The assessment of executive functions to test the integrity of the nigrostriatal network: A pilot study

Background

Parkinson’s disease (PD) is a chronic neurodegenerative disorder characterized by motor and non-motor symptoms. The latter mainly include affective, sleep, and cognitive deficits. Non-demented PD patients often demonstrate impairments in several executive domains following neuropsychological evaluation. The current pilot study aims at assessing the discriminatory power of the Frontal Assessment Battery-15 (FAB15) in differentiating (i) non-demented PD patients and healthy controls and (ii) PD patients with more and less pronounced motor symptoms.

Methods

Thirty-nine non-demented early-stage PD patients in the “on” dopamine state (26 females, mean age = 64.51 years, SD = 6.47, mean disease duration = 5.49 years, SD = 2.28) and 39 healthy participants (24 females, mean age = 62.60 years, SD = 5.51) were included in the study. All participants completed the FAB15. Motor symptoms of PD patients were quantified via the Unified Parkinson’s Disease Rating Scale-Part III (UPDRS-Part III) and Hoehn and Yahr staging scale (H&Y).

Results

The FAB15 score, adjusted according to normative data for sex, age, and education, proved to be sufficiently able to discriminate PD patients from healthy controls (AUC = 0.69 [95% CI 0.60–0.75], SE = 0.06, p = 0.04, optimal cutoff = 11.29). Conversely, the battery lacked sufficient discriminative capability to differentiate PD patients based on the severity of motor symptoms.

Conclusion

The FAB15 may be a valid tool for distinguishing PD patients from healthy controls. However, it might be less sensitive in identifying clinical phenotypes characterized by visuospatial impairments resulting from posteroparietal and/or temporal dysfunctions. In line with previous evidence, the battery demonstrated to be not expendable in the clinical practice for monitoring the severity of PD-related motor symptoms.

What makes us more susceptible to false memories in the era of COVID-19? A focus on vaccines and Green Pass

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic was accompanied by an overabundance of fake news increasing the risk of developing false memories (FMs). Previous studies have shown that the relationship between fake news and FMs could be mediated by some individual variables, including attitudinal biases. We explored the role of these variables in true memories (TMs) and FMs formation, with special emphasis on vaccine- and Green Pass (GP)-related topics.

METHOD

We set up a large online survey exploring several constructs including media usage, attitude toward vaccines and GP, perceived (PK) and objective knowledge (OK) about COVID-19-related information, fear of the disease, depression and anxiety symptoms, coping mechanisms, and reasoning skills. Then, we asked participants whether they remembered certain news (true or fake), providing confidence ratings.

RESULTS

Data from 289 respondents (198 females) from the general population were analyzed. Participants with positive attitude reported a greater fear that their loved ones contracted the COVID-19, a more frequent use of traditional media, and a higher PK when compared with respondents with negative attitude. On the whole sample, participants reported higher confidence levels when required to judge their memory of true than fake news; however, participants with positive attitude reported a higher confidence for both true and fake news. The relationship between attitude and TM confidence was mediated by the PK, whereas the relationship between attitude and FM confidence was probably affected by OK.

CONCLUSION

Attitude can modulate individual behaviors in the context of health issues. The PK and OK may interact with attitude in the memory formation.

Objective Knowledge Mediates the Relationship between the Use of Social Media and COVID-19-Related False Memories

The exposure to relevant social and/or historical events can increase the generation of false memories (FMs). The Coronavirus Disease 2019 (COVID-19) pandemic is a calamity challenging health, political, and journalistic bodies, with media generating confusion that has facilitated the spread of fake news. In this respect, our study aims at investigating the relationships between memories (true memories, TMs vs. FMs) for COVID-19-related news and different individual variables (i.e., use of traditional and social media, COVID-19 perceived and objective knowledge, fear of the disease, depression and anxiety symptoms, reasoning skills, and coping mechanisms). One hundred and seventy-one university students (131 females) were surveyed. Overall, our results suggested that depression and anxiety symptoms, reasoning skills, and coping mechanisms did not affect the formation of FMs. Conversely, the fear of loved ones contracting the infection was found to be negatively associated with FMs. This finding might be due to an empathy/prosociality-based positive bias boosting memory abilities, also explained by the young age of participants. Furthermore, objective knowledge (i) predicted an increase in TMs and decrease in FMs and (ii) significantly mediated the relationships between the use of social media and development of both TMs and FMs. In particular, higher levels of objective knowledge strengthened the formation of TMs and decreased the development of FMs following use of social media. These results may lead to reconsidering the idea of social media as the main source of fake news. This claim is further supported by either the lack of substantial differences between the use of traditional and social media among participants reporting FMs or the positive association between use of social media and levels of objective knowledge. The knowledge about the topic rather than the type of source would make a difference in the process of memory formation.

Psychometric properties of the STAI-Y scales and normative data in an Italian elderly population

BACKGROUND

Early detection of anxiety symptoms in older people is capital as it may be linked to increased physical/functional disabilities, onset and progression of neurodegenerative disorders, and poor cognitive functioning. Nonetheless, there is a paucity of psychometrically validated anxiety measures in the elderly.

AIMS

This study aimed at assessing the psychometric properties of the State-Trait Anxiety Inventory-Form Y (STAI-Y) and providing the first normative data for the Italian elderly population.

METHODS

The sample included 361 individuals aged 65-94. All subjects underwent the Mini-Mental State Examination (MMSE), the Geriatric Depression Scale (GDS), and the state (S-Anxiety) and trait anxiety (T-anxiety) scales of the STAI-Y.

RESULTS

The S-Anxiety and T-Anxiety scales showed reliable internal consistency and, overall, good item characteristics. Divergent validity was "apparently" threatened, with S-Anxiety scale correlating with MMSE and GDS, and T-Anxiety scale only with GDS. The principal component analysis revealed a three-factor solution for both scales, i.e., presence and absence of state (or trait) anxiety, and performance anxiety. Since no effect of sociodemographic variables was found, unadjusted cutoffs were provided.

CONCLUSIONS

Although some questions on the psychometric properties of the STAI-Y remain unanswered, this normative study can help clinicians and researchers to monitor anxiety levels in the Italian elderly population.

Understanding of Numerical Information during the COVID-19 Pandemic

Media news during the Coronavirus Disease 2019 (COVID-19) pandemic often entail complex numerical concepts such as exponential increase or reproduction number. This study investigated whether people have difficulties in understanding such information and whether these difficulties are related to numerical competence, reflective thinking, and risk proneness. One hundred sixty-three participants provided answers to a numeracy scale focusing on complex numerical concepts relevant to COVID-19 (COV Numeracy Scale). They also provided responses to well-established objective and subjective scales, questions about affective states, and questions about the COVID-19 pandemic. Higher scores on the COV Numeracy Scale correlated with higher scores on the Health Numeracy Scale, in the Cognitive Reflection Test (CRT), and in self-assessments of verbal comprehension, mathematical intelligence, and subjective numeracy. Interestingly, scores on the COV Numeracy Scale also positively correlated with the number of consulted information sources about COVID-19. Accuracy in the CRT emerged as a significant predictor, explaining ca. 14% of variance on the COV Numeracy Scale. The results suggest that people with lower reflective thinking skills and lower subjective and objective numerical competence can be more at disadvantage when confronted with COVID-related numerical information in everyday life. These findings advise caution in the communication of relevant public health information that entails complex numerical concepts.

Italian version of the Starkstein Apathy Scale (SAS-I) and a shortened version (SAS-6) to assess "pure apathy" symptoms: normative study on 392 individuals

OBJECTIVES

The present normative study aimed to (1) develop the Italian version of the Starkstein Apathy Scale (SAS-I) and (2) construct a shortened version including only the most sensitive items to "pure apathy" experiences.

METHODS

The normative sample included 392 healthy subjects. A regression-based procedure was used to explore the effects of sex, age, and education on the raw SAS-I score. A correction grid was designed for adjusting raw scores by adding or subtracting the contribution of any significant variable and net of sociodemographic interindividual differences. Cutoff scores were also calculated and fixed at the external tolerance limit on the ninety-fifth centile. To obtain the shortened version, each SAS-I item was correlated with the Beck's Depression Inventory (BDI) score. The only items showing no correlation with BDI were implemented to bypass the well-known overlap between apathetic and depressive symptoms.

RESULTS

The mean raw SAS-I score was 11.27 (SD = 4.42). A significant education effect was observed, with highly educated subjects obtaining lower scores than lowly educated ones. The proposed general cutoff score was 20.68. The SAS-I had fair internal consistency and discriminant validity. Internal consistency increased by removing item 3. The new SAS-6 included items 1, 2, 4, 10, 11, and 13 of the original scale.

CONCLUSION

The SAS-I is a reliable assessment tool to support the diagnosis of apathy. The SAS-6, instead, is a brief questionnaire useful for quickly screening apathetic symptoms in outpatient practice, addressing or not the clinician to further investigations.

The Impact of Failures and Successes on Affect and Self-Esteem in Young and Older Adults

Older adults are assumed to change their affect states in reaction to positive and negative stimuli across the life span. However, little is known about the impact of success and failure events on age-related changes in affect states and, particularly, in self-esteem levels. To fill this gap in the literature, in the present study changes in affect and self-esteem in 100 young (19–30 years) and 102 older adults (65–81 years) were assessed after participants experienced success and failure in a demanding cognitive task. Overall, the success-failure manipulation induced changes on affect states and on state self-esteem, not on trait self-esteem. Regarding age differences, older and young adults were affected to the same extent by experiences of successes and failures. Theoretical considerations of the empirical findings are provided in the general discussion.

Effects of self-generated versus experimenter-provided cues on the representation of future events

Most experimental studies of prospection focused on episodic forms of future events prompted by means of verbal cues. However, there is evidence suggesting that future events differ considerably according to whether they are produced in response to external, experimenter-provided verbal cues or they are self-generated. In the present study, we compared the quality, the phenomenal characteristics, the temporal distribution, and the content of imagined events prompted by experimenter-provided cues (i.e., cue-words and short verbal sentences) or elicited by means of verbal cues that were self-generated in an autobiographical fluency task. The results showed that future events prompted by means of self-generated cues contained fewer event-specific details than future events prompted by experimenter-provided cues. However, future events elicited by means of self-generated and by experimenter-provided cues did not differ with respect to their phenomenal characteristics. The temporal distribution and the thematic content of future representations were also affected by the type of cue used to elicit prospection. These results offer a holistic view of the properties of future thinking and suggest that the content and the characteristics of envisioned future events may be affected by the method used to elicit prospection.

Desirable and undesirable future thoughts call for different scene construction processes

Despite the growing interest in the ability of foreseeing (episodic future thinking), it is still unclear how healthy people construct possible future scenarios. We suggest that different future thoughts require different processes of scene construction. Thirty-five participants were asked to imagine desirable and less desirable future events. Imagining desirable events increased the ease of scene construction, the frequency of life scripts, the number of internal details, and the clarity of sensorial and spatial temporal information. The initial description of general personal knowledge lasted longer in undesirable than in desirable anticipations. Finally, participants were more prone to explicitly indicate autobiographical memory as the main source of their simulations of undesirable episodes, whereas they equally related the simulations of desirable events to autobiographical events or semantic knowledge. These findings show that desirable and undesirable scenarios call for different mechanisms of scene construction. The present study emphasizes that future thinking cannot be considered as a monolithic entity.

Does episodic future thinking improve prospective remembering?

Extant findings suggest interesting avenues for the investigation of the potential relationship between EFT and PM. However, as they stand, they are inconclusive as to the causal role that EFT may play in aiding prospective remembering. In one Experiment, we showed that accuracy in a prospective memory (PM) task performed on the second day was significantly higher when participants, on the first day, had mentally simulated the sequence of events expected to occur on the second day, including the PM task, than when they had performed control tasks. These data extend previous findings on the functional benefit of future simulations in different domains by revealing a substantial facilitation effect of future-oriented thoughts on PM performance when the mentally simulated future task matched the actually executed task.

Age Differences in Negative Priming, Episodic Memory and Frontal Lobe Tasks: A Single Inhibitory Deficit?

The present investigation aimed to assess whether a generalised inhibitory breakdown (Hasher & Zacks, 1988) can account for the well-documented age-related episodic memory deficits. It was argued that, according to whether significant correlations were found among all or between some of the measures of episodic memory and of inhibition included in the present investigation, it would be possible to assume that either a general or a specific, for instance, frontal lobe dependent inhibitory deficit (Dempster, 1992), was responsible for age-related memory deficit. At an empirical level, results from this investigation complement the large number of studies indicating an episodic memory deficit and an early deterioration of frontal lobes in the elderly. At a theoretical level, however, the failure to find age-related differences in the negative priming task challenges the hypothesis that cognitive ageing is due to a generalised inhibitory deficit. Furthermore, the failures to find significant correlations among performance on different tasks assumed to reflect the operation of inhibition processes support the hypothesis for the existence of multiple dissociable inhibitory processes (e.g., Kramer, Humphrey, Larish, Logan, and Strayer, 1994).

What differentiates episodic future thinking from complex scene imagery?

We investigated the contributions of familiarity of setting, self-relevance and self-projection in time to episodic future thinking. The role of familiarity of setting was assessed, in Experiment 1, by comparing episodic future thoughts to autobiographical future events supposed to occur in unfamiliar settings. The role of self-relevance was assessed, in Experiment 2, by comparing episodic future thoughts to future events involving familiar others. The role of self-projection in time was assessed, in both Experiments, by comparing episodic future thoughts to autobiographical events that were not temporal in nature. Results indicated that episodic future thoughts were more clearly represented than autobiographical future events occurring in unfamiliar setting and future events involving familiar others. Our results also revealed that episodic future thoughts were indistinguishable from autobiographical atemporal events with respect to both subjective and objective detail ratings. These results suggest that future and atemporal events are mentally represented in a similar way.

Normative data for a battery of free recall, cued recall and recognition tests in the elderly Italian population

The present study aimed to provide normative data on a large sample of the elderly Italian population (N = 464; range of age = 49-94; range of education = 3-25) on both the word and the picture versions of a battery of free recall, cued recall, and recognition tests of memory. Results from multiple regression analyses showed that both age and education were significant predictors of performance. Therefore, norms were calculated taking into account these demographic variables. The availability of normative data based on a large sample will allow a more reliable use of the battery for clinical assessment in Italian-speaking dementia population.

The role of past in the simulation of autobiographical future episodes

Human beings' ability to envisage the future has been recently assumed to rely on the reconstructive nature of episodic memory (Schacter & Addis, 2007). In the present research, young adults mentally reexperienced and preexperienced temporally close and distant autobiographical episodes, and rated their phenomenal characteristics as well as their novelty. Additionally, they performed a delayed recognition task including remember-know judgments on new, old-remember, and old-imagine words. Results showed that past and future temporally close episodes included more phenomenal details than distant episodes, in line with earlier studies. However, future events were occasionally rated as already occurred in the past. Furthermore, in the recognition task, participants falsely attributed old-imagine words to remembered episodes. While partially in line with previous results, these findings call for a more subtle analysis in order to discriminate representations of past episodes from true future events simulations.

Episodic future thinking in amnesic mild cognitive impairment

Results from behavioral studies of amnesic patients and neuroimaging studies of individuals with intact memory suggest that a brain system involving direct contributions from the medial temporal lobes supports both remembering the past and imagining the future (Episodic Future Thinking). In the present study, we investigated whether amnesic Mild Cognitive Impairment (aMCI) affects EFT. Amnesic MCI is a high-risk factor for Alzheimer's disease and is characterized by a selective impairment of episodic memory, likely reflecting hippocampal malfunctioning. The present study assessed, for the first time, whether the reduction of episodic specificity for past events, evident in aMCI patients, extends also to future events. We present data on 14 aMCI patients and 14 healthy controls, who mentally re-experienced and pre-experienced autobiographical episodes. Transcriptions were segmented into distinct details that were classified as either internal (episodic) or external (semantic). Results revealed that aMCI patients produced fewer episodic, event-specific details, and an increased number of semantic details for both past and future events, as compared to controls. These results are discussed with respect to the constructive episodic simulation hypothesis, which suggests that reminiscence and future thinking are the expression of the same neurocognitive system.

The role of switching, inhibition and working memory in older adults' performance in the Wisconsin Card Sorting Test

The Wisconsin Card Sorting Test (WCST) is considered a typical executive test. However, several interesting questions are still open as to the specific executive processes underlying this task. In the present study, we explored how local and global switching, inhibition and working memory, assessed through the Number-Letter, the Stop Signal and the Reading Span tasks, relate to older adults' performance in the WCST. Results showed that older adults' performance variability in the number of perseverative errors was predicted by the local switch component of the Number-Letter task. Results also showed age-related differences in inhibition, working memory and global switching, while local switching resulted largely spared in aging. This study provides evidence that switching abilities may contribute to performance of older adults in the WCST. It also provides initial evidence suggesting that switching processes, associated with local switch costs, are involved in performance on the WCST, at least in older adults.

Effects of age and mild cognitive impairment on direct and indirect access to arithmetic knowledge

The present study aimed at investigating age-related changes and mild cognitive impairment (MCI) related effects in simple arithmetic. To pursue this goal, MCI patients, healthy old adults and young adults performed three computerised tasks. The production (e.g., 3 x 4=?) and the verification task (3 x 4 12?) evaluated direct access to multiplication knowledge, the number-matching task (3 x 4 34?, 'do 3 x 4 and 34 have the same digits?') tested indirect access. In verification and number-matching, interference from related distractors (e.g., 3 x 4 followed by 16) relative to unrelated distractors (17) reflects access to stored fact representations as well as efficiency of inhibition processes. Results indicated that, compared to young adults, MCI and healthy old adults were slower in responding across tasks. In production and verification, analyses of individual latency regression slopes and intercepts suggested that these age effects were related to differences at peripheral processing stages (e.g., encoding) rather than at the central (arithmetic retrieval) stage. Differences between MCI and healthy elderly emerged only in the number-matching task. While in verification effects were comparable between groups, in number-matching MCI patients were more susceptible to interference from irrelevant information than healthy old participants. Overall, the present findings indicate that aging has a general effect on peripheral processing speed, but not on arithmetic memory retrieval. Parietal cortico-subcortical circuits mediating arithmetic fact retrieval (Dehaene, S., & Cohen, L. (1995). Towards an anatomical and functional model of number processing. Mathematical Cognition, 1, 83-120; Dehaene, S., & Cohen, L. (1997). Cerebral pathways for calculation: Double dissociation between rote verbal and quantitative knowledge of arithmetic. Cortex, 33, 219-250) thus seem to be preserved in normal aging and MCI. In contrast, MCI patients show enhanced interference in number-matching. This task-specific lack of inhibition may point to dysfunctional frontal cortico-subcortical networks in MCI.

Evidence for age-related equivalence in the directed forgetting paradigm

The directed forgetting paradigm involves, under particular experimental circumstances, inhibitory mechanisms, which operate to the successful forgetting of irrelevant words. The item-by-item cueing method (e.g., Basden & Basden, 1996) was used to investigate the directed forgetting effect in young and old adults. Processing of the experimental words was manipulated between subjects by asking participants to perform either a deep or a shallow orienting task on each word of the study list before the occurrence of the cue (to remember of to forget). Results indicated that the instruction to process deeply both to-be-remembered and to-be-forgotten words led to equivalent directed forgetting effects in young and old adults. These results are discussed with respect to the implications they have for the Inhibitory Deficit theory (e.g., Hasher & Zacks, 1988), which suggests that cognitive aging is mainly characterized by a reduction in the efficiency of inhibitory processes.

Age differences and the identity negative priming effect: An updated meta-analysis

A recent meta-analysis (P. Verhaeghen & L. De Meersman, 1998a) revealed that older adults show a reliable but significantly reduced negative priming effect compared with young adults. The present study provides an updated quantitative review on the effect of aging on the magnitude of the negative priming effect in identity tasks. This analysis demonstrated that the negative priming effect was not significantly different between young and old adults. This result differs from P. Verhaeghen and L. De Meersman's study. The implications of this finding for inhibitory-based theories of cognitive aging are discussed.

Target selection difficulty, negative priming, and aging

It has been recently suggested that the presence of identity negative priming effects in old adults could occur when there is substantial processing of the distracting information in a selective attention task (J. M. Kieley & A. A. Hartley, 1997). In three experiments, using a letter identification task, it was found that making target selection more difficult increased the magnitude of the negative priming effect to a similar extent in both young and old adults. Moreover, the size of the negative priming effect did not differ between young and elderly participants. These results are discussed with respect to the issue of age-related deficits in the mechanisms underlying negative priming.

Target selection difficulty, negative priming, and aging

It has been recently suggested that the presence of identity negative priming effects in old adults could occur when there is substantial processing of the distracting information in a selective attention task (J. M. Kieley & A. A. Hartley, 1997). In three experiments, using a letter identification task, it was found that making target selection more difficult increased the magnitude of the negative priming effect to a similar extent in both young and old adults. Moreover, the size of the negative priming effect did not differ between young and elderly participants. These results are discussed with respect to the issue of age-related deficits in the mechanisms underlying negative priming.