Crick and koch consciousness

Crick and koch consciousness. Christof Koch is meritorious investigator at the Allen Institute in Seattle and the chief scientist at the Tiny Blue Dot What Consciousness is and How to Jun 6, 2005 · This would be compatible with our idea (Crick & Koch 1995) that neurons in V1, like retinal neurons, are not strictly necessary for visual consciousness. , Koch Oct 1, 2023 · In summary, Crick and Koch (2005) proposed that the claustrum may be the center of consciousness, and may contain specialized mechanisms that bind, integrate, and synchronize discrete perceptual, cognitive, and motor information that gives rise to an apparent unity of consciousness. J. ” In summary, Crick and Koch (2005) proposed that the claustrum may be the center of consciousness, and may contain specialized mechanisms that bind, integrate, and synchronize discrete perceptual, cognitive, and motor information that gives rise to an apparent unity of consciousness. Gennaro, R. . PMID: 1502517 Consciousness* Jan 1, 2004 · Christof Koch, PhD, is a neuroscientist best known for his studies and writings exploring the basis of consciousness, starting with the molecular biologist Francis Crick more than a quarter of a century ago (Crick & Koch 1990). Francis Crick won the Nobel Prize for his contribution to discovering the structure of Nov 22, 2018 · A convenient date to mark the rehabilitation of consciousness within neuroscience is with Francis Crick and Christof Koch’s (1990) landmark paper, ‘Towards a neurobiological theory of consciousness’, which opens with the line: ‘It is remarkable that most of the work in both cognitive science and the neurosciences makes no reference to Feb 24, 2004 · Longtime collaborators Christof Koch and Francis Crick (of DNA helix fame) think that "zombie agents"--that is, routine behaviors that we perform constantly without even thinking--are so much a central facet of human consciousness that they deserve serious scientific attention. Nov 8, 2017 · Since a seminal paper by Crick and Koch (1998) claimed that a science of consciousness should first search for its neural correlates (NCC), a variety of correlates have been suggested, including both content-specific NCCs, determining particular phenomenal components within an experience, and the full NCC, the neural substrates supporting The neural basis of very short-term memory especia needs more study, and several lines of work are outfits that might advance the understanding of the neural mechanisms involved. After an introduction outlining our general strategy, we describe what is meant by the term 'framework' and set it out under ten headings. Moreover, we believe that the problem of consciousness can, inthelongrun, besolvedonlybyexplanations at theneurallevel. neuroscientists including Francis Crick and Christof Koch began to search for what they called the neural Jul 24, 2019 · Eventually, prominent scientists (including Crick) did decide to tackle consciousness, which ushered in a shift in thinking that surged in the 1990s, fuelled by the increasing availability of Figure 1. AUTHORS: Joachim Keppler Nov 22, 2018 · A convenient date to mark the rehabilitation of consciousness within neuroscience is with Francis Crick and Christof Koch’s (1990) landmark paper, ‘Towards a neurobiological theory of consciousness’, which opens with the line: ‘It is remarkable that most of the work in both cognitive science and the neurosciences makes no reference to Oct 1, 2023 · The seminal paper of Crick and Koch (2005) proposed that the claustrum, an enigmatic and thin grey matter structure that lies beside the insular cortex, may be involved in the processing of Mar 15, 2018 · Francis Crick and Christof Koch were the first ones to discuss the idea of Neural Correlates of Consciousness (NCCs) in the scientific press in a serious fashion. Francis Crick & Christof Koch - 2007 - In Max Velmans & Susan Schneider (eds. Models of consciousness should be distinguished from so-called neural correlates of consciousness (Crick & Koch 1990). e. Stemming in part from a long-standing collaboration with the late Nobel Laureate Francis Crick, Christof authored the book The Quest for Consciousness: A Neurobiological Approach. Koch, Christof Crick, Francis, 1916-2004 Seminars in the Neurosciences Publication: The Academic Press, 1990 Dec 14, 2004 · He started his long-time collaboration with Christof Koch, once a post-doctoral trainee with Poggio, on “The Problem of Consciousness” (Crick and Koch 1990, 1992). Traditionally the problem has been cast in terms of subjectivity. Francis Crick and Chri. We defined them as the minimal neural mechanisms jointly sufficient for any one specific percept. Published in Nature Neuroscience 1 February 2003. The file is annotated by Crick 'Cold Spring Harbor paper', and the majority of the file comprises notes and typescript drafts for Crick and Koch's subsequent paper 'Some Reflections on Visual Awareness', <i>Cold Spring Harbor Symposia on Quantitative Biology</i> vol Dec 7, 2020 · The claustrum is a brain region that has been investigated for over 200 years, yet its precise function remains unknown. of biology & engineering at CalTech. Feb 1, 2003 · A framework for consciousness. Feb 26, 2014 · The late Francis Crick proposed that at any one moment, human subjective consciousness of perceptual contents 1 is brought about by the activity of a limited number (~10 5) of neurons (Crick, 1995; Crick and Koch, 2003). Consciousness is a vexed and hoary topic of particular interest to philosophers and physicists. How is it, for example, that when someone Sep 7, 2023 · In summary, Crick and Koch (2005) proposed that the claustrum may be the center of consciousness, and may contain specialized mechanisms that bind, integrate, and synchronize discrete perceptual, cognitive, and motor information that gives rise to an apparent unity of consciousness. There are The seminal paper of Crick and Koch (2005) proposed that the claustrum, an enigmatic and thin grey matter structure that lies beside the insular cortex, may be involved in the processing of consciousness. Koch. X. Koch noted that the brain of a mouse is indistinguishable from a human brain at the level of the neurons. 3. A framework for consciousness Francis Crick and Christof Koch Here we summarize our present approach to the problem of consciousness. In this Review, Koch and colleagues discuss studies that distinguish the Jun 22, 2005 · In their survey of various notions about consciousness, Crick and Koch observe that a common thread through all of the thinking about consciousness is the recognition of a need to bind together Observation of perception related neurons in prefrontal cortex is consistent with the theory of Christof Koch and Francis Crick who postulated that neural correlate of consciousness resides in prefrontal cortex. 567--579. NEURAL CORRELATES OF CONSCIOUSNESS – NCC. Oct 30, 2019 · The neural correlates of consciousness have been defined as the minimal neural mechanisms that are together necessary and sufficient for experiencing any conscious percept (Crick and Koch, 1990). g. While the identification of correlations between aspects of brain activity and aspects of consciousness may constrain the specification of neurobiologically plausible models, such correlations do not by themselves provide explanatory links between neural Oct 22, 2023 · When Crick and Koch published their landmark paper “Towards a Neurobiological Theory of Consciousness” in 1990, their aim was to place consciousness—for 2,000 years the stomping ground of Oct 31, 2019 · The neural correlates of consciousness have been defined as the minimal neural mechanisms that are together necessary and sufficient for experiencing any conscious percept (Crick and Koch, 1990). Crick and Dr. ~workin~ ~~~. Koch C and Hepp K (2006) Quantum mechanics and higher brain functions: Lessons from quantum computation and neurobiology. This chapter introduces the problem of localization of mental functions within the brain, and suggests that the neural binding cannot be simply explained paradigm suggesting localization of the mental functions, thus necessitating substantial revision of the Cartesian concept of the brain and localization of consciousness. id consciousness are likely to have special properties. Affiliation 1 The Salk Institute, La Jolla, CA 92037, USA. Affiliation 1 Salk Institute for Biological Studies, San Diego. This framework offers a coherent scheme for explaining the neural correlates of (visual) consciousness in terms of competing cellular assemblies. In 1998, neuroscientist Christof Koch bet philosopher David Chalmers that the mechanism by which the brain’s neurons produce consciousness would be Apr 23, 2024 · I first read Crick and Koch’s paper in an undergraduate seminar on the philosophy of mind. Amsterdam & Philadelphia: John Benjamins, 1996. 2. After an introduction outlining our general strategy, we describe what is meant by the term ‘framework’ and set it out under ten headings. Here we summarize our present approach to the problem of consciousness. Roberts, Denver, CO. The F Crick 1 , C Koch. Talis Bachmann - 2020 - Consciousness and Cognition 82:102937. His views were developed in collaboration with Francis Crick (e. After an introduction outlining our general strategy Jul 1, 2024 · This is to a large extent because of the dominance of visual perception as a “model system” in empirical neuroscientific work on consciousness—a paradigm advocated by Crick himself in the early 1990s (Crick & Koch, 1990). His previous book, Consciousness: Confessions of a Romantic Reductionist, blends science and memoir to explore topics in discovering the roots of consciousness. Fries similarly identifies the process of “communication through coherence” (neuronal synchrony/resonance) as a critical component of neural function ( Fries, 2005 , 2015 ). Crick and Koch therefore developed a theory according to which the key to conscious perception lies not solely in the synchronization of neuronal activity, but in the synchronization of neuronal activity oscillating at frequencies in the range of 35 to 75 Hz. They postulated that the claustrum serves as a hub that Sep 1, 1992 · By Christof Koch & Francis Crick. The Astonishing Hypothesis is mostly concerned with establishing a basis for scientific study of consciousness; however, Crick places the study of consciousness within a larger social context. This framework offers a coherent scheme for explaining the neural correlates of (visual) consciousness in terms of competing cellular assemblies and outlines some general experimental approaches to the problem. Mar 1, 2003 · Crick and Koch (2003) claim that studying the easy problems of consciousness, i. Above all, the scientific study of consciousness requires two basic assumptions: 1. Above all, the scienti c study of consciousness requires two basic assumptions: Francis Crick and Christof Koch 17 A Neurobiological Framework Mar 29, 2024 · People used to think the heart was the center of consciousness. PMID How should consciousness be approached in a scientific manner, and why, according to Crick and Koch? Briefly identify the way Crick and Koch identify consciousness, then what they suggest it is better for scientists to do when thinking about it, and why. The neural mechanism that produces the least consciousness is called the related neuron of consciousness (NCC) (Crick and Koch, 2005; Cerullo, 2015; Tononi and Koch, 2015; Reddy and Pereira, 2017; Xie et al. Koch had collaborated with Francis Crick, a biologist who shared a Nobel Prize for uncovering the structure of DNA, on a quest for what they called the “neural correlate of Francis Crick & Christof Koch. Nature 440: 611-2. After an introduction outlining our general strategy, we describe what is meant by the term ‘framework’ and set it out under ten Hence, consciousness is most likely to be a continuously variable property of the brain, in both phylogenetic and ontogenetic terms. Abstract. Feb 25, 2014 · The late Francis Crick proposed that at any one moment, human subjective consciousness of perceptual contents 1 is brought about by the activity of a limited number (~10 5) of neurons (Crick, 1995; Crick and Koch, 2003). His door was always open to graduate students, postdoctoral trainees, faculty who wanted to discuss those problems as many others and we can attest. The study Swinderen, Philip Low and Christof Koch. William James thought that consciousness involved both attention and short-term memory. Its anatomy is quite remarkable in that it receives input from almost all regions of cortex and projects back to almost … Jan 8, 2017 · When he started studying consciousness — working with Nobel Prize winner Francis Crick — Koch believed that the only explanation for experience would have to invoke God. dof Koch Visual awareness ;ir a favorabk fmm of consciousness to stdy neurobiologically. Aug 24, 2023 · When Crick and Koch published their landmark paper “Towards a Neurobiological Theory of Consciousness” in 1990, their aim was to place consciousness — for 2,000 years the stomping ground of philosophers— onto a scientific footing. Most cortical areas project back to the superior colliculus as well as to the different maps in the pulvinar, which is part ofthe Crick, F. Jun 24, 2023 · A 25-year science wager has come to an end. In summary, according to this hypothesis: Mar 9, 2012 · Koch describes his own groundbreaking work with Francis Crick in the 1990s and 2000s and the gradual emergence of consciousness (once considered a “fringy” subject) as a legitimate topic for scientific investigation. F Crick 1 , C Koch. I had spent a lot of time thinking about consciousness, but I was far better acquainted with thought A framework for consciousness, Francis Crick & Christof Koch,Nature Neuroscience, February 2003 Volume 6 Number 2 pp 119 – 126; Abstract Here we summarize our present approach to the problem of consciousness. org/10. The HOT theory of consciousness: Between a rock and a hard place? Journal of Consciousness Studies 12 ( 2 ): 3 – 21, 2005. Consciousness in its entirety, they argued, was too broad and controversial a concept to serve as a Jun 21, 2001 · It may be because consciousness allows the system to plan future actions, opening up a potentially infinite behavioural repertoire and making explicit memory possible. This framework offers a coherent scheme for Crick’s closest colleague on the quest for consciousness was neuroscientist Christof Koch, then at the California Institute of Technology, with whom he published a series of papers that explored the neural correlates of consciousness (ncc; the brain structures and neural activities responsible for generating states of conscious awareness). The Mar 1, 2012 · Koch was a colleague of Francis Crick (of DNA and Nobel fame) in his (late in life) search for the mechanisms in the brain that yield consciousness. According to Crick’s analysis, these neurons must: (1) Be central in the connection scheme of the human brain, not too Gennaro, R. Mar 31, 2022 · Crick and Koch's 1990 "neurobiological theory of consciousness" sparked the race for the physical correlates of subjective experience. Jul 2, 2014 · “Francis would have been pleased as punch,” says Koch, who was told by Crick’s wife that on his deathbed, Crick was hallucinating an argument with Koch about the claustrum and its connection Jan 1, 2014 · According to Crick and Koch, the origin of consciousness can be found at the neural level and appears to have an intimate connection with other two brain properties: short-term memory and serial attention. Argumentsatthecognitivelevel From the Salk Institute, 10010 NTorrey Pines Road, LaJolla, CA92037, USA, andComputationandNeuralSystems 216-76, California Institute of Technology, Pasadena Jan 17, 2024 · Nobel-laureate biologist Francis Crick and neuroscientist Christof Koch, now at the Allen Institute for Brain Science, wrote that the moment was “ripe for an attack on the neural basis of Jun 15, 2010 · 4. We outfit several lines ofexp~‘~~~ work that might advance the understanding of the neural mechanisms involved. Some of the major cortical and sub-cortical visual areas in the macaque monkey. , Cerebral Cortex, Volume 8, Issue 2, 1 March 1998, Pages 97–107, https://doi. Most psychologists today would agree with this view. We have not attempted an exhaustive Jul 9, 2019 · The generation of consciousness depends on a neurobiological basis. Consciousness is, for each of us, all there is: the world, the self, everything. The shaded ellipsoids correspond to higher-level visual-motor areas. G, Cowan W. The main purposes of this review are to set out for neuroscientists one possible approach to the problem of consciousness and to describe the relevant ongoing experimental work. , Koch, 2004), and lately tuned in close collaboration with some colleagues such as Giulio Tononi and others (e. 4. They postulated that the claustrum serves as a hub that Dec 14, 2004 · He started his long-time collaboration with Christof Koch, once a post-doctoral trainee with Poggio, on “The Problem of Consciousness” (Crick and Koch 1990, 1992). The neural basis of very short-term memory especia& needs more exjw%nental study. These neural correlates consist of events in the brain that accompany events in Feb 1, 2005 · The Neural Correlate of Consciousness (NCC) is defined as the minimum neuronal mechanisms jointly sufficient for any one specific conscious percept (Crick and Koch, 1990; Frith, 2005). Seminars in Neuroscience, 2, 263-275. "The Neuronal Basis of Visual Consciousness", The Visual Neurosciences A similar rendition of the NCC, again without mentioning Chalmers, can be found in Koch (2004) and Koch (2012 p. In some, the prefrontal cortex is essential to consciousness; others May 9, 2018 · More than a quarter of a century ago Francis Crick and I decided to set aside philosophical discussions on consciousness (which have engaged scholars since at least the time of Aristotle) and Christof Koch (/ k ɒ x / KOKH; [1] born November 13, 1956) is a German-American neurophysiologist and computational neuroscientist best known for his work on the neural basis of consciousness. how consciousness might arise. Koch C& Crick F. Expand. , Koch on the neural basis of consciousness. Apr 8, 2004 · An important quality of The Quest for Consciousness is the book's attempt to compare the views of Koch and Crick to the work of others — in particular to Edelman's sophisticated framework, which According to Crick and Koch, the origin of consciousness can be found at the neural level and appears to have an intimate connection with other two brain properties: short-term memory and serial atten-tion. 5 In the case of visual awareness, this meant Mar 1, 1998 · F Crick, C Koch; Consciousness and neuroscience. ), The Blackwell Companion to Consciousness. 42): “In the early 1990s, Francis Crick and I focused on what we called the neural (or neuronal) correlates of consciousness (NCC). 14k Accesses. According to Crick’s analysis, these neurons must: (1) Be central in the connection scheme of the human brain, not too May 26, 2014 · This is what Crick and Koch suggested when they hypothesised the claustrum to be a “conductor of consciousness”. Only a Jul 1, 2023 · For years, Dr. The Cambridge Declaration on Consciousness in Non-Human Animals was publicly proclaimed in Cambridge, UK, on July 7, 2012, at the conclusion of the Conference, at Churchill College, University of Cambridge, by Philip Low, David Edelman and Christof Koch. 97 Aug 2, 1997 · Consciousness and neuroscience. Identifying correlates is an important first step in understanding consciousness, but it is an early step. Towards a Neurobiological Theory of Consciousness. Jacken-doff writes that consciousness is “en-riched” by attention, implying that where-as attention may not be essential for cer- Apr 13, 2004 · In tackling consciousness, Dr. As we have seen, consciousness is a process that unfolds along two dimensions (wakefulness and phenomenal contents). As a result, this otherwise obscure structure has received ever-increasing interest in the search for neural correlates of consciousness. , content consciousness, will eventually resolve the hard problem. pp. Though the claustrum … Nov 8, 2017 · Since a seminal paper by [Crick and Koch (1998][1]) claimed that a science of consciousness should first search for its neural correlates (NCC), a variety of correlates have been suggested, including both content-specific NCCs, determining particular phenomenal components within an experience, and the full NCC, the neural substrates supporting Account of consciousness by Christof Koch: Review and questions. , Crick & Koch, 1990; Crick & Koch, 2003), elaborted subsequently (e. They suggest an integrated approach that Nov 19, 2013 · Koch C and Crick FC (2001) On the zombie within. Nature Neuroscience 6, 119–126 (2003) Cite this article. Koch have reframed the central question. 2001 On the zombie within. We would like to show you a description here but the site won’t allow us. Christof Koch Search for other works by this author on: Christof Koch, Francis Crick, 2003. But how could this hypothesis about the claustrum’s role be tested? Plant Apr 3, 2008 · This review examines recent advances in the study of brain correlates of consciousness. Brief Background on Crick & Koch • Christof Koch neuroscientist & prof. 846 Citations. Yet, the connection between consciousness science and other subdisciplines of cognitive neuroscience has been unfairly Jul 1, 2020 · 1. The neural correlate of consciousness is defined as the minimal set of neuronal events that gives rise to a specific aspect of a conscious percept (Crick, 2004; Crick and Koch 2003; Tononi and Koch, 2015). The search for the NCC, the neuronal correlates of consciousness (Crick & Koch 2003, Goodale & Milner 1992) X. The Francis Crick and Chri. Francis Crick & Christof Koch. Crick and Koch’s paper persuaded me that empirical investigation of the brain might prove more effective than analytical debate about the mind in solving questions Crick, Francis Koch, Christof. Google Scholar. We then examine what has been learned by studying global changes in the level of consciousness, such as sleep, anesthesia, and seizures. (1990). TLDR. Proponents of distributed neuronal processing may likely dispute the view that consciousness has a precise localization in the brain. May 2, 2018 · Crick's and Koch's "Consciousness & Neuroscience" is an excellent adjunct to Searle's "The Mystery of Consciousness. The Consciousness Paradox Given that there is no widely accepted theory of phenomenal consciousness Crick (1994) and Crick and Koch (1998) approached the problem of the location of the substrate of consciousness by proposing that scientists search for the Neural Correlates of Consciousness. Theory of consciousness as seen by Christof Koch. But, instead of affirming religion, Koch and Crick together established consciousness as a respected branch of neuroscience and invited Buddhist teachers into the discussion. Nature 411: 893. May 11, 1995 · It is usually assumed that people are visually aware of at least some of the neuronal activity in the primary visual area, V1, of the neocortex. F. 30 Altmetric. The Declaration was publicly proclaimed in Cambridge, UK, on July 7, 2012, at the Francis Crick Memorial Conference on Consciousness in Human and non-Human Animals, at Churchill College, University of Cambridge, by Low, Edelman and Koch. Crick and Koch use an initialism and an unusual word when they refer to aspects of their work. " Crick and Koch (C & K) provide some background information about why we are conscious and then go on to discuss their approach to studying the neuronal correlate of consciousness (NCC). We propose that it takes two forms: a very fat form, &z&i to iconic naemoryr, that may be dl~cu~t to study; and a somewhat slower one involv&g visual attention and short-term memory. Aug 29, 2012 · "Romantic reductionist" neuroscientist Christof Koch discusses the search for meaning in the world of science, and the philosophical influence of working with Francis Crick. Koch, C. But the neuroanatomy of the macaque monkey suggests that, although primates may be aware of neural activity in other visual cortical areas, they are not di … Manuscript draft, undated, and typescript drafts of 'Towards a Neurobiological Theory of Consciousness', 5 April and 16 May 1990. It was the only part that was visibly moving. Crick, C. Human consciousness according to Crick is central to human existence and so scientists find themselves approaching topics traditionally left to Apr 20, 2016 · Several brain regions and physiological processes have been proposed to constitute the neural correlates of consciousness. Wrote, „The Quest for Consciousness” „To understand how consciousness is linked to the brain, how the flickering activity of myriad of nerve cells leads to ineffable experiences, of seeing blue, of being warmed by the sun, or of being scared by exposure on a climb” (Koch A neurobiological framework for consciousness. , & Koch, C. Jun 29, 2005 · Koch C The quest for consciousness: a neurobiological approach. has been cited by the following article: TITLE: On the Universal Mechanism Underlying Conscious Systems and the Foundations for a Theory of Consciousness. They postulated that the claustrum serves as a hub that Apr 8, 2013 · Introduction . The existence of zombie agents highlights the fact that much of what goes on in our heads escapes awareness. 1093/cercor/8. , 2017), which was first proposed by Crick and Koch (1990). In the final posthumously released article of Francis Crick, written with Christof Koch, the claustrum was suggested to be critically linked to consciousness. Its function is enigmatic. Here we Jun 26, 2023 · The old 40-hertz oscillation hypothesis of Crick and Koch has yielded to a welter of fancier neural-correlate models. C. Koch C (2004) The Quest for Consciousness: A Neurobiological Approach. Feb 1, 2003 · A framework for consciousness. In the slower form an at~tiona~ Oct 31, 2019 · Crick and Koch feature this concept prominently in their neurobiological theory of consciousness (Crick and Koch, 1990; Koch, 2004). 30 years later, cognitive sciences trend toward consideration of the brain's electromagnetic field as the primary seat of consciousness, the "to be" of the individua … ARTICLES Are we aware of neural activity in primary visual cortex? Francis Crick* & Christof Koch t * The Salk Institute, 10010 North Torrey Pines Road, La Jolla, California 92037, USA t Swinderen, Philip Low and Christof Koch. First, we briefly discuss some useful distinctions between consciousness and other brain functions. Biology. Account of consciousness by Christof Koch: Review and questions. Metrics. Subcortical afferents to the hippocampal formation in the monkey. Oct 9, 2018 · Modern neuroscience of consciousness has attempted to explain consciousness by focusing on neural correlates of consciousness or NCCs (Crick & Koch 1990; LeDoux, Michel, & Lau 2020; Morales & Lau 2020). Current theories of consciousness are notably influenced by works of Christof Koch. 00. References Amaral D. He was the president and chief scientist of the Allen Institute for Brain Science in Seattle. , Crick, F. 2004 Englewood, CO: Roberts & Company. The representation of conscious content must be explicit (Crick & Koch 1995, Crick & Koch 1998, Crick & Koch 2005, Fries et al 2008, Haun & Tononi 2019, Lamme & Roelfsema 2000, Singer 1998) X. M. Major pathways are indicated by bold lines, minor pathways by thin lines; dashed lines weak or uncertain. New York: Wiley-Blackwell. The Jun 29, 2005 · The claustrum is a thin, irregular, sheet-like neuronal structure hidden beneath the inner surface of the neocortex in the general region of the insula. Review of The Astonishing Hypothesis: The Scientific Search For The Soul by Francis Crick. Consciousness and Self-consciousness: A Defense of the Higher-Order Thought Theory of Consciousness. Jul 1, 2020 · Current theories of consciousness are notably influenced by works of Christof Koch. In the slower form an at~tiona~ Mar 1, 1998 · The main purposes of this review are to set out for neuroscientists one possible approach to the problem of consciousness and to describe the relevant ongoing experimental work. lghxk xmyqrq diku ggttwqm wlgrv mtdcsuy pcb admri vip xthc