wp-plugin-hostgator domain was triggered too early. This is usually an indicator for some code in the plugin or theme running too early. Translations should be loaded at the init action or later. Please see Debugging in WordPress for more information. (This message was added in version 6.7.0.) in /home4/scienrds/scienceandnerds/wp-includes/functions.php on line 6114ol-scrapes domain was triggered too early. This is usually an indicator for some code in the plugin or theme running too early. Translations should be loaded at the init action or later. Please see Debugging in WordPress for more information. (This message was added in version 6.7.0.) in /home4/scienrds/scienceandnerds/wp-includes/functions.php on line 6114Source:https:\/\/www.quantamagazine.org\/what-a-contest-of-consciousness-theories-really-proved-20230824\/#comments<\/a><\/br> Dehaene favored the second experiment, which also involved the comprehensive decoding of brain patterns. Test subjects would be randomly exposed to faces and objects flashed on a screen while they played a distracting Tetris-like video game. Shortly after an image was shown, the game would stop and the subject would be asked whether they saw it. Dehaene preferred this design because it offered a more clear-cut contrast between conscious and unconscious mental states, which he considered essential to getting unambiguous data on the correlates of consciousness.<\/p>\n Because Kahneman was so familiar with adversarial collaborations, he mentored the three project leaders. But he also warned them that, in his experience, adversaries don\u2019t change their minds after seeing the results of their collaborations. Instead, when faced with an inconvenient result, \u201ctheir IQ leaps 15 points\u201d as they invent ways to accommodate the new, conflicting data, he said.<\/p>\n The researchers set to work performing the experiments suggested by the workshop team. The GNWT-versus-IIT experiment that Tononi liked best, which tested with different levels of tasks, finished up first. It was carried out in two different labs using fMRI, MEG and intracranial electroencephalography. In all, six theory-neutral labs and 250 test subjects participated.<\/p>\n On the evening of June 23, an excited audience gathered at NYU to learn the outcome of that experiment. Writ large on a giant screen, the results were shown on a chart marked by red and green highlights, as though the researchers were reporting on a steeplechase with three types of hurdles.<\/p>\n The first hurdle checked how well each theory decoded the categories of the objects that the subjects saw in the presented images. Both theories performed well here, but IIT was better at identifying the orientation of objects.<\/p>\n The second hurdle tested the timing of the signals. IIT predicted sustained, synchronous firing in the hot zone for the duration of the conscious state. While the signal was sustained, it did not remain synchronous. GNWT predicted an \u201cignition\u201d of the workspace followed by a second spike when the stimulus disappeared. Only the initial spike was detected. In the on-screen scoring for the NYU audience, IIT pulled ahead.<\/p>\n The third hurdle concerned overall connectivity across the brain. GNWT scored better than IIT here, largely because some analyses of the results supported GNWT predictions while the signals across the hot zone were not synchronous.<\/p>\n Both theories were challenged by the results. But in the final tally on screen at the event, IIT scored more green highlights than GNWT, and the audience responded as though a victor had been crowned. Melanie Boly<\/a> of the University of Wisconsin, Madison, a supporter of IIT, was buoyed enough by the outcome to declare onstage: \u201cThe results corroborate IIT\u2019s overall claim that posterior cortical areas are sufficient for consciousness, and neither the involvement of [the prefrontal cortex] nor global broadcasting are necessary.\u201d<\/p>\n When Dehaene took to the stage, he did not admit defeat either. \u201cI\u2019ve decided to follow the advice of Dan Kahneman,\u201d he quipped. He professed to be happy because \u201cthe most interesting part of this experiment was the task-irrelevant stimuli.\u201d The question was whether they would indicate the ignition of a conscious percept in the frontal brain. \u201cThe answer is yes!\u201d he said.<\/p>\n Later, Dehaene suggested to me that the hurdles for IIT were set lower than those for his theory. \u201cThere was no real test of the complex mathematical core of [IIT],\u201d he said. And as Block noted in his remarks that night, the finding that there was support for the back-of-the-brain theories does not specifically support IIT.<\/p>\n Notwithstanding the slightly higher number of green marks scored by IIT, the project leaders themselves are adamant that there was no winner. \u201cThese results confirm some predictions of IIT and GNWT, while substantially challenging both theories,\u201d they wrote<\/a> in a paper describing the results posted on the biorxiv.org preprint server.<\/p>\n Just as Kahneman predicted, the adversaries explained away the discrepancies. Boly argued that the failure to detect sustained synchrony in the hot zone \u201cmay be due to sampling limitations.\u201d Dehaene suspected that no \u201coff\u201d signal was detected because the subjects allowed their minds to wander. \u201cMy claim is that consciousness became decoupled from the stimulus,\u201d he said.<\/p>\n Boly and Dehaene now await the results of the second experiment, involving the Tetris-like game distraction. Those results won\u2019t be available until next year.<\/p>\n So has science been advanced? Not everyone thinks so.<\/p>\n Some researchers, such as Olivia Carter<\/a>, a psychologist at the University of Melbourne and past president of the ASSC, think the two theories were too far apart for their predictions to be meaningfully compared. \u201cMy personal feeling is they are testing totally different things,\u201d she said. \u201cIIT is focusing on phenomenal content, and GNWT is much more interested in working memory and attention.\u201d<\/p>\n That assessment seems apt. Yet it\u2019s also frustrating, given that a dispositive comparison was the stated purpose of the adversarial collaboration in the first place. If it\u2019s a victory for science, it seems like a qualified one.<\/p>\n The Monash University philosopher Jakob Hohwy<\/a>, who is part of another Templeton-funded adversarial collaboration, sees it differently. \u201cThis goes to the philosophy of science,\u201d he said. He points out the field is still divided over such fundamentals as the definition of consciousness, whether it is closer to thinking or feeling, and even whether self-reported results truly confound the data. For Hohwy, this kind of collaborative effort is the way to move forward. \u201cWe will find out as we go along in exactly this type of adversarial collaboration,\u201d he said.<\/p>\n Others, like the computational neuroscientist Megan Peters<\/a> of the University of California, Irvine, bristled at media coverage that reported the results as a two-horse race between GNWT and IIT rather than a field with multiple contenders. Instead of focusing on winners and losers, Peters said, it\u2019s important to see that science advances by learning from each experimental hurdle. (Having attended the proceedings that night, however, I can attest that the event was arranged to resemble a sporting event.)<\/p>\n Still, Peters remains a fan of adversarial collaborations. During the Covid-19 lockdown, she was inspired by the Templeton process to help organize a series of workshops<\/a> hosted by the Cognitive Computational Neuroscience conference. In these \u201cgenerative adversarial collaborations,\u201d researchers engaged in robust debate. \u201cWatching the teams chew on stuff was instructive,\u201d she said.<\/p>\n The first adversarial collaboration on consciousness may not have succeeded in winnowing out any theories from the field. But it did force theorists to make more tangible predictions, and it made experimentalists work out new techniques. \u201cThe findings of the collaboration remain extremely valuable,\u201d wrote the University of Sussex neuroscientist Anil Seth<\/a> in a commentary<\/a> after the June event. \u201cThey will push forward the development of both IIT and [GNWT] \u2014 and other theories of consciousness, too \u2014 by providing new constraints and new explanatory targets.\u201d<\/p>\n For Melloni, the fact that the adversaries have not changed their minds does not detract from the value of the process. \u201cAs Kahneman says, people don\u2019t change their mind, yet the way they react to the challenges makes their theory progress or degenerate,\u201d she said. \u201cIf the latter, [then] over time the theory \u2018dies\u2019 and scientists abandon it.\u201d<\/p>\n
\nWhat a Contest of Consciousness Theories Really Proved<\/br>
\n2023-08-25 21:58:17<\/br><\/p>\nMixed Results, With No Losers<\/strong><\/h2>\n
The Pace of Progress<\/strong><\/h2>\n