Do item-dependent context representations underlie serial order in cognition? Commentary on Logan (2021)

Logan (2021) presented an impressive unification of serial order tasks including whole report, typing, and serial recall in the form of the context retrieval and updating (CRU) model. Despite the wide breadth of the model’s coverage, its reliance on encoding and retrieving context representations that consist of the previous items may prevent it from being able to address a number of critical benchmark findings in the serial order literature that have shaped and constrained existing theories. In this commentary, we highlight three major challenges that motivated the development of a rival class of models of serial order, namely positional models. These challenges include the mixed-list phonological similarity effect, the protrusion effect, and interposition errors in temporal grouping. Simulations indicated that CRU can address the mixed list phonological similarity effect if phonological confusions can occur during its output stage, suggesting that the serial position curves from this paradigm do not rule out models that rely on inter-item associations, as has been previously been suggested. The other two challenges are more consequential for the model’s representations, and simulations indicated the model was not able to provide a complete account of them. We highlight and discuss how revisions to CRU’s representations or retrieval mechanisms can address these phenomena and emphasize that a fruitful direction forward would be to either incorporate positional representations or approximate them with its existing representations.

Morphological generalization of Hebrew verb classes

The present work investigated how morphological generalization, namely the way speakers extend their knowledge to novel complex words, is influenced by sources of variability in language and speaker properties. For this purpose, the study focused on a Semitic language (Hebrew), characterized by unique non-concatenative morphology, and native (L1) as well as non-native (L2) speakers. Two elicited production tasks tested what information sources speakers employ in verbal inflectional class generalization, i.e., in forming complex novel verbs. Phonological similarity was tested in Experiment 1 and argument structure in Experiment 2. The analysis focused on the two most common Hebrew inflectional classes, Paal and Piel, which also constituted the vast majority of responses in the two tasks. Unlike the commonly found outcomes in Romance inflectional class generalization, the results yielded, solely for Piel, a graded phonological similarity effect and a robust argument structure effect, i.e., more Piel responses in a direct object context than without. The L2 pattern partially differed from the L1: (i) argument structure effect for L2 speakers was weaker, and (ii) L2 speakers produced more Paal than Piel responses. The results are discussed within the framework of rule-based and input-based accounts.

Repetition inhibition and facilitation effects for visual-verbal stimuli under conditions of concurrent articulation

This study examines the effects of within-sequence repetitions for visually presented consonants under conditions of quiet and concurrent articulation (CA). In an immediate serial recall (ISR) procedure, participants wrote down the six consonants in the order of original presentation. CA reduced serial recall and abolished the phonological similarity effect. However, the effects of within-trial repetitions were broadly similar under quiet and CA. Specifically, adjacent repetitions facilitated recall of the repeated item, whereas spaced repetitions (separated by three intervening items) impaired recall accuracy for the repeated item (i.e., the Ranschburg effect). These data are the first to demonstrate the Ranschburg effect for visual-verbal stimuli under CA.

Evidence of a Phonological Similarity Effect After Rehearsal Training in Adolescents With Intellectual Disability

A phonological similarity effect (PSE) in adolescents with an intellectual disability (ID) has previously been shown with auditory stimuli, but studies using visual stimuli are scarce. In the case of visually presented items, PSE requires verbal recoding before it appears. Using visual items, we trained 15 participants with ID to use rehearsal strategies. Another group of 13 participants took part in nonstrategic training. In both groups, PSE was tested before and after training. Participants in the strategy-training group, who showed no PSE at pretest, began to show such an effect during the training stage and maintained it until posttest as was observed through microgenetic analysis. Participants with ID showing no PSE with visual material can thus be trained to show this effect through extensive use of cumulative rehearsal. Such training would lead them to recode items verbally, which in turn would make phonological similarities more salient and lead to a PSE.