An abbreviated implicit spatial context learning task that yields greater learning

The spatial contextual cuing task (SCCT) (Chun & Jiang, 1998) is an implicit learning task that appears to depend on the medial temporal lobes. This unusual combination has been of interest in functional imaging studies and research with clinical populations, where testing time is at a premium. However, the original version of the SCCT is time-consuming. In this study, 29 young adults (age range, 18–22 years) completed the SCCT, in which participants respond to the orientation of a target in arrays containing 11 distractors. Either 12 (original version) or 6 (abbreviated version) arrays repeated across the experiment, with the remaining novel arrays being generated randomly. Results revealed that the magnitude of learning (faster responses to repeated versus novel arrays) was larger when there were fewer repeated arrays, with no explicit awareness in most participants. Thus, the abbreviated version remained implicit, with the additional benefit of increasing the magnitude of learning.     

Social feedback interferes with implicit rule learning: Evidence from event-related brain potentials

The human brain can learn contingencies built into stimulus sequences unconsciously. The quality of such implicit learning has been connected to stimulus social relevance, but results so far are inconsistent. We engaged participants in an implicit-intentional learning task in which they learned to discriminate between legal and illegal card triads on the sole basis of feedback provided within a staircase procedure. Half of the participants received feedback from pictures of faces with a happy or sad expression (social group) and the other half based on traffic light icons (symbolic group). We hypothesised that feedback from faces would have a greater impact on learning than that from traffic lights. Although performance during learning did not differ between groups, the feedback error-related negativity (fERN) was delayed by ~20 ms for social relative to symbolic feedback, and the P3b modulation elicited by infrequent legal card triads within a stream of illegal ones during the test phase was significantly larger in the symbolic than the social feedback group. Furthermore, the P3b mean amplitude recorded at test negatively correlated with the latency of the fERN recorded during learning. These results counterintuitively suggest that, relative to symbolic feedback, socially salient feedback interferes with implicit learning.     

Long-term spatial clustering in free recall

We explored the influence of space on the organisation of items in long-term memory. In two experiments, we asked our participants to explore a virtual environment and memorise discrete items presented at specific locations. Memory for those items was later on tested in immediate (T1) and 24 hours delayed (T2) free recall tests, in which subjects were asked to recall as many items as possible in any order. In experiment 2, we further examined the contribution of active and passive navigation in recollection dynamics. Results across experiments revealed a significant tendency for participants to consecutively recall items that were encountered in proximate locations during learning. Moreover, the degree of spatial organisation and the total number of items recalled were positively correlated in the immediate and the delayed tests. Results from experiment 2 indicated that the spatial clustering of items was independent of navigation types. Our results highlight the long-term stability of spatial clustering effects and their correlation with recall performance, complementing previous results collected in immediate or briefly delayed tests.     

Biased representations of the spatial structure of navigable environments

Recent studies (e.g., Shelton & McNamara in Cognitive Psychology, 43(4), 274–310, 2001; Valiquette, McNamara, & Smith in Memory and Cognition, 31(3), 479–489, 2003) have demonstrated that judgments of relative direction (JRD) access a single enduring orientation-dependent allocentric representation of the layout of objects in an environment, regardless of whether the space is viewed from one or multiple vantage points. Two experiments tested the limits of this phenomenon. In both experiments participants learned the locations of objects in a large room from two views: one view was aligned with salient environmental frames of reference (edges of the mat on which objects were placed and walls of the enclosing room) and expected to be preserved in long-term memory; the other view was misaligned and not expected to be preserved in long-term memory. The first experiment demonstrated that performing JRD between studying the misaligned view and studying the aligned view did not result in the misaligned view being maintained in long-term memory. The second experiment demonstrated that after studying the layout extensively from the misaligned view, 30 s of exposure to the aligned view (with no instructions to learn the layout from that view) resulted in the aligned but not the misaligned view being preserved in long-term memory. These findings indicate that the human spatial memory and navigation system is strongly biased to represent the spatial structure of navigable environments with reference directions or axes that are aligned with salient environmental frames of reference.     

Implicit learning of a recursive rule in an artificial grammar

Participants performed an artificial grammar learning task, in which the standard finite state grammar (J. Verb. Learn. Verb. Behavior 6 (1967) 855) was extended with a recursive rule generating self-embedded sequences. We studied the learnability of such a rule in two experiments. The results verify the general hypothesis that recursivity can be learned in an artificial grammar learning task. However this learning seems to be rather based on recognising chunks than on abstract rule induction. First, performance was better for strings with more than one level of self-embedding in the sequence, uncovering more clearly the self-embedding pattern. Second, the infinite repeatability of the recursive rule application was not spontaneously induced from the training, but it was when an additional cue about this possibility was given. Finally, participants were able to verbalise their knowledge of the fragments making up the sequences-especially in the crucial front and back positions-, whereas knowledge of the underlying structure, to the extent it was acquired, was not articulatable. The results are discussed in relation to previous studies on the implicit learnability of complex and abstract rules.     

Sensory feedback in the learning of a novel motor task

The role of different forms of feedback is examined in learning a novel motor task. Five groups of ten subjects had to learn the voluntary control of the abduction of the big toe, each under a different feedback condition (proprioceptive feedback, visual feedback, EMG feedback, tactile feedback, force feedback). The task was selected for two reasons. First, in most motor learning studies subjects have to perform simple movements which present hardly any learning problem. Second, studying the learning of a new movement an provide useful information for neuromuscular reeducation, where patients often also have to learn movements for which no control strategy exists. The results show that artificial sensory feedback (EMG feedback, force feedback) is more powerful than "natural" (proprioceptive, visual, and tactile) feedback. The implications of these results for neuromuscular reeducation are discussed.     

Developmental continuity in the processes that underlie spatial recall

This study investigated whether children's spatial recall performance shows three separable characteristics: (1) biases away from symmetry axes (geometric effects); (2) systematic drift over delays; and (3) biases toward the exemplar distribution experienced in the task (experience-dependent effects). In Experiment 1, the location of one target within each geometric category was varied. Children's responses showed biases away from a midline axis that increased over delays. In Experiment 2, multiple targets were placed within each category at the same locations used in Experiment 1. After removing geometric effects, 6-year-olds'--but not 11-year-olds'--responses were biased toward the average remembered location over learning. In Experiment 3, children responded to one target more frequently than the others. Both 6- and 11-year-olds showed biases toward the most frequent target over learning. These results provide a bridge between the performance of younger children and adults, demonstrating continuity in the processes that underlie spatial memory abilities across development.     

Advantages of recall over anticipation methods in verbal learning

The standard paired-associate anticipation procedure previously has been argued to be inferior to recall (Battig, 1965). Anticipation performance measures provide contaminated and inaccurate estimates of Ss’ current learning level, reflecting the unnecessary confusion produced by requiring S to do too many things at once. The present paper shows these arguments against anticipation procedures to apply equally to other types of verbal-learning tasks. Even stronger advantages of recall over anticipation procedures are demonstrated for serial learning, wherein recall additionally displays a markedly greater sensitivity to the effects of relevant manipulated variables, and does not result in the classical bowed serial-position curve that has proved so difficult to understand under serial anticipation.     

Recognition memory and the recall of spatial location

It is argued that memory for events should depend on the ability to recall their attributes. Two experiments suggest that this is so for the attribute of spatial location. When words presented in spatial arrays were later re-presented in a joint test of recognition memory and location recall, it was found that the surer one’s recognition, the greater the accuracy of location recall. Instructions to attend to a word’s location resulted in poorer recognition memory and marginally poorer location recall than were obtained when location was “incidentally” learned. Finally, when words were presented in color as well as in space, recognition memory was best when both attributes were recalled, was better when only location, was recalled than when only color was recalled, and was poorest when neither attribute was recalled.     

The independence of recall and recognition in motor learning

A basic tenet of both current closed-loop theories of motor learning (Adams, 1971; Schmidt, 1975) is that the generation of response specifications during learning is required for the development of recall memory. Two experiments were performed to test this tenet by attempting to demonstrate the development of recall memory in the absence of response specification production. The task in both experiments required blindfolded subjects to learn to produce a rapid, novel criterion movement on a linear positioning device. Control subjects in both experiments actively produced movements during learning with knowledge of results (KR) while experimental subjects in Experiment 1 experienced only the endpoint locations and in Experiment 2 were passively moved to the endpoint locations. Following initial KR trials, both experimental and control groups attempted to actively produce the criterion movement in the absence of KR. The results of both experiments support closed-loop theory that active practice is required to develop recall memory. There was some suggestion, however, that passive experience with sensory feedback may also aid recall memory development, contrary to the two closed-loop theories.     

The role of comprehension in children's observational learning of a syntactic rule

This experiment tested the hypothesis that there is a relationship between children's comprehension of a syntactic form and the effectiveness of modeling in promoting imitation of that form. Nursery and kindergarten children received pretests for both comprehension and production of reversible passive sentences. Children who produced no passive sentences were classified either as high, intermediate, or low comprehenders on the basis of their comprehension test performance. Within each of these three groups, children were randomly assigned either to a modeling or to a no-modeling control condition. Children in the treatment condition heard a model use passive sentences to describe a series of pictures. As predicted, the imitation post-test scores of these children were significantly related to their comprehension pretest scores. No significant relationship between the post-test scores and the comprehension scores of control subjects was detected. Children exposed to the model in all three comprehension groups received significantly higher post-test scores than did their respective counterparts in the no-modeling condition. These results are discussed in terms of the hypothesis that language learning proceeds from comprehension to imitation to production.     

Delayed sensory feedback in the learning of a novel motor task

Summary Generally the therapeutical effect of EMG feedback is viewed in terms of the immediate contiguity between response and information. According to this view any feedback delay would deteriorate the result. In this article the validity of this notion has been investigated. Three groups of normal subjects were required to perform a difficult movement under three feedback conditions: immediate EMG feedback, delayed EMG feedback, and a control (no EMG feedback) condition. The results indicated a significant difference between the EMG feedback groups and the control condition. However, no such difference was found between the immediate and delayed feedback conditions. The results suggested that the immediacy of the feedback is not the main factor in EMG feedback, but the specificity of the information.This study was supported by Grant no. 15-35-03 from the Netherlands Organization for the Advancement of Pure Research