent cortical development is a core aspect of cognitive development. During learning the model adds and removes units and connections to develop a task-specific final architecture. The model provides an integrated…

Few studies have directly compared the clinical and anatomical characteristics of patients with progressive aphasia to those of patients with aphasia caused by stroke. In the current study we examined fluent forms of aphasia in these two groups, specifically semantic dementia (SD) and persisting Wernicke's aphasia (WA) due to stroke. We compared…

Purpose: To explore whether individuals with aphasia exhibit differences in the M350, an electrophysiological marker of lexical activation, compared with healthy controls. Method: Seven people with aphasia, 9 age-matched controls, and 10 younger controls completed an auditory lexical decision task while cortical activity was recorded with…

The history of the evolution of language assessments for children and adults with language disorders is described briefly. This is followed by a discussion on language assessment of the clinical population with an emphasis on linguistic profiling, illustrated through the Linguistic Profile Test. Discourse analysis, in particular, is highlighted…

Functional magnetic resonance imaging (fMRI) was used to investigate the neural processing characteristics associated with word retrieval abilities after a phonologically-based treatment for anomia in two stroke patients with aphasia. Neural activity associated with a phonological and a semantic task was compared before and after treatment with…