Savings in relearning: II. On the formation of behavior-based trait associations and inferences.

Five experiments based on Carlston and Skowronski's (1994) relearning paradigm suggest that people spontaneously derive trait knowledge about actors from behaviors but that this knowledge may reflect either explicit trait inference processes or implicit actor–trait associations. Experiments 1 and 2 found that inference-instructed and control Ss showed equivalent savings in subsequent efforts to learn actor–trait pairs but not when instructed Ss initially inferred the wrong trait. Experiment 3 showed that savings were equivalent for stimuli from different sources, and Experiment 4 showed that savings effects persisted even when the target was only incidentally associated with a stimulus behavior. Finally, Experiment 5 suggests that after several days, even explicit trait inferences can become inaccessible to intentional retrieval, although the earlier experiments show that they continue to exert an implicit effect on learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Indirect Learning of Event Sequences: The Effects of Divided Attention and Stimulus Continuity.

In a serial reaction time (SRT) task, the learning curve is steeper when the stimuli are presented in a repeating sequential manner rather than in random order (Nissen & Bullemer, 1987). This is true even when subjects report being unaware of the presence of the repeating sequence. The present study examines the nature of this learning under conditions designed to reduce attentional resources and to disrupt the continuity of stimuli. In the first three experiments, subjects were trained in the SRT task, with or without the addition of a secondary tone counting task, and with repeating or non-repeating sequences. The results suggest that some sequence learning occurred despite the presence of a secondary task. Experiment 4 examined the extent of sequence learning when the inter-stimulus interval was varied between trials. The overall results suggest that despite reduced attentional allocation and discontinuous stimulus presentation, some sequence learning occurs. This result supports other work suggesting a dissociation between learning when measured explicitly, and when assessed through performance indicators. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit learning of semantic category sequences: Response-independent acquisition of abstract sequential regularities.

Through the use of a new serial naming task, the authors investigated implicit learning of repeating sequences of abstract semantic categories. Participants named objects (e.g., table, shirt) appearing in random order. Unbeknownst to them, the semantic categories of the objects (e.g., furniture, clothing) followed a repeating sequence. Irrespective of whether participants were instructed to attend to the categories (Experiment 1) or whether no mention was made of the categories (Experiments 2 and 3), naming latencies reliably increased when the repeating category sequence was switched to a random sequence. This was the case even for participants showing no explicit knowledge in reproduction and recognition tests. Results indicate that abstract sequential structures are learned implicitly, even if neither the surface stimuli nor the responses follow a sequence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The subliminal mere exposure effect does not generalize to structurally related stimuli.

R. F. Bornstein (1994) questioned whether subliminal mere exposure effects might generalize to structurally related stimuli, thereby providing evidence for the existence of implicit learning. Two experiments examined this claim using letter string stimuli constructed according to the rules of an artificial grammar. Experiment 1 demonstrated that brief, masked exposure to grammatical strings impaired recognition but failed to produce a mere exposure effect on novel structurally related strings seen at test. Experiment 2 replicated this result but also demonstrated that a reliable mere exposure effect could be obtained, provided the same grammatical strings were presented at test. The results suggest that the structural relationship between training and test items prevents the mere exposure effect when participants are unaware of the exposure status of stimuli, and therefore provide no evidence for the existence of implicit learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of implicit and explicit processes in learning from examples: A synergistic effect.

Four experiments are reported in which subjects gained extensive experience with artificial grammars in explicit and implicit processing tasks. Results indicate that (a) implicit processing was sufficient for learning a finite state grammar but was inadequate for learning another type of grammar based on logical rules. (b) Subjects were able to communicate some of their implicit knowledge of the grammars to another person. (c) Consistent with rule induction but not memory array models of learning, verbal protocols indicated there was no tendency to converge on the same set of cues used to identify valid strings. (d) A synergistic learning effect occurred when both implicit and explicit processing tasks were used in grammar based on logical rules but not in the finite state grammar. A theoretical framework is proposed in which implicit learning is conceptualized as an automatic, memory-based mechanism for detecting patterns of family resemblance among exemplars. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anatomy of motor learning. I. Frontal cortex and attention to action

We used positron emission tomography to study new learning and automatic performance in normal volunteers. Subjects learned sequences of eight finger movements by trial and error. In a previous experiment we showed that the prefrontal cortex was activated during new learning but not during during automatic performance. The aim of the present experiment was to see what areas could be reactivated if the subjects performed the prelearned sequence but were required to pay attention to what they were doing. Scans were carried out under four conditions. In the first the subjects performed a prelearned sequence of eight key presses; this sequence was learned before scanning and was practiced until it had become overlearned, so that the subjects were able to perform it automatically. In the second condition the subjects learned a new sequence during scanning. In a third condition the subjects performed the prelearned sequence, but they were required to attend to what they were doing; they were instructed to think about the next movement. The fourth condition was a baseline condition. As in the earlier study, the dorsal prefrontal cortex and anterior cingulate area 32 were activated during new learning, but not during automatic performance. The left dorsal prefrontal cortex and the right anterior cingulate cortex were reactivated when subjects paid attention to the performance of the prelearned sequence compared with automatic performance of the same task. It is suggested that the critical feature was that the subjects were required to attend to the preparation of their responses. However, the dorsal prefrontal cortex and the anterior cingulate cortex were activated more when the subjects learned a new sequence than they were when subjects simply paid attention to a prelearned sequence. New learning differs from the attention condition in that the subjects generated moves, monitored the outcomes, and remembered the responses that had been successful. All these are nonroutine operations to which the subjects must attend. Further analysis is needed to specify which are the nonroutine operations that require the involvement of the dorsal prefrontal and anterior cingulate cortex.     

Statistical structure and implicit serial learning.

In serial reaction time (RT) tasks, RT decreases faster with practice when a short sequence of trials is repeated continuously than when the sequence of trials is random (e.g., M. J. Nissen & P. Bullemer, 1987). Learning is implicit because Ss are not asked to learn the sequence and they often seem unaware of it. Relative to a random sequence, the repeating sequence imposes extreme statistical constraints. The present research examined the relation between these statistical constraints and implicit serial learning. Two experiments showed that the greater the statistical structure, the greater the reduction in RT with practice. Statistical structure was manipulated by varying the structure of a repeating sequence (Exp 1) and by varying the degree to which sequences approximated the statistical structure of a repeating sequence (Exp 2). The implications of these results for theories of implicit serial learning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of stimulus-based and response-based spatial information in sequence learning.

In 4 experiments, relational structures were independently varied in stimulus and response sequences in a serial reaction time task. Moreover, the use of spatial and symbolic stimuli and responses was varied between experiments. In Experiment 1, spatial stimuli (asterisk locations) triggered spatial responses (keystrokes); in Experiment 2, spatial stimuli triggered symbolic responses (verbal digit naming); in Experiment 3, symbolic stimuli (digits) triggered keystrokes; and in Experiment 4, digits triggered verbal responses. The results showed that there is a remarkably stronger effect of relational structures in spatial sequences than in symbolic sequences, irrespective of whether stimulus or response sequences are concerned. This suggests that learning is particularly effective for sequences of spatial locations. It is argued that spatial learning is a critical determinant for the debate on perceptual and motor learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response–effect learning as a major component of implicit serial learning.

Implicit response–effect learning was examined in 2 experiments, using a visual search version of the serial reaction time task introduced by M. J. Nissen and P. Bullemer (1987). In Experiment 1, the relation between the response to the current stimulus and the location of the stimulus on the next trial (i.e., effect) was varied systematically. In Experiment 2, both the frequency of the association between stimuli and responses and the frequency of the association between responses and effects were manipulated. Only the frequency of the response–effect relation influenced learning. These results indicate that response–effect learning is an important component of serial learning. It is argued that response–effect relations constitute the initial implicit component of learning in serial reaction time tasks. From this implicit knowledge, knowledge about the stimulus sequence as well as the response sequence develops later. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the implicit learning of novel associations by amnesic patients and normal subjects.

Examined whether amnesic patients and normal Ss can acquire novel associations implicitly and whether such learning can occur rapidly in a single trial. In 2 experiments, Ss studied novel word pairs either once or multiple times and were then asked to read old, new, and recombined word pairs as quickly as possible. In this paradigm, the learning of novel associations would be indicated by slower reading times for recombined word pairs than for old word pairs. In a 3rd experiment, a perceptual identification paradigm was used to assess implicit learning of new associations. One-trial learning of new associations was not observed in the 1st 2 experiments, but learning of new associations did occur after multiple learning trials. An advantage of old vs recombined word pairs was obtained after a single trial only in Exp 3 (using perceptual identification) when the results were combined across S groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On tasks, knowledge, correlations, and dissociations: Comment on Perruchet and Amorim (1992).

Many studies have suggested that under some conditions sequence learning may be implicit and outside consciousness. Others suggest that a sequence can be learned with minimal involvement of attention when it contains unique associations between some elements. P. Perruchet and M. A. Amorim (see record 1992-37919-001) have recently questioned these suggestions and concluded on the basis of 3 experiments that consciousness is necessary for learning sequences and that unique associations may not be essential in learning with distraction. Several flaws in the arguments made by Perruchet and Amorim are outlined: They equated tasks with knowledge, assumed that correlations under some conditions preclude dissociations under many other conditions, and misinterpreted claims concerning unique associations in a sequence. It is claimed that the experiments and analyses conducted by Perruchet and Amorim are not diagnostic to these issues, and their conclusions are viewed as unwarranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit learning of sequences of tasks.

Task sets can be configured in advance of performing a new task. However, the degree to which advance information is actually used for advance configuration depends on the nature of the available information. The role of implicit learning was explored in 2 experiments by means of a modified serial reaction time task with repeated sequences of 4 dimensionally organized tasks. Although there was clear evidence for implicit learning of the sequence (of length 8), the learning was not associated with a reduction of shift costs, either with a short (200 ms) or with a long (1,200 ms) response–stimulus interval. In contrast, a reduction of shift costs was observed when external precues were introduced in a 3rd experiment. According to these results, the sequences of stimulus features that serve as cues for the tasks to perform on the stimuli are learned, but the representation of the features is void of their task-associated meanings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit (and explicit) learning: acting adaptively without knowing the consequences

Subjects exposed to members of a structured domain become sensitive to the general structure of that domain, even when unaware that the domain has such structure. Numerous investigators have taken this as evidence for a mode of learning in which memory passively and unselectively absorbs the structure of the environment. The authors contend that this assumption miscasts the fundamental nature of learning. The authors demonstrate that even when task and stimulus structure are held constant, subjects react to variations in incidental stimulus properties by processing the stimuli in qualitatively different ways. The authors conclude that implicit learning, just like explicit learning, proceeds through active organization of the stimulus complex, rather than through passive absorption of any level of structure. The authors propose a synthesis in which learning, with and without awareness, is understood through a common set of principles.     

Comparisons of the restricted association of chronic schizophrenic and normal control subjects.

Obtained 11 types of restricted associations and free associations from 24 chronic schizophrenics and 24 normal controls equated for age and education. The associations of schizophrenics were more variable than those of normal Ss, especially on tasks which most restricted the choice of responses. Agreement in responding between normal and schizophrenic Ss was markedly lower when compared with that between high- and low-creative Ss, or with 1-yr, test-retest data. Repetition of responses given to the same stimuli under different instructions was markedly higher for schizophrenic than normal Ss, and thus the degree of task and response differentiation was reduced. The restricted associations overlapped with free associations more markedly for schizophrenic than for normal Ss, but the general structure of a conceptual semantic space was about the same for both groups. It is argued that when explicit constraint in tasks of verbal associations is high, schizophrenic Ss, more than normals, impose a low degree of implicit constraint on their verbal behavior; when the external constraint is low, they increase their implicit constraint. (26 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Negative transfer errors in sequential cognitive skills: Strong-but-wrong sequence application.

Three experiments investigated the role of processing sequence knowledge in negative transfer within multistep cognitive skills. In Experiments 1 and 2, more training resulted in higher error rates when new processing sequences that resembled familiar ones were introduced in transfer. Transfer error responses were executed with the same speed as correct responses to familiar sequence trials, and the errors appeared to be undetected by the performers. Experiment 3 tested whether the effects of sequence learning were attributable to explicit or implicit knowledge of processing sequences. Evidence favored the implicit learning interpretation. Findings are discussed in relationship to earlier demonstrations of the einstellung effect and to current taxonomic theories of human error. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit learning of a nonverbal sequence in younger and older adults.

Two experiments examined age-related differences in implicit serial learning using the M. J. Nissen and P. Bullemer (see record 1987-13436-001) task. Younger adults and 2 samples of older adults who differed in educational attainment, occupational status, and verbal ability were given a 10-trial repeating sequence embedded in 100-trial blocks. On each trial, participants pressed a key that matched a designated spatial location. Implicit learning was inferred from the difference in reaction time (RT) between a random sequence trial block and the immediately preceding block with the repeating sequence. Results indicated that negative transfer effects were comparable for the younger and higher ability older adults, but lower ability older adults showed less evidence of implicit learning. On an explicit task, younger and higher ability older adults were more accurate than the lower ability older adults. The implications of these findings for current views on implicit learning in adulthood are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disorganization of microfilaments and intermediate filaments interferes with the assembly and stability of desmosomes in MDCK epithelial cells

Using the serial reaction time (SRT) task developed by Nissen and Bullemer (1987, Cognitive Psychology, 19, 1-32), implicit memory performance was examined in four groups of subjects: nondemented healthy aged individuals; nondemented Parkinson's disease individuals; very mildly demented senile dementia of the Alzheimer type (SDAT) individuals; and mildly demented SDAT individuals. The SRT task involved four blocks of a repeated 10-item keypress sequence that tapped general skill development along with a fifth block of a nonrepeated sequence that presumably reflected the impact of switching from a learned set of associations (developed during the first four blocks) to a novel sequence. The increase in response latency from the fourth repeated block to the fifth nonrepeated block was used as the reflection of implicit learning. The results revealed preserved implicit memory performance in the very mildly demented individuals compared to that of the age-matched control individuals. However, the mildly demented SDAT individuals and the nondemented Parkinson's disease individuals showed reliably less implicit learning, compared to the age-matched control individuals. Differences between the past studies using the SRT task to tap implicit memory performance in SDAT individuals and the present study are discussed in some detail. We conclude that nondemented Parkinson's disease individuals and mildly demented SDAT individuals produce some deficit in the formation of new associations in implicit memory, as measured by the SRT task.     

Common and distinctive features of verbal and pictorial stimuli as determinants of psychophysiological responsivity.

The present study focuses on the relation between stimulus features and psychophysiological responsivity by using a modified version of the information detection paradigm. Compound pictorial and verbal stimuli were used as the relevant stimuli that Ss were instructed to memorize. Skin conductance responses were measured during the subsequent presentation of a sequence of test stimuli. We hypothesized that the electrodermal responsivity to the critical stimulus would reflect the degree it matches the relevant one. The results indicated that when the critical stimulus was identical to the relevant stimulus, responsivity was maximal. Neutral stimuli produced minimal responsivity, and critical stimuli that only partially matched the relevant one produced intermediate levels of responsivity (in spite of the subjects' awareness of the differences between the critical and the relevant stimuli). Comparison of the geometric and contrast models for similarity showed that the pattern of responsivity violated the minimality and symmetry assumptions of the geometric model. The relation between cognitive processes and psychophysiological responsivity is discussed, as are implications for the application of the guilty knowledge technique for detecting information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Specific associative unlearning in the AB-CD paradigm.

Since previous experiments have yielded conflicting results as to whether or not specific associative unlearning occurs in the different stimuli-different responses (AB-CD) paradigm, 2 experiments were directed at this problem. In Exp. I, with 96 undergraduates who were naive to verbal learning experiments, the response-form class of AB-CD lists was varied; no evidence of associative unlearning was found in any condition. In Exp. II, with 100 Ss, significant unlearning was found with similar and identical stimuli in both lists, but not when nonsense syllables and numbers were used as stimuli in successive lists, or when minimally related nonsense syllables were used as stimulus terms in the 2 lists. J. B. McGovern's (see record 2011-18733-001) analysis of unlearning was supported. (French summary) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Modality specificity of implicit memory for new associations.

In previous research we demonstrated that newly acquired associations between unrelated word pairs influence the magnitude of priming effects on word-completion tests. This phenomenon of implicit memory for new associations is observed only following semantic study elaboration. The present experiments reveal that implicit memory for new associations, though elaboration dependent, is also modality specific: Associative effects on a visual word-completion test were consistently reduced by study-test modality shifts. In contrast, explicit memory for new associations, as indexed by cued-recall performance, was uninfluenced by modality shifts. The modality effect on completion performance was eliminated when subjects were given brief visual preexposures to, or were required to construct visual images of, word pairs presented in auditory study conditions. The results pose a theoretical puzzle insofar as they indicate that within the domain of implicit memory, access to the products of elaborative processing depends on modality-specific, sensory-perceptual processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)