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.