Working memory capacity predicts individual differences in social-distancing compliance during the COVID-19 pandemic in the United States.

Noncompliance with social distancing during the early stage of the coronavirus disease 2019 (COVID-19) pandemic poses a great challenge to the public health system. These noncompliance behaviors partly reflect people's concerns for the inherent costs of social distancing while discounting its public health benefits. We propose that this oversight may be associated with the limitation in one's mental capacity to simultaneously retain multiple pieces of information in working memory (WM) for rational decision making that leads to social-distancing compliance. We tested this hypothesis in 850 United States residents during the first 2 wk following the presidential declaration of national emergency because of the COVID-19 pandemic. We found that participants' social-distancing compliance at this initial stage could be predicted by individual differences in WM capacity, partly due to increased awareness of benefits over costs of social distancing among higher WM capacity individuals. Critically, the unique contribution of WM capacity to the individual differences in social-distancing compliance could not be explained by other psychological and socioeconomic factors (e.g., moods, personality, education, and income levels). Furthermore, the critical role of WM capacity in social-distancing compliance can be generalized to the compliance with another set of rules for social interactions, namely the fairness norm, in Western cultures. Collectively, our data reveal contributions of a core cognitive process underlying social-distancing compliance during the early stage of the COVID-19 pandemic, highlighting a potential cognitive venue for developing strategies to mitigate a public health crisis.

Clinical risk factors for peritoneal dialysis withdrawal at different dialysis duration.

BACKGROUND: The duration of patients maintained on peritoneal dialysis (PD) varied. This study investigated the clinical risk factors for PD withdrawal at different dialysis duration. METHODS: Patients who initiated PD from 1994 to 2011 were recruited and followed for at least 10 years until 2021. Patients were grouped into four groups according to dialysis duration or time on treatment (TOT) when withdrew PD. RESULTS: A cohort of 586 patients were enrolled (mean age of 54.9 years, median dialysis duration or TOT of 47.9 months). Patients who maintained PD for longer than 10 years were younger, with lower prevalence of diabetes, lower serum C-reactive protein (CRP) level and white blood cell (WBC) count, higher serum albumin and pre-albumin level, higher normalized protein catabolic rate (nPCR) and residual kidney function, and more common use of renin-angiotensin system inhibitors (RASi) at baseline (p < 0.05 for all). Peritonitis related death and ultrafiltration failure related HD transferring increased along with time on PD (p < 0.001). Old age, diabetes, low serum albumin, high WBC count, hypertensive nephropathy, and nonuse of RASi were associated with increased risk of non-transplantation related PD withdrawal (p < 0.05 for all). Low baseline CRP and use of RASi were independent predictors for long-term PD maintenance (p < 0.05 for all). CONCLUSIONS: Long-term PD patients demonstrated young age, low prevalence of diabetes, better nutrition status, absence of inflammation, better residual kidney function, and higher proportion of RASi usage at baseline. Absence of inflammation and use of RASi were independently associated with long-term PD maintenance.

Self-care or assisted PD: development of a new approach to evaluate manual peritoneal dialysis practice ability.

BACKGROUND: Peritoneal dialysis (PD) is a home-based therapy which requires the patients or their caregivers to perform the practice. We aimed to develop a practical approach to evaluate PD practice ability of the patients and to identify berries to self-care PD. METHODS: A structural form was designed comprising measures of physical, cognitive, and operational abilities which were required to perform manual PD independently. The evaluation was jointly conducted by a PD nurse, a nephrologist and a close family member of the patient. Patients who met all the requirements were deemed as capable of performing PD independently (self-care PD) and others were deemed as needing an assistant (assisted PD). RESULTS: The evaluation form was applied in 280 prevalent PD patients and 33.9% of them were assessed as needing assisted PD, mainly due to physical (62.1%) or operational (66.3%) disabilities. The evaluation result was consistent with current dialysis status in 79.3% patients and it matched better in patients who performed PD with the help of an assistant (93.0 vs. 76.8%, p = 0.014). Patients who were evaluated as having barriers to self-care PD but still performed PD without an assistant were older and demonstrated higher prevalence of diabetic nephropathy and PD-related infection, lower education level, and lower serum albumin (p < 0.05). CONCLUSIONS: The PD practice ability assessment form is useful to identify patients with barriers to self-care PD. It provides objective information to the patients and their family to choose feasible PD practice modality, self-care, or assisted PD.

Poor Sleep Quality and Compromised Visual Working Memory Capacity.

OBJECTIVES: Reduction in the amount of information (storage capacity) retained in working memory (WM) has been associated with sleep loss. The present study examined whether reduced WM capacity is also related to poor everyday sleep quality and, more importantly, whether the effects of sleep quality could be dissociated from the effects of depressed mood and age on WM. METHODS: In two studies, WM was assessed using a short-term recall task, producing behavioral measures for both the amount of retained WM information (capacity) and how precise the retained WM representations were (precision). Self-report measures of sleep quality and depressed mood were obtained using questionnaires. RESULTS: In a sample of college students, Study 1 found that poor sleep quality and depressed mood could independently predict reduced WM capacity, but not WM precision. Study 2 generalized these sleep- and mood-related WM capacity effects to a community sample (aged 21-77 years) and further showed that age was associated with reduced WM precision. CONCLUSIONS: Together, these findings demonstrate dissociable effects of three health-related factors (sleep, mood, and age) on WM representations and highlighte the importance of assessing different aspects of WM representations (e.g., capacity and precision) in future neuropsychological research.

Familiarity Speeds Up Visual Short-term Memory Consolidation: Electrophysiological Evidence from Contralateral Delay Activities.

To test how preexisting long-term memory influences visual STM, this study takes advantage of individual differences in participants' prior familiarity with Pokémon characters and uses an ERP component, the contralateral delay activity (CDA), to assess whether observers' prior stimulus familiarity affects STM consolidation and storage capacity. In two change detection experiments, consolidation speed, as indexed by CDA fractional area latency and/or early-window (500-800 msec) amplitude, was significantly associated with individual differences in Pokémon familiarity. In contrast, the number of remembered Pokémon stimuli, as indexed by Cowan's K and late-window (1500-2000 msec) CDA amplitude, was significantly associated with individual differences in Pokémon familiarity when STM consolidation was incomplete because of a short presentation of Pokémon stimuli (500 msec, Experiment 2), but not when STM consolidation was allowed to complete given sufficient encoding time (1000 msec, Experiment 1). Similar findings were obtained in between-group analyses when participants were separated into high-familiarity and low-familiarity groups based on their Pokémon familiarity ratings. Together, these results suggest that stimulus familiarity, as a proxy for the strength of preexisting long-term memory, primarily speeds up STM consolidation, which may subsequently lead to an increase in the number of remembered stimuli if consolidation is incomplete. These findings thus highlight the importance of research assessing how effects on representations (e.g., STM capacity) are in general related to (or even caused by) effects on processes (e.g., STM consolidation) in cognition.

Mood-dependent retrieval in visual long-term memory: dissociable effects on retrieval probability and mnemonic precision.

Although memories are more retrievable if observers' emotional states are consistent between encoding and retrieval, it is unclear whether the consistency of emotional states increases the likelihood of successful memory retrieval, the precision of retrieved memories, or both. The present study tested visual long-term memory for everyday objects while consistent or inconsistent emotional contexts between encoding and retrieval were induced using background grey-scale images from the International Affective Picture System (IAPS). In the study phase, participants remembered colours of sequentially presented objects in a negative (Experiment 1a) or positive (Experiment 2a) context. In the test phase, participants estimated the colours of previously studied objects in either negative versus neutral (Experiment 1a) or positive versus neutral (Experiment 2a) contexts. Note, IAPS images in the test phase were always visually different from those initially paired with the studied objects. We found that reinstating negative context and positive context at retrieval resulted in better mnemonic precision and a higher probability of successful retrieval, respectively. Critically, these effects could not be attributed to a negative or positive context at retrieval alone (Experiments 1b and 2b). Together, these findings demonstrated dissociable effects of emotion on the quantitative and qualitative aspects of visual long-term memory retrieval.

The development of multitasking in children aged 7-12years: Evidence from cross-sectional and longitudinal data.

This study investigated the development of multitasking ability across childhood. A sample of 65 typically developing children aged 7, 9, and 11years completed two multitasking tests across three time points within a year. Cross-sectional and longitudinal data consistently indicated continuous linear growth in children's multitasking ability. By the age of 12years, children could effectively perform a simple multitasking scenario comprising six equally important tasks, although their ability to strategically organize assorted tasks with varied values and priorities in a complex multitasking setting had not reached proficiency yet. Cognitive functions underlying a complex multitasking scenario varied in their developmental trajectories. Retrospective memory developed continuously from 7 to 12years of age, suggesting its supporting role in the development of multitasking. Planning skills developed slowly and showed practice effects for older children but not for younger children. The ability to adhere to plans also developed slowly, and children of all age groups benefited from practice. This study offers a preliminary benchmark for future comparison with clinical populations and may help to inform the development of targeted interventions.

Familiarity increases the number of remembered Pokémon in visual short-term memory.

Long-term memory (LTM) can influence many aspects of short-term memory (STM), including increased STM span. However, it is unclear whether LTM enhances the quantitative or qualitative aspect of STM. That is, do we retain a larger number of representations or more precise representations in STM for familiar stimuli than unfamiliar stimuli? This study took advantage of participants' prior rich multimedia experience with Pokémon, without investing on laboratory training to examine how prior LTM influenced visual STM. In a Pokémon visual STM change detection task, participants remembered more first-generation Pokémon characters that they were more familiar with than recent-generation Pokémon characters that they were less familiar with. No significant difference in memory quality was found when quantitative and qualitative effects of LTM were isolated using receiver operating characteristic (ROC) analyses. Critically, these effects were absent in participants who were unfamiliar with first-generation Pokémon. Furthermore, several alternative interpretations were ruled out, including general video-gaming experience, subjective Pokémon preference, and verbal encoding. Together, these results demonstrated a strong link between prior stimulus familiarity in LTM and visual STM storage capacity.

Dissociations of the number and precision of visual short-term memory representations in change detection.

The present study dissociated the number (i.e., quantity) and precision (i.e., quality) of visual short-term memory (STM) representations in change detection using receiver operating characteristic (ROC) and experimental manipulations. Across three experiments, participants performed both recognition and recall tests of visual STM using the change-detection task and the continuous color-wheel recall task, respectively. Experiment 1 demonstrated that the estimates of the number and precision of visual STM representations based on the ROC model of change-detection performance were robustly correlated with the corresponding estimates based on the mixture model of continuous-recall performance. Experiments 2 and 3 showed that the experimental manipulation of mnemonic precision using white-noise masking and the experimental manipulation of the number of encoded STM representations using consolidation masking produced selective effects on the corresponding measures of mnemonic precision and the number of encoded STM representations, respectively, in both change-detection and continuous-recall tasks. Altogether, using the individual-differences (Experiment 1) and experimental dissociation (Experiment 2 and 3) approaches, the present study demonstrated the some-or-none nature of visual STM representations across recall and recognition.

Affective bias in visual working memory is associated with capacity.

How does the affective nature of task stimuli modulate working memory (WM)? This study investigates whether WM maintains emotional information in a biased manner to meet the motivational principle of approaching positivity and avoiding negativity by retaining more approach-related positive content over avoidance-related negative content. This bias may exist regardless of individual differences in WM functionality, as indexed by WM capacity (overall bias hypothesis). Alternatively, this bias may be contingent on WM capacity (capacity-based hypothesis), in which a better WM system may be more likely to reveal an adaptive bias. In two experiments, participants performed change localisation tasks with emotional and non-emotional stimuli to estimate the number of items that they could retain for each of those stimuli. Although participants did not seem to remember one type of emotional content (e.g. happy faces) better than the other type of emotional content (e.g. sad faces), there was a significant correlation between WM capacity and affective bias. Specifically, participants with higher WM capacity for non-emotional stimuli (colours or line-drawing symbols) tended to maintain more happy faces over sad faces. These findings demonstrated the presence of a "built-in" affective bias in WM as a function of its systematic limitations, favouring the capacity-based hypothesis.

The influence of emotion on face processing.

According to the broaden-and-build theory, positive emotions broaden one's thought-action repertoire, which may manifest as a widened attentional scope in cognitive processing. The present study directly tests this hypothesis by examining the influences of induced emotions (positive, neutral and negative) on holistic processing of face (Experiment 1) and face discrimination (Experiment 2). In both experiments, emotions induced with images from the International Affective Picture System significantly interacted with face processing. That is, positive emotions engendered greater holistic face encoding in a composite-face task in Experiment 1 and more accurate face discrimination in Experiment 2, relative to the neutral condition. In contrast, negative emotions impaired holistic face encoding in the composite-face task and reduced face discrimination accuracy. Taken together, these results provide further support for the attentional broadening effect of positive affect by demonstrating that induced positive emotions facilitate holistic/configural processing.

The El Greco fallacy and pupillometry: Pupillary evidence for top-down effects on perception.

In this commentary, we address the El Greco fallacy by reviewing some recent pupillary evidence supporting top-down modulation of perception. Furthermore, we give justification for including perceptual effects of attention in tests of cognitive penetrability. Together, these exhibits suggest that cognition can affect perception (i.e., they support cognitive penetrability).

Anhedonia and pain avoidance in the suicidal mind: behavioral evidence for motivational manifestations of suicidal ideation in patients with major depressive disorder.

OBJECTIVES: Psychological pain may be helpful in conceptualizing suicidal behavior, in that high motivation to avoid pain combined with painful feelings may contribute to an increased risk of suicide. However, no experimental study has tested this hypothesis. The aim of the present study is to provide empirical evidence for the relationship between anhedonia, pain avoidance motivation, and suicidal ideation. METHOD: The sample comprised 40 depressed outpatients and 20 healthy control subjects. All participants completed the Beck Scale for Suicide Ideation (BSS), Beck Depression Inventory, Psychache Scale, Three-Dimensional Psychological Pain Scale, the monetary incentive delay (MID), and affective incentive delay (AID) tasks. Based on BSS scores, clinical participants were divided into high suicidal ideation (HSI) and low suicidal ideation (LSI) groups. RESULTS: In the AID task, the HSI group had longer response times (RTs) under the reward condition than those under the punishment condition (p = .002). The LSI and control groups had shorter RTs under the reward condition compared with those under the neural condition (p <.001 and p = .008, respectively). The LSI group also had shorter RTs under the reward condition than under the punishment condition (p = .003). Pain arousal (r = -.33, p <.01) and BSS scores were significantly negatively correlated with differences in RTs between neutral and reward conditions. Pain avoidance (r = .35, p <.01) and BSS scores were positively correlated with differences in RTs between neutral and punishment conditions. CONCLUSIONS: The AID task was more sensitive than the MID task for the detection of participants' motivation in approaching hedonic experiences and avoiding pain. A suicidal mindset is manifested as decreased motivation to experience hedonia and increased motivation to avoid pain, which could be strong predictors of suicidal behavior.

Perceptual encoding benefit of visual memorability on visual memory formation.

Human observers often exhibit remarkable consistency in remembering specific visual details, such as certain face images. This phenomenon is commonly attributed to visual memorability, a collection of stimulus attributes that enhance the long-term retention of visual information. However, the exact contributions of visual memorability to visual memory formation remain elusive as these effects could emerge anywhere from early perceptual encoding to post-perceptual memory consolidation processes. To clarify this, we tested three key predictions from the hypothesis that visual memorability facilitates early perceptual encoding that supports the formation of visual short-term memory (VSTM) and the retention of visual long-term memory (VLTM). First, we examined whether memorability benefits in VSTM encoding manifest early, even within the constraints of a brief stimulus presentation (100-200 ms; Experiment 1). We achieved this by manipulating stimulus presentation duration in a VSTM change detection task using face images with high- or low-memorability while ensuring they were equally familiar to the participants. Second, we assessed whether this early memorability benefit increases the likelihood of VSTM retention, even with post-stimulus masking designed to interrupt post-perceptual VSTM consolidation processes (Experiment 2). Last, we investigated the durability of memorability benefits by manipulating memory retention intervals from seconds to 24 h (Experiment 3). Across experiments, our data suggest that visual memorability has an early impact on VSTM formation, persisting across variable retention intervals and predicting subsequent VLTM overnight. Combined, these findings highlight that visual memorability enhances visual memory within 100-200 ms following stimulus onset, resulting in robust memory traces resistant to post-perceptual interruption and long-term forgetting.

Focal seizures induce spatiotemporally organized spiking activity in the human cortex.

Epileptic seizures are debilitating because of the clinical symptoms they produce. These symptoms, in turn, may stem directly from disruptions in neural coding. Recent evidence has suggested that the specific temporal order, or sequence, of spiking across a population of cortical neurons may encode information. Here, we investigate how seizures disrupt neuronal spiking sequences in the human brain by recording multi-unit activity from the cerebral cortex in five male participants undergoing monitoring for seizures. We find that pathological discharges during seizures are associated with bursts of spiking activity across a population of cortical neurons. These bursts are organized into highly consistent and stereotyped temporal sequences. As the seizure evolves, spiking sequences diverge from the sequences observed at baseline and become more spatially organized. The direction of this spatial organization matches the direction of the ictal discharges, which spread over the cortex as traveling waves. Our data therefore suggest that seizures can entrain cortical spiking sequences by changing the spatial organization of neuronal firing, providing a possible mechanism by which seizures create symptoms.

Pupillary evidence reveals the influence of conceptual association on brightness perception.

Our visual experience often varies based on momentary thoughts and feelings. For example, when positive concepts are invoked, visual objects may appear brighter (e.g., a "brighter" smile). However, it remains unclear whether this phenomenological experience is driven by a genuine top-down modulation of brightness perception or by a mere response bias. To investigate this issue, we use pupillometry as a more objective measure of perceived brightness. We asked participants to judge the brightness level of an iso-luminant gray color patch after evaluating the valence of a positive or negative word. We found that the gray color patch elicited greater pupillary light reflex and more frequent "brighter" responses after observers had evaluated the valence of a positive word. As pupillary light reflex is unlikely driven by voluntary control, these results suggest that the conceptual association between affect and luminance can modulate brightness perception.

Effortfulness of visual working memory: Gauged by physical exertion.

Active maintenance of information in working memory (WM) is an essential but effortful cognitive process. Yet, the effortful nature of WM remains poorly understood. Here, we constructed a model to evaluate how perceived effort of WM is directly compared to that of physical exertion. In Experiment 1, participants freely chose to either remember a certain number of colors in a visual WM task or hold a hand dynamometer to a required percentage of maximal voluntary contraction (%MVC) to obtain a fixed task credit upon successful task completion. We found that participants discounted WM-related effort in the same way as they discounted handgrip-related effort based on a computation of expected choice outcomes (hence utility) associated with different task loads. This rationality in an observer's prospective choice in Experiment 1 was generalized to retrospective choice in Experiment 2 where participants reported which task was more effortful immediately after they had performed both tasks in a randomized order without any reward or feedback. Experiment 3 further probed this shared mechanism using a dual-task paradigm. As predicted by our model, we found that physical exertion could disrupt the performance in the concurrent WM task, proportional to the iso-effort relationship between WM and physical exertion when task loads were high for both tasks. Collectively, our findings converge on a shared computational principle connecting task load, perceived effort, and choice utility across physical and cognitive domains. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Negative emotion reduces visual working memory recall variability: A meta-analytical review.

Negative emotion is often hypothesized to trigger a more deliberate processing mode. This effect can manifest as increased precision of information maintained in working memory (WM) captured by reduced WM recall variability under an induced negative emotional state. However, some recent evidence shows that WM representations are immune to any emotional influences. Here, we meta-analyze existing evidence based on data from 13 experiments across 491 participants who performed a delay-estimation WM task under negative and neutral emotional states. We find that induced negative emotional state modestly reduces WM recall variability and increases recall failures relative to the neutral condition. These effects are moderated by participants' self-report negative experiences during emotion induction. Collectively, these data suggest that negative emotion influences how much and how well one can remember in WM. (PsycInfo Database Record (c) 2023 APA, all rights reserved).