Caterina Artuso

Content–context binding in verbal working memory updating: On-line and off-line effects

The role of content-context binding in working memory updating has received only marginal interest, despite its undoubted relevance for the updating process. In the classical updating paradigm, the main focus has been on the process of discarding information when new information is presented. Its efficacy has been determined by measurement of the accuracy of recalled, updated information. In the current study we measured the working memory updating process directly, employing a dynamic memory task composed of alternating sequences of learning, active maintenance and updating phases. Binding was manipulated by changing the type of updating (total or partial) and the strength of the perceptual connection between items. The on-line updating process and the off-line efficacy were separately analysed. Both on-line and off-line measures indicated that partial updating conditions, where the operation of updating content-context binding was required, were more demanding than both total updating conditions and memory and maintenance phases. Our results suggest that working memory updating can be identified not only as a process of substitution of information, but also as inhibition of no longer relevant information and, above all, as a binding updating.

Binding and content updating in working memory tasks

Working memory updating can involve processing of either a specific memory content or a binding. So far, research has focused mainly on single contents as objects of updating, via recall accuracy measures. Here, we have addressed more direct measurement of the updating process (i.e., response times), assessing individually the role of single contents, as well as bindings. To this end, we compared two updating tasks from separate research traditions: a RT-based computer task and a classical accuracy-based task. The former consisted of trials where measures of content and binding updating were obtained, allowing a dissociation between these two components. The latter measured recall accuracy and intrusion rate for lists of words under different conditions of maintenance/inhibition. These results enable a better understanding of the updating process for the dual components of binding and content updating, and their potential role in an accuracy-based task. An overlap between the underlying components of updating tasks was demonstrated, specifically between binding updating RT and intrusion rate. Notably, binding updating appears to be a more sensitive measure in explaining results in the classical updating task.

How do we update faces? Effects of gaze direction and facial expressions on working memory updating.

The aim of the study was to investigate how the biological binding between different facial dimensions, and their social and communicative relevance, may impact updating processes in working memory (WM). We focused on WM updating because it plays a key role in ongoing processing. Gaze direction and facial expression are crucial and changeable components of face processing. Direct gaze enhances the processing of approach-oriented facial emotional expressions (e.g., joy), while averted gaze enhances the processing of avoidance-oriented facial emotional expressions (e.g., fear). Thus, the way in which these two facial dimensions are combined communicates to the observer important behavioral and social information. Updating of these two facial dimensions and their bindings has not been investigated before, despite the fact that they provide a piece of social information essential for building and maintaining an internal ongoing representation of our social environment. In Experiment 1 we created a task in which the binding between gaze direction and facial expression was manipulated: high binding conditions (e.g., joy-direct gaze) were compared to low binding conditions (e.g., joy-averted gaze). Participants had to study and update continuously a number of faces, displaying different bindings between the two dimensions. In Experiment 2 we tested whether updating was affected by the social and communicative value of the facial dimension binding; to this end, we manipulated bindings between eye and hair color, two less communicative facial dimensions. Two new results emerged. First, faster response times were found in updating combinations of facial dimensions highly bound together. Second, our data showed that the ease of the ongoing updating processing varied depending on the communicative meaning of the binding that had to be updated. The results are discussed with reference to the role of WM updating in social cognition and appraisal processes.

Updating working memory: memory load matters with aging

Age-related effects in working memory updating were investigated by administering a response time-based task to three adult age groups (young, young-old, and old-old). The task differentiated objects to update; participants were asked to update single memory contents or content-context bindings. The data showed an overall delay of response latencies in the elderly groups (both young-old and old-old), relative to the younger. Specifically, each age group showed longer latencies for content-context binding updating, than single memory content updating. However, an interaction with age was obtained when memory load was manipulated across content-context binding updating conditions. These results were taken as evidence of differences between specific objects of updating and age-related changes in cognition and were discussed with reference to the relevant aging literature.

Effects of Global and Local Processing on Visuospatial Working Memory

If you want to find something, you need to know what you are looking for and where it was last located. Successful visuospatial working memory (VSWM) requires that a stimulus identity be combined with information about its location. How identity and location information interact during binding presents an interesting question because of 1) asymmetries in cognitive demands required by location and identity processing and 2) the fact that the two types of information are processed in different neural streams. The current studies explore how global and local processing approaches impact binding in VSWM. Experiment 1 explores effects of global spatial organization. Experiment 2 induces local processing demands through memory updating. Results show better location memory with both global and local processing, but also suggest that the processing focus (global or local) affects the interaction of location and identity processing in VSWM.

Modulation of working memory updating: Does long-term memory lexical association matter?

The aim of the present study was to investigate how working memory updating for verbal material is modulated by enduring properties of long-term memory. Two coexisting perspectives that account for the relation between long-term representation and short-term performance were addressed. First, evidence suggests that performance is more closely linked to lexical properties, that is, co-occurrences within the language. Conversely, other evidence suggests that performance is linked more to long-term representations which do not entail lexical/linguistic representations. Our aim was to investigate how these two kinds of long-term memory associations (i.e., lexical or nonlexical) modulate ongoing working memory activity. Therefore, we manipulated (between participants) the strength of the association in letters based on either frequency of co-occurrences (lexical) or contiguity along the sequence of the alphabet (nonlexical). Results showed a cost in working memory updating for strongly lexically associated stimuli only. Our findings advance knowledge of how lexical long-term memory associations between consonants affect working memory updating and, in turn, contribute to the study of factors which impact the updating process across memory systems.

How sublexical association strength modulates updating: Cognitive and strategic effects

In the current study, we investigated updating of long-term memory (LTM) associations. Specifically, we examined sublexical associations by manipulating preexisting LTM relations between consonant couplets (in encoding and updating phases), and explicitly instructed participants to engage with a specific strategy for approaching the task (item disjunction, grouping, or none). In two experiments, we used a multistep subject-based memory updating task in which we measured processing response times (RTs; Exp. 1, Exp. 2) and recognition RTs (Exp. 2). For the first time, in both experiments, we found costs in dismantling strong pre-existing associations from LTM and benefits in recreating strong preexisting associations. In addition, we found that control of irrelevant information was more difficult when this belonged to a strong association. Regarding task strategies, we showed that inducing a disjunction strategy enhanced updating, no matter the strength of the association. Results were discussed in the light of updating as a process of dismantling and recreating associations. The role of a specific strategic approach in enhancing the updating was also discussed.

The role of memory updating in shallow native and opaque second language learning

The current study investigates the relation between working memory updating and second language learning (L2) outcomes in typically-developing fourth grade children. Our primary aim was to replicate and extend previous findings on the relationship between updating and low-level reading skills, i.e. fluency. Our second objective was to examine possible updating transfer effects across languages, from the native language (L1) to L2 learning. The languages considered have different orthographic features; shallow for L1 (Italian), and opaque for L2 (English). Mediation analyses were tested using the bootstrapping method; we found that updating was directly related to reading fluency in L2 learning. Moreover, we showed evidence of the mediating role of L1 fluency in the relation between memory updating and L2 fluency. Our findings suggest that updating processes may act at a low level for reading, and are potentially independent from specific language features, both for opaque and regular orthographies.

Working Memory Updating: Load and Binding

ABSTRACT In the present study, we aimed to examine how specific objects are updated in working memory. We compared conditions in which contents or content-context bindings from working memory were both encoded and updated (Experiment 1). In addition, for bindings, we manipulated the memory load (i.e., number of contents) to maintain during updating. Results indicated that memory load did not specifically affect the process; rather, the content-context binding (vs. single contents) was critical in determining the increase in response latencies. Results were replicated even in Experiment 2, in which we manipulated the spatial locations of the to-be-recognized probes. Results showed evidence of a potential dissociation between updating of memory contents-only and content-context bindings. In addition, memory load and spatial coherence between phases and probe recognition did not interact with updating performance. Overall, results were taken as a contribution toward mapping the complex nature of the updating mechanism.