Aging and Cognition
Aging, emotion, and memory: Using a speeded word fragment completion task, Yang and Hasher (2011) revealed an arousal-based word accessibility bias in older adults coupled with a valence-based bias in young adults from semantic memory. In addition, Yang and Ornstein (2011) suggested that unlike older adults who spontaneously attend to emotion, young adults activate emotional goals in response to external demands. Furthermore, we found age-equivalent self-reference effect (i.e., better memory for self-referential information; Yang, Truong, Fuss, & Bislimovic, 2012) and survival effect (i.e., better memory for information processed in a survival mode; Yang, Lau, & Truong, 2014) in memory.
Aging, emotion, and cognitive control: Truong and Yang (2014) examined the effects of emotional content and aging on working memory for target information in the presence of distraction. Young and older participants viewed two target words intermixed with two distracter words, and then judged whether a subsequently presented probe word was one of the target words. The emotional content (valence and arousal) of targets and distracters was systematically manipulated. Results indicated that emotional targets facilitated working memory in both age groups. In contrast, emotional distracters disrupted performance. Negative distracters were particularly disruptive for older adults, but younger adults did not show an emotional interference effect. These findings help clarify discrepancies in the literature and contribute to the sparse research on emotional working memory in older adults.
The dissertation by Linda Truong (defended in 2016) examined the effect of mood induction and cue salience on cognitive control in young and older adults with a standard letter AX-CPT task (with low cue salience) and a modified face cue version of AX-CPT task (with high cue salience) The results showed little evidence for mood effect on cognitive control in both age groups. Although the typical pattern of dominant proactive control in young adults and reactive control in older adults was shown in the standard letter AX-CPT task, the two age groups showed comparable level of proactive control in the salient face cue condition, suggesting that cue salience rather than mood is effective in facilitating proactive control in older adults. The data are currently in preparation for publication.
Aging, emotion, and directed forgetting: The dissertation by Sara Gallant (defended in 2017) aimed to examine age-related changes in cognitive control of emotional memory, including its underlying metacognitive and neural components. In three experiments, young and older adults completed a cue- or value-based version of the item-directed forgetting task for positive, negative, and neutral words. Results consistently demonstrated that young and older adults could strategically control encoding of emotional information, by prioritizing relevant over irrelevant words in memory. Extending previous research on metacognition and aging, results indicated age invariance in prospective judgments of learning made during the encoding of TBR and TBF words that varied in emotion. In contrast, age groups differed when retrospectively monitoring the source of words. Whereas young adults’ source monitoring was not influenced by emotion or cues, older adults tended to attribute positive items to sources that were higher in value for memory (TBR or +10 cues), consistent with an age-related bias to prioritize positivity. Finally, age differences in ERPs underlying encoding of TBR and TBF words provided evidence that older adults may recruit additional resources in frontal regions of the brain to facilitate task performance. Moreover, in line with behavioural results, the ERP signatures of directed forgetting were not modulated by emotion. Altogether, this dissertation demonstrates that cognitive control over emotional memory is intact in later life; however, it highlights important age differences in the metacognitive and neural correlates of this ability. The data are currently in preparation for publication.
Aging, stress, and executive function: This research project was devised in an attempt to examine the effects that psychosocial stress has on executive functioning performance in young and older adult populations. Participants are randomly assigned to one of two conditions: stress or control. The stress condition involves the participants to be subjected to a version of the standardized Trier Social Stress Test (TSST; Kirschbaum & Hellhamer, 1993). Executive functioning was measured at the start of the study and after the conclusion of the TSST/control task. Stress was indexed by multiple physiological aspects (salivary cortisol and heart rate) and subjective feelings of self-reported stress.
Aging and associative memory: In her dissertation (defended in 2017), Brenda Wong examined the role of attentional resources in associative deficit, and to explore encoding manipulations that might alleviate the deficit in older adults. The results suggested that when cognitive resources were depleted through divided-attention during encoding, young adults showed the same associative deficit as older adults. Furthermore, when resource load for associative memory was minimized through pre-exposure of item learning before pair learning, older adults were able to use effective encoding strategies and performed equivalently to young adults. Finally, age-related associative deficit was entirely eliminated when the associative learning was cued by positive values (high or low). Taken together, these results suggest that depletion of attentional resources during encoding could impair associative memory. Furthermore, older adults’ associative deficit could be effectively alleviated with sufficient environmental support during encoding, such as when resource competition between item and associative encoding is minimized or when being guided to prioritize encoding of associations over items. The data are currently in preparation for publication.
In an on-going dissertation project, Lingqian Li intended to examine whether the unitization strategy will differentially benefit the associative memory performance of young and older adults.
Boundary Conditions for Age-related Associative Deficit: Behavioural Moderators and Neural Mechanisms:Although aging does not typically impact semantic memory (i.e., memory for general knowledge or facts), older adults tend to exhibit a reduced episodic memory (i.e., memory for specific details of an event). Specifically, older adults exhibit difficulty remembering associations among memory elements (i.e., associative memory) rather than individual items (i.e., item memory), a phenomenon called associative deficit. However, past research has documented some boundary conditions in which the deficit was attenuated or absent. These conditions include intrinsic manipulations (i.e., built in testing stimuli) or extrinsic manipulations (i.e., provided strategies or instructions). However, the specific mechanisms for this attenuation effect are still unclear. The proposed research will take a novel approach to further test these boundary conditions and the associated behavioural moderators and neural mechanisms within normally aging adults.
Adding Inhibition to Cognitive Control in the Dual Mechanisms of Control Framework: Every day activities require us to hold information in our memory in order to reach a goal. When an obstacle presents itself, we mentally adapt our behaviors to meet that goal through cognitive control. Sometimes, when trying to remember information related to a goal, outdated content can create interference in our memory. Compared to young adults, older adults tend to show greater susceptibility to this form of memory interference. Yet, the cognitive mechanisms surrounding this memory interference, particularly during goal completion, remain unclear. Thus, the aim of this project is to evaluate the performance of young and older adults on a modified cognitive control task where the level of memory interference is varied systematically.
Plasticity of the Aging Brain
Self-guided retest learning in older adults: One earlier research focus of Dr. Yang is on self-guided retest learning (i.e., learning/improvement from repeated testing), as a basic form of cognitive plasticity, in older adults (Yang, 2011). The results suggest that retest learning can be extended to the oldest old who are aged 80 and above (Yang, Krampe, and Baltes, 2006). Both young old and oldest old adults are able to maintain the learning benefits over an 8-month period (Yang & Krampe, 2009). Furthermore, retest learning can occur at conceptual level, beyond the perceptual item-specific effects in advanced age (Yang, Reed, Russo, & Wilkinson, 2009; Yang, Reed, & Kuan, 2012). These findings challenge the traditional view that learning is limited, fragile, or short-lived in the very elderly, and provide important and inspiring insights in learning capacity of the aging brain. The results have been featured in a variety of media reports, including the Ryerson Media News, newspapers, radio, and TV shows.
Plasticity of inhibition in the aging brain: Recently, in an effort to assess plasticity of inhibition, Wilkinson and Yang (2012) trained older adults with a 6-session self-guided training paradigm with an inhibition task, the Stroop task. The results demonstrated substantial practice-induced benefits, and the learning is not item-specific and not contingent to feedback. However, the training did not transfer to other tasks. Nevertheless, older adults maintained the training benefits for up to 3 years (Wilkinson & Yang, 2016, JGPS). Furthermore, we also found sizable retest practice effects in all three sub-functions (access, deletion, and restraint) of inhibition, but transfer effects were only evident for the near-near tasks (same task but with different items, e.g., letters instead of digits; Wilkinson & Yang, 2016, Neural Plasticity). These results shed important light on our understanding of the cognitive plasticity of inhibition, and will greatly inform the development of optimal cognitive remediation programs for older adults.
Exercise mind vs. exercise heart: Currently, the team of CAL is dedicated to an on-going research project “Training-Induced Cognitive and Neural Plasticity of the Aging Brain: Effects of Self-guided Cognitive and Physical Training Programs (PAB)”. This project aims to compares the effects of cognitive and physical training in cognitive and neural plasticity in older adults. To evaluate neural plasticity, Event-Related Potential (ERP) technique will be adopted to record brain activity during executive function tasks and a working memory task administered at pretest and posttest sessions. In light of previous findings, we predict that the cognitive training effect will be ability-specific and more localized in electrical brain activity (specific to frontal lobe). In contrast, the physical training transfer effect will be smaller in magnitude, but broader in both behavioral and neural measures. We will also follow up to examine the long-term maintenance of the training benefits.
Culture and Memory
Culture, aging, and memory: In a series of studies conducted in collaboration with my colleagues in China, I took a novel approach to investigate the effects of culture and age on memory for information learned in different contexts or through different strategies. In Yang, Li et al. (2013), we reported a context memory advantage for Chinese over Canadians in memory for holistically rated socially meaningful contexts (e.g., fostering interpersonal relationship or leading an independent life in a new city) for both young and older adults. In Yang, Chen et al (2013), we reported a memory advantage favoring Canadians over Chinese for categorically processed information. These results are insightful for understanding the underlying factors that affect cultural and age differences in memory processing.
In the study by Wong and Yang (in press), we examined cultural differences in memory for individual objects and backgrounds that have been studied together in one picture. The results showed cultural difference in memory for the isolated objects. However, Canadian participants showed significantly better memory for backgrounds than Chinese participants. Our supplementary data suggested that this effect appeared primarily among participants who self-reported paying attention to both objects and backgrounds. We speculated that relative to Canadian participants, Chinese participants might be more likely to engage in a holistic processing style and thus spontaneously bind background scenes with their associated focal objects when viewing both elements in pictures, which made it more difficult for them to “unbind” the information and recognize backgrounds in isolation. The results of this study add new insights into cultural differences in memory for individual elements in pictures.
In the MA theses by Lingqian Li and Khushi Patel, we also examined cultural differences in memory for face-characteristic and object-location associations. Results were currently in preparation for publication.
COVID-19 and the Chinese Community
The COVID-19 Mobility Project: The COVID-19 Mobility Project is examining risk perception, prevention behaviours, and the impact of the pandemic on individual mobility patterns. The CIHR-funded project is led by researchers from Ryerson University (Dr. Lu Wang and Dr. Lixia Yang) and Queen’s University (Dr. Dongmei Chen). It has been reviewed and approved by the Ryerson University Research Ethics Board [REB 2020-206].
The COVID-19 Impact on Chinese Immigrants (Stage Two): The survey is funded through CIHR and has received ethics approval from the Memorial University of Newfoundland (20201772-ME) and Ryerson University (REB 2020-328；REB2020-132). The leading researchers are Dr. Peizhong Wang (Memorial University of Neufoundland), Dr. Lixia Yang (Ryerson University), Dr. Weiguo Zhang and Dr. Xioalin Wei (University of Toronto). The survey intends to examine the impact of the COVID-19 pandemic on Chinese living in North America (e.g., Canada), including attitudes, cognition, and behavioral measures, and psychological responses. The results will shed light on the effective measures restricting the spread of the disease and inform the policy making of the related Public Health organizations to best support the Chinese community during the pandemic.
The Psychological Impact of the COVID-19 In the Chinese Community: The large NFRF-funded CIHR research program aims: 1) to assess Chinese immigrants’ knowledge, attitudes/beliefs, and protection practices toward the COVID-19; 2) to evaluate the effectiveness and identify the specific needs of the currently on-going self-support volunteer programs; and 3) to assess the psychological impacts of the COVID-19 pandemic. Three studies will be conducted, each address one of the three aforementioned objectives. Study 1 will adopt an on-line survey to gather information on the knowledge, attitudes, and behavioral responses to COVID-19. Study 2 will adopt an interview to assess the volunteer programs in the GTA Chinese communities. Study 3 will adopt an on-line survey and an individual Zoom interview to assess the psychological impact of the COVID-19 outbreak. Dr. Yang is the PI on Study 3. It has two specific objectives: 1) to assess the psychological impact of the COVID-19 outbreak; and 2) to identify individual and environmental predictors for the psychological impacts of the COVID-19 in the GTA Chinese community. An on-line survey and an individual zoom interview will be conducted to address these questions.
Crossing the Cultural Bridge (CCB): Acculturation and Wellbeing in Older Chinese Immigrants during the COVID-19 Pandemic: The current project addresses the following aims: 1) to identify salient factors predicting acculturation; 2) to examine the role of acculturation in engagement; and 3) to examine the role of acculturation wellbeing among older Chinese immigrants. Given the current situation of the COVID-19 outbreak, this project will address all these questions in light of the COVID-19 which exerts much mental and social stress on Chinese older adult population, a most vulnerable population given its age and close cultural tie to China.
The Psychosocial and Cognitive Impacts of the COVID-19 Pandemic on Older Adults: The current study aims to understand how the experience of the COVID-19 pandemic relates to older adults’ psychosocial and cognitive functioning. The psychological impact of a pandemic may increase feelings of depression, anxiety, and trauma symptoms, potentially exacerbated by feelings of loneliness caused by social distancing and isolation. Disruptions in performing community activities due to safety precautions (i.e., reduced hours, longer wait times) could negatively affect the functional independence of older adults. Negative psychosocial effects of the pandemic may be influenced by different coping strategies, which may also be moderated by executive function. The researcher hypothesizes that increase feelings of loneliness and psychological distress, decreased engagement in daily activities, and avoidant-style coping strategies will be related to decreased performances on executive functioning tasks in older adults. Data will be collected through an online experiment which will include an online survey that will assess feelings of loneliness, level of depression/anxiety, coping strategies, changes in engagement with daily activities, and adherence to COVID-19 safety protocol; and a cognitive task component which will assess cognitive performance in executive functioning.