Having shaved a kiwi fruit: Memory of unfamiliar subject-performed actions

When the Action to Be Performed at the Stage of Retrieval Enacts Memory of Action Verbs

According to the embodied approach of language, concepts are grounded in sensorimotor mental states, and when we process language, the brain simulates some of the perceptions and actions that are involved when interacting with real objects. Moreover, several studies have highlighted that cognitive performances are dependent on the overlap between the motor action simulated and the motor action required by the task. On the other hand, in the field of memory, the role of action is under debate. The aim of this work was to show that performing an action at the stage of retrieval influences memory performance in a recognition task (experiment 1) and a cued recall task (experiment 2), even if the participants were never instructed to consider the implied action. The results highlighted an action-based memory effect at the retrieval stage. These findings contribute to the debate about the implication of motor system in action verb processing and its role for memory.

Integrative representation of semantic and motor information underlies the enactment effect in memory for actions

The present study adopted the retrieval-induced forgetting (RIF) effect to determine whether semantic representation might favour the enactment effect, in which noun-verb phrases are remembered better by enacting during learning (subject-performed tasks, SPTs) than by studying verbally (verbal tasks, VTs). Experiment 1 controlled the semantic category to investigate the RIF effect in SPT vs. VT conditions. The RIF effect was similar irrespective of the mode of encoding (SPT vs.VT), indicating that semantic representation was not the main factor for favouring the enactment effect. Furthermore, Experiment 2 added motor physical properties to simultaneously control the semantic category and one category by motor features. The results of Experiment 2 showed stronger cooperative representation of semantic and motor information under the VT condition, indicating that the processing of action memory may be conceptual.

Do Physical Properties Affect Enactment Effect? The Regulatory Function of Item Familiarity

Our aim was to examine the regulatory function that item familiarity has for the impact of physical properties on the enactment effect. We also evaluated the relation between motor and imagery encoding. In 2 experiments controlling for the familiarity of nouns in action phrases, free recall data showed that the presence of physical properties improved memory performance under verbal task-encoding conditions, regardless of item familiarity. In the subject-performed task-encoding condition, physical properties played a positive role in memorizing familiar items but not in unfamiliar items. These findings revealed the correlation between motor encoding and imagery encoding. The regulatory function of item familiarity was demonstrated, because the presence of physical properties had no impact on the enactment effect of familiar items but determined whether the enactment effect of unfamiliar items was significant. These findings provide empirical support for both the multimodal theory and the motor encoding theory of subject-performed tasks. We summarized the “item character view” to analyze the divergent conclusions about the enactment effect from the perspective of research methods and to promote the standardized development of action memory.

The residual protective effects of enactment

Research has demonstrated the importance of the quality of initial retrieval events (Test 1) for performance on later memory tests (Test 2). We explored whether enacting words at encoding, relative to simply reading them, provided protection against the detrimental effects of a degraded retrieval experience, through the addition of motor processing to the extant memory representation. Participants encoded a mixed list of enacted and read words, then completed Test 1, and a later Test 2. Encoding and Test 2 were always completed under full attention (FA). Critically though, Test 1 was completed either under FA, or under divided attention (DA) with a distracting task requiring semantic and phonological processing. We predicted a larger enactment effect following DA relative to FA, indicating greater preservation of enacted words from dual-task interference. In Experiment 1, we demonstrated that the enactment effect was indeed larger following DA than FA, indicating greater preservation of enacted words after dual-task interference. In Experiment 2, we showed that this effect was even more potent over longer time scales, which served as a conceptual replication. In Experiment 3, we showed that enactment provides little to no protection when the distracting task requires motor processing, and in Experiment 4, we returned to the phonological distracting task and showed that in contrast with enactment, generation at encoding does not afford the same protection to memory. Taken together, these finding suggest that enactment renders words relatively immune to the detrimental effects of dual-tasking during testing, through the addition of a different kind, rather than a greater degree, of processing to the memory trace at encoding.

Individual and combined effects of enactment and testing on memory for action phrases

We investigated the individual and combined effects of enactment and testing on memory for action phrases to address whether both study techniques commonly promote item-specific processing. Participants (N = 112) were divided into four groups (n = 28). They either exclusively studied 36 action phrases (e.g., "lift the glass") or both studied and cued-recalled them in four trials. During study trials participants encoded the action phrases either by motorically performing them, or by reading them aloud, and they took final verb-cued recall tests over 18-min and 1-week retention intervals. A testing effect was demonstrated for action phrases, however, only when they were verbally encoded, and not when they were enacted. Similarly, enactive (relative to verbal) encoding reduced the rate of forgetting, but only when the action phrases were exclusively studied, and not when they were also tested. These less-than-additive effects of enactment and testing on the rate of forgetting, as well as on long-term retention, support the notion that both study techniques effectively promote item-specific processing that can only be marginally increased further by combining them.

An action video clip database rated for familiarity in China and Germany

Stimulus material for studying object-directed actions is needed in different research contexts, such as action observation, action memory, and imitation. Action items have been generated many times in individual laboratories across the world, but they are used in very few experiments. For future studies in the field, it would be worthwhile to have a larger set of action stimulus material available to a broader research community. Some smaller action databases have already been published, but those often focus on psycholinguistic parameters and static action stimuli. With this article, we introduce an action database with dynamic action stimuli. The database contains action descriptions of 1,754 object-directed actions that have been rated for familiarity in Germany and in China. For 784 of these actions, action video clips are available. With the use of our database, it is possible to identify actions that differ in familiarity between Western and Eastern cultures. This variable may be of interest to some researchers in the field, since it has been shown that familiarity influences action information processing. Action descriptions are listed and categorized in tables that can be downloaded, along with the corresponding video clips, as supplemental material.

Retrieval-Induced Forgetting of Performed and Observed Bizarre and Familiar Actions

To investigate whether people show retrieval-induced forgetting (RIF) for bizarre and familiar actions that they performed or observed, three experiments were conducted. In Experiment 1, participants performed bizarre and familiar actions with different objects during learning (e.g., pencil: balance the pencil across the cup, sharpen the pencil). They repeatedly performed a set of the bizarre or familiar actions during retrieval practice. After a distracter task, participants’ cued recall was tested. Participants showed RIF for both bizarre and familiar actions. In Experiment 2, half of the participants performed the bizarre and familiar actions themselves; the other half observed the experimenter performing the actions. Replicating the results of Experiment 1, participants who performed the actions showed RIF for bizarre and familiar actions. In contrast, participants who observed the actions did not show RIF for either action type. Experiment 3 examined whether this lack of RIF for observed actions occurred due to a lack of active recall during retrieval practice; it did. Overall, the three experiments demonstrated RIF for both bizarre and familiar performed and observed actions. A distinctiveness account of the results is provided.

Exploring the enactment effect from an information processing view: what can we learn from serial position analyses?

The focus of the present article was to analyze processes that determine the enactment and age effect in a multi-trial free recall paradigm by looking at the serial position effects. In an experimental study (see Schatz et al 2010), the performance-enhancing effect of enactive encoding and repeated learning was tested with older and younger participants. As expected, there was a steady improvement of memory performance as a function of repeated learning regardless of age. In addition, enactive encoding led to a better memory performance than verbal encoding in both age groups. Furthermore, younger adults outperformed the elderly regardless of type of encoding. Analyses in the present article show that encoding by enacting seems to profit especially from remembering the last items of a presented list. Regarding age differences, younger outperformed older participants in nearly all item positions. The performance enhancement after task repetition is due to a higher amount of recalled items in the middle positions in a subject performed task (SPT) and a verbal task (VT) as well as the last positions of a learned list in VT.

Is there a memory profit after repeated learning of subject-performed actions? Comparing direct and long-term memory performance level as a function of age

The present two studies investigated the possibility for improvement and maintenance of episodic memory in young and older adults. In a first study, the performance-enhancing effect of two separate as well as combined learning devices, enactive encoding and repeated learning, was tested. With a time lag of one week, four different series of 30 action phrases were encoded either verbally or by enacting them symbolically. Memory was assessed in four immediate free recall tests. In a second study, the maintenance of the memory profit was tested in an unexpected fifth session half a year later. As expected, there was a steady improvement of memory performance as a function of repeated learning in study one. This holds true regardless of age. In addition, enactive encoding led to a better memory performance than verbal encoding in both age groups. Moreover, younger adults outperformed the elderly regardless of type of encoding. The combination of the two learning devices was not efficient enough to eliminate aging effects in episodic memory. However, memory flexibility is demonstrated also in the elderly. In the long-term follow-up, maintenance of learning and memory could be found in all participant groups.

Does action make you faster? A retrieval-based approach to investigating the origins of the enactment effect

The enactment effect, the stable finding that memory for action phrases is enhanced in a subject-performed compared to a verbal task (SPT; VT), has repeatedly been demonstrated. The question remains whether the enactment effect has to do with specific characteristics of the SPT-retrieval process. Experiment 1 tested younger and older adults in a within-subjects design with two direct free recall tests. Thorough analyses of the recall process showed that the benefit from self-performing the items becomes apparent early into the retrieval phase for both age groups. Experiment 2 tested the same age groups with a retention phase of 30 minutes. The same general results pattern emerged. The acceleration of the recall process in SPTs is indicative of a heightened accessibility of the actively encoded material, making it less susceptible to forgetting. This property of SPTs must be taken into account when trying to determine the origins of the enactment effect.

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.

Subject-performed tasks improve associative learning in amnestic mild cognitive impairment

Subject-performed tasks (SPTs) may facilitate the deficit in associative learning among individuals with amnestic mild cognitive impairment (aMCI) by inducing episodic integration of object-action associations. To test this hypothesis, we examined free recall and recognition memory following enactment and verbal encoding in healthy elderly controls and individuals with aMCI. Study lists contained either semantically integrated ("Bounce the ball") or crossed object-action commands, in which episodic and semantic associations were placed in opposition ("Pet the compass"). Associative learning was indeed better after SPT than verbal encoding and with integrated relative to crossed lists for the aMCI group, as it was for controls. Moreover, the degree to which SPTs reduced the semantic interference inherent in the crossed conditions was equivalent for the two groups. The results showed that enactment facilitates formation of episodic associations, even when not supported by preexisting semantic knowledge, and even among individuals who have particular difficulty forming new associations.

Improved episodic integration through enactment: implications for aging

Enactment may improve memory for verb phrases by facilitating episodic integration of object-action components into a unitized whole. It is unclear, however, whether the influence of enactment on episodic integration is related to or independent of the strength of the preexisting semantic relationship between components. To address this issue, the authors examined the influence of enactment on memory for lists of semantically related object-action phrases ("Put money in the wallet") and semantically unrelated phrases created by repairing these objects and actions to make phrases that were unusual but still were possible to perform ("String a thread through the wallet," "Put money in the napkin"). As such, phrases in the related and unrelated lists were matched for familiarity of the individual components and differed only in the associative strength of the object-action relationship. Although verbatim recall of unrelated lists was poorer under standard verbal encoding conditions, enactment succeeded in bringing performance to the level of related lists, indicating that enactment's influence on episodic integration was independent of the semantic relatedness of the object and action components. Analysis of partial recall errors (accurate recall of only one component) suggested that enactment benefited recall in the unrelated lists by improving memory for the action and reducing fragmentation of the association, providing further support for the unitization view. This pattern of results was replicated in normal older adults, a population that exhibits particular difficulty with episodic memory for unrelated associations. The cognitive mechanisms by which enactment may improve episodic integration in both younger and older adults are discussed.

Differential relational encoding of categorical information in memory for action events

Memory for action phrases is better if the actions are enacted in subject-performed tasks (SPTs) than if they are only listened to in verbal tasks (VTs). This effect is ascribed to better item-specific encoding of SPTs than of VTs. The role of interitem relational information is controversial, and the findings of clustering with categorically structured lists are inconsistent (see Engelkamp, 1998). The present study contributes to clarifying these effects by demonstrating that intentional relational encoding can be used more efficiently in VTs than in SPTs and influences the degree of clustering. If the list structure is not obvious, inducing intentional encoding by presenting the category labels prior to list presentation and asking subjects to use this preinformation increases clustering in VTs but not in SPTs. Without preinformation, clustering scores of VTs and SPTs did not differ, with preinformation, clustering of VTs was stronger than that of SPTs. The authors suggest how the inconsistent findings with regard to clustering effects can be explained.

Memory for actions: Item and relational information in categorized lists

Enacting action phrases in subject-performed tasks (SPTs) leads to better free recall than hearing or reading the same materials in verbal tasks (VTs). This enactment effect is usually explained by better item-specific information in SPTs than in VTs. The role of relational information is controversial. In the present paper, we will take the multiple recall approach to study the role of item and relational information in memory for actions by computing the number of item gains and the number of item losses over trials. This approach has previously been applied to lists of unrelated action phrases. We applied it to categorically related lists, also allowing a measure of relational information by clustering scores. It was found that SPTs produced more item gains than VTs. This finding confirmed the assumption that SPTs provide better item-specific information than VTs. The number of item losses did not differ between VTs and SPTs. This finding suggests that relational information is equally provided by VTs and SPTs. However, the organizational scores showed a more differentiated picture. Clustering was greater in SPTs than in VTs with randomly presented lists, but not with blocked lists. We suggested that these results, as well as other findings from the literature, could be explained by distinguishing automatic and strategic processes and the types of item associations that are addressed by these processes.

Gains and losses in action memory

Enacting action phrases (SPT for subject-performed task) produces better free recall than only learning the phrases verbally (VT for verbal task). A widespread explanation of the enactment effect is based on the distinction between item-specific and relational information. There is widespread agreement that the main reason is the excellent item-specific encoding by enactment. However, there is little direct evidence in the case of free recall. The role of relational information is less clear. We suggest that content-based relational encoding is better in VTs than in SPTs. In three experiments, in which multiple free recall testing used item gains and losses as indices of item-specific and content-based relational encoding, respectively, these assumptions were confirmed. Consistently more gains (indexing better item-specific encoding) and more losses (indexing poorer relational encoding) were observed in SPTs than in VTs (Experiments 1 and 2). Furthermore, it was demonstrated that the content-based relational information underlying losses is not identical with order-relational information (Experiment 2). In Experiment 3, it was shown that an item-specific orienting task for VTs produced an equivalent number of item gains and losses as did the SPT condition.

Test of competing explanations of the bizarre response bias in recognition memory

Recent research has demonstrated that a more liberal response criterion is used when people make judgments about bizarre items than about common items in old-new tests of recognition. The present study was designed to test 2 possible explanations of the bizarre response bias. The bizarre-relations explanation suggests that the bizarre response bias is triggered by the bizarre relations depicted in test items. The target-constituent explanation suggests that the bizarre response bias is the result of a sense of familiarity with constituents of bizarre test items. These explanations were tested by examining the influence of lure manipulations on memory discrimination and response bias for common and bizarre hand-drawn pictures. The results indicated support for the target-constituent explanation by reversing the response bias (obtaining a common response bias) in a recognition test that used common lures containing constituents from bizarre target items and bizarre lures containing constituents from common target items. The results also indicated that increased verbal elaboration enhanced memory discrimination and reduced response bias for both common and bizarre stimuli. The implications of these results are discussed with regard to the false memory controversy.

Memory discrimination for self-performed and imagined acts: bizarreness effects in false recognition

Two experiments investigated the susceptibility of common and unusual action events to memory distortion under incidental learning and delayed testing conditions. Experiment 1 tested the influence of imaginal and enactment instructions at testing on memory discrimination for self-performed and imagined acts. The influence of hypnotic procedures at testing on memory discrimination for action events was tested in Experiment 2. The results of both experiments suggest that the likelihood of confusing details associated with separate, previously experienced unusual action events is greater than the likelihood of confusing details associated with separate, previously experienced common action events. Based on the results of both experiments, it is concluded that bizarreness has both memory-facilitating and memory-inhibiting qualities.

Objektbezogenes Handeln:Der Gebrauch von Erinnerungen bei Antizipation und Ausführung

Zusammenfassung. Eine Betrachtung des Verlaufs einer alltäglichen Handlung, in der mit verschiedenen materiellen Objekten hantiert wird, legt nahe, daß die Abfolge von einzelnen Aktivitäten im Gedächtnis nicht als Kette, sondern als Netzwerk mit bestimmten Charakteristiken repräsentiert sein müßte. Die Charakteristiken lassen vermuten, daß Aktivitäten, mit denen Objekte verändert werden, besser erinnerbar sind als Aktivitäten, die in Umorientierungen der Aufmerksamkeit während der Ausführung einer Handlung bestehen. Die Ergebnisse des Experiments 1 stützen diese Vermutung. Weiterhin ist anzunehmen, daß komplexe Handlungen vor ihrer Ausführung nicht vollständig antizipiert werden, sondern zunächst nur bestimmte Teile. Hypothesen, die eine zeitliche Abfolge der Antizipation verschiedener Teile betreffen, werden im Experiment 2 untersucht, dessen Ergebnisse für diese Hypothesen sprechen. Insgesamt stützen die erzielten Ergebnisse bestimmte Annahmen, die dem Gedächtnismodell Netz erinnerbaren Handelns zugrunde liegen.

The role of relational processing in memory for actions: a negative enactment effect in free recall

The enactment effect occurs if people remember items that they enacted or enacted symbolically during study better than items that they were simply asked to remember. Enactment is generally believed to lead to thorough processing of individual items. There has been some controversy as to whether the superior processing of information concerning the relations between action phrases (i.e. whole-list relational information) may additionally contribute to the enactment effect. The extant empirical data on this issue seem contradictory. In the account brough forward here, it is hypothesized that whole-list relational information is processed better during enactment than during verbal learning only if it taps the same aspect of a concept as the verb-object relational information within each action phrase. It is processed worse if these two types of information tap different aspects of a concept. This explanation represents an extension of the three-factor account of positive and negative generation effects to the field of memory for actions. To provide evidence for this account, positive and, notably, negative enactment effects in object recall and in organization scores are demonstrated in three experiments with a total of 246 participants.

Memory for to-be-performed tasks versus memory for performed tasks

Memory for subject-performed tasks-that is, for simple actions such as lifting a pen, which subjects perform overtly-is better than memory for verbal tasks-that is, when subjects only listen to the action phrases. Here I investigated whether this effect depends on actual performance or whether it also shows up when there is only an intention to perform the task. Koriat, Ben-Zur, and Nussbaum (1990) found that the intention to perform items at test enhanced free recall more than did verbal tasks. Brooks and Gardiner (1994), however, were not able to replicate this finding. In four experiments, I attempted to reconcile this discrepancy by comparing subject-performed tasks, to-be-performed tasks, and verbal tasks under different conditions. The outcome depended on whether a within-subjects design or a between-subjects design was used. In the between-subjects design, memory for subject-performed tasks was better than memory for to-be-performed tasks, and both of these led to better recall performance than did verbal tasks. In a within-subjects design, in contrast, memory for to-be-performed tasks was no different from memory for verbal tasks. These results were independent of whether the test mode was congruent or incongruent. Thus, the discrepant findings of Koriat et al and of Brooks and Gardiner seem to be due to the design used, pointing to encoding processes as the critical variable. The present results are interpreted to show that actual performance of actions at study provides more information than does only the intention to perform actions at test.

The effect of enactment on memory for order

The effect of enactment on memory for serial order was investigated in two experiments. In both experiments a reconstruction task was used to separate order from item information. In Experiment 1 enactment and test information was manipulated between groups. For subjects who had not been informed about the reconstruction test, performance of verbal and motor groups was similar with regard to both serial-position curves and overall performance. For subjects who knew beforehand that they would be tested for memory of the order of the action events, performance in the verbal condition was significantly better than in the motor condition. In Experiment 2, the reversed enactment effect for test-informed subjects was replicated with a within-subjects design. The results agree with Engelkamp and Zimmer's (1984, 1994) position that enactment serves exclusively to enhance item information, and indicate that subjects have less control over the encoding processes when they are enacting than during verbal encoding (cf. Cohen, 1981).

Routes to actions and their efficacy for remembering

Four experiments focused on the influence that different controls of actions have on memory for these actions. A verbal-to-action task in which subjects had to perform actions on verbal command was distinguished from a movement-to-action task in which subjects had to perform the same action that a model had shown (imitation). We expected free recall to be worse for the imitation condition than for the enactment-on-command condition. The following rank order of recall performances was observed: verbal learning << perceiving the model = imitating the watched model < performing on command = performing on command in addition to perceiving the model. The less pronounced effect of imitation on memory is explained by the fact that subjects in this condition could directly use the information provided by perception for enactment without selection and detailed planning of motor actions. In contrast, subjects in the command-to-action condition had to look up the "motor program". The inefficiency of using two modalities, i.e. perception and action, as compared to using only one is explained by the redundancy of encoded information in the visual and "motor" modality.

Dissociative effects of elaboration on memory of enacted and non-enacted events: a case of a negative effect

One experiment compared the effect of elaboration on enacted and non-enacted events. The commands were either presented in a basic form (e.g., "wave your hands") or in an enriched form. The commands were enriched by adding statements to the commands of how to perform the actions (e.g., "wave your hands as a conductor"). Free- and cued-recall data showed elaboration to have a dissociative effect on enacted and non-enacted events. Memory for the non-enacted events benefited from enrichment, whereas simple enacted events were remembered to a higher extent than complex enacted events. Lack of benefit from elaboration on memory of enacted events is suggested to be due to enactment leading to a sufficient degree of item-specific processing, and a negative effect of elaboration is suggested to occur when the way of manipulating item complexity decreases the familiarity of the actions. Familiarity ratings of the items by two independent groups of subjects supported this interpretation.

Motor similarity in subject-performed tasks

In two experiments, subjects learned action phrases in verbal and subject-performed tasks. They had to recognize these action phrases among foils that denoted either completely different actions, conceptually similar actions, or actions that were conceptually and motorically similar. It was found that recognition performance was impaired equally after both kinds of learning when conceptually similar distractors were used, but was impaired more after subject-performed-task learning when the distractors were both conceptually and motorically similar. The possible contribution of motor information in this interaction is discussed.

Memory of self-performed tasks: self-performing during recognition

Two experiments focused on whether performing actions described by to-be-remembered phrases during recognition enhances recognition compared with results of a standard verbal recognition test. The enhancement was predicted when the actions described by the phrases had been performed during study, but not when the phrases were verbally encoded by simply listening to and memorizing the material. Both experiments showed that enactment prior to recognition improved memory performance, but only when subjects had encoded by enactment. Experiment 1 also demonstrated that this test-procedure effect was independent of a bizarreness effect, which was observed only with the verbal encoding task. Experiment 2 showed that the effect of enactment during recognition was reduced when subjects used different hands for performing the actions during study and recognition. The findings support the assumption that some kind of motor memory record underlies the enactment effect that occurs when actions are performed during recognition.