BackgroundIt is possible to calculate the number of years to the expected clinical onset (YECO) of autosomal-dominant Alzheimer's disease (adAD). A similar time scale is lacking for sporadic Alzheimer's disease (sAD). The purpose was to design and validate a time scale in YECO for patients with sAD in relation to CSF and PET biomarkers.MethodsPatients diagnosed with Alzheimer's disease (AD, n = 48) or mild cognitive impairment (MCI, n = 46) participated in the study. They underwent a standardized clinical examination at the Memory clinic, Karolinska University Hospital, Stockholm, Sweden, which included present and previous medical history, laboratory screening, cognitive assessment, CSF biomarkers (A beta(42), total-tau, and p-tau), and an MRI of the brain. They were also assessed with two PET tracers, C-11-Pittsburgh compound B and F-18-fluorodeoxyglucose. Assuming concordance of cognitive decline in sAD and adAD, YECO for these patients was calculated using equations for the relationship between cognitive performance, YECO, and years of education in adAD (Almkvist et al. J Int Neuropsychol Soc 23:195-203, 2017).ResultsThe mean current point of disease progression was 3.2 years after the estimated clinical onset in patients with sAD and 3.4 years prior to the estimated clinical onset in patients with MCI, as indicated by the median YECO from five cognitive tests. The associations between YECO and biomarkers were significant, while those between chronological age and biomarkers were nonsignificant. The estimated disease onset (chronological age minus YECO) followed a bimodal distribution with frequency maxima before (early-onset) and after (late-onset) 65 years of age. The early- and late-onset subgroups differed significantly in biomarkers and cognition, but after control for YECO, this difference disappeared for all except the APOE e4 gene (more frequent in early- than in late-onset).ConclusionsA novel time scale in years of disease progression based on cognition was designed and validated in patients with AD using CSF and PET biomarkers. Two early- and late-disease onset subgroups were identified differing with respect to APOE e4.

Objective: To elaborate on possible cognitive sequelae related to COVID-19, associated cerebrovascular injuries as well as the general consequences from intensive care. COVID-19 is known to have several, serious CNS-related consequences, but neuropsychological studies of severe COVID-19 are still rare.

Methods: M., a 45-year-old man, who survived a severe COVID-19 disease course including Acute Respiratory Distress Syndrome (ARDS), cerebral microbleeds, and 35 days of mechanical ventilation, is described. We elaborate on M’s recovery and rehabilitation process from onset to the 8-month follow-up. The cognitive functions were evaluated with a comprehensive screening battery at 4 weeks after extubation and at the 8-month follow-up.

Results: Following extubation, M. was delirious, reported visual hallucinations, and had severe sleeping difficulties. At about 3 months after COVID-19 onset, M. showed mild to moderate deficits on tests measuring processing speed, working memory, and attention. At assessments at 8 months, M. performed better, with results above average on tests measuring learning, memory, word fluency, and visuospatial functions. Minor deficits were still found regarding logical reasoning, attention, executive functioning, and processing speed. There were no lingering psychiatric symptoms. While M. had returned to a part-time job, he was not able to resume previous work-tasks.

Conclusion: This case-study demonstrates possible cognitive deficits after severe COVID-19 and emphasizes the need of a neuropsychological follow-up, with tests sensitive to minor deficits. The main findings of this report provide some support that the long-term prognosis for cognition in severe COVID-19 may be hopeful.

The reminiscence bump is the disproportionally high reporting of autobiographical memories from adolescence and early adulthood and is typically observed when memories are evoked by cues, such as words, pictures, and sounds. However, when odors are used the bump shifts to early childhood. Although these findings indicate that sensory modality affects the bump, the influence of the individual's sensory function on the reminiscence bumps is unknown. We examined the reminiscence bumps of sound- and odor-evoked autobiographical memories of early blind and sighted individuals, since early blindness implies considerable effects on sensory experience. Despite differences in sensory experience between blind and sighted individuals, the groups displayed similar age distributions of both sound- and odor-evoked memories. The auditory bump spanned the first two decades of life, whereas the olfactory bump was once again found in early childhood. These results demonstrate that the reminiscence bumps are robust to fundamental differences in sensory experience.

Cross-sectional studies have suggested age-related differences in decision-making competence, but these differences may also reflect cohort-related effects. We present a longitudinal study of age-related changes over 5 years in older adults (aged 60–85) for 3 important aspects of decision-making competence: resistance to framing, applying decision rules, and resistance to sunk costs. The findings show small age-related longitudinal declines in resistance to framing but no decline in applying decision rules or resistance to sunk costs. The results also indicate that individuals’ decision-making competence after 5 years is significantly related to their initial decision-making competence assessment and that the contribution of crystallized abilities to decision making in older adults is greater than previously thought.

Research on prospective memory has paid no attention to the way in which the intentions to be remembered are framed. In two studies on time-based prospective memory, participants had to remember multiple delayed intentions framed as time rules (i.e., respond every 7 min, every 10 min) or as a series of corresponding instances (i.e., respond at Times 7, 10, 14, 20, 21, 28, 30, etc.). We appraised the effects of intention framing on intention learning, intention representation, strategies used to set the upcoming intention, cognitive load (monitoring cost), and prospective memory performance. Study 1 involved three time rules and corresponding instances. The results showed that time rules are learned faster than corresponding instances and that intention frames shaped the way intentions were mentally represented. Furthermore, the rule frame was associated with a more cognitively demanding incremental planning strategy to establish the upcoming intention, whereas the instance frame promoted the serial recall of intentions. Study 2 replicated the results on representations and strategies with four time rules and corresponding sets of instances, and it showed better prospective memory performance following the instance frame than rule frame. Together, these studies show that two alternative ways of framing multiple delayed intentions in the same prospective memory task induce significant differences in the way intentions are represented, in the cognitive strategies used to set the upcoming intention, and in performance. Theoretical and applied implications of the results for the prospective memory field are discussed.

The study investigates how psychological and social factors relate to productive collocation knowledge in late L2 learners of Swedish (French L1) (N = 59). The individual factors are language aptitude (measured through the LLAMA aptitude test), reported language use, social networks, acculturation, and personality. Multiple linear regression analysis showed that positive effects were found for LLAMA D (phonetic memory), LLAMA E (sound-symbol correspondence), reported language use, and length of residence (LOR). Furthermore, a negative effect was found for the personality variable Open-mindedness. These variables explained 63% (adjusted R²) of the variance, which represents large effects compared to other studies on individual factors. In sum, the findings confirm earlier results on the importance of language aptitude and language use for productive collocation knowledge. They also add evidence of the importance of personality and LOR. In sum, cognitive and social factors combine to explain different outcomes in adult L2 acquisition.

This study investigated what psychological and social factors predict 'perceived nativelikeness' in late second language (L2) learners of French (L1 Swedish) (N = 62) with a minimum length of residence (LOR) of 5 years in France. The included factors were: language aptitude (LLAMA), acculturation (VIA), personality (MPQ), target language engagement and social networks (number of relations in L2). LOR and Length of French studies were also included as extraneous variables. Multiple linear regression analyses showed that positive effects were found for LLAMA D (sound recognition), acculturation (VIA France and VIA Sweden), number of relations in L2 and LOR. A negative effect was found for the personality variable Social initiative. The strongest effects were found for LLAMA D, Social initiative and LOR. All variables together explained 25% (adjusted R-2) of the variance in the sample, which represents medium-sized effects in relation to other studies on individual factors. In sum, these findings confirm results from earlier studies on the importance of language aptitude and acculturation in late L2 acquisition. They also add evidence of the importance of personality, social networks, and LOR. On a more general note psychological and social factors combine to explain different outcomes in adult L2 acquisition, although the effects of psychological variables are deemed somewhat stronger.

The development of multitasking abilities was investigated in relation to working memory capacity, sustained attention, inhibition, and task switching. Using a new touch-screen task, 90 children aged 7-10 years were asked to monitor several timers running at different paces, and to press a button whenever a timer had completed its cycle. Results showed that a significant part of the variance in children's multitasking performance was explained by age, and performance increased significantly until about 8-9 years. Multitasking performance was generally affected by the number of tasks, but even more so in younger children. Sustained attention explained a significant part of the variance in triple-, but not dual-task performance; visuospatial working memory capacity explained variance in dual- and triple-task performance, even after controlling for age. In conclusion, multitasking develops considerably in middle childhood and may involve different processes than dualtasking.

Growth models (GM) of the mixed-effects and latent curve varieties have become popular methodological tools in lifespan research. One of the major advantages of GM is their flexibility in studying individual differences in change. We scrutinized the change functions of GM used in five years of publications on cognitive aging. Of the 162 publications that we identified, 88% test linear or quadratic polynomials, and fewer than 5% apply functions that are nonlinear in their parameters, such as exponential decline. This apparent bias in favor of polynomial decomposition calls for exploring what conclusions about individual differences in change are likely to be drawn if one applies linear or quadratic GMs to data simulated under a conceptually and empirically plausible model of exponential cognitive decline from adulthood to old age. Hence, we set up a simulation that manipulated the rate of exponential decline, measurement reliability, number of occasions, interval width, and sample size. True rate of decline and interval width influenced results strongly, number of occasions and measurement reliability exerted a moderate effect, and the effects of sample size appeared relatively minor. Critically, our results show that fit statistics generally do not differentiate misspecified linear or quadratic models from the true exponential model. Moreover, power to detect variance in change for the linear and quadratic GMs is low, and estimates of individual differences in level and change can be highly biased by model misspecification. We encourage researchers to also consider plausible nonlinear change functions when studying behavioral development across the lifespan.

Measurements of human attitudes and perceptions have traditionally used numerical point judgments. In the present study, we compared conventional point estimates of weight with an interval judgment method. Participants were allowed to make step by step judgments, successively converging towards their best estimate. Participants estimated, in grams, the weight of differently sized boxes, estimates thus susceptible to the size-weight illusion. The illusion makes the smaller of two objects of the same weight, differing only in size, to be perceived as heavier. The self-selected interval method entails participants judging a highest and lowest reasonable value for the true weight. This is followed by a splitting procedure, consecutive choices of selecting the upper or lower half of the interval the individual estimates most likely to include the true value. Compared to point estimates, interval midpoints showed less variability and reduced the size-weight illusion, but only to a limited extent. Accuracy improvements from the interval method were limited, but the between participant variation suggests that the method has merit.

An important task for the law enforcement is to assess the accuracy of eyewitness testimonies. Recent research show that indicators of effortful memory retrieval, such as pausing and hedging (e.g. “I think”, “maybe”), are more common in incorrect recall. However, a limitation in these studies is that participants are interviewed shortly after witnessing an event, as opposed to after greater retention intervals. We set out to mitigate this shortcoming by investigating the retrieval effort-accuracy relationship over time. In this study, participants watched a staged crime and were interviewed directly afterwards, and two weeks later. Half the participants also carried out a repetition task during the two-week retention interval. Results showed that the retrieval-effort cues Delays and Hedges predicted accuracy at both sessions, including after repetition. We also measured confidence, and found that confidence also predicted accuracy over time, although repetition led to increased confidence for incorrect memories. Moreover, retrieval-effort cues partially mediated between accuracy and confidence. 

Recent research has shown that incorrect statements in eyewitness testimonies contain more cues to effortful memory retrieval than correct statements. In two experiments, we attempted to improve judgments of testimony accuracy by informing participants about these effort cues. Participants read eyewitness testimony transcripts and judged statement accuracy. Performance was above chance in both experiments, but there was only a significant effect of the effort-cue instruction in Experiment 2. In Experiment 1, we also compared judgment accuracy between police detectives, police students and laypersons, and found no significant difference, in contrast to previous studies. Moreover, the current study corroborates previous findings that (a) judging testimony accuracy is a difficult task and (b) people spontaneously rely on effort cues to some extent when judging accuracy. However, a complete reliance on effort cues showed substantially better performance than relying on one's own judgments skills at best, and offered equal performance at worst.

Background: Psychopathic traits have been associated with impaired emotion recognition in criminal, clinical and community samples. A recent study however, suggested that cognitive impairment reduced the relationship between psychopathy and emotion recognition. We therefore investigated if reasoning ability and psychomotor speed were impacting emotion recognition in individuals with psychotic spectrum disorders (PSD) with and without a history of aggression, as well as in healthy individuals, more than self-rated psychopathy ratings on the Triarchic Psychopathy Measure (TriPM). 

Methods: Eighty individuals with PSD (schizophrenia, schizoaffective disorder, delusional disorder, other psychoses, psychotic bipolar disorder) and documented history of aggression (PSD+Agg) were compared with 54 individuals with PSD without prior aggression (PSD-Agg) and with 86 healthy individuals on the Emotion Recognition Assessment in Multiple Modalities (ERAM test). Individuals were psychiatrically stable and in remission from possible substance use disorders. Scaled scores on matrix reasoning, averages of dominant hand psychomotor speed and self-rated TriPM scores were obtained. 

Results: Associations existed between low reasoning ability, low psychomotor speed, patient status and prior aggression with total accuracy on the ERAM test. PSD groups performed worse than the healthy group. Whole group correlations between total and subscale scores of TriPM to ERAM were found, but no associations with TriPM scores within each group or in general linear models when accounting for reasoning ability, psychomotor speed, understanding of emotion words and prior aggression. 

Conclusion: Self-rated psychopathy was not independently linked to emotion recognition in PSD groups when considering prior aggression, patient status, reasoning ability, psychomotor speed and emotion word understanding. 

Introduction Previous studies have demonstrated increased suicide rates on holidays such as New Year, nationally and internationally. Comparable to New Year's Eve, Swedish Midsummer is a major holiday, linked to high levels of alcohol consumption in the population. We, therefore, hypothesized that suicides and deaths with undetermined intent would increase during the Midsummer celebration. Methods We used a retrospective death registry design to investigate all suicides that occurred on Midsummer's Eve (ME), Midsummer's Day (MD) and 28 adjacent days (AD) during 1980-2018. Data were stratified by diagnosis type, sex and age, and was analyzed with paired t-tests, Poisson regression, and time-series charts with 95% confidence intervals. Results During the 30-day investigation period, the observed average was 4.3 deaths per day (23.3% cases with undetermined intent). ME, but not MD, was associated with significantly fewer suicides compared to AD (-1.08 deaths, p < .01). ME, but not MD, was simultaneously associated with more deaths with undetermined intent (+0.58 deaths, p = .007). No moderating sex or age effects were found. Descriptive statistics showed that poisonings, drownings and traffic-related injuries were common among the undetermined ME cases. Discussion The study found that suicide decreases and deaths with undetermined intent increases on ME. The findings are interpreted considering that substance use may affect both suicidal intentions and diagnosis classifications. Social and cultural support and holiday anticipations might also account for suicidal behaviors on ME.

The current research addresses gender trouble (acts that question the naturalness of a binary gender system) in two parts of the recruitment situation: applicant attraction and evaluation. Experiment 1 (N = 1,147) investigated how different Equal Employment Opportunity (EEO) statements in an organization description influenced organizational evaluations. The EEO statements emphasized gender as binary (women and men), gender as diverse (multi-gender), or gender as irrelevant (de-gender; compared with no EEO statement). Gender minority participants experienced decreased identity threat in response to the multi-gendered and the de-gendered EEO statements, which increased organizational attractivity. There was no significant effect of EEO statement for gender majority participants. Multi-gendered and de-gendered EEO statements increased perceived gender diversity within the organization. Experiment 2 (N = 214) investigated how applicants with a normative or non-normative gender expression were evaluated by HR-specialists. Applicants with a non-normative gender expression were rated as more suitable for the position and recommended a higher starting salary than applicants with a normative gender expression. Women with a non-normative gender expression were rated as more likely to be employed than men with a non-normative gender expression, while women applicants regardless of gender expression were rated as the most likely to acquire the position. This research indicates that gender minorities can be explicitly included in EEO statements without negative impact on gender majority groups and with a positive impact on gender minority groups. Furthermore, a non-normative gender expression was not found to be a cause for biased evaluations in an initial recruitment situation.

Most everyday activities involve delayed intentions referring to different event structures and timelines. Yet, past research has mostly considered prospective memory (PM) as a dual-task phenomenon in which the primary task to fulfill PM intentions is realized within an ongoing secondary task. We hypothesized that these simplified simulations of PM may have obscured the role of spatial relational processing that is functional to represent and meet the increased temporal demands in more complex PM scenarios involving multiple timelines. To test this spatiotemporal hypothesis, participants monitored four digital clocks, with PM deadlines referring either to the same clock (single-context condition) or different clocks (multiple-context condition), along with separate tests of spatial ability (mental rotation task) and executive functioning (working memory updating). We found that performance in the mental rotation task incrementally explained PM performance in the multiple-context, but not in the single-context, condition, even after controlling for individual differences in working memory updating and ongoing task performance. These findings suggest that delayed intentions occurring in multiple ongoing task contexts reflect independent contributions of working memory updating and mental rotation and that spatial relational processing may specifically be involved in higher cognitive functions, such as complex PM in multiple contexts or multitasking.

When making memory predictions (judgments of learning; JOLs), people typically underestimate the recall gain across multiple study–test cycles, termed the underconfidence-with-practice (UWP) effect. This is usually studied with verbal materials, but little is known about how people repeatedly learn and monitor their own actions and to what extent retrieval practice via interim tests influence the progression of JOLs across cycles. Using action phrases (i.e., squeeze the lemon) as learning material, we demonstrated the UWP effect after both verbal and enactive encoding, although we did not get first-cycle overconfidence. As predicted, participants exhibited underconfidence in Cycles 2 and 3, as an error of calibrations. However, people’s resolution of JOLs (i.e., ability to discriminate recalled from unrecalled items) increased across study–test cycles. Importantly, JOLs for study–test (relative to study–study) items increased faster across cycles suggesting that repeated study–test practice not only produces underconfidence across cycles, but also reduces underconfidence relative to study–study practice. We discuss these findings in terms of current explanations of the underconfidence-with-practice effect.

Retrieval practice improves long-term retention. However, it is currently debated if this testing effect can be further enhanced by overtly producing recalled responses. We addressed this issue using a standard cued-recall testing-effect paradigm with verb–noun action phrases (e.g., water the plant) to prompt motor actions as a specifically powerful response format of recall. We then tested whether motorically performing the recalled verb targets (e.g., ?–the plant) during an initial recall test (enacted retrieval) led to better long-term retention than silently retrieving them (covert retrieval) or restudying the complete verb–noun phrases (restudy). The results demonstrated a direct testing effect, in that long-term retention was enhanced for covert retrieval practice compared to restudy practice. Critically, enactment during retrieval further improved long-term retention beyond the effect of covert memory retrieval, both in a congruent noun-cued recall test after 1 week (Experiment 1) and in an incongruent verb-cued recall test of nouns after 2 weeks (Experiment 2). This finding suggests that successful memory retrieval and ensuing enactment contribute to future memory performance in parts via different mechanisms.

The Wechsler Adult Intelligence Scale, fourth version (WAIS-IV), is a frequently used instrument for neuropsychological assessment. The aim was to assess the degree of conformity between the Scandinavian adaptation of the WAIS-IV and a short form of this scale (SF) in a mixed sample of neurological diagnoses. The SF comprised Block Design, Similarities, Digit Span, Arithmetic, Information, Digit Symbol (in the WAIS-IV named Coding), and Picture Completion, the latter here replaced by Matrix Reasoning. The sample consisted of 150 patients and included multiple sclerosis (n = 27), brain tumor (n = 15), traumatic brain injury (n = 60) and vascular brain damage (n = 48). There was a lack of congruence between the WAIS-IV and the SF in the entire sample, revealing selectively significantly higher scores for the SF on Full Scale IQ (FSIQ) and Processing Speed Index (PSI). On a diagnostic group level, the discrepancies were as follows: in the traumatic brain injury group on FSIQ, Verbal Comprehension Index (VCI) and PSI, in the vascular damage group the FSIQ was significantly higher on SF compared to the WAIS-IV. Since the results revealed several mismatches between the SF and the WAIS-IV, except for the MS and traumatic brain tumor group, there is a lack of interchangeability between these two sets of tests. Thus, generally the SF cannot be recommended as a substitute for the WAIS-IV in this type of mixed Swedish neurological sample. The small sample sizes make the generalizability of this study limited.

People display motivational biases when interpreting numerical information on politically polarized topics. We investigated how disambiguating informationof a numerical problem affected biased reasoning. Results showed that participants’ initial conclusions were biased in line with their ideology, but that biases dropped significantly with the simplified version of the problem.

Abstract for the symposium "Psychological drivers of misinformation and misperception"

We have increasingly sophisticated ways of acquiring and communicating knowledge, but at the same time, efforts to communicate this knowledge often encounter resistance. The aim of the symposium is to understand and characterize the role of drivers such as trust, conformity, ideology and information complexity in motivated reasoning and knowledge resistance.