Semantic feedback processing mechanism of the enactment effect: Evidence from event-related potentials

The enactment effect refers to a phenomenon in which the memory performance for action phrases is enhanced by performing the described action (e.g., sharpen a pencil) compared with simply reading the action phrase. This produced effect can result in improved motor processing. This study investigated the contribution of semantic integration to the enactment effect by contrasting well-integrated phrases, such as “blow up the balloon,” with poorly integrated phrases, such as “sew the toothpick,” and analysing the N400 component of event-related potentials (ERPs). The subjects encoded action phrases with different degrees of semantic integration by either pretending to perform or reading action phrases. They then completed a phrase recognition test, while electroencephalographic signals were simultaneously recorded. The behavioural results showed that semantic integration improved memory performance under the motor encoding condition but not under the verbal encoding condition. The ERP results revealed that, regardless of whether it was an old (memorised) or new (distractor) phrase, a larger N400 component was elicited under the motor encoding condition than under the verbal encoding condition. In the motor encoding condition, poorly integrated phrases elicited a larger N400 component than well-integrated phrases; in the verbal encoding condition, this effect was not observed. The N400 effect associated with semantic processing was enhanced by semantic integration under the motor encoding condition rather than the verbal encoding condition. These results supported a deep semantic processing mechanism under the motor encoding condition, and a semantic feedback processing mechanism for the enactment effect was partially supported.

Building Embodied Spaces for Spatial Memory Neurorehabilitation with Virtual Reality in Normal and Pathological Aging

Along with deficits in spatial cognition, a decline in body-related information is observed in aging and is thought to contribute to impairments in navigation, memory, and space perception. According to the embodied cognition theories, bodily and environmental information play a crucial role in defining cognitive representations. Thanks to the possibility to involve body-related information, manipulate environmental stimuli, and add multisensory cues, virtual reality is one of the best candidates for spatial memory rehabilitation in aging for its embodied potential. However, current virtual neurorehabilitation solutions for aging and neurodegenerative diseases are in their infancy. Here, we discuss three concepts that could be used to improve embodied representations of the space with virtual reality. The virtual bodily representation is the combination of idiothetic information involved during virtual navigation thanks to input/output devices; the spatial affordances are environmental or symbolic elements used by the individual to act in the virtual environment; finally, the virtual enactment effect is the enhancement on spatial memory provided by actively (cognitively and/or bodily) interacting with the virtual space and its elements. Theoretical and empirical findings will be presented to propose innovative rehabilitative solutions in aging for spatial memory and navigation.

EXPRESS: Investigating the underlying mechanisms of the Enactment Effect: The role of action-object bindings in aiding immediate memory performance

Previous research has established that enacted action-object phrases lead to superior immediate memory performance compared to purely verbal memory. In the current investigation, Experiment 1 examined how enactment separately affects immediate memory for actions and objects in 24 adults by presenting action-object phrases and asking participants to recall either the actions or the objects presented in correct serial order. The results showed that when employed at presentation, enactment led to superior recall performance compared to verbal repetition, but this effect was significant only for memory for actions and not objects. Enactment during immediate recall did not lead to better memory performance compared to verbal recall for either actions or objects. In order to examine whether the lack of an enactment at recall was due to the splitting of action-object phrases at retrieval, Experiment 2 (n=24) examined memory for whole action-object phrases under enactment at recall. The results showed a typical enactment at recall benefit. Furthermore, a novel binding analysis showed that enactment recall increased the likelihood of action features being remembered in a bound pair rather than alone. Together these findings suggest that action-object bindings play a crucial role in the manifestation of the enactment effect in immediate recall, especially when enactment is employed at the recall phase.

Virtual Enactment Effect on Memory in Young and Aged Populations: A Systematic Review

Background: Spatial cognition is a critical aspect of episodic memory, as it provides the scaffold for events and enables successful retrieval. Virtual enactment (sensorimotor and cognitive interaction) by means of input devices within virtual environments provides an excellent opportunity to enhance encoding and to support memory retrieval with useful traces in the brain compared to passive observation. Methods: We conducted a systematic review with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines concerning the virtual enactment effect on spatial and episodic memory in young and aged populations. We aim at giving guidelines for virtual enactment studies, especially in the context of aging, where spatial and episodic memory decline. Results: Our findings reveal a positive effect on spatial and episodic memory in the young population and promising outcomes in aging. Several cognitive factors (e.g., executive function, decision-making, and visual components) mediate memory performances. Findings should be taken into account for future interventions in aging. Conclusions: The present review sheds light on the key role of the sensorimotor and cognitive systems for memory rehabilitation by means of a more ecological tool such as virtual reality and stresses the importance of the body for cognition, endorsing the view of an embodied mind.

Effect of Emotion and Type of Encoding on Memory for Actions: Verbal and Subject-Performed Tasks

Background: The present study examines whether the interaction between emotion and the enactment effect (body involvement) improves memory in people with Alzheimer disease (AD). Methods: Two experiments with drawings of actions were conducted, in which two types of encoding were used: motor and verbal. In experiment 1, with 13 AD patients and 13 older healthy adults, the encoding was incidental. In experiment 2, with 17 mild AD patients and 21 older healthy adults, it was intentional. Results: In experiment 1, no effect of enactment or emotion was observed in the AD patients. In experiment 2, effects of enactment and emotion (better recall for negative actions) were observed in the AD patients. This pattern of results was also observed in the elderly control adults in both experiments. Conclusion: These results confirm effects observed in normal ageing and indicate a more subtle effect on AD.