What does it take for context to support action memory?

Previous research on the relation between context and action memory has given ambiguous results. Some experiments have found positive context effects, whereas other experiments have failed to demonstrate a context effect in action memory. Under nonmotor encoding conditions orderly action-locus pairings have been found to yield better recall than random pairings, this not being the case with motor encoding (Helstrup, 1989 a ). Three new experiments explored whether memory for loci could be linked with memory for action–using modified replications. The first experiment provided item-specific reasons for the action-locus connections, whereas the second experiment used a whole-list relational context task. Both experiments indicated that contexts can influence action memory also under enactment conditions, with strongest effect for whole-list contexts. The third experiment demonstrated how a positive context effect can be removed when the functional value of whole-list relational support cues is reduced.     

In search of a motor element in memory for enacted events

Four experiments tried with different methods to locate a theoretically expected motor factor in memory of enacted movement patterns. The first experiment examined forward versus backward reporting; the second and third looked at possible interactions between encoding and retrieval modalities, whereas the fourth experiment examined whether motor aspects would come more clearly to the fore with practice on the task. Since none of the experiments could detect motor effects, motor factors were suggested to be more important for execution than for memory of actions.     

Does motor encoding enhance relational information?

Summary Three 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.     

Inter-event differences in action memory

Two experiments examined the effect of verb-noun connectivity on recall of simple action phrases, under motor and nonmotor encoding conditions. Connectivity, measured by associative overlap and rated belongingness, was found to make a difference. High-connectivity pairs are better recalled than low-connectivity pairs. Primacy effects are absent with low-connectivity pairs, but generally present with high-connectivity pairs—irrespective of encoding conditions. Inter-item action phrase differences thus influence the effects studied in action memory research. The results were discussed in terms of strategic and nonstrategic conceptions of memory for actions.     

Memory for truths and falsehoods

Three experiments were carried out to determine whether recognition memory was more efficient for true statements (on the basis of the subjects’ stable body of knowledge) than for false statements. The first two experiments did not show any difference. In a third experiment, the distractors were structured to prevent subjects from responding on the basis of the familiarity of individual component words rather than on the basis of the complete sentences. This experiment showed a clear difference between sentence classes, with true sentences remembered more accurately and faster than false sentences. The data fit, in general, the hypothesis that true sentences are doubly represented in memory. The relation of these findings to the findings on the effects of encoding tasks is also noted.     

Attentional demands and recall of verbal and color information in action events

Two experiments addressed the influence of secondary task performance at encoding on recall of different features of subject-performed tasks (SPTs) involving objects (e.g., turn the wallet). In Experiment 1, memory for verbs and colors of objects was assessed, with object names serving as cues. In Experiment 2, object and color memory were assessed, with verbs serving as cues. Results from both experiments indicated a greater deterioration of memory performance under divided attention for verbal features than for colors. In addition, intention to remember did not affect performance for any feature in either experiment. The overall pattern of outcome is discussed relative to the view that encoding of verbal features of SPTs is more attention-demanding than encoding of physical task features, such as color.     

Bias in spatial memory: a categorical endorsement

Two experiments investigated how angular estimates reflect bias as a function of response mode, geometric plane of variation, number of implicit categories, memory load and intervening task conditions. In Experiment 1, participants made motor and verbal estimates of incline and azimuth from memory. Estimates in both response modes showed signs of bias predicted by a single-category adaptation of Huttenlocher et al. [Huttenlocher, J., Hedges, L. V., & Duncan, S. (1991). Categories and particulars: Prototype effects in estimating spatial location. Psychological Review, 98, 352-376] category-adjustment model. In Experiment 2, participants made motor estimates of azimuth from memory under a variety of conditions. Stimuli in this experiment were distributed along two contiguous spatial categories. Although increasing levels of cognitive load did not produce a graded effect, participants' estimates were biased and were well described by a multiple-category adaptation of the category-adjustment model. Results from both studies supported an implicit region-based model of bias in spatial memory. These findings were discussed with respect to accounts of spatial memory that propose multiple systems or formats for coding.     

Asymmetry between encoding and retrieval processes: Evidence from divided attention and a calibration analysis

Two experiments provide further information on the effects of divided attention (DA) on encoding and retrieval processes. The first experiment examined the effects of decision and motor difficulty of a concurrent reaction time task. A calibration analysis was used in the second experiment to test the hypothesis that shifting attentional emphasis away from encoding to the secondary task reduces the level of processing the to-be-remembered items receive. Overall, the results confirm and extend the conclusions of Craik, Govoni, Naveh-Benjamin, and Anderson (1996) and Naveh-Benjamin, Craik, Guez, and Dori (1998), by pointing to clear differences between encoding and retrieval processes: Encoding is affected by simultaneous task demands, especially those associated with "central" resources involved in conscious decision making, whereas retrieval is obligatory in that it is largely immune to the effects of simultaneous demands. The results of the calibration analysis suggest that one reason for the poorer memory performance as a result of DA at encoding is a qualitative shift to less deep, elaborative strategies.     

Depressive deficits in memory: processing initiative and resource allocation

Hertel and Hardin investigated the effects of depressed mood states on recognition memory in three experiments. They report that mood effects on memory depend on the subjects' awareness of the task. Four issues are considered in this article: natural and induced moods, processing initiative, initiative versus resource allocation, and strategies.     

Truly incidental encoding of frequency information

Four experiments demonstrated that adults can reliably remember frequency of occurrence information about items they have been exposed to under truly incidental memory conditions. Subjects neither knew that the ultimate test task would concern item frequency nor that they had any reason to remember the items. This was accomplished by presenting items under the guise of one of three cover tasks: anagram solving, sentence completion, and picture naming in a Stroop-like task. In addition, one experiment found that subjects who were prewarned for either a nonspecific memory test or a frequency test were no better able to judge frequency than were subjects operating under truly incidental conditions.     

Concurrent and retroactive interference effects in memory of movement patterns

Three experiments examined memory for enacted and observed movement patterns. The effect of visuo-spatial tracing tasks requiring overt motor movements, comparable to those required by the to-be-recalled movement pattern task when enacted, were compared with the effects of non-motor interference tasks, such as articulatory suppression and counting backwards. None of the experiments was able to detect indices of motor mechanisms in memory of movement patterns. The results are discussed in terms of theories of action memory and working memory and of a problem-solving account.     

Why faces are and are not special: an effect of expertise

Recognition memory for faces is hampered much more by inverted presentation than is memory for any other material so far examined. The present study demonstrates that faces are not unique with regard to this vulnerability to inversion. The experiments also attempt to isolate the source of the inversion effect. In one experiment, use of stimuli (landscapes) in which spatial relations among elements are potentially important distinguishing features is shown not to guarantee a large inversion effect. Two additional experiments show that for dog experts sufficiently knowledgeable to individuate dogs of the same breed, memory for photographs of dogs of that breed is as disrupted by inversion as is face recognition. A final experiment indicates that the effect of orientation on memory for faces does not depend on inability to identify single features of these stimuli upside down. These experiments are consistent with the view that experts represent items in memory in terms of distinguishing features of a different kind than do novices. Speculations as to the type of feature used and neuropsychological and developmental implications of this accomplishment are offered.     

Procedural dependence in action memory: Effects of verb form and individual vs group conditions

Two experiments explored whether the magnitude of the enactment effect in action memory (i. e., higher recall with motor than with non-motor encoding) may depend upon the use of individual or group testing procedures. Nonmotor encoding instructions, requiring the subjects to listen to orally presented action items, were compared to instructions which also required enactment. With encoding treated as a within-subject factor, the observations failed to reveal any significant difference between individual and group testing. With encoding treated as a between-subject factor, the results showed an interaction between test and encoding conditions, such that an enactment effect was found only with group testing. Different support value for auditory cues in group and individual test situations was assumed to account for this difference. In a third experiment the indicative and imperative verb forms were compared. An interaction was observed, showing that in Norwegian, enacted verbs were remembered better when presented in the indicative than in the imperative. No corresponding difference was found under non-enactment conditions. For this finding, a social interaction interpretation was offered.     

Multiple spatial learning strategies in goldfish (Carassius auratus)

There is a considerable amount of evidence that mammals and birds can use different spatial learning strategies based on multiple learning and memory systems. Unfortunately, only a few studies have investigated spatial learning and memory mechanisms in other vertebrates. This study aimed to identify the strategies used by goldfish to solve two different spatial tasks in a series of three experiments. In experiment 1, two groups of goldfish (Carassius auratus) were trained either in a spatial constancy task (SC), in which visual cues signalled the goal indirectly, or in a directly cued task (DC) in which similar cues signalled the goal directly. Transfer tests were conducted to study the effects of discrete cue deletion on the performance in both tasks. In these transfer tests the performance of the animals trained in the DC task dropped to chance level when the cue that signalled the goal directly was removed. In contrast, the removal of any single cue did not disrupt SC performance. In experiment 2, fish trained in the SC or the DC task were trained with the goal reversed. Goldfish in the SC group needed fewer sessions to master the reversal task than DC animals. Finally, experiment 3 investigated the effects of a substantial modification of the geometrical features of the apparatus on the performance of animals trained in the SC or in the DC condition. The performance of DC goldfish was not affected, whereas the same change disrupted performance in the SC animals despite the presence of the visual cues. These results suggest that there are separate spatial learning and memory systems in fish. Whereas the DC animals used a typical guidance strategy, relying only on the cue that signalled the goal directly, SC fish relied on a strategy with the properties of an actual spatial mapping system. Thus, the comparative approach points to the generality of these learning strategies among vertebrates. Received: 10 October 1998 / Accepted after revision: 16 April 1999     

Why do the effects of delaying reinforcement in animals and delaying feedback in humans differ? A working-memory analysis

Animal research has shown that reinforcement is substantially less effective when it is delayed, but in studies of human motor learning delays in providing feedback typically have much less effect. One possible explanation is that in human research participants know the response to be learned and can thus focus on it during the delay; that is not the case in experiments on animals. We tested this hypothesis using a task in which participants had minimal information on what movement was correct and found that, as in animal experiments, participants learned only when feedback was immediate. A second experiment confirmed that the effects of the delay depended on how many responses had to be held in working memory: the greater the memory load, the poorer the learning. The results point to the importance of activity during a delay on learning; implications for the teaching of motor skills are discussed.     

Why do the effects of delaying reinforcement in animals and delaying feedback in humans differ? A working-memory analysis

Animal research has shown that reinforcement is substantially less effective when it is delayed, but in studies of human motor learning delays in providing feedback typically have much less effect. One possible explanation is that in human research participants know the response to be learned and can thus focus on it during the delay; that is not the case in experiments on animals. We tested this hypothesis using a task in which participants had minimal information on what movement was correct and found that, as in animal experiments, participants learned only when feedback was immediate. A second experiment confirmed that the effects of the delay depended on how many responses had to be held in working memory: the greater the memory load, the poorer the learning. The results point to the importance of activity during a delay on learning; implications for the teaching of motor skills are discussed.     

The relationship between initial errorless learning conditions and subsequent performance

This experiment explores a suggestion by [Maxwell, J.P., Masters, R.S.W., Kerr, E., Weedon, E. (2001). The implicit benefit of learning without errors. Quarterly Journal of Experimental Psychology A 54, 1049-1068] that an initial bout of implicit motor learning confers beneficial performance characteristics, such as robustness under secondary task loading, despite subsequent explicit learning. Participants acquired a complex motor skill (golf putting) over 400 trials. The environment was constrained early in learning to minimize performance error. It was predicted that in the absence of explicit instruction, reducing error would prevent hypothesis testing strategies and the concomitant accrual of declarative (explicit) knowledge, thereby reducing dependence on working memory resources. The effect of an additional cognitive task on putting performance was used to assess reliance on working memory. Putting performance of participants in the Implicit-Explicit condition was unaffected by the additional cognitive load, whereas the performance of Explicit participants deteriorated. The relationship between error correction and episodic verbal reports suggested that the explicit group were involved in more hypothesis testing behaviours than the Implicit-Explicit group early in learning. It was concluded that a constrained, uninstructed, environment early in learning, results in procedurally based motor output unencumbered by disadvantages associated with working memory control.     

Working Memory Constraints on Linear Reasoning with Spatial and Temporal Contents

The present article reports two experiments testing the use of working memory components during reasoning with temporal and spatial relations in four-term series problems. In the first experiment four groups of subjects performed reasoning tasks with temporal and with spatial contents either without (control) or with a secondary task (articulatory suppression, visuospatial suppression or central executive suppression). The second experiment tested the secondary task effects in a within-subjects design either on problems with a spatial content or on problems with a temporal content, and within each content domain either under conditions of self-paced or of fixed presentation of the premises. Both experiments found effects of all three secondary tasks on reasoning accuracy. This supports the hypothesis that the subjects construct spatial representations of the premise information with the support of visuo-spatial resources of working memory. The second experiment also showed that during premise intake, only visuo-spatial and central executive secondary tasks had an effect. The implications of the data for the working memory requirements of reasoning and for theories of linear reasoning are discussed.     

Sensory and motor aspects of pseudoneglect, hemifield, and hemispace in the tactile modality

Two experiments were conducted with right-handed adult subjects to investigate motor and sensory components of a tactual line bisection task performed under three conditions: at midline, in the left, and in the right hemispaces. In the sensory experiment we found a left-hand rather than a right-hand superiority under the midline condition and, in the motor experiment, a right-hand rather than a left-hand superiority. The results were discussed with respect to hemispheric specialization and hemispace theories. Furthermore, we found a pseudoneglect (subjects bisected to the left of the midpoint) in the sensory experiment and a surprising reversed pseudoneglect (subjects bisected to the right of the midpoint) in the motor experiment.     

Schedule-induced defecation.

Excessive defecation, typically considered to be a concomitant of stress, was experimentally induced or eliminated under specific schedules of positive reinforcement of lever pressing by rats. The schedules were, by and large, those under which polydipsia is typically induced. In the first of three experiments, rats under fixed-interval 32-second schedules and variable interval 32-second schedules for food and water reinforcers defecated profusely, but not under fixed-interval one-second schedules or other small interval schedules. Somewhat higher rates of defecation were observed on variable interval 32-second schedules than on fixed-interval 32-second schedules. In a second experiment, fixed-ratio schedules were used, some of which resulted in responding such that reinforcement densities were similar to those on the interval schedules that induced defecation. Defecation was not systematically induced by these ratio schedules. In a third experiment, fixed-time schedules of food presentations were utilized. High rates of defecation were induced comparable to those induced by interval schedules of the same time parameter. No other behavior commonly termed "emotional" was observed in any of these experiments.