Newly-acquired words are more phonologically robust in verbal short-term memory when they have associated semantic representations

Abstract

(2016) Newlyacquired words are more phonologically robust in verbal short-term memory when they have associated semantic representations. Neuropsychologia, 98. pp. 85-97. AbstractVerbal short-term memory (STM) is a crucial cognitive function central to language learning, comprehension and reasoning, yet the processes that underlie this capacity are not fully understood. In particular, although STM primarily draws on a phonological code, interactions between long-term phonological and semantic representations might help to stabilise the pho ologi al t a e fo o ds se a ti i di g h pothesis . This idea was first proposed to explain the frequent phoneme recombination errors made by patients with semantic dementia when recalling words that are no longer fully understood. However, converging evidence in support of semantic binding is scant: it is unusual for studies of healthy participants to examine serial recall at the phoneme level and also it is difficult to separate the contribution of phonological-lexical knowledge from effects of word meaning. We used a new method to disentangle these influences in healthy individuals t ai i g e o ds ith o ithout associated semantic information. We examined phonological coherence in immediate serial recall (ISR), both immediately and the day after training. Trained items were more likely to be recalled than novel nonwords, confirming the importance of phonological-lexical knowledge, and items with semantic associations were also produced more accurately than those with no meaning, at both time points. For semantically-trained items, there were fewer phoneme ordering and identity errors, and consequently more complete target items were produced in both correct and incorrect list positions. These data show that lexical-semantic knowledge improves the robustness of verbal STM at the sub-item level, even when the effect of phonological familiarity is taken into account.3

Keeping it together: Semantic coherence stabilizes phonological sequences in short-term memory

“…Consequently, all of the effects in this study could be explained in terms of the contribution of phonological-lexical representations, as opposed to a role for conceptual knowledge. Encoding tasks that require participants to attend to semantic and nonsemantic features of words have revealed fewer phoneme migrations for semantically encoded items, which aligns with the semantic-binding account (Savill, Metcalfe, Ellis, & Jefferies, 2015); however, studies investigating the effect of training new lexical-phonological forms with or without associated meanings have produced conflicting results (Benetello, Cecchetto, & Papagno, 2015;Savill et al, 2017).…”

“…However, the relative contributions of phonological and semantic representations to verbal STM, and the ways in which they interact, are unclear. Semantic manipulations typically have relatively subtle effects on STM, as compared to phonological manipulations (e.g., Baddeley, 1966;Jefferies, Frankish, & Lambon Ralph, 2006;Majerus & van der Linden, 2003;Savill, Ellis, & Jefferies, 2017), so the consensus view is that STM is best explained by factors that influence the efficiency of phonological processing. Traditional accounts of STM suggest that the semantic contribution operates at the whole-word level-for example, activated semantic and lexical representations allow people to complete missing pieces of a phonological trace.…”

Verbal working memory and linguistic long-term memory: Exploring the lexical cohort effect

“…At the same time, it should be noted that other evidence is not in favor of a redintegration mechanism as the exclusive account of psycholinguistic effects in vWM. For instance, strong lexicality effects have been observed in vWM tasks that do not require overt recall and redintegration (Jefferies, Frankish, & Lambon Ralph, 2006b;Kowialiewski & Majerus, 2018a;Savill, Ellis, & Jefferies, 2016). The neighborhood density effect is also of interest here.…”

Individual differences in verbal short-term memory and reading aloud: Semantic compensation for weak phonological processing across tasks.

“…However, studies of semantic contributions to verbal short-term memory have focused on effects arising at the group level (single word repetition: Tyler et al, 2000;; immediate serial recall: Acheson, Postle, & MacDonald, 2010;Jefferies, Frankish, & Lambon Ralph, 2006;Majerus & van der Linden, 2003;Savill et al, 2018Savill et al, , 2017Savill et al, , 2015 and have not considered how these influences may vary across individuals as a function of phonological capacity, as we test here.…”

“…In the context of relatively preserved phonological function (Jefferies, Jones, Bateman, & Lambon Ralph, 2005), they often make specific phonological errors during the short-term recall of words that are no longer fully understood (e.g., Jefferies, Hoffman, Jones, & Lambon Ralph, 2008;Knott et al, 1997;Majerus, Norris, & Patterson, 2007; see also Peters, Majerus, De Baerdemaeker, Salmon, & Collette, 2009, for similar effects of semantic impairment in Alzheimer's Disease). Some converging support for the view that semantic information helps to stabilise the phonological trace has also been provided by studies of healthy participants (Hoffman, Jefferies, Ehsan, Jones, & Lambon Ralph, 2009;Jefferies, Frankish, & Lambon Ralph, 2006;Savill et al, 2018;Savill, Ellis, & Jefferies, 2017;Savill, Metcalfe, Ellis, & Jefferies, 2015).…”