The contralateral delay activity (CDA) is a negative slow wave sensitive to the number of objects maintained in visual working memory (VWM). In recent years, a growing number of labs started to use the CDA in order to investigate VWM, leading to many fascinating discoveries. Here, we discuss the recent developments and contribution of the CDA in various research fields. Importantly, we report two meta-analyses that unequivocally validate the relationship between the set-size increase in the CDA amplitude and the individual VWM capacity, and between the CDA and filtering efficiency. We further discuss how the CDA was used to study the role of VWM in visual search, multiple object tracking, grouping, binding, and whether VWM capacity allocation is determined by the items’ resolution or instead by the number of objects regardless of their complexity. In addition, we report how the CDA has been used to characterize specific VWM deficits in special populations.

The authors examined the role of online order control in the psychological refractory period (PRP) paradigm. In the first 2 experiments, participants switched between color-letter and letter-color orders so that subtask order was isolated as the only element being switched. The results indicated that order switching impaired the 2 PRP responses and modulated the PRP effect. Importantly, these effects were reduced by advance preparation, demonstrating that order representation was activated before the subtasks themselves. Preparation for subtask order did not reflect preparation for hand order, as shown in Experiment 3. In addition, there was no evidence that subtask order information dissipated between trials. The relevance of the results to theories of the PRP paradigm and task switching is discussed.Many everyday tasks consist of multiple actions. While performing these multistep tasks, one has to follow a series of subtasks, and often each subtask is dependent on the outcome of a preceding one. Because each subtask can also be independentnamely, it can be executed alone-organization of subtasks in the proper order is a key element for successful performance. This article focuses on providing evidence that explicit subtask order information is used for online order control and is activated in the initial stages of multistep tasks.Models of action address representation of order by assuming that order is explicitly (e

Does the capacity of visual short-term memory (VSTM) depend on the complexity of the objects represented in memory? Although some previous findings indicated lower capacity for more complex stimuli, other results suggest that complexity effects arise during retrieval (due to errors in the comparison process with what is in memory) that is not related to storage limitations of VSTM, per se. We used ERPs to track neuronal activity specifically related to retention in VSTM by measuring the sustained posterior contralateral negativity during a change detection task (which required detecting if an item was changed between a memory and a test array). The sustained posterior contralateral negativity, during the retention interval, was larger for complex objects than for simple objects, suggesting that neurons mediating VSTM needed to work harder to maintain more complex objects. This, in turn, is consistent with the view that VSTM capacity depends on complexity.

The integrated object view of visual working memory (WM) argues that objects (rather than features) are the building block of visual WM, so that adding an extra feature to an object does not result in any extra cost to WM capacity. Alternative views have shown that complex objects consume additional WM storage capacity so that it may not be represented as bound objects. Additionally, it was argued that two features from the same dimension (i.e., color-color) do not form an integrated object in visual WM. This led some to argue for a “weak” object view of visual WM. We used the contralateral delay activity (the CDA) as an electrophysiological marker of WM capacity, to test those alternative hypotheses to the integrated object account. In two experiments we presented complex stimuli and color-color conjunction stimuli, and compared performance in displays that had one object but varying degrees of feature complexity. The results supported the integrated object account by showing that the CDA amplitude corresponded to the number of objects regardless of the number of features within each object, even for complex objects or color-color conjunction stimuli.

The goal of the present investigation was to discover whether visual working memory maintenance for faces is modulated by facial expression using event-related potentials (ERPs). Each trial consisted of two sequential arrays, a memory array and a test array, each including either two or four faces with neutral or fearful expressions. The faces were displayed to the left and to the right of a central fixation cross. Two central arrows cued participants to encode one face or two faces displayed on one side of the memory array. The sustained posterior contralateral negativity (SPCN) component of the ERP time-locked to the onset of the memory array was used as an index of visual working memory maintenance. Visual working memory performance was quantified using indexes of memory capacity (Cowan's K and K-iterative), a standard index of sensitivity (d'), and reaction times (RTs). Relative to neutral faces, superior memory and longer change-detection RTs to fearful face identities were observed when two faces were displayed on the cued side of the memory array. Fearful faces elicited an enhanced SPCN relative to neutral faces, especially when only one face was displayed on the cued side of the memory array. These findings suggest increased maintenance in visual working memory of faces with a fearful expression relative to faces with a neutral expression and that the representational format in which fearful faces are stored in memory may be characterized by enhanced resolution relative to that subtended in the maintenance of neutral faces.