Stimulus novelty, task demands, and strategy use in episodic memory

From task-general towards task-specific cognitive operations in a few minutes? Working memory performance as an adaptive process

Measurement of cognitive functions is typically based on the implicit assumption that the mental architecture underlying cognitive task performance is constant throughout the task. In contrast, skill learning theory implies that cognitively demanding task performance is an adaptive process that progresses from initial heavy engagement of effortful and task-general metacognitive and executive control processes towards more automatic and task-specific performance. However, this hypothesis is rarely applied to the short time spans of traditional cognitive tasks such as working memory (WM) tasks. We utilised longitudinal structural equation models on two well-powered data sets to test the hypothesis that the initial stages of WM task performances load heavily on a task-general g-factor and then start to diverge towards factors specific to task structure. In line with the hypothesis, data from the first experiment (N = 296) were successfully fitted in a model with task-initial unity of the WM paradigm-specific latent factors, after which their intercorrelations started to diverge. The second experiment (N = 201) replicated this pattern except for one paradigm-specific latent factor. These preliminary results suggest that the processes underlying WM task performance tend to progress rapidly from more task-general towards task-specific, in line with the cognitive skill learning framework. Such task-internal dynamics has important implications for the measurement of complex cognitive functions.

The effects of task novelty for age cohort and cognition level on memory for everyday virtual meal preparation tasks

Nonsensical information increases task novelty, which makes it difficult to rely on previous learning and provides insight into the learning of new tasks. This study investigated procedural-based action scripts in everyday memory for meal preparation tasks in virtual reality. The sample (N = 171) consisted of 3 groups determined by age and cognitive function: young adults (YA; n = 61), older adults with normal cognition (OA; n = 82), and older adults with impaired cognition (IC; n = 28). The three groups completed the Virtual Kitchen Protocol, a virtual reality-based measure of learning and memory for cooking both familiar and nonsensical meals. Results showed that YAs had a greater recall for both familiar and nonsensical meals than OAs or ICs. Additionally, novel stimuli (i.e., nonsensical meal tasks) appear to impact older adults more than young adults. Among older adults, impaired cognition was associated with lower performance on both the sensical and nonsensical meals compared to normal cognition. All three groups performed better on familiar tasks than nonsensical tasks. These results were consistent with the notion that familiarity may be of greater use than novelty in the context of procedural-based action scripts.

Spontaneous memory strategies in a videogame simulating everyday memory tasks

People can use different internal strategies to manage their daily tasks, but systematic research on these strategies and their significance for actual performance is still quite sparse. Here we examined self-reported internal strategy use with a 10-block version of the videogame EPELI (Executive Performance in Everyday LIving) in a group of 202 neurotypical adults of 18-50 years of age. In the game, participants perform lists of everyday tasks from memory while navigating in a virtual apartment. Open-ended strategy reports were collected after each EPELI task block, and for comparison also after an EPELI Instruction Recall task and a Word List Learning task assessing episodic memory. On average, 45% of the participants reported using some strategy in EPELI, the most common types being grouping (e.g., performing the tasks room by room), utilising a familiar action schema, and condensing information (e.g., memorising only keywords). Our pre-registered hypothesis on the beneficial effect of self-initiated strategy use gained support, as strategy users showed better performance on EPELI as compared with no strategy users. One of the strategies, grouping, was identified as a clearly effective strategy type. Block-by-block transitions suggested gradual stabilisation of strategy use over the 10 EPELI blocks. The proneness to use strategies showed a weak but reliable association between EPELI and Word List Learning. Overall, the present results highlight the importance of internal strategy use for understanding individual differences in memory performance, as well as the potential benefit for internal strategy employment when faced with everyday memory tasks.

Self-reported strategy use in working memory tasks

Mnemonic strategies can facilitate working memory performance, but our knowledge on strategy use as a function of task characteristics remains limited. We examined self-reported strategy use in several working memory tasks with pretest data from two large-scale online training experiments. A three-level measure of strategy sophistication (no strategy, maintenance, manipulation) was coded based on participants' open-ended strategy reports. A considerable portion of participants reported some memory strategy, and strategy sophistication was associated with objective task performance. We found a consistent effect of stimulus type: verbal stimuli (letters or digits) elicited higher strategy sophistication than nonverbal ones (colours or spatial positions). In contrast, the association between task paradigm and strategy sophistication was less consistent in the two experiments. The present results highlight the importance of self-generated strategies in understanding individual differences in working memory performance and the role of stimulus characteristics as one of the task-related determinants of strategy use.

Strategy use and its evolvement in word list learning: a replication study

Spontaneous strategy employment is important for memory performance, but systematic research on strategy use and within-task evolvement is limited. This online study aimed to replicate three main findings by Waris and colleagues in Quarterly Journal of Experimental Psychology (2021): in word-list learning, spontaneous strategy use (1) predicts better task performance, (2) stabilizes along the task, and (3) increases during the first two task blocks. We administered a shortened version of their original real-word list-learning task to 209 neurotypical adults. Their first finding was partly replicated: manipulation strategies (grouping, visualization, association, narrative, other strategy) but not maintenance strategies (rehearsal/repetition, selective focus) were associated with superior word recall. The second finding on the decrease in strategy changers over task blocks was replicated. The third finding turned out to be misguided: neither our nor the original study showed task-initial increase in strategy use in the real-word learning condition. Our results confirm the important role of spontaneous strategies in understanding memory performance and the existence of task-initial dynamics in strategy employment. They support the general conclusions by Waris and colleagues: task demands can trigger strategy use even in a familiar task like learning a list of common words, and evolution of strategy use during a memory task reflects cognitive skill learning.

Assessment of goal-directed behavior and prospective memory in adult ADHD with an online 3D videogame simulating everyday tasks

The diagnosis of ADHD is based on real-life attentional-executive deficits, but they are harder to detect in adults than in children and objective quantitative measures reflecting these everyday problems are lacking. We developed an online version of EPELI 3D videogame for naturalistic and scalable assessment of goal-directed action and prospective memory in adult ADHD. In EPELI, participants perform instructed everyday chores in a virtual apartment from memory. Our pre-registered hypothesis predicted weaker EPELI performances in adult ADHD compared to controls. The sample comprised 112 adults with ADHD and 255 neurotypical controls comparable in age (mean 31, SD = 8 years), gender distribution (71% females) and educational level. Using web-browser, the participants performed EPELI and other cognitive tasks, including Conner's Continuous Performance Test (CPT). They also filled out questionnaires probing everyday executive performance and kept a 5-day diary of everyday prospective memory errors. Self-reported strategy use in the EPELI game was also examined. The ADHD participants' self-ratings indicated clearly more everyday executive problems than in the controls. Differences in the EPELI game were mostly seen in the ADHD participants' higher rates of task-irrelevant actions. Gender differences and a group × gender interaction was found in the number of correctly performed tasks, indicating poorer performance particularly in ADHD males. Discriminant validity of EPELI was similar to CPT. Strategy use strongly predicted EPELI performance in both groups. The results demonstrate the feasibility of EPELI for online assessment and highlight the role of impulsivity as a distinctive everyday life problem in adult ADHD.

Impairment of aversive episodic memories during Covid-19 pandemic: The impact of emotional context on memory processes

The threatening context of the COVID-19 pandemic provided a unique setting to study the effects of negative psychological symptoms on memory processes. Episodic memory is an essential function of the human being related to the ability to store and remember experiences and anticipate possible events in the future. Studying this function in this context is crucial to understand what effects the pandemic will have on the formation of episodic memories. To study this, the formation of episodic memories was evaluated by free recall, recognition, and episode order tasks for an aversive and neutral content. The results indicated that aversive episodic memory is impaired both in the free recall task and in the recognition task. Even the beneficial effect that emotional memory usually has for the episodic order was undermined as there were no differences between the neutral and aversive condition. The present work adds to the evidence that indicates that the level of activation does not modify memory processes in a linear way, which also depends on the type of recall and the characteristics of the content to be encoded.

The Pursuit of Effective Working Memory Training: a Pre-registered Randomised Controlled Trial with a Novel Varied Training Protocol

Working memory (WM) training, typically entailing repetitive practice with one or two tasks, has mostly yielded only limited task-specific transfer effects. We developed and tested a new WM training approach where the task paradigm, stimulus type, and predictability of the stimulus sequence were constantly altered during the 4-week training period. We expected that this varied training protocol would generate more extensive transfer by facilitating the use of more general strategies that could be applied to a range of WM tasks. Pre-post transfer effects following varied training (VT group, n = 60) were compared against traditional training (TT group, training a single adaptive WM task, n = 63), and active controls (AC, n = 65). As expected, TT evidenced strong task-specific near transfer as compared to AC. In turn, VT exhibited task-specific near transfer only on one of the measures, and only as compared to the TT group. Critically, no evidence for task-general near transfer or far transfer effects was observed. In sum, the present form of VT failed to demonstrate broader transfer. Nevertheless, as VT has met with success in other cognitive domains, future studies should probe if and how it would be possible to design WM training protocols that promote structural learning where common features of specific tasks would be identified and utilised when selecting strategies for novel memory tasks.