Reexposure to a sensorimotor perturbation produces opposite effects on explicit and implicit learning processes

The motor system demonstrates an exquisite ability to adapt to changes in the environment and to quickly reset when these changes prove transient. If similar environmental changes are encountered in the future, learning may be faster, a phenomenon known as savings. In studies of sensorimotor learning, a central component of savings is attributed to the explicit recall of the task structure and appropriate compensatory strategies. Whether implicit adaptation also contributes to savings remains subject to debate. We tackled this question by measuring, in parallel, explicit and implicit adaptive responses in a visuomotor rotation task, employing a protocol that typically elicits savings. While the initial rate of learning was faster in the second exposure to the perturbation, an analysis decomposing the 2 processes showed the benefit to be solely associated with explicit re-aiming. Surprisingly, we found a significant decrease after relearning in aftereffect magnitudes during no-feedback trials, a direct measure of implicit adaptation. In a second experiment, we isolated implicit adaptation using clamped visual feedback, a method known to eliminate the contribution of explicit learning processes. Consistent with the results of the first experiment, participants exhibited a marked reduction in the adaptation function, as well as an attenuated aftereffect when relearning from the clamped feedback. Motivated by these results, we reanalyzed data from prior studies and observed a consistent, yet unappreciated pattern of attenuation of implicit adaptation during relearning. These results indicate that explicit and implicit sensorimotor processes exhibit opposite effects upon relearning: Explicit learning shows savings, while implicit adaptation becomes attenuated

Sex Does Not Sell: Effects of Sexual Advertising Parameters on Women Viewers’ Implicit and Explicit Recall of Ads and Brands

This study investigated implicit and explicit memory effects of sexual and non-sexual advertisements embedded in either a sexual or non-sexual program among women viewers. We predicted that sexual appeals would facilitate implicit memory for the brand, and we explored whether program-type (sexual or non-sexual) and its associated congruity would impact or moderate recall of the surrounding advertisement among a small sample (n = 52) of exclusively women advertisement viewers. Sexual (versus non-sexual) advertising led to significantly worse implicit memory for the brand logo but better explicit recall for the advertisement scene itself. There was no effect of sexual appeals on explicit brand name recall, and no significant effect on advertisement recall of the program type. There was a significant interaction effect for program type and advertisement type for explicit recall of the advertisement scene, in which program-type moderated sexual advertisement recall. These results suggest that sexual advertising may increase memory for the advertisement at the expense of recalling the brand advertised. Limitations and implications of this study are discussed.

Learning new words: memory reactivation as a mechanism for strengthening and updating a novel word´s meaning

In the present study we explored the post-learning changes in a novel word’s definition using a cue-induced memory reactivation. Native speakers of Spanish (N=373) learned low-frequency words with their corresponding definitions. The following day, reactivated groups were exposed to a reminder and provided a subjective assessment of reactivation for each word, while control groups did not receive a reactivation. Study A demonstrated that memory reactivation enhances both explicit recall and semantic integration of new meanings. Study B investigated the effect of memory reactivation in the modification of the new meanings, through three different experiments. Results show an improvement of the updated definitions according to each word´s reactivation strength. In addition, congruence with previous knowledge was found to be a boundary condition, while consolidation time had a positive modulatory effect. Our findings call attention to reactivation as a factor allowing for malleability as well as persistence of long-term memories for words.

Consumers’ Implicit and Explicit Recall, Understanding and Perceptions of Products with Nutrition-Related Messages: An Online Survey

This study aimed to assess consumers’ implicit and explicit recall, understanding and perceptions of products with a nutrition claim and a symbol depicting ‘health,’ and to determine whether these perceptions differed among Nutrition Facts table (NFt) users vs. nonusers. In an online survey, participants (n = 1997) were randomized to one of eight conditions in a 2 × 2 × 2 factorial design, consisting of a label with a claim (present/absent) a heart-shaped symbol depicting ‘health’ (present/absent) for a healthier or less healthy soup. Participants were shown a label for 10 s and asked whether they recalled seeing a claim. If participants answered yes, they were then asked to describe their response using open-ended questions. Participants also rated the product’s perceived nutritional quality and purchase intentions using seven-point Likert scales. In the claim condition, most participants (75%) were able to recall the presence of a claim, while 12% incorrectly mentioned the presence of a claim when there was none. Claims likely attracted consumers’ attention and increased perceived nutritional quality, although with limited influence among NFt users (23%). The symbol depicting ‘health’ did not enhance perceived nutritional quality or purchase intentions. Although most participants (77%) made their decisions implicitly using the front of labels, those who used the NFt had a better understanding of the nutritional quality of products.

Re-exposure to a sensorimotor perturbation produces opposite effects on explicit and implicit learning processes

The motor system demonstrates an exquisite ability to adapt to changes in the environment, and to quickly reset when these changes prove transient. If similar environmental changes are encountered in the future, learning may be faster, a phenomenon known as savings. In studies of sensorimotor learning, a central component of savings is attributed to the explicit recall of the task structure and appropriate compensatory strategies. Whether implicit adaptation also contributes to savings remains subject to debate (Leow et al., 2020; Yin and Wei, 2020). We tackled this question by measuring, in parallel, explicit and implicit adaptive responses in a visuomotor rotation task, employing a protocol that typically elicits savings. The initial rate of learning, a measure encompassing both processes, was faster in the second exposure to the perturbation. Surprisingly, the overall level of implicit adaptation was lower during relearning. Moreover, we found a significant decrease after relearning in aftereffect magnitudes during no-feedback trials, a direct measure of implicit adaptation. In a second experiment, we isolated implicit adaptation using clamped visual feedback, a method known to eliminate the contribution of explicit learning processes. Consistent with the results of the first experiment, participants exhibited a marked reduction in the adaptation function, as well as an attenuated aftereffect when re-learning from the clamped feedback. These results provide evidence that explicit and implicit sensorimotor processes exhibit opposite effects upon relearning: Explicit learning shows savings, while implicit adaptation becomes attenuated.

Explicit recall related to mechanical ventilation: An evolutionary concept analysis

Mechanical ventilation combined with sedation is widely used in the intensive care unit (ICU). However, this intervention is not without consequence on the patient. ICU patients can, in fact, remember perceptions that occurred during their mechanical ventilation—a phenomenon known as explicit recall. This phenomenon is not well defined, and no common terminology exists in the medical and nursing literature, where a variety of concepts are used interchangeably to describe the same experience. The goal of this concept analysis was to address the conceptual vagueness that surrounds explicit recall. Using Rodgers’ evolutionary approach, a total of 68 articles were analyzed to identify the concept’s antecedents, attributes, and consequences. The findings revealed that the explicit recall concept is perceptive, interpretative, subjective, dynamic, and temporal. It occurs following treatment that requires general anesthesia or sedation. It is also shaped by the modalities of anesthesia and sedation, as well as individual characteristics. Consequences of explicit recall can include anxiety, flashbacks, and post-traumatic stress disorder.

Exploring Contextual Interference in Implicit and Explicit Motor Learning

The classic advice given to anyone learning a new skill is “practice makes perfect.” While this provides a good general rule to follow, it lacks any detail on what form of practice will efficiently maximize learning. So when faced with the task of acquiring multiple skills, what is the optimal way to learn? Would it be more beneficial to master each skill separately or learn them all at once in an interleaved fashion? A concept known as contextual interference suggests that using a random practice schedule leads to better retention than a blocked one. There are some motor learning studies that are consistent with this hypothesis and some that are not. In order to explore these conflicting results, we applied contextual interference to a simple reaching task that could allow us to observe its effects to various components of motor learning. We had participants learn three different visuomotor rotations and manipulated interference by placing them in groups characterized by how training targets are ordered (blocked vs. random). Using reaction time and hand angle as our measures of performance, we found that participants who experienced a random practice schedule had significant improvements in their ability to retain information, which was manifest as higher levels of implicit adaptation and faster reaction times. However, this did not necessarily mean the information was executed accurately since hand angles did not differ between groups. These findings suggest contextual interference will be most advantageous in situations that require fast explicit recall of a motor plan to use rather than those that emphasize accuracy.

Literature Review: Awareness of Anaesthesia

A review of qualitative literature regarding ‘awareness under general anaesthesia’ was undertaken, this term being defined as full consciousness during surgery with explicit recall of events. This study was designed to explore a perioperative practitioner's knowledge, skill base and education on the subject of awareness. It also explores the practitioner's role in ‘looking out for’ and ‘rectification’, their obligations to the patient and their statutory bodies, as well as adherence to standards of conduct, performance and ethics. The paper aims to shed light on this phenomenon and to empower a practitioner to act for the benefit of the service user.

Central nervous system physiology in anaesthetic practice

How and where consciousness is generated and maintained remains an unsolved scientific mystery, and this has impeded progress in understanding anaesthesia. In recent years, however, significant progress has been made in understanding the neurobiology of anaesthetic-induced loss of consciousness. This has been made possible by advances in molecular biology techniques, which have helped shed light on the molecular mechanisms of action of the anaesthetic agents. In parallel, the development of neuroimaging techniques, such as functional magnetic resonance imaging and positron emission tomography, has also provided an enormous impetus. These techniques are providing new insights into the neural correlates of consciousness, and new insights into the alterations in neurophysiology associated with impaired consciousness caused by sleep, sedation, and anaesthesia. The information being gained from these studies on the neurobiology of impairments of attention, awareness, and memory will hopefully eventually not only lead to improvements in our understanding of consciousness and anaesthesia, but also to better clinical care. Understanding of memory functions during sedation and anaesthesia may, for example, lead to better strategies for preventing awareness with subsequent explicit recall of intraoperative events. Further, a better understanding of the neurobiology of anaesthetic-induced unconsciousness may inform future development of better anaesthetic agents, with a broader therapeutic index, and fewer unwanted effects.