We report the development of a core lexicon, differences in core-lexicon usage between speakers, and the relationship between core-lexicon and main-concept scores. Research is needed to determine the clinical utility and psychometric properties of these discourse measures and their potential contribution to multilevel discourse analysis of functional communication.
Purpose
The purposes of this study are to provide clinicians and researchers with introductory psychometric data for the main concept analysis (MCA), a measure of discourse informativeness, and specifically, to provide descriptive and comparative statistical information about the performance of a large sample of persons not brain injured (PNBIs) and persons with aphasia (PWAs) on AphasiaBank discourse tasks.
Method
Transcripts of 5 semi-spontaneous discourse tasks were retrieved from the AphasiaBank database and scored according to detailed checklists and scoring procedures. Transcripts from 145 PNBIs and 238 PWAs were scored; descriptive statistics, median tests, and effect sizes are reported.
Results
PWAs demonstrated overall lower informativeness scores and more frequent production of statements that were inaccurate and/or incomplete. Differences between PNBIs and PWAs were observed for all main concept measures and stories. Comparisons of PNBIs and aphasia subtypes revealed significant differences for all groups, although the pattern of differences and strength of effect sizes varied by group and discourse task.
Conclusions
These results may improve the investigative and clinical utility of the MCA by providing descriptive and comparative information for PNBIs and PWAs for standardized discourse tasks that can be reliably scored. The results indicate that the MCA is sensitive to differences in discourse as a result of aphasia.
Supplemental Material
https://doi.org/10.23641/asha.7485647
The infralimbic (IL) cortex is a key node in an inter-connected network involved in fear and emotion processing. The cellular and circuit-level mechanisms whereby IL neurons receive, filter, and modulate incoming signals they project onward to diverse downstream nodes in this complex network remain poorly understood. Using the mouse as our model, we applied anatomical labeling strategies, brain slice electrophysiology, and focal activation of caged glutamate via laser scanning photostimulation (glu-LSPS) for quantitative neurophysiological analysis of projectionally defined neurons in IL. Injection of retrograde tracers into the periaqueductal gray (PAG) and basolateral amygdala (BLA) was used to identify cortico-PAG (CP) and cortico-BLA (CA) neurons in IL. CP neurons were found exclusively in layer 5 (L5) of IL whereas CA neurons were detected throughout layer 2, 3, and 5 of IL. We also identified a small percentage of IL neurons that project to both the PAG and the BLA. We found that L5 CP neurons have a more extensive dendritic structure compared to L5 CA neurons. Neurophysiological recordings performed on retrogradely labeled neurons in acute brain slice showed that CP and CA neurons in IL could be broadly classified in two groups: neuronal resonators and non-resonators. Layer 2 CA neurons were the only class that was exclusively non-resonating. CP, CA, and CP/CA neurons in layers 3 and 5 of IL consisted of heterogeneous populations of resonators and non-resonators showing that projection target is not an exclusive predictor of intrinsic physiology. Circuit mapping using glu-LSPS revealed that the strength and organization of local excitatory and inhibitory inputs were stronger to CP compared to CA neurons in IL. Together, our results establish an organizational scheme linking cellular neurophysiology with microcircuit parameters of defined neuronal subclasses in IL that send descending commands to subcortical structures involved in fear behavior.
Individuals with aphasia who score above the WAB-R Aphasia Quotient cutoff demonstrate discourse impairments that warrant both treatment and special attention in the research literature.
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