Serge Brédart

Bio: Serge Brédart is an academic researcher from University of Liège. The author has contributed to research in topics: Recall & Proper noun. The author has an hindex of 33, co-authored 122 publications receiving 4280 citations. Previous affiliations of Serge Brédart include University of British Columbia & Catholic University of Leuven.

Two distinct neuronal networks mediate the awareness of environment and of self

Abstract: Evidence from functional neuroimaging studies on resting state suggests that there are two distinct anticorrelated cortical systems that mediate conscious awareness: an "extrinsic" system that encompasses lateral fronto-parietal areas and has been linked with processes of external input (external awareness), and an "intrinsic" system which encompasses mainly medial brain areas and has been associated with internal processes (internal awareness). The aim of our study was to explore the neural correlates of resting state by providing behavioral and neuroimaging data from healthy volunteers. With no a priori assumptions, we first determined behaviorally the relationship between external and internal awareness in 31 subjects. We found a significant anticorrelation between external and internal awareness with a mean switching frequency of 0.05 Hz (range: 0.01-0.1 Hz). Interestingly, this frequency is similar to BOLD fMRI slow oscillations. We then evaluated 22 healthy volunteers in an fMRI paradigm looking for brain areas where BOLD activity correlated with "internal" and "external" scores. Activation of precuneus/posterior cingulate, anterior cingulate/mesiofrontal cortices, and parahippocampal areas ("intrinsic system") was linearly linked to intensity of internal awareness, whereas activation of lateral fronto-parietal cortices ("extrinsic system") was linearly associated with intensity of external awareness.

Brain Response to One's Own Name in Vegetative State, Minimally Conscious State, and Locked-in Syndrome

Abstract: Background A major challenge in the management of severely brain-injured patients with altered states of consciousness is to estimate their residual perception of the environment. Objective To investigate the integrity of detection of one's own name in patients in a behaviorally well-documented vegetative state (VS), patients in a minimally conscious state (MCS), and patients with locked-in syndrome. Design We recorded the auditory evoked potentials to the patient's own name and to 7 other equiprobable first names in 15 brain-damaged patients. Results A P3 component was observed in response to the patient's name in all patients with locked-in syndrome, in all MCS patients, and in 3 of 5 patients in a VS. P3 latency was significantly ( P Conclusions These results suggest that partially preserved semantic processing could be observed in noncommunicative brain-damaged patients, notably for the detection of salient stimuli, such as the subject's own name. This function seems delayed in MCS and (if present) in VS patients. More important, a P3 response does not necessarily reflect conscious perception and cannot be used to differentiate VS from MCS patients.

Age-related differences in updating working memory.

Abstract: Age-related differences in updating working memory were investigated in two experiments using a running memory task. In the first experiment, the task of the young and elderly subjects was to watch strings of four to 10 consonants and then to recall serially the four most recent items. Results revealed no age effect. A second experiment was then carried out using a memory load that was close to memory span: lists of six to 12 consonants were presented and subjects had to recall the last six items. Age interacted with list length but not with serial position. This dissociation is discussed in terms of Baddeley's (1986) model.

Remembering. A Study in Experimental and Social Psychology, Cambridge (University Press) 1964.

Abstract: Part I. Experimental Studies: 2. Experiment in psychology 3. Experiments on perceiving III Experiments on imaging 4-8. Experiments on remembering: (a) The method of description (b) The method of repeated reproduction (c) The method of picture writing (d) The method of serial reproduction (e) The method of serial reproduction picture material 9. Perceiving, recognizing, remembering 10. A theory of remembering 11. Images and their functions 12. Meaning Part II. Remembering as a Study in Social Psychology: 13. Social psychology 14. Social psychology and the matter of recall 15. Social psychology and the manner of recall 16. Conventionalism 17. The notion of a collective unconscious 18. The basis of social recall 19. A summary and some conclusions.

How do you feel--now? The anterior insula and human awareness.

Abstract: The anterior insular cortex (AIC) is implicated in a wide range of conditions and behaviours, from bowel distension and orgasm, to cigarette craving and maternal love, to decision making and sudden insight. Its function in the re-representation of interoception offers one possible basis for its involvement in all subjective feelings. New findings suggest a fundamental role for the AIC (and the von Economo neurons it contains) in awareness, and thus it needs to be considered as a potential neural correlate of consciousness.

Simple Heuristics That Make Us Smart

Abstract: Fast and frugal heuristics - simple rules for making decisions with realistic mental resources - are presented here. These heuristics can enable both living organisms and artificial systems to make smart choices, classifications, and predictions by employing bounded rationality. But when and how can such fast and frugal heuristics work? What heuristics are in the mind's adaptive toolbox, and what building blocks compose them? Can judgments based simply on a single reason be as accurate as those based on many reasons? Could less knowledge even lead to systematically better predictions than more knowledge? This book explores these questions by developing computational models of heuristics and testing them through experiments and analysis. It shows how fast and frugal heuristics can yield adaptive decisions in situations as varied as choosing a mate, dividing resources among offspring, predicting high school drop-out rates, and playing the stock market.