Neuroimage
October 17, 2022
Natália Bezerra Mota, Ernesto Soares, Edgar Altszyler et al.
5 citations
The 'day residue' - the presence of waking memories into dreams - is a century-old concept that remains controversial in neuroscience. Even at the psychological level, it remains unclear how waking imagery cedes into dreams. Are visual and affective residues enhanced, modified, or erased at sleep onset? Are they linked, or dissociated? What are the neural correlates of these transformations? To...
Cortex; a journal devoted to the study of the nervous system and behavior
September 1, 2021
Santiago Alcaide, Jacobo Sitt, Tomoyasu Horikawa et al.
13 citations
The brain mechanisms by which we transition from sleep to a conscious state remain largely unknown in humans, partly because of methodological challenges. Here we study a pre-existing dataset of waking up participants originally designed for a study of dreaming (Horikawa, Tamaki, Miyawaki, & Kamitani, 2013) and suggest that suddenly awakening from early sleep stages results from a two-stage...
Conscious Cogn
December 8, 2020
Camila Sanz, Carla Pallavicini, Facundo Carrillo et al.
34 citations
Serotonergic psychedelics have been suggested to mirror certain aspects of psychosis, and, more generally, elicit a state of consciousness underpinned by increased entropy of on-going neural activity. We investigated the hypothesis that language produced under the effects of lysergic acid diethylamide (LSD) should exhibit increased entropy and reduced semantic coherence. Computational analysis...
J Affect Disord
April 1, 2018
Facundo Carrillo, Mariano Sigman, Diego Fernández Slezak et al.
57 citations
Natural speech algorithm applied to baseline interview data can predict which patients will respond to psilocybin for treatment-resistant depression.
Neuroimage
April 1, 2018
Ezequiel Mikulan, Eugenia Hesse, Lucas Sedeño et al.
Neural synchrony in the γ-band is considered a fundamental process in cortical computation and communication and it has also been proposed as a crucial correlate of consciousness. However, the latter claim remains inconclusive, mainly due to methodological limitations, such as the spectral constraints of scalp-level electroencephalographic recordings or volume-conduction confounds. Here, we...
Consciousness and Cognition
November 1, 2017
Edgar Altszyler, Sidarta Ribeiro, Mariano Sigman et al.
Computer-based dreams content analysis relies on word frequencies within predefined categories in order to identify different elements in text. As a complementary approach, we explored the capabilities and limitations of word-embedding techniques to identify word usage patterns among dream reports. These tools allow us to quantify words associations in text and to identify the meaning of target...
arXiv Preprint Archive
October 5, 2016
Edgar Altszyler, Mariano Sigman, Sidarta Ribeiro et al.
Word embeddings have been extensively studied in large text datasets. However, only a few studies analyze semantic representations of small corpora, particularly relevant in single-person text production studies. In the present paper, we compare Skip-gram and LSA capabilities in this scenario, and we test both techniques to extract relevant semantic patterns in single-series dreams reports. LSA...
Behavioral and brain functions : BBF
December 23, 2013
Margherita Melloni, Lucas Sedeño, Blas Couto et al.
Interoception refers to the conscious perception of body signals. Mindfulness is a meditation practice that encourages individuals to focus on their internal experiences such as bodily sensations, thoughts, and emotions. In this study, we selected a behavioral measure of interoceptive sensitivity (heartbeat detection task, HBD) to compare the effect of meditation practice on interoceptive...
Neuroimage
February 1, 2012
Sebastien Marti, Mariano Sigman, Stanislas Dehaene
Doing two things at once is difficult. When two tasks have to be performed within a short interval, the second is sharply delayed, an effect called the Psychological Refractory Period (PRP). Similarly, when two successive visual targets are briefly flashed, people may fail to detect the second target (Attentional Blink or AB). Although AB and PRP are typically studied in very different...
Frontiers in Psychology
2011
Tristán Bekinschtein, Moos Peeters, Diego E. Shalóm et al.
15 citations
Classical (trace) conditioning is a specific variant of associative learning in which a neutral stimulus leads to the subsequent prediction of an emotionally charged or noxious stimulus after a temporal gap. When conditioning is concurrent with a distraction task, only participants who can report the relationship (the contingency) between stimuli explicitly show associative learning. This...
Cognition
May 2010
Sebastien Marti, Jérôme Sackur, Mariano Sigman et al.
Psychologists often dismiss introspection as an inappropriate measure, yet subjects readily volunteer detailed descriptions of the time and effort that they spent on a task. Are such reports really so inaccurate? We asked subjects to perform a psychological refractory period experiment followed by extensive quantified introspection. On each trial, just after their objective responses, subjects...
Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference
2010
Martin Graziano, Lucas C Parra, Mariano Sigman
In a partial report paradigm, subjects observe during a brief presentation a cluttered field and after some time - typically ranging from 100 ms to a second - are asked to report a subset of the presented elements. A vast buffer of information is transiently available to be broadcasted which, if not retrieved in time, fades rapidly without reaching consciousness. An interesting feature of this...