Memory as a scale of simulation depending on the trace distinctiveness.

It has been proposed that representations emerge from a single memory system organized along a continuum of specificity. This continuum is assumed to reflect a scale between the simulation of overlapping and specific features of the traces, which depends on trace distinctiveness. More specifically, higher trace distinctiveness facilitates the simulation of trace-specific features, which increase the discriminability of traces and lead to the emergence of a more specific representation. In two experiments, participants were asked to identify match (low task discrimination demand) or mismatch (high task discrimination demand) associations between actions and characters that were visually either highly or lowly distinctive. The results of Experiment 1 show that in the high-distinctiveness context, performance was better when identifying a mismatch rather than a match, while the opposite was true in the low-distinctiveness context. The results of Experiment 2 show that using a dynamic visual noise to interfere with the participants' ability to simulate the features of the characters also reduced the benefit of the high-distinctiveness context for the mismatch trials (Experiment 2a and 2b) and increased the benefit of the low-distinctiveness context for the match trials (Experiment 2b). Taken together, these results suggest that the simulation of trace-specific features underlies the emergence of specific representations, which can be beneficial when the discrimination demand of the task is high and detrimental when this demand is low. Memory might therefore be viewed as a scale of simulation between overlapping and specific trace features.

Executive deficits in schizophrenia: mediation by processing speed and its relationships with aging.

BACKGROUND: Executive deficits are a core characteristic of schizophrenia. Yet, the origin of these impairments remains unclear as they may be caused by processing slowing. This issue is of particular interest for aging insofar as cognitive aging is also associated with a decline in executive functioning and a slowing of processing speed. As schizophrenia patients' life expectancy increases, a better understanding of the origin of older patients' cognitive deficits becomes essential so that healthcare can be adapted to suit them. This study aims to determine whether processing speed mediates how schizophrenia affects executive functions and whether these relationships are moderated by age. METHODS: Sixty-two schizophrenia patients (27 women) and 62 healthy comparison subjects matched for age (range: 18-76 years), gender and education performed neurocognitive tests to evaluate their executive functions (shifting, updating, inhibition and access) and processing speed. RESULTS: Processing speed mediated the effect of schizophrenia on the four specific executive functions, and age moderated this mediation for shifting, updating and access, but in different ways. Age moderated the effect of processing speed on shifting, the direct effect of schizophrenia on access, and both the effect of processing speed and the direct effect of schizophrenia on updating. CONCLUSIONS: This research highlights the need to evaluate processing speed routinely during therapeutic follow-up, as it is easy and simple to assess and appears to be at the heart of the cognitive deficits in schizophrenia. Finally, processing speed abilities yield information about the evolution of cognition with aging in schizophrenia.

Playing "guess who?": when an episodic specificity induction increases trace distinctiveness and reduces memory errors during event reconstruction.

The constructive nature of memory implies a possible confusion between details of similar events. Memory interventions should thus target the reduction of memory errors. We postulate that a brief intervention called Episodic Specificity Induction (ESI) facilitates the sensorimotor simulation of event-related details by improving the distinctiveness of the event memory trace. As such, ESI should reduce memory errors only when event memory traces are strongly overlapping based on their sensorimotor features. Participants memorised videos showing characters performing an action on a given object. The characters were either visually very similar to each other or very distinct (low vs. high distinctiveness condition). Next, participants performed either an imagination version of the ESI or a control induction. Finally, a voice announced one of the actions seen and a character was then briefly displayed. The participants had to indicate whether the association was correct. For incorrect associations, in the low distinctiveness condition, false alarms were more likely than in the high distinctiveness condition and were reduced after the ESI. It suggests that facilitating the simulation of specific details through the ESI increased trace distinctiveness and reduced memory errors at the critical time of event reconstruction. Future clinical applications might be possible.

When motion improves working memory.

In the present study, we used a complex span task to explore how memory traces resulting from Self-Performed Task (SPT) and Verbal Task (VT) are maintained in working memory. Participants memorised series of five sentences describing an action either through SPT or VT. Between pairs of sentences, participants performed a concurrent task that varied according to its nature and its cognitive load. The concurrent task was either a verbal task, a low cognitive load motor task or a high cognitive load motor task. A control condition served as a baseline. First, we observed that performance in SPT and VT did not decrease with verbal or motor suppression, but was lower with an increase of the cognitive load. This suggests that memory traces are maintained through attentional refreshing whatever the encoding (SPT or VT). Second, while the enactment effect was replicated in the control condition, it tended to vanish with a verbal concurrent task; moreover, it was reversed with motor concurrent tasks. Surprisingly, the latter effect resulted from an increase of VT memory performance when participants repeated the same gesture between sentences. Finally, our results provide additional evidence that the enactment effect does not rely on attention.

Visual and auditory perceptual strength norms for 3,596 French nouns and their relationship with other psycholinguistic variables.

Perceptual experience plays a critical role in the conceptual representation of words. Higher levels of semantic variables such as imageability, concreteness, and sensory experience are generally associated with faster and more accurate word processing. Nevertheless, these variables tend to be assessed mostly on the basis of visual experience. This underestimates the potential contributions of other perceptual modalities. Accordingly, recent evidence has stressed the importance of providing modality-specific perceptual strength norms. In the present study, we developed French Canadian norms of visual and auditory perceptual strength (i.e., the modalities that have major impact on word processing) for 3,596 nouns. We then explored the relationship between these newly developed variables and other lexical, orthographic, and semantic variables. Finally, we demonstrated the contributions of visual and auditory perceptual strength ratings to visual word processing beyond those of other semantic variables related to perceptual experience (e.g., concreteness, imageability, and sensory experience ratings). The ratings developed in this study are a meaningful contribution toward the implementation of new studies that will shed further light on the interaction between linguistic, semantic, and perceptual systems.

Norms of conceptual familiarity for 3,596 French nouns and their contribution in lexical decision.

In the last decade, research has shown that word processing is influenced by the lexical and semantic features of words. However, norms for a crucial semantic variable-that is, conceptual familiarity-have not been available for a sizeable French database. We thus developed French Canadian conceptual familiarity norms for 3,596 nouns. This enriches Desrochers and Thompson's (2009) database, in which subjective frequency and imageability values are already available for the same words. We collected online data from 313 Canadian French speakers. The full database of conceptual familiarity ratings is freely available at http://lingualab.ca/fr/projets/normes-de-familiarite-conceptuelle . We then demonstrated the utility of these new conceptual familiarity norms by assessing their contribution to lexical decision times. We conducted a stepwise regression model with conceptual familiarity in the last step. This allowed us to assess the independent contribution of conceptual familiarity beyond the contributions of other well-known psycholinguistic variables, such as frequency, imageability, and age of acquisition. The results showed that conceptual familiarity facilitated lexical decision latencies. In sum, these ratings will help researchers select French stimuli for experiments in which conceptual familiarity must be taken into account.

Getting a tool gives wings: overestimation of tool-related benefits in a motor imagery task and a decision task.

Two experiments examine whether people overestimate the benefits provided by tool use in motor tasks. Participants had to move different quantities of objects by hand (two at a time) or with a tool (four at a time). The tool was not within reach so participants had to get it before moving the objects. In Experiment 1, the task was performed in a real and an imagined situation. In Experiment 2, participants had to decide for each quantity, whether they preferred moving the objects by hand or with the tool. Our findings indicated that people perceive tool actions as less costly in terms of movement time than they actually are (Experiment 1) and decide to use a tool even when it objectively provides less time-based benefits than using the hands (Experiment 2). Taken together, the data suggest that people overestimate the benefits provided by tool use.

Mind your heart to bear the weight: Cardiac interoception predicts action-related visual perception when wearing a heavy backpack.

Visual perception can be modulated by the physiological potential for action. For instance, it was famously shown that a geographical slant appears steeper when wearing a heavy backpack than not wearing any. However, those results are not always replicated. In the present exploratory study, we test the hypothesis that the backpack weight's effect on perception relies on the ability of the cognitive system to integrate the physiological constraint's change rather than the change itself. Young adults (n = 54) wore an electrocardiogram monitor and completed a computerised task in which photographs of real geographical slants were displayed on a screen while wearing a heavy versus light backpack. The activity of the vagus nerve, as an index of physiological adaptability, was recorded as a proxy of the physiological state during the task. The participants also completed an interoception task assessing one's ability to detect his or her own heartbeat as the index of integration ability of the cognitive system. While Bayesian analyses revealed no difference in angle estimation between carrying a heavy versus light backpack, the results indicated that interoception predicted less accurate angle estimation only when wearing a heavy backpack. In contrast, there was anecdotal evidence that vagal activity changes predicted visual perception. Interoception might thus play a crucial role in the interplay between the physiological potential for action and action-related visual perception.

Improving Audiology Student Training by Clinical Simulation of Tinnitus: A Glimpse of the Lived Experience of Tinnitus.

PURPOSE: Student audiology training in tinnitus evaluation and management is heterogeneous and has been found to be insufficient. We designed a new clinical simulation laboratory for training students on psychoacoustic measurements of tinnitus: one student plays the role of the tinnitus patient, wearing a device producing a sound like tinnitus on one ear, while another student plays the role of the audiologist, evaluating their condition. The objective of the study was to test this new clinical simulation laboratory of tinnitus from the perspective of the students. METHOD: This study reports the findings from twenty-one audiology students (20 female and 1 male, mean age = 29, SD = 7.7) who participated in this laboratory for a mandatory audiology class at the Laval University of Quebec. Three students had hearing loss (one mild, two moderate). All students played the role of both the clinician and the patient, alternately. They also had to fill out a questionnaire about their overall experience of the laboratory. RESULTS: The qualitative analysis revealed three main themes: "Benefits of the laboratory on future practice", "Barriers and facilitators of the psychoacoustic assessment", and "Awareness of living with tinnitus". The participants reported that this experience would have a positive impact on their ability to manage tinnitus patients in their future career. CONCLUSION: This fast, cheap, and effective clinical simulation method could be used by audiology and other healthcare educators to strengthen students' skills and confidence in tinnitus evaluation and management. The protocol is made available to all interested parties.

The role of social representations on embodied and situated cognitive aging: The example of the transition to retirement / Rôle des représentations sociales sur le vieillissement cognitif incarné et situé : l'exemple du passage à la retraite

Aging is a complex process characterized by physical, psychological, and social changes. The interactions between these different aspects are naturally explained by embodied and situated approaches to cognition that offer a global, integrated, and unified understanding of aging. They propose a dynamic cognition emerging from the interaction of sensory-motor perceptions (embodied aspect) and the context of the present situation (situated aspect). However, very few studies have focused on this situated aspect of cognition in the study of cognitive aging. Yet, aging is also a social process, associated with many representations, often negative, that have effects on health and cognition. Stereotype embodiment theory proposes that representations of aging are internalized by everyone over time, gradually modifying intrapersonal behaviors. This article proposes that the cognitive changes observed in aging are partly the result of physical changes, related to repeated behavioral changes, caused by the effect of representations of aging. However, unlike other forms of stigmatization, the factors of belonging to the social group of the elderly are neither clear nor static. Only the transition to retirement seems to constitute a key stage in social aging. Therefore, the transition to retirement represents a unique situation to study the impact of a major social and physical context change on cognitive functioning. It would act as a catalyst for the effect of representations of aging by marking the social transitions toward aging and retirement. Different perspectives of applied research are also discussed, around prevention interventions and preparation for retirement.

Le vieillissement est un processus complexe caractérisé par des changements physiques, psychologiques et sociaux. Les interactions entre ces différents aspects sont naturellement expliquées par l'approche incarnée et située de la cognition qui offre une compréhension globale, intégrée et unifiée du vieillissement. Elle propose une cognition dynamique émergente de l'interaction des composants sensori-moteurs (aspect incarné) et du contexte de la situation présente (aspect situé). Cependant, très peu d'études se sont intéressées à cet aspect situé de la cognition dans l'étude du vieillissement cognitif. Pourtant, le vieillissement est aussi un processus social, associé à de nombreuses représentations souvent négatives ayant des effets sur les comportements de santé et la cognition. Cet article propose que les variations cognitives observées au cours du vieillissement résultent en partie de modifications physiques, liées à des changements comportementaux répétés, provoqués par l'effet des représentations du vieillissement. Dans cette perspective, le passage à la retraite représente une situation unique pour étudier les répercussions d'un changement de contexte social et physique majeur sur le fonctionnement cognitif. Il agirait comme un catalyseur de l'effet des représentations du vieillissement en marquant les transitions sociales vers le vieillissement et la retraite. Différentes possibilités de recherches appliquées sont également discutées.

The heart to make the right choice: Vagal (re)activity and recovery predict advantageous decision-making.

From simple everyday choices to life-altering decisions, decision-making is a crucial cognitive process in our daily life. Psychophysiological theories of heart-brain interactions involvement in cognition predict that general self-regulation capacities underlie cognitive processes including decision-making. Yet, in the context of decision-making, the somatic maker hypothesis postulates that the adaptability of the current physiological state should be the best predictor of advantageous decision-making. The present study tests compare self-regulation in general (indexed by resting vagal activity) and in a specific decisional context (vagal reactivity and recovery) to explain advantageous decision-making. Young adults (n = 54) completed a decision-making task while wearing a heart rate monitor. Bayesian regressions show that vagal reactivity and recovery combined is the preferred statistical model to explain advantageous decision-making (BF10 = 163.85). Those findings 1) support the somatic marker hypothesis highlighting the key role of in situ self-regulation in decision-making processes and 2) show that the popular and often used index of general self-regulation, resting vagal activity, is not the best predictor of decision-making performance, and perhaps even for other cognitive functions. A next step could be interventional studies to test whether vagal modulation of heart rate underlies decision-making through interventions that influence vagal activity, which could provide relevant clinical leads.

When does vagal activity benefit to the discrimination of highly overlapping memory traces?

Distinguishing among similar events is indeed crucial to memory. In a dangerous context, this ability may be less essential, whereas in a secure context it may provide an adaptative advantage notably in social situations. Vagal activity as a marker of the individual's adaptation in social engagement contexts might predict the ability to discriminate highly similar memories in an unthreatening context. The present study aims to test the relation between vagal activity and memory discrimination by manipulating the visual distinctiveness of stimuli (high vs. low) in an ecological memory discrimination task with humanoid characters. It was expected that vagal activity support adaptive self-regulatory processes which may be needed only when the memory discrimination is challenging (low distinctiveness between true memory and lure). In a study phase, multiple realistic fictional humanoid characters performed the same action on different objects. The characters could be very similar or very distinct one to each other. Then, during a test phase, the participants had to discriminate whether a displayed character on the screen was exactly matched the one performing the given action on a specific object in the study phase (target). Vagal activity was assessed in undergraduate students (n = 40) before the study phase. Higher vagal activity predicted better memory discrimination performance specifically when the distinctiveness between the lure and target was low. These data extend previous work on vagal activity and memory suggesting that heart-brain interactions represent an adaptive psychophysiological mechanism underlying memory discrimination specifically when it is challenging in an unthreatening context.

Does an increase in physiological indexes predict better cognitive performance: the PhyCog randomised cross-over protocol in type 2 diabetes.

INTRODUCTION: There has been a growing interest towards cognitive-training programmes to improve cognition and prevent cognitive impairment despite discrepant findings. Physical activity has been recognised in maintaining or improving cognitive ability. Based on a psychoneurophysiological approach, physiological indexes should partly determine neuronal dynamics and influence cognition as any effects of cognitive training. This study's primary aim was to examine if improved physiological indexes predict improved cognitive variables in the context of a clinical intervention programme for type 2 diabetes (T2D). METHOD AND ANALYSIS: PhyCog will be a 22-week randomised controlled trial comparing cognitive performance between three arms: (1) physical activity (1 month), a 15-day wash-out, then cognitive training (1 month), (2) cognitive training (1 month), a 15-day wash-out and physical activity (1 month), and (3) an active breathing condition (psychoeducation and resonance frequency breathing for 1 month), then a 15-day wash-out, and combined physical activity and cognitive training (1 month), allowing to determine the most effective intervention to prevent cognitive impairment associated with T2D. All participants will be observed for 3 months following the intervention. The study will include a total of 81 patients with T2D.Cognitive performance and physiological variables will be assessed at baseline (week 0-W0), during the washout (W5, 72-96 hours after week 4), at the end of the intervention (W10), and at the end of the follow-up (W22). The main variables of interest will be executive function, memory and attention. Physiological testing will involve allostatic load such as heart rate variability, microcirculation, cortisol and dehydroepiandrosterone sulfate levels. Sociodemographic and body composition will also be a consideration. Assessors will all be blinded to outcomes. To test the primary hypothesis, the relationship between improvement in physiological variables and improvement in cognitive variables (executive, memory and attention) will be collected. ETHICS AND DISSEMINATION: This protocol was approved by the Est III French Ethics Committee (2020-A03228-31). Results will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04915339.

Does heart rate variability predict better executive functioning? A systematic review and meta-analysis.

The recent focus on the bidirectional heart-brain interactions in psychoneurophysiological research has led to a variety of findings suggesting vagal activity is associated with cognition and, possibly, specifically with executive functioning. This systematic review and meta-analysis aimed to provide a better understanding of the association between vagally-mediated heart rate variability (HRV) and executive functioning. We included 13 correlational studies. We found a small positive association between vagally-mediated HRV and executive functioning (r = .19, 95% CI .15 to .23, p < .0001) using a quantitative synthesis of existing studies with random-effect models. Conducting meta-regression analyses, we found that vagally-mediated HRV predicts cognitive inhibition and cognitive flexibility more than working memory. In addition to the specific executive function measured, this relationship is moderated by the HRV measurement used, and age. After proposing a theoretical interpretation of the results, we emphasized the need for further research in light of the methodological issues identified in the included studies, and we outline several aspects to consider in future studies.

Work-related stress of companies' directors during the first lockdown due to the COVID-19.

Background: The COVID-19 pandemic and the first lockdown were particularly stressful with a major economic impact, but the impact on stress of company directors was not known. Therefore, this study aimed to assess that impact and the characteristics of companies the most at risk. Method: A online questionnaire was sent to 13,114 company. It assessed stress at work, number of employees, sector of activity, business activity rate and geographical location. It studied the mean stress levels, the percentage of stress > 8/10 and carried out an analysis of the characteristics of the most at-risk companies. Results: A total of 807 company directors responded. Their stress levels increased by 25.9% during lockdown and 28.7% of them had a stress > 8/10. Sectors which had the biggest increase in stress levels during lockdown were retail trade, wholesale trade, and nursing homes. Sectors the most at risk of stress >8/10 during lockdown tended to be nursing homes, pharmacies, and IT activities. Biggest companies had the highest increase in stress levels. Conclusion: The first lockdown of the COVID-19 pandemic had a major impact on the stress of company directors. Directors of large companies were the most exposed to stress as well as medical and IT activities.

The Negative Impact of Night Shifts on Diet in Emergency Healthcare Workers.

Despite the consequences of night-shift work, the diet of night-shift workers has not been widely studied. To date, there are no studies related to food intake among emergency healthcare workers (HCWs). We performed a prospective observational study to assess the influence of night work on the diet of emergency HCWs. We monitored 24-h food intake during a day shift and the consecutive night, and during night work and the daytime beforehand. We analyzed 184 emergency HCWs' food intakes. Emergency HCWs had 14.7% lower (-206 kcal) of their 24-h energy intake during night shifts compared to their day-shift colleagues (1606.7 ± 748.2 vs. 1400.4 ± 708.3 kcal, p = 0.049) and a 16.7% decrease in water consumption (1451.4 ± 496.8 vs. 1208.3 ± 513.9 mL/day, p = 0.010). Compared to day shifts, night-shift had 8.7% lower carbohydrates, 17.6% proteins, and 18.7% lipids. During the night shift the proportion of emergency HCWs who did not drink for 4 h, 8 h and 12 h increased by 20.5%, 17.5%, and 9.1%, respectively. For those who did not eat for 4 h, 8 h and 12 h increased by 46.8%, 27.7%, and 17.7%, respectively. A night shift has a huge negative impact on both the amount and quality of nutrients consumed by emergency healthcare workers.

A cross-sectional study to assess job strain of emergency healthcare workers by Karasek questionnaire: The SEEK study.

Background: Emergency healthcare workers (eHCWs) are particularly at risk of stress, but data using the gold standard questionnaire of Karasek are scarce. We assessed the level of stress of eHCWs and aimed to compare it with the general population. Methods: This is a cross-sectional nationwide study in French Emergency Departments (EDs), using the job-content questionnaire of Karasek, compared with the 25,000 answers in the French general population (controls from the SUMER study). The descriptions of job demand, job control, and social support were described as well as the prevalence of job strain and isostrain. Putative factors were searched using mixed-method analysis. Results: A total of 166 eHCWs (37.9 ± 10.5 years old, 42% men) from five French EDs were included: 53 emergency physicians and 104 emergency paramedics, compared to 25,000 workers with other occupations. Job demand was highest for physicians (28.3 ± 3.3) and paramedics (25.9 ± 3.8), compared to controls (36.0 ± 7.2; p < 0.001). Job control was the lowest for physicians (61.2 ± 5.8) and paramedics (59.1 ± 6.8), compared to controls (70.4 ± 11.7; p < 0.001). Mean social support did not differ between groups (23.6 ± 3.4 for physicians, 22.6 ± 2.9 for paramedics, and 23.7 ± 3.6 for controls). The prevalence of job strain was massively higher for physicians (95.8%) and paramedics (84.8%), compared to controls (23.9%; p < 0.001), as well as for isostrain (45.1% for physicians, 56.8% for paramedics, and 14.3% for controls, p < 0.001). We did not find any significant impact of sociodemographic characteristics on job control, job demand, or social support. Conclusion: Emergency healthcare workers have a dramatic rate of job strain, necessitating urgent promotion of policy to take care of them.

Benefits from one session of deep and slow breathing on vagal tone and anxiety in young and older adults.

Anxiety is recognized as a major health issue and is quite prevalent among older adults. An efficient way to manage anxiety is abdominal breathing. Breathing exercises seem to reduce anxiety and to increase parasympathetic activity assessed by HRV indexes. Yet, the effect of abdominal breathing on physiological stress (HRV) and anxiety in older adults remains poorly understood. Therefore, the aim of this study is to test the effects of deep and slow breathing (DSB, low inhale/exhale ratio) on physiological stress and anxiety in older adults (n = 22) in comparison with younger ones (n = 25). DSB increased significantly HFpower and reduced state anxiety in both younger and older adults. Interestingly, the increased in HF power was significantly higher among older adults than younger ones. As expected, the ratio inhale/exhale being not equal, RMSSD did not increase following DSB. Thus, we provide evidence suggesting that DSB is more beneficial to older adults than younger ones to restore vagal outflow. Despite future work being required, those results provide relevant clinical application leads to manage state anxiety among older adults and to promote successfull aging.

Sedentary Lifestyle Matters as Past Sedentariness, Not Current Sedentariness, Predicts Cognitive Inhibition Performance among College Students: An Exploratory Study.

Background: Currently, sedentariness is assessed over a short period of time, thus it is difficult to study its cognitive implications. To investigate the cognitive consequences of a sedentary lifestyle, the past level (i.e., the sedentary time accumulated over the years) and current level of sedentariness should be considered. This pilot study aimed to investigate the negative association between a sedentary lifestyle and cognition by considering both the current and past sedentariness. It was expected that the physical activity level moderates the potential negative association between sedentariness and cognition. Methods: 52 college students (Mage = 20.19, SDage = 2; 36 women) participated in the study. Current sedentariness (ratio of sedentary time in the last year), past sedentariness (ratio of sedentary time accumulated in previous years), and physical activity (ratio of time spent in physical activity in years) were assessed using a questionnaire. Cognitive inhibition, cognitive flexibility, and working memory updating were measured through three specific tests. Results: Past sedentariness significantly explained the inhibition performance when controlled for physical activity, whereas current sedentariness did not. More precisely, past sedentariness only negatively predicted cognitive inhibition when the physical activity level was low (ß = -3.15, z(48) = -2.62, p = 0.01). Conclusions: The impact of sedentariness on cognitive functioning might only be revealed when past sedentariness and physical activity are controlled.

Low-Resolution Neurocognitive Aging and Cognition: An Embodied Perspective.

Consistent with embodied cognition, a growing evidence in young adults show that sensorimotor processing is at the core of cognition. Considering that this approach predicts direct interaction between sensorimotor processing and cognition, embodied cognition may thus be particularly relevant to study aging, since this population is characterized by concomitant changes in sensorimotor and cognitive processing. The present perspective aims at showing the value and interest to explore normal aging throughout embodiment by focusing on the neurophysiological and cognitive changes occurring in aging. To this end, we report some of the neurophysiological substrates underpinning the perceptual and memory interactions in older adults, from the low and high perceptual processing to the conjunction in the medial temporal lobe. We then explore how these changes could explain more broadly the cognitive changes associated with aging in terms of losses and gains.