Memory and metamemory for social interactions: Evidence for a metamemory expectancy illusion

People do not always have accurate metacognitive awareness of the conditions that lead to good source memory. In Experiment1, participants studied words referring to bathroom and kitchen items that were either paired with an expected or unexpectedroom as the source. Participants provided judgments of item and source learning after each item–source pair. In line with previousstudies, participants incorrectly predicted their memory to be better for expected than for unexpected sources. Here, we show thatthis metamemory expectancy illusion generalizes to socially relevant stimuli. In Experiment2, participants played a prisoner’sdilemma game with trustworthy-looking and untrustworthy-looking partners who either cooperated or cheated. After each roundof the game, participants provided metamemory judgments about how well they were going to remember the partner’sfaceandbehavior. On average, participants predicted their source memory to be better for behaviors that were expected based on the facialappearances of the partners. This stands in contrast to the established finding that veridical source memory is better for unex-pected than expected information. Asking participants to provide metamemory judgments at encoding selectively enhancedsource memory for the expected information. These results are consistent with how schematic expectations affect source memoryand metamemory for nonsocial information, suggesting that both are governed by general rather than by domain-specificprinciples. Differences between experiments may be linked to the fact that people may have special beliefs about memory forsocial stimuli, such as the belief that cheaters are particularly memorable (Experiment3)

Dark matter concentration in the galactic center

It is shown that the matter concentration observed through stellar motion at the galactic center (Eckart & Genzel, 1997, MNRAS, 284, 576 and Genzel et al., 1996, ApJ, 472, 153) is consistent with a supermassive object of $2.5 \times 10^6$ solar masses composed of self-gravitating, degenerate heavy neutrinos, as an alternative to the black hole interpretation. According to the observational data, the lower bounds on possible neutrino masses are $m_\nu \geq 12.0$ keV$/c^2$ for $g=2$ or $m_\nu \geq 14.3$ keV$/c^2$ for $g=1$, where $g$ is the spin degeneracy factor. The advantage of this scenario is that it could naturally explain the low X-ray and gamma ray activity of Sgr A$^*$, i.e. the so called "blackness problem" of the galactic center.Comment: ApJ, 500, 591 (1998), AASTEX, aasms4.sty, v2 reference adde

Metacognition in Auditory Distraction: How Expectations about Distractibility Influence the Irrelevant Sound Effect

Task-irrelevant, to-be-ignored sound disrupts serial short-term memory for visually presented items compared to a quiet control condition. We tested whether disruption by changing state irrelevant sound is modulated by expectations about the degree to which distractors would disrupt serial recall performance. The participants’ expectations were manipulated by providing the (bogus) information that the irrelevant sound would be either easy or difficult to ignore. In Experiment 1, piano melodies were used as auditory distractors. Participants who expected the degree of disruption to be low made more errors in serial recall than participants who expected the degree of disruption to be high, independent of whether distractors were present or not. Although expectation had no effect on the magnitude of disruption, participants in the easy-to-ignore group reported after the experiment that they were less disrupted by the irrelevant sound than participants in the difficult-to-ignore group. In Experiment 2, spoken texts were used as auditory distractors. Expectations about the degree of disruption did not affect serial recall performance. Moreover, the subjective and objective distraction by irrelevant speech was similar in the easy-to-ignore group and in the difficult-to-ignore group. Thus, while metacognitive beliefs about whether the auditory distractors would be easy or difficult to ignore can have an effect on task engagement and subjective distractibility ratings, they do not seem to have an effect on the actual degree to which the auditory distractors disrupt serial recall performance

Emerging perspectives on distraction and task interruptions: metacognition, cognitive control and facilitation - part I

Modern technology allows for the control of learning and work environments to an unprecedented degree. Therefore, the focus of research shifts from how learning and work performance are passively affected by environmental factors to how people actively shape their own learning and work experiences. This includes task-irrelevant stimuli and task interruptions. For instance, modern headphones allow one to switch between two modes: Active noise cancelling eliminates all background sounds while acoustic transparency allows certain signals to pass through the headphones, creating a customisable audio space. Modern devices also allow us to plan certain task interruptions (for example, by email alerts) in advance. This gives users unprecedented autonomy over their learning and work environments. However, increased control does not necessarily imply that these environments are free of distraction and interruptions. In fact, quite the opposite is true: Modern-day digital learning and work environments are full of distractions and interruptions. With users’ increased control over their learning and work environments, new research questions arise that emphasise the active role of the individual in shaping their own learning and work experiences: Are people capable of distinguishing between harmful and helpful task-irrelevant stimuli and activities? Can the harmful aspects of distractions and interruptions be brought under cognitive control? Are distraction and task interruptions always harmful or are they sometimes helpful? Within this Special Issue, we primarily focus on the following emerging trends in distraction and attention

How Specific Is Source Memory for Faces of Cheaters? Evidence for Categorical Emotional Tagging

Two experiments designed to examine the specificity of emotional source memory are reported. In the encoding phase, participants saw faces along with emotional context information, that is, descriptions of cheating, trustworthy, or irrelevant behavior. In the test phase, participants were required to complete a source classification test and a cued recall test. In both experiments, the source memory advantage for faces characterized by negative context information (cheating) was replicated. Extending previous research, a multinomial source-monitoring model was applied to distinguish between specific source memory for individual behavior descriptions and partial source memory in the sense of only a rough classification of the behavior as belonging to a particular emotional category-cheating, trustworthy, or neither of these. The results indicate that the source memory advantage for the emotional context information is not always accompanied by enhanced recollection of the specific details of the learning episode and might rather reflect unspecific memory for categorical emotional information

A multilingual preregistered replication of the semantic mismatch effect on serial recall

Visual-verbal serial recall is disrupted when task-irrelevant background speech has to be ignored. Contrary to previous suggestion, it has recently been shown that the magnitude of disruption may be accentuated by the semantic properties of the irrelevant speech. Sentences ending with unexpected words that did not match the preceding semantic context were more disruptive than sentences ending with expected words. This particular instantiation of a deviation effect has been termed the semantic mismatch effect. To establish a new phenomenon, it is necessary to show that the effect can be independently replicated and does not depend on specific boundary conditions such as the language of the stimulus material. Here we report a preregistered replication of the semantic mismatch effect in which we examined the effect of unexpected words in 4 different languages (English, French, German, and Swedish) across 4 different laboratories. Participants performed a serial recall task while ignoring sentences with expected or unexpected words that were recorded using text-to-speech software. Independent of language, sentences ending with unexpected words were more disruptive than sentences ending with expected words. In line with previous results, there was no evidence of habituation of the semantic mismatch effect in the form of a decrease in disruption with repeated exposure to the occurrence of unexpected words. The successful replication and extension of the effect to different languages indicates the expression of a general and robust mechanism that reacts to violations of expectancies based on the semantic content of the irrelevant speech. (PsycInfo Database Record (c) 2021 APA, all rights reserved

Changing-state Irrelevant Speech Disrupts Visual-Verbal but not Visual-Spatial Serial Recall

In an influential paper, Jones et al. (1995) provide evidence that auditory distraction by changing relative to repetitive auditory distracters (the changing-state effect) did not differ between a visual-verbal and visual-spatial serial recall task, providing evidence for an amodal mechanism for the representation of serial order in short-term memory that transcends modalities. This finding has been highly influential for theories of short-term memory and auditory distraction. However, evidence vis-à-vis the robustness of this result is sorely lacking. Here, two high-powered replications of Jones et al.’s (1995) crucial Experiment 4 were undertaken. In the first partial replication (n = 64), a fully within-participants design was adopted, wherein participants undertook both the visual-verbal and visual-spatial serial recall tasks under different irrelevant sound conditions, without a retention period. The second near-identical replication (n = 128), incorporated a retention period and implemented the task-modality manipulation as a between-participants factor, as per the original Jones et al. (1995; Experiment 4) study. In both experiments, the changing-state effect was observed for visual-verbal serial recall but not for visual-spatial serial recall. The results are consistent with modular and interference-based accounts of distraction and challenge some aspects of functional equivalence accounts

Registered Replication Report on Fischer, Castel, Dodd, and Pratt (2003)

The attentional spatial-numerical association of response codes (Att-SNARC) effect (Fischer, Castel, Dodd, & Pratt, 2003)—the finding that participants are quicker to detect left-side targets when the targets are preceded by small numbers and quicker to detect right-side targets when they are preceded by large numbers—has been used as evidence for embodied number representations and to support strong claims about the link between number and space (e.g., a mental number line). We attempted to replicate Experiment 2 of Fischer et al. by collecting data from 1,105 participants at 17 labs. Across all 1,105 participants and four interstimulus-interval conditions, the proportion of times the effect we observed was positive (i.e., directionally consistent with the original effect) was .50. Further, the effects we observed both within and across labs were minuscule and incompatible with those observed by Fischer et al. Given this, we conclude that we failed to replicate the effect reported by Fischer et al. In addition, our analysis of several participant-level moderators (finger-counting habits, reading and writing direction, handedness, and mathematics fluency and mathematics anxiety) revealed no substantial moderating effects. Our results indicate that the Att-SNARC effect cannot be used as evidence to support strong claims about the link between number and space

Registered replication report on Fischer, Castel, Dodd, and Pratt (2003)

The attentional spatial-numerical association of response codes (Att-SNARC) effect (Fischer, Castel, Dodd, & Pratt, 2003)—the finding that participants are quicker to detect left-side targets when the targets are preceded by small numbers and quicker to detect right-side targets when they are preceded by large numbers—has been used as evidence for embodied number representations and to support strong claims about the link between number and space (e.g., a mental number line). We attempted to replicate Experiment 2 of Fischer et al. by collecting data from 1,105 participants at 17 labs. Across all 1,105 participants and four interstimulus-interval conditions, the proportion of times the effect we observed was positive (i.e., directionally consistent with the original effect) was .50. Further, the effects we observed both within and across labs were minuscule and incompatible with those observed by Fischer et al. Given this, we conclude that we failed to replicate the effect reported by Fischer et al. In addition, our analysis of several participant-level moderators (finger-counting habits, reading and writing direction, handedness, and mathematics fluency and mathematics anxiety) revealed no substantial moderating effects. Our results indicate that the Att-SNARC effect cannot be used as evidence to support strong claims about the link between number and space

Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial

Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma. Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding. Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries. Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to 100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable. This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124. Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid (5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18). Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of 5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98). Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a randomised trial