Maud Boyer Arnaud Destrebecqz Axel Cleeremans.

Studies of implicit learning have shown that individuals exposed to a rule-governed environment often learn to exploit 'rules' which describe the structural relationship between environmental events. While some authors have interpreted such demonstrations as evidence for functionally separate implicit learning systems, others have argued that the observed changes in performance result from explicit knowledge which has been inadequately assessed. In this paper we illustrate this issue by considering one commonly used implicit learning task, the Serial reaction time task, and (...) outline what we see as an important problem associated with each of the commonly used methods used to assess explicit knowledge. This is that each measure requires a form of response which is dependent on the subjects having some knowledge of the serial-order of the sequence. We argue that such methods, or more specifically their analyses, seriously underestimate other sources of knowledge, which may be available to subjects during their performance of the SRT task. In support of this argument we demonstrate that subjects' serial-order knowledge can, in principle, be independent of subjects' knowledge of the statistical structure of the sequence, and we propose an alternative method for analysing performance on the Generate task which avoids this problem. (shrink)

This chapter contains sections titled: Are They Blameworthy for What They Do? The Puzzle On the Virtues of Philosophy Interruptus What You Don't Know About Psychopathic Serial Killers Back to Philosophy Psychopathic Serial Killing and Evil.

When humans are required to perform two or more tasks concurrently, their performance declines as the tasks get closer together in time. Here, we investigated the mechanisms of this cognitive performance decline using a dual-task paradigm in a simulated driving environment, and using drift-diffusion modeling, examined if the two tasks are processed in a serial or a parallel manner. Participants performed a lane change task, along with an image discrimination task. We systematically varied the time difference between the onset (...) of the two tasks and measured its effect on the amount of dual-task interference. Results showed that the reaction times of the two tasks in the dual-task condition were higher than those in the single-task condition. SOA influenced the RTs of both tasks when they were presented second and the RTs of the image discrimination task when it was presented first. Results of drift-diffusion modeling indicated that dual-task performance affects both the rate of evidence accumulation and the delays outside the evidence accumulation period. These results suggest that a hybrid model containing features of both parallel and serial processing best accounts for the results. Next, manipulating the predictability of the order of the two tasks, we showed that in unpredictable conditions, the order of the response to the two tasks changes, causing attenuation in the effect of SOA. Together, our findings suggest higher-level executive functions are involved in managing the resources and controlling the processing of the tasks during dual-task performance in naturalistic settings. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:A Bibliography of Bertrand Russell. Volume I: Separate Publications, 1896–1990 by Kenneth Blackwell, Harry RujaG. A. Wedeking and A. D. IrvineKenneth Blackwell and Harry Ruja. A Bibliography of Bertrand Russell. Volume I: Separate Publications, 1896–1990. Pp. lvi + 611. Volume II: Serial Publications, 1890–1990. Pp. xiv + 575. Volume III: Indexes. Pp. xi + 305. London: Routledge, 1994. Cloth, $455.00 the set.As Russell remarked: “It is a (...) curious fact that the most indubitably useful books are those most devoid of literary merit; for example, railway timetables and the telephone [End Page 146] book” (Vol. I, p. xlviii). Even so, since it will be agreed immediately that, for anyone interested in learning more about Russell’s writings, this beautifully crafted bibliography will be extremely useful, it would be a disservice to the authors to imply that it has no more literary merit than a railway timetable. The entire project simply has too much style.When Russell’s bibliographers began their task, fewer than 600 publications by Russell were known. By the time of publication they were able to record 181 of Russell’s books, pamphlets and leaflets, 629 contributions to books, pamphlets, and leaflets primarily authored by others, and approximately 3,550 serial publications of various types. Not being content merely to record the details of these publications, the authors follow each publication through its various editions, impressions, reprints, and translations. This is no mean task, given that Russell’s work has been translated into some 47 languages. In addition, the authors cite related pre-publication materials, give sources for rare and difficult-to-find books and documents, and include a comprehensive index. In short, they do nothing less than provide an authoritative, detailed record of Russell’s published work from 1890 to 1990.As the authors also point out, this is “a bibliography not only of Russell’s writings submitted and actually published, but also of certain other texts. Together they can be regarded as his published thoughts” (I: xix). Thus the bibliography mentions not only Russell’s books, articles, and published letters, but published accounts of his speeches, addresses, press conferences, and interviews; book reviews and recommendations (what Russell called “puffs”) for other people’s books; multiple-signatory letters to the editor and other similar documents; published extracts from Russell’s private correspondence and originally unpublished manuscripts; and audio recordings and films. A mark of the bibliography’s completeness is its catalogue of works that have been spuriously attributed to Russell, including two posthumous “spirit communications” (II: 573–74).The authors candidly describe Russell’s reaction when in 1966 he was shown slips of accumulated new entries: “ ‘I am impressed’, he said, ‘but I don’t think it’s worth it’ “ (I: li). Now, after several decades, we are finally in a position to evaluate Russell’s opinion. To do so, users of the bibliography will want to know the answer to three questions: Is the bibliography complete? Is it accurate? Is it easy to use?With regard to the first two of these three questions, the authors have made a commendable effort to balance comprehensiveness with accuracy (see their discussion of some problem cases, “Introduction,” I: xxvi ff.), rightly preferring accuracy to other desiderata. Concerning ease of use, one issue which comes to mind is whether the inclusion of such minor items as political pamphlets, letters to the editor, and statements made at news conferences, are always worth recording, or whether these items simply make the project so large as to be unmanageable. Once again, upon seeing the completed work, the reader will have little doubt that the correct decision has been made. Researchers interested in Russell’s political involvements and their relation to his more theoretical works, for example, will find this an invaluable resource. All in all, we believe that the bibliography will surpass the requirements of even the most demanding of users. It was, pace Russell, definitely worth it. [End Page 147]As with other volumes associated with the Collected Papers of Bertrand Russell project, these three volumes are beautifully typeset and bound. They will be a pleasure to use for both students and scholars alike for generations to... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:A Bibliography of Bertrand Russell. Volume I: Separate Publications, 1896–1990 by Kenneth Blackwell, Harry RujaG. A. Wedeking and A. D. IrvineKenneth Blackwell and Harry Ruja. A Bibliography of Bertrand Russell. Volume I: Separate Publications, 1896–1990. Pp. lvi + 611. Volume II: Serial Publications, 1890–1990. Pp. xiv + 575. Volume III: Indexes. Pp. xi + 305. London: Routledge, 1994. Cloth, $455.00 the set.As Russell remarked: “It is a (...) curious fact that the most indubitably useful books are those most devoid of literary merit; for example, railway timetables and the telephone [End Page 146] book” (Vol. I, p. xlviii). Even so, since it will be agreed immediately that, for anyone interested in learning more about Russell’s writings, this beautifully crafted bibliography will be extremely useful, it would be a disservice to the authors to imply that it has no more literary merit than a railway timetable. The entire project simply has too much style.When Russell’s bibliographers began their task, fewer than 600 publications by Russell were known. By the time of publication they were able to record 181 of Russell’s books, pamphlets and leaflets, 629 contributions to books, pamphlets, and leaflets primarily authored by others, and approximately 3,550 serial publications of various types. Not being content merely to record the details of these publications, the authors follow each publication through its various editions, impressions, reprints, and translations. This is no mean task, given that Russell’s work has been translated into some 47 languages. In addition, the authors cite related pre-publication materials, give sources for rare and difficult-to-find books and documents, and include a comprehensive index. In short, they do nothing less than provide an authoritative, detailed record of Russell’s published work from 1890 to 1990.As the authors also point out, this is “a bibliography not only of Russell’s writings submitted and actually published, but also of certain other texts. Together they can be regarded as his published thoughts” (I: xix). Thus the bibliography mentions not only Russell’s books, articles, and published letters, but published accounts of his speeches, addresses, press conferences, and interviews; book reviews and recommendations (what Russell called “puffs”) for other people’s books; multiple-signatory letters to the editor and other similar documents; published extracts from Russell’s private correspondence and originally unpublished manuscripts; and audio recordings and films. A mark of the bibliography’s completeness is its catalogue of works that have been spuriously attributed to Russell, including two posthumous “spirit communications” (II: 573–74).The authors candidly describe Russell’s reaction when in 1966 he was shown slips of accumulated new entries: “ ‘I am impressed’, he said, ‘but I don’t think it’s worth it’ “ (I: li). Now, after several decades, we are finally in a position to evaluate Russell’s opinion. To do so, users of the bibliography will want to know the answer to three questions: Is the bibliography complete? Is it accurate? Is it easy to use?With regard to the first two of these three questions, the authors have made a commendable effort to balance comprehensiveness with accuracy (see their discussion of some problem cases, “Introduction,” I: xxvi ff.), rightly preferring accuracy to other desiderata. Concerning ease of use, one issue which comes to mind is whether the inclusion of such minor items as political pamphlets, letters to the editor, and statements made at news conferences, are always worth recording, or whether these items simply make the project so large as to be unmanageable. Once again, upon seeing the completed work, the reader will have little doubt that the correct decision has been made. Researchers interested in Russell’s political involvements and their relation to his more theoretical works, for example, will find this an invaluable resource. All in all, we believe that the bibliography will surpass the requirements of even the most demanding of users. It was, pace Russell, definitely worth it. [End Page 147]As with other volumes associated with the Collected Papers of Bertrand Russell project, these three volumes are beautifully typeset and bound. They will be a pleasure to use for both students and scholars alike for generations to... (shrink)

According to the attentional resources account, mind wandering (or “task-unrelated thought”) is thought to compete with a focal task for attentional resources. Here, we tested two key predictions of this account: First, that mind wandering should not interfere with performance on a task that does not require attentional resources; second, that as task requirements become automatized, performance should improve and depth of mind wandering should increase. Here, we used a serial reaction time task with implicit- and explicit-learning groups to (...) test these predictions. Providing novel evidence for the attentional resource account’s first prediction, results indicated that depth of mind wandering was negatively associated with learning in the explicit, but not the implicit, group, indicating that mind wandering is associated with impaired explicit, but not implicit, learning. Corroborating the attention resource account’s second prediction, we also found that, overall, performance improved while at the same time depth of mind wandering increased. From an implicit learning perspective, these results are consistent with the claim that explicit learning is impaired under attentional load, but implicit learning is not. (shrink)

Sequential action makes up the bulk of human daily activity, and yet much remains unknown about how people learn such actions. In one motor learning paradigm, the serial reaction time (SRT) task, people are taught a consistent sequence of button presses by cueing them with the next target response. However, the SRT task only records keypress response times to a cued target, and thus it cannot reveal the full time‐course of motion, including predictive movements. This paper describes a mouse (...) movement trajectory SRT task in which the cursor must be moved to a cued location. We replicated keypress SRT results, but also found that predictive movement—before the next cue appears—increased during the experiment. Moreover, trajectory analyses revealed that people developed a centering strategy under uncertainty. In a second experiment, we made prediction explicit, no longer cueing targets. Thus, participants had to explore the response alternatives and learn via reinforcement, receiving rewards and penalties for correct and incorrect actions, respectively. Participants were not told whether the sequence of stimuli was deterministic, nor if it would repeat, nor how long it was. Given the difficulty of the task, it is unsurprising that some learners performed poorly. However, many learners performed remarkably well, and some acquired the full 10‐item sequence within 10 repetitions. Comparing the high‐ and low‐performers’ detailed results in this reinforcement learning (RL) task with the first experiment's cued trajectory SRT task, we found similarities between the two tasks, suggesting that the effects in Experiment 1 are due to predictive, rather than reactive processes. Finally, we found that two standard model‐free reinforcement learning models fit the high‐performing participants, while the four low‐performing participants provide better fit with a simple negative recency bias model. (shrink)

Sequential action makes up the bulk of human daily activity, and yet much remains unknown about how people learn such actions. In one motor learning paradigm, the serial reaction time (SRT) task, people are taught a consistent sequence of button presses by cueing them with the next target response. However, the SRT task only records keypress response times to a cued target, and thus it cannot reveal the full time‐course of motion, including predictive movements. This paper describes a mouse (...) movement trajectory SRT task in which the cursor must be moved to a cued location. We replicated keypress SRT results, but also found that predictive movement—before the next cue appears—increased during the experiment. Moreover, trajectory analyses revealed that people developed a centering strategy under uncertainty. In a second experiment, we made prediction explicit, no longer cueing targets. Thus, participants had to explore the response alternatives and learn via reinforcement, receiving rewards and penalties for correct and incorrect actions, respectively. Participants were not told whether the sequence of stimuli was deterministic, nor if it would repeat, nor how long it was. Given the difficulty of the task, it is unsurprising that some learners performed poorly. However, many learners performed remarkably well, and some acquired the full 10‐item sequence within 10 repetitions. Comparing the high‐ and low‐performers’ detailed results in this reinforcement learning (RL) task with the first experiment's cued trajectory SRT task, we found similarities between the two tasks, suggesting that the effects in Experiment 1 are due to predictive, rather than reactive processes. Finally, we found that two standard model‐free reinforcement learning models fit the high‐performing participants, while the four low‐performing participants provide better fit with a simple negative recency bias model. (shrink)

Statistical learning enables humans to involuntarily process and utilize different kinds of patterns from the environment. However, the cognitive mechanisms underlying the simultaneous acquisition of multiple regularities from different perceptual modalities remain unclear. A novel multidimensional serial reaction time task was developed to test 40 participants’ ability to learn simple first‐order and complex second‐order relations between uni‐modal visual and cross‐modal audio‐visual stimuli. Using the difference in reaction times between sequenced and random stimuli as the index of domain‐general statistical learning, (...) a significant difference and dissociation of learning occurred between the initial and final learning phases. Furthermore, we used a negative and positive occurrence‐frequency‐and‐reaction‐time correlation to indicate implicit and explicit learning, respectively, and found that learning simple uni‐modal patterns involved an implicit‐to‐explicit segue, while acquiring complex cross‐modal patterns required an explicit‐to‐implicit segue, resulting in a X‐shape crossing of regularity learning. Thus, we propose an X‐way hypothesis to elucidate the dynamic interplay between the implicit and explicit systems at two distinct stages when acquiring various regularities in a multidimensional probability space. (shrink)

In this article, we explore the extraction of recursive nested structure in the processing of binary sequences. Our aim was to determine whether humans learn the higher-order regularities of a highly simplified input where only sequential-order information marks the hierarchical structure. To this end, we implemented a sequence generated by the Fibonacci grammar in a serial reaction time task. This deterministic grammar generates aperiodic but self-similar sequences. The combination of these two properties allowed us to evaluate hierarchical learning while (...) controlling for the use of low-level strategies like detecting recurring patterns. The deterministic aspect of the grammar allowed us to predict precisely which points in the sequence should be subject to anticipation. Results showed that participants’ pattern of anticipation could not be accounted for by “flat” statistical learning processes and was consistent with them anticipating upcoming points based on hierarchical assumptions. We also found that participants were sensitive to the structure constituency, suggesting that they organized the signal into embedded constituents. We hypothesized that the participants built this structure by merging recursively deterministic transitions. (shrink)

A serial reaction time experiment tested the hypothesis that there are two independent forms of implicit learning: learning that is linked to making judgments about stimuli, and learning that is linked to motor processing. Participants performed 2, 6, or 12 blocks of single task SRT, dual task SRT, or observation with one of five sequences; each sequence had the same underlying structure. Participants then performed two implicit tests, SRT and pattern judgment, as well as a generation test and an (...) explicit knowledge test. There was a double dissociation of the effect of sequence surface structure on SRT and pattern judgment. SRT and pattern judgment competence developed independently of each other across length of acquisition task. Performance on both implicit tasks did not depend on explicit knowledge. These results indicate that the SRT and pattern judgment measures tap independent forms of implicit learning, which is consistent with the modular nature of memory and cognition. (shrink)

Nissen and Bullemer's serial reaction time task has proven to be a useful model task for exploring implicit sequence learning. Neuropsychological research indicates that SRT learning may depend on the integrity of the basal ganglia, but not on medial temporal and diencephalic structures that are crucial for explicit learning. Recent neuroimaging research demonstrates that motor cortical areas , prefrontal, and parietal cortex also may be involved. This paper reviews this neuropsychological and neuroimaging research, but finds it lacking specific links (...) between structure and function. In order to promote better functional hypotheses, the second part of the paper examines the function of these brain areas from a broader perspective. Neuroimaging and neuropsychological research with human subjects, as well as neurophysiological and lesion research with animals, suggests a number component operations that these brain mechanisms may contribute to learning in the SRT task. (shrink)

We first describe how the concept of “fringe consciousness” can characterise gradations of consciousness between the extremes of implicit and explicit learning. We then show that the NEO-PI-R personality measure of openness to feelings, chosen to reflect the ability to introspect on fringe feelings, influences both learning and awareness in the serial reaction time task under conditions that have previously been associated with implicit learning . This provides empirical evidence for the proposed phenomenology and functional role of fringe consciousness (...) in so-called implicit learning paradigms . Introducing an individual difference variable also helped to identify possible limitations of the exclusion task as a measure of conscious sequence knowledge. Further exploration of individual differences in fringe awareness may help to avoid polarity in the implicit learning debate, and to resolve apparent inconsistencies between previous SRT studies. (shrink)

In a serial reaction time task, procedural memory was examined in Dissociative Identity Disorder . Thirty-one DID patients were tested for inter-identity transfer of procedural learning and their memory performance was compared with 25 normal controls and 25 controls instructed to simulate DID. Results of patients seemed to indicate a pattern of inter-identity amnesia. Simulators, however, were able to mimic a pattern of inter-identity amnesia, rendering the results of patients impossible to interpret as either a pattern of amnesia or (...) a pattern of simulation. It is argued that studies not including DID-simulators or simulation-free memory tasks, should not be taken as evidence for amnesia in DID. (shrink)

This paper uses the Process Dissociation Procedure to explore whether people can acquire unconscious knowledge in the serial reaction time task [Destrebecqz, A., & Cleeremans, A. . Can sequence learning be implicit? New evidence with the Process Dissociation Procedure. Psychonomic Bulletin & Review, 8, 343–350; Wilkinson, L., & Shanks, D. R. . Intentional control and implicit sequence learning. Journal of Experimental Psychology: Learning, Memory, and Cognition, 30, 354–369]. Experiment 1 showed that people generated legal sequences above baseline levels under (...) exclusion instructions. Reward moved exclusion performance towards baseline, indicating that the extent of motivation in the test phase influenced the expression of unconscious knowledge. Experiments 2 and 3 revealed that even with reward, adding noise to the sequences or shortening training led to above-baseline exclusion performance, suggesting that task difficulty and the amount of training also affected the expression of unconscious knowledge. The results help resolve some current debates about the role of conscious awareness in sequence learning. (shrink)

Individual differences in phonological processing abilities have often been attributed to perceptual factors, rather than to factors relating to learning and memory. Here, we consider the contribution of individual differences in declarative and procedural memory to phonological processing performance in adulthood. We examined the phonological processing, declarative memory, and procedural memory abilities of 79 native English-speaking young adults with typical language and reading abilities. Declarative memory was assessed with a recognition memory task of real and made-up objects. Procedural memory was (...) assessed with a serial reaction time task. For both tasks, learning was assessed shortly after encoding, and again after a 12-h, overnight delay. We regressed phonological processing ability with memory performance on both days. We found that declarative memory, but not procedural memory, was highly predictive of phonological processing abilities. Specifically, declarative memory scores obtained shortly after learning were associated with non-word repetition performance, whereas declarative memory scores obtained after the overnight delay were associated with phonological awareness. Procedural memory was not associated with either of the phonological processing measures. We discuss these findings in the context of adult participants with mature phonological systems. We examine possible implications for the relationship between declarative memory and phonological processing in adulthood. (shrink)

We argue performance in the serial reaction time task is associated with gradations of awareness that provide examples of fringe consciousness [Mangan, B. . Taking phenomenology seriously: the “fringe” and its implications for cognitive research. Consciousness and Cognition, 2, 89–108, Mangan, B. . The conscious “fringe”: Bringing William James up to date. In B. J. Baars, W. P. Banks & J. B. Newman , Essential sources in the scientific study of consciousness . Cambridge, MA: The MIT Press.], and address (...) limitations of the traditional SRT procedure, including criticism of exclusion generation tasks. Two experiments are conducted with a modified SRT procedure where irrelevant stimulus attributes obscure the sequence rule. Our modified paradigm, which includes a novel exclusion task, makes it easier to demonstrate a previously controversial influence of response stimulus interval on awareness. It also allows identification of participants showing fringe consciousness rather than explicit sequence knowledge, as reflected by dissociations between different awareness measures. The NEO-PI-R variable Openness to Feelings influenced the diversity of subjective feelings reported during two awareness measures, but not the degree of learning and awareness as previously found with traditional SRT tasks [Norman, E., Price, M. C., & Duff, S. C. . Fringe consciousness in sequence learning: the influence of individual differences. Consciousness and Cognition, 15, 723–760.]. This suggests possible distinctions between two components of fringe consciousness. (shrink)