No evidence yet for functional independence of verbal short‐term memory and long‐term verbal knowledge

Bormann et al. (2025) argue that their case studies provide 'unequivocal evidence for the functional independence of short-and long-term memory'.We would like to challenge this conclusion.First, theories assuming that verbal short-term memory (STM) or working memory (WM) depends on language do not imply that language impairment always leads to verbal STM or WM impairment.Acquired language impairment can affect different linguistic representations and processes.These impairments affect verbal STM if and only if they concern representations or processes that are involved in STM tasks.In verbal immediate serial recall tasks, participants need to be able to decode, identify and repeat the verbal stimuli.This requires access to underlying sublexical and lexical input and output phonological representations, and potential additional access to associated semantic representations.Impairments to these processes can furthermore be highly specific relative to the type of material, with low frequency words being often more affected than high frequency words, or nonwords more than words.This situation is demonstrated by verbal STM performance of patients with semantic dementia.These patients show progressive loss of semantic representations associated with words and objects.Their verbal STM spans can be reduced for word but not nonword lists, and, most critically, they are reduced for those words which they do not know anymore (Majerus et al., 2007; Patterson et al., 1994).To argue that the conjunction of preserved performance on a verbal STM/WM task with impaired performance on various language tasks is evidence for a functional independence of verbal STM and language systems, it needs to be demonstrated that patients have difficulties in perceiving, identifying and repeating specific words in a language task but not in a verbal STM task.Second, theories assuming a close relation between verbal STM/WM and language also do not imply that verbal STM/WM impairment should always go along with impaired performance on language tasks.This assumption can also only be properly tested if exactly the same stimuli are used for the STM and language tasks and if the language tasks test those linguistic processes that are involved in tests of STM/WM (e.g.repetition of verbal sequences).Furthermore, even within a cognitive model that reduces verbal WM to an emergent property of the language system (e.g.Martin et al., 1996), dissociations between performance in language tests and STM tests are possible.Computational modelling of the profile of patients with deep dysphasia, a repetition-based aphasic condition, suggests that depending