Verbal Working Memory Encodes Phonological and Semantic Information Differently

Abstract

Working memory (WM) is often tested through immediate serial recall of word lists. Performance in such tasks is negatively influenced by phonological similarity: People more often get the order of words wrong when they are phonologically similar to each other (e.g., cat, fat, mat). This phonological-similarity effect shows that phonology plays an important role for the representation of serial order in these tasks. By contrast, semantic similarity usually does not impact performance negatively. To resolve and understand this discrepancy, we tested the effects of phonological and semantic similarity for the retention of positional information in WM. Across six experiments (all Ns = 60 young adults), we manipulated between-item semantic and phonological similarity in tasks requiring participants to form and maintain new item-context bindings in WM. Participants were asked to retrieve items from their context, or the contexts from their item. For both retrieval directions, phonological similarity impaired WM for item-context bindings across all experiments. Semantic similarity did not. These results demonstrate that WM encodes phonological and semantic information differently. We propose a WM model accounting for semantic-similarity effects in WM, in which semantic knowledge supports WM through activated long-term memory.

Does semantic similarity affect immediate memory for order? Usually not, but sometimes it does

“…The fact that order recall benefits from semantic grouping is in striking contrast with the usual null effect of semantic similarity on order memory, when pure lists of semantically similar or dissimilar words are compared (Kowialiewski et al, 2023;Neale & Tehan, 2007;Neath et al, 2022;Poirier & Saint-Aubin, 1995;Saint-Aubin & Poirier, 1999). However, as we did not include pure semantically similar lists, we cannot rule out the possibility that there are some peculiarities in our materials by which semantic similarity improved order memory even without a grouping structure.…”

“…This recall advantage is characterized by an increase of item memory. In contrast, semantic similarity does not impair order memory (Neale & Tehan, 2007;Poirier & Saint-Aubin, 1995;Saint-Aubin & Poirier, 1999), a phenomenon which has now been replicated across a variety of experimental conditions and different semantic similarity metrics (Kowialiewski et al, 2023;Neath et al, 2022). If WM encoded semantic information through item-context binding, we expect that semantically similar items should be recalled more often in the wrong order than semantically dissimilar items.…”

“…The null effect of semantic similarity on order memory is a well-replicated phenomenon (Kowialiewski et al, 2023;Neale & Tehan, 2007;Neath et al, 2022;Poirier & Saint-Aubin, 1995Saint-Aubin & Poirier, 1999). However, most manipulations of semantic similarity involved lists composed of purely similar or dissimilar items.…”

“…People tend to confuse similar items in their order more often than dissimilar ones, a classical phenomenon observed across a variety of domains (Guitard & Cowan, 2020;Gupta et al, 2005;Jalbert et al, 2008;Lin & Luck, 2009;Logie et al, 2016;Saito et al, 2008;Visscher et al, 2007). In contrast to other types of similarity, semantic similarity does not decrease people's ability to recall items in their presentation order (Kowialiewski et al, 2023;Neale & Tehan, 2007;Poirier & Saint-Aubin, 1995;Saint-Aubin & Poirier, 1999). Still, there are some studiesreviewed belowshowing subtle but intriguing effects of semantic similarity on order memory.…”

“…When items are cued, other items sharing these markers are also partially retrieved, thus increasing the probability to retrieve an adjacent than distant item when a transposition occurs. The binding mechanism also predicts that it should be possible to retrieve a context when an item is given (i.e., retrieving "position 1" from the word "monkey"), a prediction which has received empirical support in the verbal WM literature (Guérard et al, 2009;Kowialiewski et al, 2023).…”