Johannes Engelkamp

Item and order information in subject-performed tasks and experimenter-performed tasks.

This study investigated the enactment effect from the perspective of the item-order hypothesis (e.g., M. Serra & J. S. Nairne, 1993). The authors assumed that in subject-performed tasks (SPTs), item encoding is improved but order encoding is disrupted compared with experimenter-performed tasks (EPTs), that order encoding of EPTs is only better in pure lists, and that the item--order hypothesis is confined to short lists. Item information was tested in recognition memory tests, order information in order reconstruction tasks, and both item and order information in free-recall tests. The results of 5 experiments using short (8 items) and long lists (24 items) in a design with list type (pure, mixed) and encoding condition (EPT, SPT) as factors supported the hypotheses.

Motor programme information as a separable memory unit

SummaryTwo experiments produced further evidence for the claim that motor programme information may be considered as a separate memory unit, partially independent of other memory representations. In Experiment 1, it was shown that for the comparison of shared movement components in two actions such as “turning the handle” and “stirring the ingredients”, the activation of their motor programmes is required. This is demonstrated by the finding that the execution of the first action, which preactivates its motor programmes, leads to shorter reaction times than under control conditions in which the verbally described action is only spoken. In Experiment 2, it was further shown that the execution of the action does not in every case expedite the assessment of a connection between a prime item and a target item vis à vis verbal repetition, but only where the task requires the activation of motor programmes.

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.

Cognitive and Neuropsychological Approaches to Mental Imagery

The locus of concreteness effects in memory for verbal materials has been described here in terms of the processing of shared and distinctive information. This theoretical view is consistent with a variety of findings previously taken as support for dual coding, insofar as both verbal and perceptual information may be involved in comprehending high-imagery sentences and in learning lists of concrete words. But going beyond previous accounts of imagery, this view also can provide explanations for several findings that appear contradictory to the thesis that concrete and abstract materials differ in the form of their storage in long-term memory. Although this does not rule out a role for imagery in list learning or text comprehension, it is clear that the complex processes involved in comprehension and memory for language go beyond mechanisms supplied by a theory based on the availability of modality-specific mental representations. The task now is to determine the viability of the theory in other domains. Several domains of imagery research presented at EWIC provided fertile ground for evaluating my theoretical viewpoint. Although not all provide a basis for distinguishing representational theories of imagery from the imagery as process view, there are data in several areas that are more consistent with the latter than the former. In other cases, there are at least potential sources of evidence that would allow such a distinction.

Sensory factors in memory for subject-performed tasks

Abstract Action phrases such as “lift the pen” are recalled better when they are enacted by subjects in subject-performed tasks (SPTs) than when only listened to during verbal tasks (VTs). This SPT effect is usually attributed to the good item-specific information provided by enactment. A series of experiments investigated what role the use of real objects and the perception of the action play in the good recall of SPTs. For this purpose, recall of action phrases with and without using real objects was studied in VTs, EPTs (experimenter-performed tasks) and SPTs. It was found that the perception of real objects improved recall equally in EPTs and SPTs, but more so in VTs. Furthermore there was a recall advantage of SPTs over EPTs. However, with short lists, this advantage depended on whether the encoding condition was varied within subjects or between subjects. It was concluded that perceiving the objects used as well as perceiving the action proper does not play a decisive role in the good SPT recall. It was further concluded that EPTs and SPTs differentially depend on item-specific and relational encoding, and that relational encoding suffers from using a within-subjects mixed list design.

Recall and recognition of self-performed acts

SummaryIn Experiment 1, recall and recognition of 80 action phrases were compared under two encoding conditions: verbal and motor (performing the denoted acts). Memory performance was better under motor encoding than under verbal encoding, and more so in recognition than in recall. We assume that this finding is due to the item-specific effect of a specific motor component in the memory trace after enacting. In Experiments 2 and 3 we further investigated whether false-alarm rates are dependent on the motoric similarity of distractor items. The rate of false alarms was lower under motor encoding than under verbal encoding, but the motoric similarity of distractor items to list items did not influence the false alarms. The results were interpreted as support for the assumption that motor encoding enhances item-specific information in relation to verbal encoding, but that during verbal recognition the motoric quality of the depicted movement is not processed.

Memory for actions in obsessive-compulsive disorder

Frequent checkers with obsessive-compulsive disorder (OCD ; n=24), high checking controls (n=24) and low checking controls (n-48) were instructed to learn action phrases such as to open the book by performing the action themselves with imaginary objects (motor encoding), by imagining how one performs the action oneself (motor-imaginal encoding), by imagining seeing somebody else performing the action (visual-imaginal encoding) and by subvocal rehearsal. Compared to low checking controls, OCD checkers showed poorer free recall of motorically encoded actions and poorer reality monitoring, i.e. they confused motor and motor-imaginal encoding more frequently. The results are consistent with a specific motor memory deficit in OCD checkers. Moreover, memory performance of OCD checkers differed from that of high checking controls.

Does motor encoding enhance relational information

SummaryThree experiments investigated whether learning action phrases by enacting the denoted action enhances organization or not. In the first experiment it was shown that, compared to a standard learning instruction, enacting did not enhance the clustering of episodic and taxonomic lists, but it did enhance memory performance. Furthermore, the enacting effect was strongest with an unrelated list; in all lists, organization and recall correlated only under a verbal instruction and not under an enacting instruction. In the second experiment, subjects were also informed about the categories of the lists and instructed to use them to learn the items. The organization was enhanced in all cases by this procedure, but the recall performance was enhanced only with a standard learning instruction. Under enacting, information about the categories had no influence. In the third experiment this effect was replicated for a taxonomic list and could be generalized for a motor list, in which categories were in accordance with the similarities of the movement pattern. Here too the explicit category information had an effect only under a standard learning instruction, but not with enacting. We interpret these effects as support for the assumption that enacting does not enhance memory performance by better relational information. Relational information is, on the contrary, less important for recall under enacting than under a standard learning instruction.

Pop-out into memory: A retrieval mechanism that is enhanced with the recall of subject-performed tasks.

Subject-performed tasks (SPTs; i.e., carrying out the actions during study) improve free recall of action phrases without enhancing relational information. By this mechanism, items pop into a persons mind without active search, and this process especially extends the recency effect. The authors demonstrated the existence of the extended recency effect and its importance for the SPT recall advantage (Experiments 1 and 2). Carrying out the action and not semantic processing caused the effect (Experiment 3). The extended recency effect was also not a consequence of a deliberate last-in, first-out strategy (Experiment 4), and performing a difficult secondary task (an arithmetic task) during recall reduced memory performances but did not influence the extended recency effect (Experiment 5). These data support the theory that performing actions during study enhances the efficiency of an automatic pop-out mechanism in free recall.

An attempt to distinguish between kinematic and motor memory components

Abstract Against the background of a modality-specific representation, we suggest the existence, in addition to motor programs, of movement representations which represent items of kinematic information, i.e. movement vectors. We discuss the possible existence of such representations and their features, in the light of available theories and findings. We then report on two experiments designed to show by selective interference the partial dependence of movement representations and motor programs. The experiments, whose distraction tasks differed, yielded the same results. Recall of motor learning material is more strongly interfered with by a secondary motor task than recall of kinematic learning material. The secondary motor and kinematic tasks finding supports the theory that the two systems are partially independent. However, it has, as yet, only been possible to demonstrate a selective distraction for the secondary motor task; proof of a selectively effective secondary kinematic task is still to be attained.