In this thesis I explore how older people make use of, and interact with, their physical environment in home and near-by settings to manage cognitive situations, specifically prospective memory situations. Older adults have in past research been shown to perform better on prospective memory in real-life settings than what findings in laboratory-like settings predict. An explanation for this paradox is that older adults has a more developed skill of using the environment for prospective memory than younger adults. However, research investigating this explanation has primarily been based on self-reports. I contribute to the understanding of this skill by doing two related things. First I introduce distributed cognition, a theoretical perspective that primarily has been used within professional and socio-technical environments, to the research field of prospective memory in everyday life. Second I present a cognitive ethnography conducted during two years across eight home, and near-by, environments and old-age retired persons, for which I have used theoretical concepts from distributed cognition to analyze observations. The analysis shows rich variations in how participants use common cultural cognitive tools, invent their own cognitive tools, deliberately and incidentally shape more or less functional spaces, make use of other physical features, orient themselves toward and make sense of cognitive resources. I complement both prospective memory and distributed cognition research by describing both the intelligent shaping and use of space. Furthermore, by taking a distributed cognitive perspective I show that prospective memory processes in home environments involve properties, and the management, of a multipurpose environment. Altogether this supports the understanding of distributed cognition as a perspective on all cognition. Distributed cognition is not a reflection of particular work practices, instead it is a formulation of the general features of human cognition. Prospective memory in everyday life can be understood as an ability persons have. However, in this thesis I show that prospective memory can also be understood as a process that takes place between persons, arrangements of space, and tools.

According to the Socioemotional Selectivity Theory (SST), the normal aging process is associated with a greater emphasis on self-regulation of emotional states, and this fosters a bias in cognitive processing for information that is positively valenced (e.g., pleasant images and autobiographical events, happy faces), such that older adults have better memory for, and pay greater attention to, positive relative to negative valenced information (a ???positivity effect???). Two hypotheses have recently emerged which differ in the cognitive mechanism proposed to account for the emergence of aging-related positivity effects. The first, termed the ???cognitive control??? hypothesis, suggests that positivity effects arise from older adults' directed application of cognitive efforts to preferentially process positive information, essentially a top-down explanation. The second is a bottom-up hypothesis, suggesting that positive information is relatively easier (more fluent) for older adults to detect and process, compared to negative information, due to changes in amygdala reactivity to negative stimuli, and is termed the "processing fluency" hypothesis. To evaluate these hypotheses, I conducted a suite of memory and attention experiments and compared performance of younger and older adults. I used five different tasks (three different memory tasks, and two different attention tasks) which varied with respect to the degree to which each allowed for the use of cognitive control, and was reflective in nature, or emphasized fluency (i.e., speed of processing and output). In Experiments 1 and 2, I examined the effect of age on two different types of memory task that differed with respect to the degree to which participants must rely on cognitive control/reflective processing or processing fluency to successfully complete the task. Clear positivity effects were found on the task that was reflective in nature (autobiographical memory task) but not on the task that relied more heavily on fluency (phonemic fluency task). In Experiment 3, I examined whether older adults strategically select positive information to later remember (i.e., use cognitive control to regulate encoding of positive material), by asking participants to judge the likelihood of remembering positive, negative, and neutral pictures for a later memory test. In line with a strategic bias, older, but not younger, adults showed a positivity effect in terms of the number of pictures selected as particularly memorable, though both age groups showed a positivity effect in picture recall. Within the domain of attention-based tasks, in Experiments 4a and 4b I used a Rapid Serial Visual Presentation (RSVP) paradigm to examine whether older adults were more likely to detect (or have attention captured by) rapidly presented positive, than negative or neutral, pictures compared to younger adults. Given the rapid rate of presentation in this paradigm, it is unlikely that participants would be able to use cognitive control to strategically direct attention to positive stimuli, thus performance was taken to measure fluency-mediated biases for the pictures of different valence. Results showed little evidence for a positivity effect. In Experiments 5a and 5b, again within the domain of attention, I examined whether older adults preferentially oriented attention toward positive, and/or away from negative, relative to neutral stimuli, on a dot probe task in which trial timings were long enough to allow for strategic control. Experiment 5a used faces whereas Experiment 5b used pictures as stimuli, in an effort to determine whether findings could generalize across different types of stimuli. Some evidence of positivity effects were found, as older adults were less biased to attend to negative (angry) faces compared to younger adults. Results across this series of experiments are consistent with the hypothesis that positivity effects in older adults' memory and attention stem from the strategic application of effortful, reflective, cognitive processing, rather than a bottom-up difference in processing fluency.

Introduction: The prefrontal cortex (PFC) is highly susceptible to age-related deterioration. As such, executive function deficits are commonly observed when older adults process two attention-demanding tasks simultaneously. Everyday tasks such as walking and talking on the phone involve executive functions and the integration of cognitive-motor pathways. However, less is known about this relationship as cognitive demands increase. Methods: Twenty healthy older adults (M = 71.8 years, SD = 6.4) performed four auditory cognitive tasks of increasing demand, including a simple reaction time (SRT), go/no-go (GNG), n-back (NBK), and double number sequence (DNS) task with or without self-paced walking (i.e., single- versus dual-task). Using a blocked design, prefrontal hemodynamic changes (i.e., oxy- [∆HbO2] and deoxyhemoglobin [∆HbR]) were measured using functional near-infrared spectroscopy (fNIRS) and performance was assessed using measures of response time (s), accuracy (% correct) and gait speed (m/s). Results: Prefrontal activation decreased between the single- and dual-tasks across all task demands. Behaviourally, the SRT response times were significantly faster than GNG and NBK. Accuracy decreased between single- and dual-tasks and with increasing demand, but the NBK and DNS tasks were not significantly different. An interaction between task and demand was observed for gait speed such that the DNS dual-task was significantly slower than the single-task. Conclusion: Neural findings support an automatic locomotor control strategy in that cerebral oxygenation decreased between single- and dual-tasks and gait speed was maintained up until the most demanding cognitive task. However, decreased prefrontal activation was inefficient at supporting response time and accuracy performance which may indicate that cognitive performance is differentially affected by cognitive demand and deficits in executive functioning.

Metamemory is “knowing about knowing” (Flavell, 1971) and is theorized as a cognitive process that monitors and controls the memory system (Flavell & Wellman, 1975; Nelson & Narens, 1990). The predominate finding in the metamemory and aging literature is that metamemory is unimpaired by aging, even when memory is impaired by aging (Eakin & Hertzog, 2006; 2012; Connor, Hertzog, & Dunlosky, 1997; Hertzog, Sinclair, & Dunlosky, 2010; Eakin, Hertzog, & Harris, 2014, but see Souchay, Moulin, Clarys, Taconnat, & Isingrini, 2007). However, a study examining metamemory for emotional words suggests older adults may show metamemory impairment when predicting memory for emotional words (Tauber & Dunlosky, 2012). This finding challenges the supposition that metamemory is unimpaired with aging. The purpose of the current study was to expand on the results from Tauber and Dunlosky (2012) to determine whether their findings were due to methodological issues rather than age-related deficits in metamemory.

Older adults' ability to make accurate metamemory judgments indicates that aging spares metamemory (Eakin & Hertzog, 2006; 2012a; but see Souchay et al., 2006). However, age differences in metamemory accuracy for emotional information, particularly lists of positive and neutral words, indicate potential age-related impairment of metamemory (Tauber & Dunlosky, 2012; Flurry & Eakin, manuscript in preparation). These age differences may be explained by potential cue overshadowing effects (Price & Yates, 1993) in which older adults primarily used the salient cue, emotional valence, and overlooked additional cues that were diagnostic of memory. We hypothesized that age differences in metamemory for emotional words may be eliminated when older adults have a second salient and diagnostic cue to inform judgments of learning (JOLs). We manipulated multiple cues, emotional valence and endorsement (Craik & Tulving, 1975), using a category inclusion task in which participants responded "yes" or "no" to endorse positive words (e.g. "champion") or neutral words (e.g. "sphere") as category members (e.g. "is an achievement"). Age comparisons in free recall and JOL magnitude between levels of emotional valence (positive, neutral) and levels of endorsement (yes, no) indicate that both younger and older adults' JOL magnitudes responded to emotional valence and endorsement effects in which memory was higher for positive than neutral words, and "yes" versus "no" words. JOL accuracy results demonstrate that both age groups' JOLs were significantly accurate above chance within each level of valence and endorsement. Age comparisons in JOL accuracy suggest that including a second salient cue eliminated previously reported age differences in metamemory for positive and neutral words. These results demonstrate that older adults can use multiple cues to make accurate JOLs in the presence of a salient cue. This finding supports a conclusion that previously reported age differences in metamemory for emotional words can be attributed to cue overshadowing effects that diminished older adults' ability to use multiple cues. This conclusion has implications on the aging and metamemory literature such that additional age differences reported in episodic metamemory may also be attributed to conditions that hindered multiple cue use by older adults.

Résumé : La psychologie cognitive s'intéresse depuis quelques années à un effet de positivité qui semble apparaître avec l'avancement en âge. Cet effet serait également lié à la diminution, voire la disparition, d'un biais attentionnel négatif, naturellement présent chez les jeunes adultes. Celui-ci consiste en une plus grande perturbation de l'attention sélective en présence de stimuli négatifs. Une tâche cognitive d'attention sélective très utilisée pour étudier ce biais cognitif est le Stroop émotion. Présentant des mots à valence négative, positive et neutre, il permet de vérifier l'effet d'interférence que produisent ces stimuli sur la capacité d'inhibition. Jusqu'à présent, les rares études utilisant le Stroop émotion auprès d'une population âgée sans trouble cognitif ne présentent pas de consensus permettant de statuer clairement sur la modification de ce biais cognitif dans le vieillissement. La présente étude proposait d'utiliser le Stroop émotion pour observer l'effet du vieillissement sur l'attention sélective, en répondant aux principales recommandations méthodologiques tirées des études précédentes. Il était attendu que les âgés ne devaient pas présenter d'effet d'interférence en réponse aux stimuli négatifs, contrairement aux jeunes adultes. Les résultats obtenus ont toutefois révélé la présence d'un biais attentionnel négatif tant chez les âgés que chez les jeunes adultes. L'interprétation de ces performances est discutée en regard des exigences cognitives du Stroop émotion. Il pourrait ainsi être plus facile de mettre en évidence la diminution du biais attentionnel négatif à l'aide d'une présentation différente des stimuli qui permettrait la mise en place de l'effet de positivité chez les âgés.||Abstract : For some years now, cognitive psychology has taken an interest in a positivity effect that appears with increased age. This effect is claimed to be related to the decrease in, or even disappearance of, a negative attentional bias that is naturally present in young adults; this effect consists in a greater disruption of selective attention in the presence of negative stimuli. A cognitive task measuring selective attention that is often used to study this cognitive bias is the emotional Stroop test. This task presents words with negative, positive and neutral valence and tests how these stimuli interfere with inhibition capacity. To date, the few studies that have used the emotional Stroop in an elderly population without cognitive disorders have not produced a consensus that would give us a clear sense of the change in this cognitive bias with aging. This study proposed to use the emotional Stroop to observe the effect of aging on selective attention by following the main methodological recommendations arising from earlier studies. It was expected that elderly people would not present an interference effect in response to negative stimuli, unlike young adults. However, the results revealed a negative attentional bias in both older and younger adults. This finding is interpreted in relation to the cognitive demands of the emotional Stroop. It could therefore be easier to highlight the decrease in negative attentional bias by using a different method of presenting stimuli, which would reveal the positivity effect in elderly people.

As life expectancy increases in modern societies, a greater importance has recently started to be given to cognitive aging. Alzheimer's disease (AD) affects the memory capability of individuals at advanced ages, independently of their general physical health. However, AD is suggested to have an undetectable development many years prior the first clear behavioral symptoms. This silent presence of AD may allow scientists to detect its initial stages, at which a combination of prevention treatments, such as medication and cognitive training, can be more effective. This study extends a line of research that aims to identify possible 'silent' biomarkers of AD using working memory performance and electrophysiological recordings (EEG) in healthy adults. Working memory (aka., short-term memory) is a memory sub-type used in everyday life that allows us to execute tasks in short periods of time. Given the significant parallels of working memory with other forms of long-term memory and its clear facility to be employed in experimental settings of short duration, working memory is a suitable candidate to identify early biomarkers of memory deficits ingeneral. In this study we assessed the cognitive performance and the electrophysiological response - via EEG signals - in a visual working memory recognition task that included the interference of past memories over the present ones. This 'proactive interference' effect is evaluated has a possible biomarker candidate for AD. Our findings reveal that subjects take longer reaction times in the recognition of visual items in the proactive interference condition in comparison to no interference. Additionally, we report an early (170-180 ms) and a later (430-450 ms) EEG components (ERP) that underlies the neural processing responsible for the resolution of this working memory interference. These two time intervals are interpreted as revealing the resolution of proactive interference at two difference stages of visual information processing ('letters'): the phonological (sub-lexical) and semantic (lexical) levels respectively. / --

Distinctive encoding is the processing of unique item-specific information in the context of more general relational or organizational information. It enhances memory performance for both younger and older adults (Smith, 2006). The current work examined how adults use distinctive encoding to aid their free recall performance and whether task experience alters subsequent use of a distinctive encoding strategy. At study participants saw a series of five-item taxonomically categorized lists (e.g., FRUITS). They were first required to generate a category-consistent label (e.g., TASTY FRUIT). In the guided condition, they were then required to generate a single word representing either (1) another category-consistent characteristic (e.g., GROWS) or (2) a characteristic that distinguished a study target from the other items (e.g., FUZZY for the target KIWI). In the self-initiated condition, participants were allowed to select an encoding strategy on their own. After test, all participants completed a second study-test phase with self-initiated strategies. Younger adults initially rated distinctive encoding as more effective, relative to relational encoding, than did older adults, and this difference persisted after test experience, indicating an age difference in learning about the relative superiority of distinctive processing. Consistent with these ratings, distinctive encoding was implemented more so by unguided younger adults than older adults in phase 1. However, both strategy use and recall performance were similar across age and study conditions in phase 2. Both older and younger adults were capable of utilizing distinctive encoding effectively following task experience, although perceptions of strategic effectiveness did not always correspond to self-initiated study behaviors.

Detecting contingency relationships between causal events allows us to adapt to and control these events. However, research has shown age-related impairments in this ability. The goal of this study was to examine how reduced processing speed in older adults affects contingency learning. Manipulating the time during which to generate the response, to test the limited time mechanism of processing speed, had little effect on contingency judgments. Varying the temporal contiguity of events, to test the simultaneity mechanism of processing speed, affected young adults’ contingency judgments. Older adults’ judgments were less accurate overall, and young adults’ judgments were similarly less accurate when there was less temporal contiguity of events. These findings lend support for a processing speed theory of contingency learning.

The ability to make associations between causal cues and outcomes is an important adaptive trait that allows us to properly prepare for an upcoming event. Encoding context is a type of associative processing; thus, context is also an important aspect of acquiring causal relationships. Context gives us additional information about how two events are related and allows us to be flexible in how we respond to causal cues. Research indicates that older adults exhibit an associative deficit as well as a deficit in contextual processing; therefore, it seems likely that these deficits are responsible for the deficit in older adults’ causal learning. The purpose of the current study was to more directly test how associative deficits related to older adults’ contextual processing affect their causal learning. Based on past research, it was hypothesized that older adults would be less likely than younger adults to acquire and use contextual information in causal learning. A causal learning scenario from Boddez, Baeyens, Hermans, and Beckers (2011) was used to test the hypothesis that older adults show deficits in contextual processing in a causal learning scenario. This task examined contextual processing using blocking and extinction. Participants went through eight blocks of trials in which they were exposed to various cues and outcomes. They provided expectancy ratings that indicated how likely they believed an outcome was to occur, and these ratings were used to assess age differences in use of contextual information in a causal learning scenario. As expected, both younger and older adults demonstrated blocking in that they assigned higher causal value to a previously trained target cue (A+) than to another cue (X) that was only presented in compound with cue A later in the task (i.e., AX+). Additionally, when tested in the context where the association was originally learned following extinction training (i.e., A-), the causal value of cue A decreased for all groups, even if extinction training took place in a different context. However, ratings for cue A decreased even more for younger adults whose extinction training took place in a different context when tested in their extinction context.