Abstract■ The dorsal attention network is consistently involved in verbal and visual working memory ( WM) tasks and has been associated with task-related, top-down control of attention. At the same time, WM capacity has been shown to depend on the amount of information that can be encoded in the focus of attention independently of top-down strategic control. We examined the role of the dorsal attention network in encoding load and top-down memory control during WM by manipulating encoding load and memory control requirements during a short-term probe recognition task for sequences of auditory (digits, letters) or visual (lines, unfamiliar faces) stimuli. Encoding load was manipulated by presenting sequences with small or large sets of memoranda while maintaining the amount of sensory stimuli constant. Top-down control was manipulated by instructing participants to passively maintain all stimuli or to selectively maintain stimuli from a predefined category. By using ROI and searchlight multivariate analysis strategies, we observed that the dorsal attention network encoded information for both load and control conditions in verbal and visuospatial modalities. Decoding of load conditions was in addition observed in modality-specific sensory cortices. These results highlight the complexity of the role of the dorsal attention network in WM by showing that this network supports both quantitative and qualitative aspects of attention during WM encoding, and this is in a partially modality-specific manner. ■

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Introduction Verbal working memory (WM) is defined as the ability to temporarily store verbal information, with or without further manipulation of this information, in order to fulfill cognitive tasks such as language processing or reasoning (Baddeley, 1992). This ability has been considered to also play a crucial role in the acquisition of new verbal information, such as during native and second language learning (e.g., Baddeley, Gathercole, & Papagno, 1998). A large number of studies have shown reliable associations between verbal WM and lexical learning abilities as involved in native language or foreign language vocabulary learning (e.g., Gathercole,

Working memory (WM) precision has received little interest in the verbal WM domain, contrary to the visual WM domain. The aim of this study was to assess the precision with which words can be maintained in verbal WM. A probe-recognition task was used, in which the amount of phonological overlap between target and probe items was varied (25-75%). In Experiment 1, we assessed WM precision in monolingual, French-speaking young adults. In Experiment 2, we assessed WM precision in multilingual speakers with variable levels of language proficiency in German (L1), French (L2), and English (L3) in order to determine the extent to which WM precision is determined by the quality of underlying language representations. In Experiment 1, we observed that WM precision at the single-phoneme level was limited, with recognition performance decreasing considerably for the 75% overlap trials in which the probe and the target differed by a single phoneme. At the same time, recognition performance stayed above chance. In Experiment 2, we showed in multilingual speakers that discrimination accuracy was further reduced when tested in a second language. This study shows that phonological WM precision at the single-phoneme level is limited and furthermore depends upon the precision of the lexical representations in the linguistic system. Overall, this study provides support for theoretical models considering that verbal WM is grounded in the language architecture.