Cognitive style of field dependence-independence modulates the working memory storage of biological motion.

The biological motion refers to the continuous configuration movement of live agents in space. The perceptual processing of biological motion has the specificity of the dissociation between body form and body motion. However, there is limited evidence for whether such specificity continues when holding biological motion in working memory. We explored this question from the perspective of field dependence (FD) and field independence (FI) cognitive styles in the current study. Three categories of biological motion have been developed: intact movement, motion feature, and form feature. We examined the working memory capacity of motion features, form features, intact movements (Experiments 1-3), and the recognition of three categories of biological motion when remembering intact movements (Experiment 4). The results showed that for the motion features, FI individuals had better memory performance when remembering five items and showed greater working memory capacity and recognition compared with FD individuals, whereas the opposite pattern was observed between FI and FD individuals for the form features. The cognitive style could modulate the working memory storage of biological motion when the task becomes demanding, suggesting that body form and body motion are dissociable in working memory. Our study provided additional evidence for the specificity of biological motion processing in working memory, extending the hierarchical neural model. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The Reactivation of working memory representations affects attentional guidance.

Recent studies have suggested that the neural activity that supported working memory (WM) storage is dynamic over time and this dynamic storage decides memory performance. Does the temporal dynamic of the WM representation also affect visual search, and how does it interact with distractor suppression over time? To address these issues, we tracked the time course of the reactivation of WM representations during visual search by analyzing the electroencephalogram (EEG) and event-related optical signals (EROS) in Experiments 1 and 2, respectively, and investigated the interaction between the representation reactivation and distractor suppression in Experiment 3. Participants had to maintain a color in WM under high- or low-precision requirement and perform a subsequent search task. The reactivation of WM representations was defined by the above-chance decoding accuracy. The EEG results showed that compared with the low-precision requirement, WM-matching distractors captured more attention and the WM representation were reactivated more frequently under high-precision requirement. The EROS results showed that compared with the low-precision requirement, the increased activity in occipital cortex in the WM-matching versus WM-mismatching conditions was observed at 224 ms during visual search under high-precision requirement. Regression analysis showed that the representation reactivation during visual search directly predicted the behavioral WM-based attentional capture effect, while the representation reactivation before visual search impacted the WM-based attentional capture effect through the mediation of distractor suppression during visual search. These results suggest that the reactivation of WM representations and distractor suppression collectively determine WM-based attentional capture.

Decoding Color Visual Working Memory from EEG Signals Using Graph Convolutional Neural Networks.

Color has an important role in object recognition and visual working memory (VWM). Decoding color VWM in the human brain is helpful to understand the mechanism of visual cognitive process and evaluate memory ability. Recently, several studies showed that color could be decoded from scalp electroencephalogram (EEG) signals during the encoding stage of VWM, which process visible information with strong neural coding. Whether color could be decoded from other VWM processing stages, especially the maintaining stage which processes invisible information, is still unknown. Here, we constructed an EEG color graph convolutional network model (ECo-GCN) to decode colors during different VWM stages. Based on graph convolutional networks, ECo-GCN considers the graph structure of EEG signals and may be more efficient in color decoding. We found that (1) decoding accuracies for colors during the encoding, early, and late maintaining stages were 81.58%, 79.36%, and 77.06%, respectively, exceeding those during the pre-stimuli stage (67.34%), and (2) the decoding accuracy during maintaining stage could predict participants' memory performance. The results suggest that EEG signals during the maintaining stage may be more sensitive than behavioral measurement to predict the VWM performance of human, and ECo-GCN provides an effective approach to explore human cognitive function.

Indirect photodegradation of sulfadiazine in the presence of DOM: Effects of DOM components and main seawater constituents.

The presence of pharmaceuticals and personal care products in coastal waters has caused concern over the past decade. Sulfadiazine (SD) is a very common antibiotic widely used as human and fishery medicine, and dissolved organic matter (DOM) plays a significant role in the indirect photodegradation of SD; however, the influence of DOM compositions on SD indirect photodegradation is poorly understood. The roles of reactive intermediates (RIs) in the indirect photolysis of SD were assessed in this study. The reactive triplet states of DOM (3DOM∗) played a major role, whereas HO· and 1O2 played insignificant roles. DOM was divided into four components using excitation-emission matrix spectroscopy combined with parallel factor analysis. The components included three allochthonous humic-like components and one autochthonous humic-like component. The allochthonous humic-like components contributed more to RIs generation and SD indirect photolysis than the autochthonous humic-like component. A significant relationship between the indirect photodegradation of SD and the decay of DOM fluorescent components was found (correlation coefficient, 0.99), and the different indirect photodegradation of SD in various DOM solutions might be ascribed to the different components of DOM. The indirect photolysis rate of SD first increased and then decreased with increasing pH. SD photolysis was enhanced by low salinity but remained stable at high salinity. The increased carbonate concentration inhibited SD photolysis, whereas nitrate showed almost no effect in this study.

[Indirect Photodegradation of Sulfamethoxazole in Water].

Indirect photodegradation is one of the primary approaches for the removal of pharmaceutical contaminants from water. This degradation process is dominated by chromophoric dissolved organic matter (CDOM). After illumination, CDOM produces many reactive intermediates, which can react with drug pollutants to achieve indirect photodegradation. In this article, we focused on four different sources of CDOM and factors affecting indirect sulfamethoxazole (SMZ) photolysis. The results show that the indirect photodegradation effect of SMZ is significantly influenced by CDOM. This indirect photodegradation has a dual nature. It promotes the indirect photodegradation of SMZ through the formation of various reactive intermediates and at the same time inhibits the photodegradation of SMZ through light shielding and masking of reactive intermediates. The indirect photodegradation of SMZ is mainly controlled by active intermediates such as 3CDOM*, HO·, and 1O2 produced by CDOM; 3CDOM* is the main participant in indirect photodegradation of SMZ. In addition, the pH, salinity, and nitrate ions have a significant effect on the indirect photodegradation of SMZ, while bicarbonate ions have no significant effect on the indirect photodegradation of SMZ.

Does maintaining bindings in visual working memory require more attention than maintaining features?

Whether more attention is required for maintaining bindings than maintaining features in visual working memory (VWM) remains an open question. If maintaining bindings in VWM does not require more attention than maintaining features, is it related to the stability of binding representations? In this study, we explored whether maintaining bindings requires more attention than maintaining features for similar and dissimilar objects by inserting a feature report task into the maintenance phase of VWM in Experiments 1 and 2. We also investigated whether the effect of similarity on the attentional requirement for maintaining bindings and features is due to the stability of VWM representations by inserting a suffix during the maintenance phase of VWM in Experiment 3. The results showed that when object-based attention was consumed, bindings were more impaired than features for dissimilar objects but not for similar objects. We also found that the bindings of similar objects were less interfered by the suffix than those of dissimilar objects. Our findings suggest that maintaining bindings does not require more attention than maintaining features when the binding representations are stable in VWM and similarity improves the stability of binding representations.

The effects of direction similarity in visual working memory: Behavioural and event-related potential studies.

Object similarity can improve visual working memory (VWM) performance in the change-detection task, but impair the recognition performance when it occurs at retrieval of VWM in the recognition task. The effect of direction similarity is an issue that has not been well resolved. Furthermore, electrophysiological evidence in support of the mechanisms that underlie the effects of similarity is still scarce. In the current study, we conducted three behavioural experiments to examine the effects of direction similarity on memory performance with regard to both the encoding and retrieval phases of VWM and one event-related potential (ERP) experiment to explore the neural signatures of direction similarity in VWM. Our behavioural studies indicated that direction similarity improved performance when it occurred at the encoding phase but impaired performance when it occurred at the retrieval phase. Moreover, the ERP experiment showed that the amplitude of the contralateral delay activity (CDA) increased with the increasing set size for similar but not dissimilar directions. In addition, the CDA amplitude for similar directions was lower than that for dissimilar directions at set size 2. Taken together, these findings suggest that direction similarity at encoding has a positive effect on VWM performance and at retrieval has a negative effect. Given that VWM capacity depends on information load and the number of objects, the positive effect of similarity may be attributed to reduced information load of memory objects.