The human brain’s ongoing activity is characterized by intrinsic networks of coherent fluctuations, measured for example with correlated functional magnetic resonance imaging signals. So far, however, the brain processes underlying this ongoing blood oxygenation level dependent (BOLD) signal orchestration and their direct relevance for human behavior are not sufficiently understood. In this study, we address the question of whether and how ongoing BOLD activity within intrinsic occipital networks impacts on conscious visual perception. To this end, backwardly masked targets were presented (...) in participants’ left visual field only, leaving the ipsi-lateral occipital areas entirely free from direct effects of task throughout the experiment. Signal time courses of ipsi-lateral BOLD fluctuations in visual areas V1 and V2 were then used as proxies for the ongoing contra-lateral BOLD activity within the bilateral networks. Magnitude and phase of these fluctuations were compared in trials with and without conscious visual perception, operationalized by means of subjective confidence ratings. Our results show that ipsilateral BOLD magnitudes in V1 were significantly higher at times of peak response when the target was perceived consciously. A significant difference between conscious and non-conscious perception with regard to the pre-target phase of an intrinsic-frequency regime suggests that ongoing V1 fluctuations exert a decisive impact on the access to consciousness already before stimulation. Both effects were absent in V2. These results thus support the notion that ongoing slow BOLD activity within intrinsic networks covering V1 represents localized processes that modulate the degree of readiness for the emergence of visual consciousness. (shrink)

We present a neuro-geometrical model for generating the shape of Kanizsa's modal subjective contours which is based on the functional architecture of the primary areas of the visual cortex. We focus on V1 and its pinwheel structure and model it as a discrete approximation of a continuous fibration π: R × P → P with base space the space of the retina R and fiber the projective line P of the orientations of the plane. The horizontal cortico-cortical connections of V1 (...) implement what the geometers call the contact structure of the fibration π, and defines therefore an integrability condition which can be shown to correspond to Field's, Hayes', and Hess' psychophysical concept of association field. We present then a variational model of curved modal illusory contours based on the idea that virtual contours are “geodetic” integral curves of the contact structure. (shrink)

Master Nikon's first mirrorless camera with this full-color guide The Nikon 1 is a revolutionary new pocket-size camera line that packs the power of a digital SLR into a smaller body. This easy-to-follow guide covers both the J1 and V1 models, showing you all the modes and capabilities of each and how to use them. Illustrated with full-color images to show what you can achieve, it explores all the controls, different lenses, auto and video shooting modes, and how you can (...) take creative control of your photos. It also teaches you which format to use, how to organize and manage your images, and how to get super shots of people, landscapes, action, and more. This guide by leading photography instructor Julie Adair King provides a complete introduction to using the new Nikon 1 J1 and V1 models Covers all the camera controls and how to use them, lenses, auto and video modes, and how to take control of exposure, color, and lighting Explains how to get images from the camera to the computer, manage your photo files, and make basic edits Full-color illustrations show the great effects you can achieve Nikon 1 J1/V1 For Dummieshelps you get the most from Nikon's new mirrorless camera. (shrink)

A key question in understanding visual awareness is whether any single cortical area is indispensable. In a transcranial magnetic stimulation experiment, we show that observers' awareness of activity in extrastriate area VS depends on the amount of activity in striate cortex (Vl). From the timing and pattern of effects, we infer that back-projections from extrastriate cortex influence information content in Vl, but it is Vl that determines whether that information reaches awareness.

This collection of essays showcases the most important and influential philosophical works of the ancient and medieval period, roughly from 600 BC to AD 1600. Each chapter takes a particular work of philosophy and discusses its proponent, its content and central arguments. These are: Plato's Republic; Aristotle' Nichomachean Ethics; Lucretius' On the Nature of the Universe; Sextus Emperiicus' Outlines of Pyrrhonism; Plotinus' The Enneads; Augustine's City of God; Anselm's Proslogion; Aquinas' Summa Theologia; Duns Scotus' Ordinatio; William of Ockham's Summa Logicae.

This collection of essays showcases the most important and influential philosophical works of the ancient and medieval period, roughly from 600 BC to AD 1600. Each chapter takes a particular work of philosophy and discusses its proponent, its content and central arguments. These are: Plato's Republic; Aristotle' Nichomachean Ethics; Lucretius' On the Nature of the Universe; Sextus Emperiicus' Outlines of Pyrrhonism; Plotinus' The Enneads; Augustine's City of God; Anselm's Proslogion; Aquinas' Summa Theologia; Duns Scotus' Ordinatio; William of Ockham's Summa Logicae.

The extent to which visual processing can proceed in the visual hierarchy without awareness determines the magnitude of perceptual delay. Increasing data demonstrate that primary visual cortex (V1) is involved in consciousness, constraining the magnitude of visual delay. This makes it possible that visual delay is actually within the optimal lengths to allow sufficient computation; thus it might be unnecessary to compensate for visual delay.

This paper focuses on meditation as natural luminousity.

This paper describes the non dual relationship between the visible and the invisible.

Vacuolar ATPases (V‐ATPases, V1Vo‐ATPases) are rotary motor proton pumps that acidify intracellular compartments, and, when localized to the plasma membrane, the extracellular space. V‐ATPase is regulated by a unique process referred to as reversible disassembly, wherein V1‐ATPase disengages from Vo proton channel in response to diverse environmental signals. Whereas the disassembly step of this process is ATP dependent, the (re)assembly step is not, but requires the action of a heterotrimeric chaperone referred to as the RAVE complex. Recently, an alternative pathway (...) of holoenzyme disassembly was discovered that involves binding of Oxidation Resistance 1 (Oxr1p), a poorly characterized protein implicated in oxidative stress response. Unlike conventional reversible disassembly, which depends on enzyme activity, Oxr1p induced dissociation can occur in absence of ATP. Yeast Oxr1p belongs to the family of TLDc domain containing proteins that are conserved from yeast to mammals, and have been implicated in V‐ATPase function in a variety of tissues. This brief perspective summarizes what we know about the molecular mechanisms governing both reversible (ATP dependent) and Oxr1p driven (ATP independent) V‐ATPase dissociation into autoinhibited V1 and Vo subcomplexes. (shrink)

A model of face representation, inspired by the biology of the visual system, is compared to experimental data on the perception of facial similarity. The face representation model uses aggregate primary visual cortex (V1) cell responses topographically linked to a grid covering the face, allowing comparison of shape and texture at corresponding points in two facial images. When a set of relatively similar faces was used as stimuli, this Linked Aggregate Code (LAC) predicted human performance in similarity judgment experiments. When (...) faces of perceivable categories were used, dimensions such as apparent sex and race emerged from the LAC model without training. The dimensional structure of the LAC similarity measure for the mixed category task displayed some psychologically plausible features but also highlighted differences between the model and the human similarity judgements. The human judgements exhibited a racial perceptual bias that was not shared by the LAC model. The results suggest that the LAC based similarity measure may offer a fertile starting point for further modelling studies of face representation in higher visual areas, including studies of the development of biases in face perception. (shrink)

We consider two models V1, V2 of ZFC such that V1 ⊆ V2, the cofinality functions of V1 and of V2 coincide, V1 and V2 have that same hereditarily countable sets, and there is some uncountable set in V2 that is not covered by any set in V1 of the same cardinality. We show that under these assumptions there is an inner model of V2 with a measurable cardinal κ of Mitchell order κ++. This technical result allows us to show (...) that changing cardinal characteristics without changing cofinalities or ω-sequences has consistency strength at least Mitchell order κ++. From this we get that the changing of cardinal characteristics without changing cardinals or ω-sequences has consistency strength Mitchell order ω1, even in the case of characteristics that do not stem from a transitive relation. Hence the known forcing constructions for such a change have lowest possible consistency strength. We consider some stronger violations of covering which have appeared as intermediate steps in forcing constructions. (shrink)

Kohlenbach, U., Effective moduli from ineffective uniqueness proofs. An unwinding of de La Vallée Poussin's proof for Chebycheff approximation, Annals of Pure and Applied Logic 64 27–94.We consider uniqueness theorems in classical analysis having the form u ε U, v1, v2 ε Vu = 0 = G→v 1 = v2), where U, V are complete separable metric spaces, Vu is compact in V and G:U x V → is a constructive function.If is proved by arithmetical means from analytical assumptions x (...) εXy ε Yx z ε Z = 0) only , then we can extract from the proof of → an effective modulus of uniqueness, which depends on u, k but not on v1,v2, i.e., u ε U, v1, v2 ε Vu, k εG, G 2-φuk→dv2-itk). Such a modulus φ can e.g. be used to give a finite algorithm which computes the zero of G on Vu with prescribed precision if it exists classically.The extraction of φ uses a proof-theoretic combination of functional interpretation and pointwise majorization. If the proof of → uses only simple instances of induction, then φ is a simple mathematical operation. (shrink)

Visual imagery is a form of sensory imagination, involving subjective experiences typically described as similar to perception, but which occur in the absence of corresponding external stimuli. We used the Activation Likelihood Estimation algorithm (ALE) to identify regions consistently activated by visual imagery across 40 neuroimaging studies, the first such meta-analysis. We also employed a recently developed multi-modal parcellation of the human brain to attribute stereotactic co-ordinates to one of 180 anatomical regions, the first time this approach has been combined (...) with the ALE algorithm. We identified a total 634 foci, based on measurements from 464 participants. Our overall comparison identified activation in the superior parietal lobule, particularly in the left hemisphere, consistent with the proposed ‘top-down’ role for this brain region in imagery. Inferior premotor areas and the inferior frontal sulcus were reliably activated, a finding consistent with the prominent semantic demands made by many visual imagery tasks. We observed bilateral activation in several areas associated with the integration of eye movements and visual information, including the supplementary and cingulate eye fields (SCEFs) and the frontal eye fields (FEFs), suggesting that enactive processes are important in visual imagery. V1 was typically activated during visual imagery, even when participants have their eyes closed, consistent with influential depictive theories of visual imagery. Temporal lobe activation was restricted to area PH and regions of the fusiform gyrus, adjacent to the fusiform face complex (FFC). These results provide a secure foundation for future work to characterise in greater detail the functional contributions of specific areas to visual imagery. (shrink)

We define a new NP search problem, the “local improvement” principle, about labellings of an acyclic, bounded-degree graph. We show that, provably in , it characterizes the consequences of and that natural restrictions of it characterize the consequences of and of the bounded arithmetic hierarchy. We also show that over V0 it characterizes the consequences of V1 and hence that, in some sense, a miniaturized version of the principle gives a new characterization of the consequences of . Throughout our search (...) problems are “type-2” NP search problems, which take second-order objects as parameters. (shrink)

There are two concepts of consciousness that are easy to confuse with one another, access-consciousness and phenomenal consciousness. However, just as the concepts of water and H2O are different concepts of the same thing, so the two concepts of consciousness may come to the same thing in the brain. The focus of this paper is on the problems that arise when these two concepts of consciousness are conflated. I will argue that John Searle’s reasoning about the function of consciousness goes (...) wrong because he conflates the two senses. And Francis Crick and Christof Koch fall afoul of the ambiguity in arguing that visual area V1 is not part of the neural correlate of consciousness. Crick and Koch’s work raises issues that suggest that these two concepts of consciousness may have different (though overlapping) neural correlates--despite Crick and Koch’s implicit rejection of this idea. (shrink)

Blindsight, the ability to blindly discriminate wavelength and other aspects of stimuli in a blind field, sometimes occurs in people with lesions to striate (V1) cortex. There is currently no consensus on whether qualitative color information of the sort that is normally computed by double opponent cells in striate cortex is indeed computed in blindsight but doesn’t reach awareness, perhaps owing to abnormal neuron responsiveness in striate or extra-striate cortical areas, or is not computed at all. The existence of primesight, (...) the experience of colored afterimages in blindsight, has been taken to suggest that qualitative color information is computed either in pre-striate or striate cortical areas but is not broadcast to working memory. I argue here that a recent study in which color phosphenes were induced in a blindsighter using bilateral transcranial magnetic stimulation indicates that computations necessary for conscious color vision are lost in blindsight. Owing to this loss, the neural responsiveness in extrastriate cortical areas is abnormal and hence is unable to give rise to color awareness. Blindsight is thus degraded vision in which the computations necessary for conscious color vision have been lost. (shrink)

David Milner and Melvyn Goodale’s dissociation hypothesis is commonly taken to state that there are two functionally specialized cortical streams of visual processing originating in striate (V1) cortex: a dorsal, action-related “unconscious” stream and a ventral, perception-related “conscious” stream. As Milner and Goodale acknowledge, findings from blindsight studies suggest a more sophisticated picture that replaces the distinction between unconscious vision for action and conscious vision for perception with a tripartite division between unconscious vision for action, conscious vision for perception, and (...) unconscious vision for perception. The combination excluded by the tripartite division is the possibility of conscious vision for action. But are there good grounds for concluding that there is no conscious vision for action? There is now overwhelming evidence that illusions and perceived size can have a significant effect on action (Bruno & Franz, 2009; Dassonville & Bala, 2004; Franz & Gegenfurtner, 2008; McIntosh & Lashley, 2008). There is also suggestive evidence that any sophisticated visual behavior requires collaboration between the two visual streams at every stage of the process (Schenk & McIntosh, 2010). I nonetheless want to make a case for the tripartite division between unconscious vision for action, conscious vision for perception, and unconscious vision for perception. My aim here is not to refute the evidence showing that conscious vision can affect action but rather to argue (a) that we cannot gain cognitive access to action-guiding dorsal stream representations, and (b) that these representations do not correlate with phenomenal consciousness. This vindicates the semi-conservative view that the dissociation hypothesis is best understood as a tripartite division. (shrink)

We discuss cases where subjects seem to enjoy conscious experience when the relevant first-order perceptual representations are either missing or too weak to account for the experience. Though these cases are originally considered to be theoretical possibilities that may be problematical for the higher-order view of consciousness, careful considerations of actual empirical examples suggest that this strategy may backfire; these cases may cause more trouble for first-order theories instead. Specifically, these cases suggest that (I) recurrent feedback loops to V1 are (...) most likely not the neural correlate of first-order representations for conscious experience, (II) first-order views seem to have a problem accounting for the phenomenology in these cases, and either (III) a version of the ambitious higher-order approach is superior in that it is the simplest theory that can account for all results at face value, or (IV) a view where phenomenology is jointly determined by both first-order and higher-order states. In our view (III) and (IV) are both live options and the decision between them may ultimately be an empirical question that cannot yet be decided. (shrink)

Blindsight and vision for action seem to be exemplars of unconscious visual processes. However, researchers have recently argued that blindsight is not really a kind of uncon- scious vision but is rather severely degraded conscious vision. Morten Overgaard and col- leagues have recently developed new methods for measuring the visibility of visual stimuli. Studies using these methods show that reported clarity of visual stimuli correlates with accuracy in both normal individuals and blindsight patients. Vision for action has also come under (...) scrutiny. Recent findings seem to show that information processed by the dor- sal stream for online action contributes to visual awareness. Some interpret these results as showing that some dorsal stream processes are conscious visual processes (e.g., Gallese, 2007; Jacob & Jeannerod, 2003). The aim of this paper is to provide new support for the more traditional view that blindsight and vision for action are genuinely unconscious per- ceptual processes. I argue that individuals with blindsight do not have access to the kind of purely qualitative color and size information which normal individuals do. So, even though people with blindsight have a kind of cognitive consciousness, visual information process- ing in blindsight patients is not associated with a distinctly visual phenomenology. I argue further that while dorsal stream processing seems to contribute to visual awareness, only information processed by the early dorsal stream (V1, V2, and V3) is broadcast to working memory. Information processed by later parts of the dorsal stream (the parietal lobe) never reaches working memory and hence does not correlate with phenomenal awareness. I con- clude that both blindsight and vision for action are genuinely unconscious visual processes. (shrink)

Blindsight is a kind of residual vision found in people with lesions to V1. Subjects with blindsight typically report no visual awareness, but they are nonetheless able to make above-chance guesses about the shape, location, color and movement of visual stimuli presented to them in their blind field. A different kind of blindsight, sometimes called type 2 blindsight, is a kind of residual vision found in patients with V1 lesions in the presence of some residual awareness. Type 2 blindsight differs (...) from ordinary visual experience in lacking the particularity, transparency and fine-grainedness often taken to be essential to visual experience, at least in veridical cases. I argue that the case of type 2 blindsight provides a counterexample to the view that these characteristics are essential to veridical visual experience and that this gives us reason to resist the view that visual experience is essentially a perceptual relation to external objects. In the second part of the paper I argue that the case of type 2 blindsight yields important insights into the effects of attentional modulation on perceptual content and that cases of attentional modulation of appearance are not at odds with the view that the phenomenology of visual experience flows from its content. (shrink)

A virtual reality translation of Robert Nozick's "Experience Machine" thought experiment from his "Anarchy, State, and Utopia" (1974). These modules are free to download and use in the classroom and for research/x-phi purposes. NPCs are randomized for gender during startup of each run. *Requires an Oculus Rift or HTC Vive and VR capable computer. To open the files, uncompress the downloaded .zip folder and run the executable (.exe) file. -/- V1.2 Fixed missing projector video footage during experience machine sales pitch.

In some presentations of classical and intuitionistic logics, the objectlanguage is assumed to contain (two) truth-value constants: ⊤ (verum) and ⊥ (falsum), that are, respectively, true and false under every bivalent valuation. We are interested to define and study analogical constants ‡, 1 ≤ i ≤ n, that in an arbitrary multi-valued logic over truth-values V = {v1,..., vn} have the truth-value vi under every (multi-valued) valuation. As is well known, the absence or presence of such constants has a significant (...) deductive impact on the logics studied. We define such constants proof-theoretically via their associated I/E-rules in a natural-deduction proof system. In particular, we propose a generalization of the notions of contradiction and explosiveness of a logic to the context of multi-valued logics. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Philosophy 41.1 (2003) 25-49 [Access article in PDF] Descartes's Nomic Concurrentism:Finite Causation and Divine Concurrence Andrew Pessin DESCARTES APPEARS TO HOLD the traditional view that God acts in the world via willing. 1 In recent papers on his successor Malebranche, who also holds that view, I have argued that since volitions are paradigm representational states, close attention to the representational content of God's volitions (...) has substantial exegetical rewards. 2 The same, I will argue, is true regarding Descartes. In particular, due to lack of such attention, scholars have largely failed to realize that Descartes retains [End Page 25] a version of the scholastic doctrine that God ordinarily concurs with the causal activities of both mental and material finite substances ("concurrentism"). 3 Since concurrentism implies the true causal powers of those finite substances, in exposing Descartes's adherence to it I aim to open up new ways of thinking about some old problems in Cartesian exegesis.The plan:(I) I will first sketch a partial "worldview," along with evidence that Descartes held something like it, then(II) argue, both on the basis of this worldview and other evidence, that we should interpret Descartes's account of divine and finite causality as a version of concurrentism, then(III) show how interpreting Descartes this way has significant implications for understanding his views on the causal powers of both mental and material finite substances, and finally(IV) contrast my interpretation with two recent relevant ones: Kenneth Clatterbaugh's and Daniel Garber's. 1. A Partial Worldview If Descartes's God acts on the world via willing, we may inquire into the contents of those volitions. I suggest that Descartes's God has, among others, distinguishable volitions with roughly the following contents. 4 These constitute a partial worldview (W), and will be discussed in turn:(V1) At all times beginning with original Creation matter exists everywhere.(V2) There is at original Creation a particular quantity q and particular distribution d of motion.(V3) At all times, the laws of motion apply.(V4) Mind m exists at time t (appropriately substituted).(V5) At all times, the laws of mind-body union apply.Our first task is to accommodate God's role in the Cartesian system as the continuous conserver of the material world. 5 One divine volition which would accomplish that might have the content, not that each individual body persists, but rather, simply, that [End Page 26](V1) at all times beginning with original Creation matter exists everywhere. 6Now (V1) may require us to rethink the way continuous conservation arguments are typically framed. In the texts of La Forge and Malebranche, for example, what God conserves are individual bodies,and Cartesian texts seem sometimes to suggest the same. 7 Such framing might suggest, contra (V1), that God's conservational volitional contents make explicit reference to each individual body. Nevertheless, there are reasons to think that Descartes's God's conserving activity is and ought to be framed as in (V1):(i) God's willing that (V1) provides an easy way to reconcile Cartesian mind —> body causal interaction with continuous conservation. 8 Many think that there is a tension between these two doctrines, since God, in conserving bodies, would seem to be responsible for all their modes including motion, leaving nothing for minds to contribute to them. Now that might be true where God's conserving volition explicitly represents each individual body, particularly given the role that motion plays in distinguishing individual Cartesian bodies. 9 (V1), however, in making no reference to individual bodies, is perfectly consistent with minds affecting either the quantity or distribution of motion in the material world.(ii) Similarly in Physiologia, Des Chene convincingly defends the claim that for Descartes, "since the existence of motion... is not entailed by the existence of matter, the creation of motion [is] independent of the creation of matter" (329). In light, again, of Descartes's conception of individual bodies (n. 9, below), this independence is best modeled by distinguishing God's conserving volition from those volitions... (shrink)

In traditional 3D reconstruction methods, using a single view to predict the 3D structure of an object is a very difficult task. This research mainly discusses human pose recognition and estimation based on 3D multiview basketball sports dataset. The convolutional neural network framework used in this research is VGG11, and the basketball dataset Image Net is used for pretraining. This research uses some modules of the VGG11 network. For different feature fusion methods, different modules of the VGG11 network are used (...) as the feature extraction network. In order to be efficient in computing and processing, the multilayer perceptron in the network model is implemented by a one-dimensional convolutional network. The input is a randomly sampled point set, and after a layer of perceptron, it outputs a feature set of n × 16. Then, the feature set is sent to two network branches, one is to continue to use the perceptron method to generate the feature set of n × 1024, and the other network is used to extract the local features of points. After the RGB basketball sports picture passes through the semantic segmentation network, a picture containing the target object is obtained, and the picture is input to the constructed feature fusion network model. After feature extraction is performed on the RGB image and the depth image, respectively, the RGB feature, the local feature of the point cloud, and the global feature are spliced and fused to form a feature vector of N × 1152. There are three branches for this vector network, which, respectively, predict the object position, rotation, and confidence. Among them, the feature dimensionality reduction is realized by one-dimensional convolution, and the activation function is the ReLU function. After removing the feature mapping module, the accuracy of VC-CNN_v1 dropped by 0.33% and the accuracy of VC-CNN_v2 dropped by 0.55%. It can be seen from the research results that the addition of the feature mapping module improves the recognition effect of the network to a certain extent. (shrink)

Blindsight is classically defined as residual visual capacity, e.g., to detect and identify visual stimuli, in the total absence of perceptual awareness following lesions to V1. However, whereas most experiments have investigated what blindsight patients can and cannot do, the literature contains several, often contradictory, remarks about remaining visual experience. This review examines closer these remarks as well as experiments that directly approach the nature of possibly spared visual experiences in blindsight.

How tight is the conceptual connection between imagination and perception? A number of philosophers, from the early moderns to present-day predictive processing theorists, tie the knot as tightly as they can, claiming that states of the imagination, i.e. mental imagery, are a proper subset of perceptual experience. This paper labels such a view ‘perceptualism’ about the imagination and supplies new arguments against it. The arguments are based on high-level perceptual content and, distinctly, cognitive penetration. The paper also defuses a recent, (...) influential argument for perceptualism based on the ‘discovery’ that visual perception and mental imagery share a significant neural substrate: circuitry in V1, the brain’s primary visual cortex. Current neuropsychology is shown to be equivocal at best on this matter. While experiments conducted on healthy, neurotypical subjects indicate substantial neural overlap, there is extensive clinical evidence of dissociations between imagery and perception in the brain, most notably in the case of aphantasia. (shrink)

Reichenbach's principles of a probabilistic common cause of probabilistic correlations is formulated in terms of relativistic quantum field theory, and the problem is raised whether correlations in relativistic quantum field theory between events represented by projections in local observable algebrasA(V1) andA(V2) pertaining to spacelike separated spacetime regions V1 and V2 can be explained by finding a probabilistic common cause of the correlation in Reichenbach's sense. While this problem remains open, it is shown that if all superluminal correlations predicted by the (...) vacuum state between events inA(V1) andA(V2) have a genuinely probabilistic common cause, then the local algebrasA(V1) andA(V2) must be statistically independent in the sense of C*-independence. (shrink)

We have used fMRI to measure responses to chromatic and achromatic contrast in retinotopically defined regions of macaque and human visual cortex. We make four observations. Firstly, the relative amplitudes of responses to color and luminance stimuli in macaque area V1 are similar to those previously observed in human fMRI experiments. Secondly, the dorsal and ventral subdivisions of macaque area V4 respond in a similar way to opponent (L j M)-cone chromatic contrast suggesting that they are part of a single (...) functional area. Thirdly, we find that macaque area V4, like area V1, responds preferentially to chromatic contrast compared to luminance contrast and the degree of preference is strongly influenced by the temporal frequency of the stimulus. Finally, we observe that while macaque V4d is a region on the dorsal surface of the macaque visual cortex that responds robustly to chromatic stimuli, human chromatic responses to identical stimuli are largely confined to the ventral surface suggesting a fundamental difference in the topographical organization of higher visual areas between humans and macaques. (shrink)

There are two concepts of consciousness that are easy to confuse with one another, access-consciousness and phenomenal consciousness. However, just as the concepts of water and H 2 O are different concepts of the same thing, so the two concepts of consciousness may come to the same thing in the brain. The focus of this paper is on the problems that arise when these two concepts of consciousness are conflated. I will argue that John Searle's reasoning about the function of (...) consciousness goes wrong because he conflates the two senses. And Francis Crick and Christof Koch fall afoul of the ambiguity in arguing that visual area V1 is not part of the neural correlate of consciousness. Crick and Koch's work raises issues that suggest that these two concepts of consciousness may have different neural correlates – despite Crick and Koch's implicit rejection of this idea. (shrink)