Exploring the Semantic Structure of WMS-IV Verbal Paired Associates using the Hub-and-Spoke Model

Abstract

Objectives: This study aimed to identify a well-fitting and theoretically justified item-level latent factor structure for the Wechsler Memory Scales (WMS)-IV verbal paired associates (VerbalPA) subtest to facilitate the ease and accuracy of score interpretations for patients with lateralized temporal lobe epilepsy (TLE). Methods: Archival data were used from 250 heterogeneous neurosciences patients who were administered the WMS-IV as part of a standard neuropsychological assessment. Three theoretically motivated models for the latent structure of VerbalPA were tested using confirmatory factor analysis. The first model, based on cognitive principles of semantic processing from hub-and-spoke theory, tested whether performance is related to specific semantic features of target words. The second, motivated by the Cattell–Horn–Carroll (CHC) model of cognitive abilities, investigated whether the associative properties of items influence performance. A third, Hybrid model tested whether performance is related to both semantic and associative properties of items. The best-fitting model was tested for diagnostic group effects contrasting the heterogeneous neuroscience patients with subsets of left and right TLE (n = 51, n = 26, respectively) patients. Results: The Hybrid model was found to have the best fit. Patients with left TLE scored significantly less well than the heterogeneous neurosciences sample on selected semantic factor scores, although the effect size was small. Conclusions: Future editions of the WMS may consider implementing a semantic scoring structure for the VerbalPA to facilitate test score interpretation. Additionally, these results suggest that principles of hub-and-spoke theory may be integrated into CHC cognitive ability taxonomy.

Epilepsy and neuropsychology.

“…In the analysis mentioned earlier (Furey et al, 2020), memory acquisition of Wechsler Memory Scale, fourth edition (WMS-IV), paired-associate items was more closely associated with the hub-and-spoke semantic categorization of target items than alternative models and better fitting than a simple model of an easy-hard distinction (Rausch & Babb, 1993). Similar results were observed in a larger heterogeneous patient group as well as in a smaller series of left and right TLE patients.…”

“…An example is provided by analysis of the item-level structure of Verbal Paired Associates (VPA) from the Wechsler Memory Scale. Although low semantic content of hard pairs and a stronger arbitrary-binding requirement are thought to make this test particularly useful for testing medialtemporal memory function in the languagedominant temporal lobe (for a review, see Furey et al, 2020), an alternative interpretation of the cognitive processes involved with this task is that the semantic processing component reflects a continuum rather than being absolutely present or absent. Thus, the semantic integration networks in the anterior temporal neocortex are likely to invoke semantic organization for the stimulus items in any auditory-verbal memory test (Furey et al, 2020).…”

“…Although low semantic content of hard pairs and a stronger arbitrary-binding requirement are thought to make this test particularly useful for testing medialtemporal memory function in the languagedominant temporal lobe (for a review, see Furey et al, 2020), an alternative interpretation of the cognitive processes involved with this task is that the semantic processing component reflects a continuum rather than being absolutely present or absent. Thus, the semantic integration networks in the anterior temporal neocortex are likely to invoke semantic organization for the stimulus items in any auditory-verbal memory test (Furey et al, 2020). The hub-and-spoke model of semantic integration (Patterson & Lambon Ralph, 2016) can be used to predict semantic categorization in any stimulus material, including cultural-linguistic knowledge as an extension of the narrow ability of lexical or general verbal knowledge under the broad ability of Gc (Woodcock et al, 2018).…”

“…Thus, the principles of cognitive function described by the CHC model can be integrated with findings from cognitive neuroscience and used to predict performance on individual tests items. The major implication for clinical assessment is that hard pairs in Wechsler VPA are not a distinct arbitrary association test but, rather, another long-term retrieval test with inevitable semantic recall structure that is best combined with other memory tests with more obvious semantic content to obtain a more reliable measure of long-term memory and learning (Gl in the CHC taxonomy; Furey et al, 2020Furey et al, , 2021.…”