Activity in motor areas while remembering action events

Redundancy effect of initial enactment encoding and subsequent testing on memory enhancement: Insights from an electrophysiological study

Testing is more beneficial for memory retention than restudying the same content. However, the effect of the initial encoding method on the testing effect remains unclear. In this study, a classical testing effect paradigm was employed, along with event-related potentials (ERP), to investigate the electrophysiological processes underlying the effect of enactment encoding on the testing effect. Participants were randomly assigned to the Self-Performed Test (SPT) or Verbalized Test (VT) groups. Both groups underwent three stages: an initial encoding phase, an initial test phase (comprising a source memory task and a restudy task), and a final test phase. During the initial encoding phase, the SPT group encoded action phrases through enactment, while the VT group encoded information through reading. During the initial test phase, the SPT group exhibited superior recognition performance in item memory compared with the VT group. Both groups exhibited significant parietal old/new effects in the source memory task, with only the SPT group displaying parietal positivity during the restudy task. During the final test phase, the behavioral testing effect was exclusively observed in the VT group. Furthermore, the VT group displayed a more pronounced parietal positivity in the test condition compared to the restudy condition, while the parietal positivity between the two conditions was comparable in the SPT group. In summary, the absence of a final behavioral testing effect in the SPT group may be attributed to both enactment and testing primarily enhancing memory performance through recollection-based retrieval, as indicated by the parietal positivity. Consequently, the initial enactment encoding method leaves limited scope for further improvements through subsequent testing. These findings suggest that initial enactment encoding, and subsequent testing may be redundant in improving episodic memory performance.

Hippocampal and motor regions contribute to memory benefits after enacted encoding: cross-sectional and longitudinal evidence

The neurobiological underpinnings of action-related episodic memory and how enactment contributes to efficient memory encoding are not well understood. We examine whether individual differences in level (n = 338) and 5-year change (n = 248) in the ability to benefit from motor involvement during memory encoding are related to gray matter (GM) volume, white matter (WM) integrity, and dopamine-regulating genes in a population-based cohort (age range = 25-80 years). A latent profile analysis identified 2 groups with similar performance on verbal encoding but with marked differences in the ability to benefit from motor involvement during memory encoding. Impaired ability to benefit from enactment was paired with smaller HC, parahippocampal, and putamen volume along with lower WM microstructure in the fornix. Individuals with reduced ability to benefit from encoding enactment over 5 years were characterized by reduced HC and motor cortex GM volume along with reduced WM microstructure in several WM tracts. Moreover, the proportion of catechol-O-methyltransferase-Val-carriers differed significantly between classes identified from the latent-profile analysis. These results provide converging evidence that individuals with low or declining ability to benefit from motor involvement during memory encoding are characterized by low and reduced GM volume in regions critical for memory and motor functions along with altered WM microstructure.

Why art? The role of arts in arts and health

This article is an answer to a report called "What is the evidence on the role of the arts in improving health and well-being?" The authors conclude that the arts have an impact on mental and physical health. Yet, the question of the role of the arts remains unanswered. What is and what is not an art effect? Recently, embodied theory has inspired articles on the perception of art. These articles have not yet received attention in the field of Arts and Health. Scholars in psychosomatic medicine have argued for an approach based on recent work in enactive embodied theory to investigate the connection between the body and the mind. The present article examines how key concepts in this theory relate to art. This leads to a discussion of art in terms of empathy-the relation between the internal state of the artist and the internal state of the beholder. I exemplify with a conceptual framework of musical empathy. Implications for health are addressed.

Do graspable objects always leave a motor signature? A study on memory traces

Several studies have reported the existence of reciprocal interactions between the type of motor activity physically performed on objects and the conceptual knowledge that is retained of them. Whether covert motor activity plays a similar effect is less clear. Certainly, objects are strong triggers for actions, and motor components can make the associated concepts more memorable. However, addition of an action-related memory trace may not always be automatic and could rather depend on 'how' objects are encountered. To test this hypothesis, we compared memory for objects that passive observers experienced as verbal labels (the word describing them), visual images (color photographs) and actions (pantomimes of object use). We predicted that the more direct the involvement of action-related representations the more effective would be the addition of a motor code to the experience and the more accurate would be the recall. Results showed that memory for objects presented as words i.e., a format that might only indirectly prime the sensorimotor system, was generally less accurate compared to memory for objects presented as photographs or pantomimes, which are more likely to directly elicit motor simulation processes. In addition, free recall of objects experienced as pantomimes was more accurate when these items afforded actions performed towards one's body than actions directed away from the body. We propose that covert motor activity can contribute to objects' memory, but the beneficial addition of a motor code to the experience is not necessarily automatic. An advantage is more likely to emerge when the observer is induced to take a first-person stance during the encoding phase, as may happen for objects affording actions directed towards the body, which obviously carry more relevance for the actor.

Visual recognition of words learned with gestures induces motor resonance in the forearm muscles

According to theories of Embodied Cognition, memory for words is related to sensorimotor experiences collected during learning. At a neural level, words encoded with self-performed gestures are represented in distributed sensorimotor networks that resonate during word recognition. Here, we ask whether muscles involved in gesture execution also resonate during word recognition. Native German speakers encoded words by reading them (baseline condition) or by reading them in tandem with picture observation, gesture observation, or gesture observation and execution. Surface electromyogram (EMG) activity from both arms was recorded during the word recognition task and responses were detected using eye-tracking. The recognition of words encoded with self-performed gestures coincided with an increase in arm muscle EMG activity compared to the recognition of words learned under other conditions. This finding suggests that sensorimotor networks resonate into the periphery and provides new evidence for a strongly embodied view of recognition memory.

Non-verbal Enrichment in Vocabulary Learning With a Virtual Pedagogical Agent

Non-verbal enrichment in the form of pictures or gesture can support word learning in first and foreign languages. The present study seeks to compare the effects of viewing pictures vs. imitating iconic gestures on learning second language (L2) vocabulary. In our study participants learned L2 words (nouns, verbs, and adjectives) together with a virtual, pedagogical agent. The to-be-learned items were either (i) enriched with pictures, or (ii) with gestures that had to be imitated, or (iii) without any non-verbal enrichment as control. Results showed that gesture imitation was particularly supportive for learning nouns, whereas pictures showed to be most beneficial for memorizing verbs. These findings, suggesting that the type of vocabulary learning strategy has to match with the type of linguistic material to be learned, have important educational implications for L2 classrooms and technology-enhanced tutoring systems.

Auditory Categorization of Man-Made Sounds Versus Natural Sounds by Means of MEG Functional Brain Connectivity

Previous neuroimaging studies have shown that sounds can be discriminated due to living-related or man-made-related characteristics and involve different brain regions. However, these studies have mainly provided source space analyses, which offer simple maps of activated brain regions but do not explain how regions of a distributed system are functionally organized under a specific task. In the present study, we aimed to further examine the functional connectivity of the auditory processing pathway across different categories of non-speech sounds in healthy adults, by means of MEG. Our analyses demonstrated significant activation and interconnection differences between living and man-made object sounds, in the prefrontal areas, anterior-superior temporal gyrus (aSTG), posterior cingulate cortex (PCC), and supramarginal gyrus (SMG), occurring within 80–120 ms post-stimulus interval. Current findings replicated previous ones, in that other regions beyond the auditory cortex are involved during auditory processing. According to the functional connectivity analysis, differential brain networks across the categories exist, which proposes that sound category discrimination processing relies on distinct cortical networks, a notion that has been strongly argued in the literature also in relation to the visual system.

Depth of Encoding Through Observed Gestures in Foreign Language Word Learning

Word learning is basic to foreign language acquisition, however time consuming and not always successful. Empirical studies have shown that traditional (visual) word learning can be enhanced by gestures. The gesture benefit has been attributed to depth of encoding. Gestures can lead to depth of encoding because they trigger semantic processing and sensorimotor enrichment of the novel word. However, the neural underpinning of depth of encoding is still unclear. Here, we combined an fMRI and a behavioral study to investigate word encoding online. In the scanner, participants encoded 30 novel words of an artificial language created for experimental purposes and their translation into the subjects' native language. Participants encoded the words three times: visually, audiovisually, and by additionally observing semantically related gestures performed by an actress. Hemodynamic activity during word encoding revealed the recruitment of cortical areas involved in stimulus processing. In this study, depth of encoding can be spelt out in terms of sensorimotor brain networks that grow larger the more sensory modalities are linked to the novel word. Word retention outside the scanner documented a positive effect of gestures in a free recall test in the short term.

Remembering actions without proprioception

It has been suggested that agency signals generated by enactment provide memories with an enduring episodic marker that can successively be exploited to facilitate recall. Current theories of motor awareness highlight the role of prospective and retrospective sensorimotor cues in the construction of sense of agency (SA). To explore how these signals impact on memory for actions, we studied the effect of enactment in a patient with complete loss of somatic sensation below nose level, and compared her performance to that of a group of neurologically intact individuals. A memory advantage for enacted material was clearly detectable in the control group and, interestingly, also in sensory deafferented patient GL. This novel finding shows that robust memory for actions can be obtained even in the absence of somatosensory reafferences. We hypothesize that the neural processes evoked by intention to move, together with visual experience about one's actions, provide the long-lasting agency signals that are responsible for the special quality of self-performed actions and may support autobiographical experience. Proprioceptive cues, being more time-constrained, are critical to online SA but do not necessarily partake in offline action representations.

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.

The beneficial effect of a speaker's gestures on the listener's memory for action phrases: The pivotal role of the listener's premotor cortex

Memory for action phrases improves in the listeners when the speaker accompanies them with gestures compared to when the speaker stays still. Since behavioral studies revealed a pivotal role of the listeners' motor system, we aimed to disentangle the role of primary motor and premotor cortices. Participants had to recall phrases uttered by a speaker in two conditions: in the gesture condition, the speaker performed gestures congruent with the action; in the no-gesture condition, the speaker stayed still. In Experiment 1, half of the participants underwent inhibitory rTMS over the hand/arm region of the left premotor cortex (PMC) and the other half over the hand/arm region of the left primary motor cortex (M1). The enactment effect disappeared only following rTMS over PMC. In Experiment 2, we detected the usual enactment effect after rTMS over vertex, thereby excluding possible nonspecific rTMS effects. These findings suggest that the information encoded in the premotor cortex is a crucial part of the memory trace.

Relevance of the listener's motor system in recalling phrases enacted by the speaker

Memory for series of action phrases improves in listeners when speakers accompany each phrase with congruent gestures compared to when speakers stay still. Studies reveal that the listeners' motor system, at encoding, plays a crucial role in this enactment effect. We present two experiments on gesture observation, which explored the role of the listeners' motor system at recall. The participants listened to the phrases uttered by a speaker in two conditions in each experiment. In the gesture condition, the speaker uttered the phrases with accompanying congruent gestures, and in the no-gesture condition, the speaker stayed still while uttering the phrases. The participants were then invited, in both conditions of the experiments, to perform a motor task while recalling the phrases proffered by the speaker. The results revealed that the advantage of observing gestures on memory disappears if the listeners move at recall arms and hands (same motor effectors moved by the speaker, Experiment 1a), but not when the listeners move legs and feet (different motor effectors from those moved by the speaker, Experiment 1b). The results suggest that the listeners' motor system is involved not only during the encoding of action phrases uttered by a speaker but also when recalling these phrases during retrieval.

Motor expertise interacts with physical enactment to enhance action memory

Previous research on action memory showed the advantage for performing the action in memorising the action phrases. We tested if performing the action would help participants with or without motor expertise to memorise the novel action poses. Thirty novel action poses performed by an expert were photographed to constitute memory and interference stimuli. Eighty college students observed to remember the randomly displayed stimuli; however, half were asked to perform the displayed stimuli. Both free-recall and recognition tests were administered immediately and 24 h after the memory task. The results showed that acting was better than observing for memorising the novel action poses, which not only promoted the absolute retention but also alleviated the retention loss caused by interference. Motor expertise enhanced the overall memory performance by promoting a deeper motor encoding. Based on our results, novices should act with (rather than just observe) the model to learn novel motor skills.

Reinstatement of pain-related brain activation during the recognition of neutral images previously paired with nociceptive stimuli

Remembering an event partially reactivates cortical and subcortical brain regions that were engaged during its experience and encoding. Such reinstatement of neuronal activation has been observed in different sensory systems, including the visual, auditory, olfactory, and somatosensory domain. However, so far, this phenomenon of incidental memory has not been explored in the context of pain. In this functional magnetic resonance imaging study, we investigated the neural reinstatement of pain-related and tone-related activations during the recognition of neutral images that had been encoded during (1) painful stimulation, (2) auditory stimulation of comparable unpleasantness, or (3) no additional stimulation. Stimulus-specific reinstatement was tested in 24 healthy male and female participants who performed a visual categorization task (encoding) that was immediately followed by a surprise recognition task. Neural responses were acquired in both sessions. Our data show a partial reinstatement of brain regions frequently associated with pain processing, including the left posterior insula, bilateral putamen, and right operculum, during the presentation of images previously paired with painful heat. This effect was specific to painful stimuli. Moreover, the bilateral ventral striatum showed stronger responses for remembered pain-associated images as compared with tone-associated images, suggesting a higher behavioral relevance of remembering neutral pictures previously paired with pain. Our results support the biological relevance of pain in that only painful but not equally unpleasant auditory stimuli were able to "tag" neutral images during their simultaneous presentation and reactivate pain-related brain regions. Such mechanisms might contribute to the development or maintenance of chronic pain and deserve further investigation in clinical populations.

The role of movement representation in episodic memory for actions: A study of patients with apraxia

In attempting to memorize a sentence about an action, such as "Pick up the glass," performing the action (motor encoding) results in better memory performance than simply memorizing the words (verbal encoding). Such enhancement of memory is known as the enactment effect. Several theories have been proposed to explain this phenomenon using concepts such as physical motor information associated with speed, form, amplitude of movement and/or movement representations involved in movement imaging, knowledge on manipulating tools, and spatial relationships in the enactment effect. However, there have been no cognitive neuropsychological studies investigating whether the enactment effect is crucially influenced by physical motor information or movement representations. To clarify this issue, we compared healthy adult control participants with two different types of apraxia patients. One patient with left hemisphere lesions caused by cerebral infarction had a disability involving multiple movement representations. The other patient showed symptoms of corticobasal syndrome and was not able to benefit from feedback on the accuracy of her motor movements during enactment. Participants memorized action sentences via either verbal or motor encoding and responded to recall and recognition tests. Results indicated that the patient with the movement representation deficits exhibited worse memory performance than the other patient or control participants following both verbal and motor encoding. Although the enactment effect was present during recall in both patients, the effect was not observed for recognition in the patient with severe movement representation deficits. These results suggest that movement representations are involved in encoding episodic memories of action. Moreover, the role of movement representations appears to depend on the form of retrieval that is being used.

Memory for shape reactivates the lateral occipital complex

Memory is thought to be a constructive process in which the cortical regions associated with processing event features are reactivated during retrieval. Although there is evidence for non-detailed cortical reactivation during retrieval (e.g., memory for visual or auditory information reactivates the visual or auditory processing regions, respectively), there is limited evidence that memory can reactivate cortical regions associated with processing detailed, feature-specific information. Such evidence is critical to our understanding of the mechanisms of episodic retrieval. The present functional magnetic resonance imaging (fMRI) study assessed whether the lateral occipital complex (LOC), a region that preferentially processes shape, is associated with retrieval of shape information. During encoding, participants were presented with colored abstract shapes that were either intact or scrambled. During retrieval, colored disks were presented and participants indicated whether the corresponding shape was previously "intact" or "scrambled". To assess whether conscious retrieval of intact shapes reactivated LOC, we conducted a conjunction of shape perception/encoding and accurate versus inaccurate retrieval of intact shapes, which produced many activations in LOC. To determine whether activity in LOC was specific to intact shapes, we conducted a conjunction of shape perception/encoding and intact versus scrambled shapes, which also produced many activations in LOC. Furthermore, memory for intact shapes in each hemifield produced contralateral activity in LOC (e.g., memory for left visual field intact shapes activated right LOC), which reflects the specific reinstatement of perception/encoding activity. The present results extend previous feature-specific memory reactivation evidence and support the view that memory is a constructive process.

Effects of enactment in episodic memory: a pilot virtual reality study with young and elderly adults

None of the previous studies on aging have tested the influence of action with respect to the degree of interaction with the environment (active or passive navigation) and the source of itinerary choice (self or externally imposed), on episodic memory (EM) encoding. The aim of this pilot study was to explore the influence of these factors on feature binding (the association between what, where, and when) in EM and on the subjective sense of remembering. Navigation in a virtual city was performed by 64 young and 64 older adults in one of four modes of exploration: (1) passive condition where participants were immersed as passengers of a virtual car [no interaction, no itinerary control (IC)], (2) IC (the subject chose the itinerary, but did not drive the car), (3) low, or (4) high navigation control (the subject just moved the car on rails or drove the car with a steering-wheel and a gas pedal on a fixed itinerary, respectively). The task was to memorize as many events encountered in the virtual environment as possible along with their factual (what), spatial (where), and temporal (when) details, and then to perform immediate and delayed memory tests. An age-related decline was evidenced for immediate and delayed feature binding. Compared to passive and high navigation conditions, and regardless of age-groups, feature binding was enhanced by low navigation and IC conditions. The subjective sense of remembering was boosted by the IC in older adults. Memory performance following high navigation was specifically linked to variability in executive functions. The present findings suggest that the decision of the itinerary is beneficial to boost EM in aging, although it does not eliminate age-related deficits. Active navigation can also enhance EM when it is not too demanding for subjects' cognitive resources.

Human fMRI reveals that delayed action re-recruits visual perception

Behavioral and neuropsychological research suggests that delayed actions rely on different neural substrates than immediate actions; however, the specific brain areas implicated in the two types of actions remain unknown. We used functional magnetic resonance imaging (fMRI) to measure human brain activation during delayed grasping and reaching. Specifically, we examined activation during visual stimulation and action execution separated by a 18-s delay interval in which subjects had to remember an intended action toward the remembered object. The long delay interval enabled us to unambiguously distinguish visual, memory-related, and action responses. Most strikingly, we observed reactivation of the lateral occipital complex (LOC), a ventral-stream area implicated in visual object recognition, and early visual cortex (EVC) at the time of action. Importantly this reactivation was observed even though participants remained in complete darkness with no visual stimulation at the time of the action. Moreover, within EVC, higher activation was observed for grasping than reaching during both vision and action execution. Areas in the dorsal visual stream were activated during action execution as expected and, for some, also during vision. Several areas, including the anterior intraparietal sulcus (aIPS), dorsal premotor cortex (PMd), primary motor cortex (M1) and the supplementary motor area (SMA), showed sustained activation during the delay phase. We propose that during delayed actions, dorsal-stream areas plan and maintain coarse action goals; however, at the time of execution, motor programming requires re-recruitment of detailed visual information about the object through reactivation of (1) ventral-stream areas involved in object perception and (2) early visual areas that contain richly detailed visual representations, particularly for grasping.

Variations in retrieval monitoring during action memory judgments: evidence from event-related potentials (ERPs)

The present study investigated the neuroscience of memory for actions using event-related potentials (ERPs). Actions were performed, initiated but not completed (i.e., interrupted), or watched while the experimenter performed the action during encoding. Memory was assessed in a reality monitoring (RM) test (performed vs. watched actions), as well as in an internal source monitoring (ISM) test (performed vs. interrupted) while ERPs were recorded. Behavioral measures provided evidence of robust old/new recognition for all actions, but the analysis of source errors revealed that interrupted actions were often confused with performed actions. The ERP correlate of recollection, the parietal "old/new" effect (700-900ms), was observed for all actions. The right frontal "old/new" effect (1500-1800ms) that correlates with general memory monitoring was observed in RM but not in ISM. Instead, ISM was associated with the late posterior negativity (LPN) that has been connected to more specific memory monitoring. This pattern of ERP findings suggest that, in this context, general monitoring was used to discriminate self- versus other-performed actions, whereas more specific monitoring was required to support the discrimination of completed and interrupted actions. We argue that the mix of general/specific monitoring processes is shaped by the global retrieval context, which includes the number of memory features that overlap and the combination of sources being considered among other factors.

Active learning of novel sound-producing objects: motor reactivation and enhancement of visuo-motor connectivity

Our experience with the world commonly involves physical interaction with objects enabling us to learn associations between multisensory information perceived during an event and our actions that create an event. The interplay among active interactions during learning and multisensory integration of object properties is not well understood. To better understand how action might enhance multisensory associative recognition, we investigated the interplay among motor and perceptual systems after active learning. Fifteen participants were included in an fMRI study during which they learned visuo-auditory-motor associations between novel objects and the sounds they produce, either through self-generated actions on the objects (active learning) or by observing an experimenter produce the actions (passive learning). Immediately after learning, behavioral and BOLD fMRI measures were collected while perceiving the objects used during unisensory and multisensory training in associative perception and recognition tasks. Active learning was faster and led to more accurate recognition of audiovisual associations than passive learning. Functional ROI analyses showed that in motor, somatosensory, and cerebellar regions there was greater activation during both the perception and recognition of actively learned associations. Finally, functional connectivity between visual- and motor-related processing regions was enhanced during the presentation of actively learned audiovisual associations. Overall, the results of the current study clarify and extend our own previous work [Butler, A. J., James, T. W., & Harman James, K. Enhanced multisensory integration and motor reactivation after active motor learning of audiovisual associations. Journal of Cognitive Neuroscience, 23, 3515-3528, 2011] by providing several novel findings and highlighting the task-based nature of motor reactivation and retrieval after active learning.

Effects of modality on memory for original and misleading information

This study examined the role of modality in correct recognition and misinformation acceptance in a naturalistic event cognition task that reflected an everyday life sequence of events. Participants heard, observed or acted out a sequence of events and were tested on memory for these events after being presented with an accurate description of the events or a description containing misinformation. The results indicated that recognition of unaltered information was higher in the enactment condition than the auditory or visual conditions and that this effect persisted over time. Misinformation acceptance for the immediate recognition test was lowest in the auditory condition but this advantage disappeared over time. Modality congruence of the auditory condition with the modality in which misinformation was presented and different retrieval processes underlying recognition of altered and unaltered information may explain these findings.

Cortical regions recruited for complex active-learning strategies and action planning exhibit rapid reactivation during memory retrieval

Memory retrieval can involve activity in the same sensory cortical regions involved in perception of the original event, and this neural "reactivation" has been suggested as an important mechanism of memory retrieval. However, it is still unclear if fragments of experience other than sensory information are retained and later reactivated during retrieval. For example, learning in non-laboratory settings generally involves active exploration of memoranda, thus requiring the generation of action plans for behavior and the use of strategies deployed to improve subsequent memory performance. Is information pertaining to action planning and strategic processing retained and reactivated during retrieval? To address this question, we compared ERP correlates of memory retrieval for objects that had been studied in an active manner involving action planning and strategic processing to those for objects that had been studied passively. Memory performance was superior for actively studied objects, and unique ERP retrieval correlates for these objects were identified when subjects remembered the specific spatial locations at which objects were studied. Early-onset frontal shifts in ERP correlates of retrieval were noted for these objects, which parallel the recruitment of frontal cortex during learning object locations previously identified using fMRI with the same paradigm. Notably, ERPs during recall for items studied with a specific viewing strategy localized to the same supplementary motor cortex region previously identified with fMRI when this strategy was implemented during study, suggesting rapid reactivation of regions directly involved in strategic action planning. Collectively, these results implicate neural populations involved in learning in important retrieval functions, even for those populations involved in strategic control and action planning. Notably, these episodic features are not generally reported during recollective experiences, suggesting that reactivation is a more general property of memory retrieval that extends beyond those fragments of perceptual information that might be needed to re-live the past.

The impact of iconic gestures on foreign language word learning and its neural substrate

Vocabulary acquisition represents a major challenge in foreign language learning. Research has demonstrated that gestures accompanying speech have an impact on memory for verbal information in the speakers' mother tongue and, as recently shown, also in foreign language learning. However, the neural basis of this effect remains unclear. In a within-subjects design, we compared learning of novel words coupled with iconic and meaningless gestures. Iconic gestures helped learners to significantly better retain the verbal material over time. After the training, participants' brain activity was registered by means of fMRI while performing a word recognition task. Brain activations to words learned with iconic and with meaningless gestures were contrasted. We found activity in the premotor cortices for words encoded with iconic gestures. In contrast, words encoded with meaningless gestures elicited a network associated with cognitive control. These findings suggest that memory performance for newly learned words is not driven by the motor component as such, but by the motor image that matches an underlying representation of the word's semantics.

Enhanced multisensory integration and motor reactivation after active motor learning of audiovisual associations

Everyday experience affords us many opportunities to learn about objects through multiple senses using physical interaction. Previous work has shown that active motor learning of unisensory items enhances memory and leads to the involvement of motor systems during subsequent perception. However, the impact of active motor learning on subsequent perception and recognition of associations among multiple senses has not been investigated. Twenty participants were included in an fMRI study that explored the impact of active motor learning on subsequent processing of unisensory and multisensory stimuli. Participants were exposed to visuo-motor associations between novel objects and novel sounds either through self-generated actions on the objects or by observing an experimenter produce the actions. Immediately after exposure, accuracy, RT, and BOLD fMRI measures were collected with unisensory and multisensory stimuli in associative perception and recognition tasks. Response times during audiovisual associative and unisensory recognition were enhanced by active learning, as was accuracy during audiovisual associative recognition. The difference in motor cortex activation between old and new associations was greater for the active than the passive group. Furthermore, functional connectivity between visual and motor cortices was stronger after active learning than passive learning. Active learning also led to greater activation of the fusiform gyrus during subsequent unisensory visual perception. Finally, brain regions implicated in audiovisual integration (e.g., STS) showed greater multisensory gain after active learning than after passive learning. Overall, the results show that active motor learning modulates the processing of multisensory associations.

Gesturing makes memories that last

When people are asked to perform actions, they remember those actions better than if they are asked to talk about the same actions. But when people talk, they often gesture with their hands, thus adding an action component to talking. The question we asked in this study was whether producing gesture along with speech makes the information encoded in that speech more memorable than it would have been without gesture. We found that gesturing during encoding led to better recall, even when the amount of speech produced during encoding was controlled. Gesturing during encoding improved recall whether the speaker chose to gesture spontaneously or was instructed to gesture. Thus, gesturing during encoding seems to function like action in facilitating memory.

The ghosts of brain states past: remembering reactivates the brain regions engaged during encoding

There is growing evidence that the brain regions involved in encoding an episode are partially reactivated when that episode is later remembered. That is, the process of remembering an episode involves literally returning to the brain state that was present during that episode. This article reviews studies of episodic and associative memory that provide support for the assertion that encoding regions are reactivated during subsequent retrieval. In the first section, studies are reviewed in which neutral stimuli were associated with different modalities of sensory stimuli or different valences of emotional stimuli. When the neutral stimuli were later used as retrieval cues, relevant sensory and emotion processing regions were reactivated. In the second section, studies are reviewed in which participants used different strategies for encoding stimuli. When the stimuli were later retrieved, regions associated with the different encoding strategies were reactivated. Together, these studies demonstrate not only that the encoding experience determines which regions are activated during subsequent retrieval but also that the same regions are activated during encoding and retrieval. In the final section, relevant questions are posed and discussed regarding the reactivation of encoding regions during retrieval.

Enactment versus conceptual encoding: equivalent item memory but different source memory

It has been suggested that performing a physical action (enactment) is an optimally effective encoding task, due to the incorporation of motoric information in the episodic memory trace, and later retrieval of that information. The current study contrasts old/new recognition of objects after enactment to a conceptual encoding task of cost estimation. Both encoding tasks yielded high accuracy, and robust differences in brain activity as compared to new objects, but no differences between encoding tasks. These results are not supportive of the idea that encoding by enactment leads to the spontaneous retrieval of motoric information. When participants were asked to discriminate between the two classes of studied objects during a source memory task, perform-encoded objects elicited higher accuracy and different brain activity than cost-encoded objects. The extent and nature of what was retrieved from memory thus depended on its utility for the assigned memory test: object information during the old/new recognition test, but additional information about the encoding task when necessary for a source memory test. Event-related potentials (ERPs) recorded during the two memory tests showed two orthogonal effects during an early (300-800 msec) time window: a differentiation between studied and unstudied objects, and a test-type (retrieval orientation) effect that was equivalent for old and new objects. Later brain activity (800-1300 msec) differentiated perform- from cost-encoded objects, but only during the source memory test, suggesting temporally distinct phases of retrieval.

Prospective, randomized trial of the effectiveness and retention of 30-min layperson training for cardiopulmonary resuscitation and automated external defibrillators: The American Airlines Study

OBJECTIVE

A head-to-head trial was conducted to compare laypersons' long-term retention of life-saving psychomotor and cognitive skills learned in the traditional multi-hour training format for basic cardiopulmonary resuscitation and automated external defibrillator use to those learned in an abbreviated (30 min) course.

METHODS

Laypersons were randomized to either: (1) the traditional multi-hour Heartsaver-Automated External Defibrillator (Heartsaver-AED) group; or (2) the 30-min course group (cardiopulmonary resuscitation, choking, and automated external defibrillator use). Immediately after training, and at 6 months, participants were provided identical individual testing scenarios. In addition to audio-video recordings, computerized recordings of compression rate/depth, ventilation rates, and related pauses were obtained and subsequently rated by blinded reviewers.

RESULTS

Performance following 30-min training was either equivalent or superior (p<0.007) to the multi-hour Heartsaver-Automated External Defibrillator training in all measurements, both immediately and 6 months after training. Although retention of certain skills deteriorated over the 6 months among a significant number of participants from both groups, 84% of the 30-min training group still was judged, overall, to perform cardiopulmonary resuscitation adequately. Moreover, 93% still were performing chest compressions adequately and 93% continued to apply the automated external defibrillator and deliver shocks correctly.

CONCLUSIONS

Using innovative learning techniques, 30-min cardiopulmonary resuscitation and automated external defibrillator training is as effective as traditional multi-hour courses, even after 6 months. Thirty-minute courses should decrease labor intensity, demands on resources, and time commitments for cardiopulmonary resuscitation courses, thus facilitating more widespread and frequent retraining.

Layperson training for cardiopulmonary resuscitation: when less is better

PURPOSE OF REVIEW

Basic cardiopulmonary resuscitation, including use of automated external defibrillators, unequivocally saves lives. However, even when motivated, those wishing to acquire training traditionally have faced a myriad of barriers including the typical time commitment (3-4 h) and the number of certified instructors and equipment caches required.

RECENT FINDINGS

The recent introduction of innovative video-based self-instruction, utilizing individualized inflatable manikins, provides an important breakthrough in cardiopulmonary-resuscitation training. Definitive studies now show that many dozens of persons can be trained simultaneously to perform basic cardiopulmonary resuscitation, including appropriate use of an automated external defibrillator, in less than 30 min. Such training not only requires much less labor intensity and avoids the need for multiple certified instructors, but also, because it is largely focused on longer and more repetitious performance of skills, these life-saving lessons can be retained for long periods of time.

SUMMARY

Simpler to set-up and implement, the half-hour video-based self-instruction makes it easier for employers, churches, civic groups, school systems and at-risk persons at home to implement such training and it will likely facilitate more frequent re-training. It is now hoped that the ultimate benefit will be more lives saved in communities worldwide.

Event-related potential (ERP) evidence for sensory-based action memories

Memory for performed and motioned actions was measured on source recognition and source recall tests in order to investigate memory for actions or output monitoring (OM). Event-related potentials (ERPs) were recorded during the source recognition test to provide insight into the basis of OM. Source identification and recall of performed actions was greater than motioned actions indicating that sensory characteristics provide unique information for action memories. The ERP data supported this interpretation because the brain activity elicited by performed actions differed from motioned and new actions. Early parietal ERP differences suggest that sensory information leads to selective recollection of performed actions or that more sensory information was activated by performed actions during remembering. A large late posterior negativity (LPN) was also observed in the absence of frontal ERP differences, which are typically observed during source monitoring. This pattern of ERP differences is evidence that frontal ERPs and the LPN reflect distinct source monitoring processes. Based on the available data, we argue that frontal ERPs reflect general decision processes that evaluate diagnostic information, whereas the LPN reflects processes that are engaged when a detailed inspection of information is required by the context.

Reactivation of physical motor information in the memory of action events

When attempting to memorize action sentences (e.g., open an umbrella), performing the action of the sentence (enacted encoding) results in better memory performance than simply memorizing the sentences (verbal encoding). This memory enhancement is called the enactment effect. Magnetoencephalography (MEG) was used to elucidate whether the enactment effect is due to physical motor information or whether movement representation is the critical factor in the enactment effect. Physical motor information, which is implicated in the primary motor cortex, represents the speed, form, and kinematic sense of a movement, while movement representation indicates semantic and conceptual information such as movement formulae, movement ideas, and movement imagery, which are especially associated with the parietal cortex. We measured activities within the motor region and parietal cortex during a recognition test and compared activities during recognition with enacted and verbal encoding condition. The results showed that recognition performance was better for enacted encoding. The MEG data indicated that the left primary motor cortex with enacted encoding condition was activated in all subjects, though with verbal encoding condition, this activation appeared in only one subject. These activities were observed between 150 and 250 ms after recognition stimuli onset and were transmitted into the left parietal cortex. Moreover, activities in the right parietal cortex following enacted encoding were greater than those following verbal encoding, and the activities appeared 600-700 ms after onset of the recognition stimuli. These results suggest that the enactment effect occurs by the reactivation of the physical motor information and that this information facilitates activities related to movement representation.

Further evidence for a comparable memory advantage of self-performed tasks in Korsakoff's syndrome and nonamnesic control subjects

Two experiments were carried out to examine memory in persons with amnesia using self-performed tasks. In Experiment 1, persons with Korsakoff's syndrome and nonamnesic participants with alcoholism learned action phrases not involving real objects by either self-performed tasks or verbal tasks. As indexed by free recall and recognition tests, a memory advantage favoring self-performed tasks was confirmed in both participant groups. In Experiment 2, persons with Korsakoff's syndrome, nonamnesic alcoholic participants, and young control participants learned object names under three different study conditions that differed from one another as to whether actions for each name were verbally generated and whether actions actually were performed. Verbal generation with or without performing the action facilitated recognition, whereas recall advantage was found only in the verbal generation-plus performance condition. These findings confirm a comparable memory advantage of self-performed tasks for a group with Korsakoff's syndrome and a group of nonamnesic comparison participants. Action memory therefore has potential therapeutic implications for memory rehabilitation.

Visual cognition: a new look at the two-visual systems model

In this paper, we argue that no valid comparison between visual representations can arise unless provision is made for three critical properties: their direction of fit, their direction of causation and the level of their conceptual content. The conceptual content in turn is a function of the level of processing. Representations arising from earlier stages of processing of visual input have very little or no conceptual content. Higher order representations get their conceptual content from the connections between visual cognition and other parts of the human cognitive system. The two other critical properties of visual representations are their mind/world direction of fit and their mind/world direction of causation. The output of the semantic processing of visual input has a full mind-to-world direction of fit and a full world-to-mind direction of causation: it visually registers the way the world is and is caused by what it represents. The output of the pragmatic processing yields information for the benefit of intentions, which clearly have a world-to-mind direction of fit and a mind-to-world direction of causation. An intention is both the representation of a goal and a cause of the transformation of a goal into a fact. These properties segregate representations specialized for perception from those specialized for action. Perception implies comparison between simultaneously represented and analyzed objects: hence, object perception presupposes the representation of spatial relationships among objects in a coordinate system independent from the perceiver. Spatial relationships carry cues for attributing meaning to an object, so that their processing is actually part of semantic processing of visual information. These considerations lead to a re-evaluation of the role of the two classical pathways of the human visual system: the ventral and the dorsal cortical pathways. The parietal lobe, which has been identified with the dorsal pathway, cannot be considered as a unitary entity with a single function. The superior parietal lobule carries visuomotor processing, a non-lateralized process. The right inferior parietal lobule contributes to the perception of spatial relationships, a process with a mind-to-world direction of fit and a world-to-mind direction of causation. Finally, the left inferior parietal lobule contributes to still another type of representation, related to visually goal-directed action, i.e., with both a world-to-mind direction of fit and a mind-to-world direction of causation.

Memory and action: an experimental study on normal subjects and schizophrenic patients

Psychologists have shown that recall of sentences describing previously performed actions is enhanced compared to recall of heard-only action-phrases (enactment effect). One interpretation of this effect argues that subjects benefit from a multi-modal encoding where movement plays a major role. In line with this motor account, it is conceivable that the beneficial effect of enactment might rely, at least in part, on procedural learning, thus tapping more directly implicit memory functions. Neuropsychological observations support this hypothesis, as shown by the fact that the enactment effect is quite insensitive to perturbations affecting declarative memories. i.e. Alzheimer disease. Memory for subject performed tasks in patients with Korsakoff syndrome. The present study attempts to evaluate whether pure motor activity is sufficient to guarantee the described memory facilitation or alternatively, whether first-person experience in carrying out the action (i.e. true enactment) would be required. To this purpose, in a first experiment on healthy subjects, we tested whether sentence meaning and content of the executed action should match in order to produce facilitation in recall of enacted action-phrases. In a second experiment, we explored whether the enactment effect is present in patients suffering from psychiatric disorders supposed to spare procedural memory but to alter action awareness (e.g. schizophrenia). We show that better recall for action phrases is found only when the motor component is a true enactment of verbal material. Moreover, this effect is nearly lost in schizophrenia. This latter result, on the one hand, queries the automatic/implicit nature of the enactment effect and supports the role of the experience of having performed the action in the first-person. On the other hand, it questions the nature of the memory impairments detected in schizophrenia.

Learned regulation of spatially localized brain activation using real-time fMRI

It is not currently known whether subjects can learn to voluntarily control activation in localized regions of their own brain using neuroimaging. Here, we show that subjects were able to learn enhanced voluntary control over task-specific activation in a chosen target region, the somatomotor cortex. During an imagined manual action task, subjects were provided with continuous direction regarding their cognitive processes. Subjects received feedback information about their current level of activation in a target region of interest (ROI) derived using real-time functional magnetic resonance imaging (rtfMRI), and they received automatically-adjusted instructions for the level of activation to achieve. Information was provided both as continously upated graphs and using a simple virtual reality interface that provided an image analog of the level of activation. Through training, subjects achieved an enhancement in their control over brain activation that was anatomically specific to the target ROI, the somatomotor cortex. The enhancement took place when rtfMRI-based training was provided, but not in a control group that received similar training without rtfMRI information, showing that the effect was not due to conventional, practice-based neural plasticity alone. Following training, using cognitive processes alone subjects could volitionally induce fMRI activation in the somatomotor cortex that was comparable in magnitude to the activation observed during actual movement. The trained subjects increased fMRI activation without muscle tensing, and were able to continue to control brain activation even when real-time fMRI information was no longer provided. These results show that rtfMRI information can be used to direct cognitive processes, and that subjects are able to learn volitionally regulate activation in an anatomically-targeted brain region, surpassing the task-driven activation present before training.

Being the agent: Memory for action events

Whoever paid the bill at the restaurant last night, will clearly remember doing it. Independently from the type of action, it is a common experience that being the agent provides a special strength to our memories. Even if it is generally agreed that personal memories (episodic memory) rely on separate neural substrates with respect to general knowledge (semantic memory), little is known on the nature of the link between memory and the sense of agency. In the present paper, we review results from two experiments investigating the effects of agency on both explicit and implicit memory traces. Performance of normal subjects is compared to that of schizophrenic patients in order to explore the role of awareness of action on memory. It is proposed that reliable first-person information is necessary to create a stable and coherent motor memory trace.

Memory effects of motor activation in subject-performed tasks and sign language

Research on memory has consistently shown that when a subject-performed task (SPT) is compared with a traditional verbal task (VT), enactment at the encoding of verbal materials (i.e., SPT) yields better memory performance than does nonenactment (i.e. VT). There is some controversy regarding the extent to which motor activation per se might be causing this effect, and whether or not SPTs may be influenced by memory strategies. The purpose of this study was to contribute toward a solution of these questions. The effect of SPT encoding was compared with the effect of encoding by means of a sign language task (SLT). The SLT condition is claimed to be a verbal/linguistic task with a major relevant motor component. The motor activation in SLT is in the present study seen to be the main difference between the SLT and the VT, and the main similarity between the SLT and the SPT. Control conditions were tested in order to evaluate possible effects of translation and imagery in the SLT condition. Subjects in the SLT condition performed similarly to subjects in the SPT condition in free recall. Subjects in both these conditions outperformed subjects in the control conditions. The SPT and SLT superiority is suggested to be caused mainly by relevant motor activation.

Enactment effect in memory: evidence concerning the function of the supramarginal gyrus

Experimental behavioral data show that written action descriptions are remembered better when encoded by enacting them compared with merely verbal encoding. To explore this facilitating effect of encoding by performing actions ('enactment effect'), a functional magnetic resonance imaging (fMRI) study was conducted with n=18 normal subjects. During a learning condition, subjects encoded action phrases like 'cut the bread' either by reading aloud or by enacting them. The same phrases plus additional distractors were presented during fMRI scanning, and the task was to decide (yes/no key press) whether a displayed phrase was previously learned or whether it was a new one. Retrieval--independent of encoding type--activated anterior cingulate, SMA, and visual cortex bilaterally. Activations of the inferior frontal and sensorimotor cortex, and the precentral sulcus, were only left sided. The right cerebellum was also activated. The subtraction of the brain activations in the verbal condition from the enactment condition resulted in significant clusters located in middle temporal and inferior parietal left cortical areas, and, on the right side, in superior temporal, postcentral and inferior parietal cortical areas. Most striking were the bilateral inferior parietal activations, covering the supramarginal gyrus (SMG). Therefore it is concluded that SMG may be a central structure in a neurofunctional explanation of the enactment effect.