A general definition of consciousness is: ‘consciousness is a mental aspect of a system or a process, which is a conscious experience, a conscious function, or both depending on the context’, where the term context refers to metaphysical views, constraints, specific aims, and so on. One of the aspects of visual consciousness is the visual subjective experience (SE) or the first person experience that occurs/emerges in the visual neural-network of thalamocortical system (which includes dorsal and ventral visual pathways and frontal (...) cortex) during dynamic interactions among widely distributed neuronal groups. In this article, however, consciousness and SE are interchangeably used unless noted. Consciousness can be either access (reportable) or phenomenal consciousness. For access consciousness, the interactions are between feed forward stimulus dependent signals and fronto-parietal feedback attentional signals. The necessary ingredients for access (reportable) consciousness are (i) wakefulness, (ii) reentrant interactions among neural populations, (iii) fronto-parietal and thalamic-reticular-nucleus attentional signals that modulate consciousness, (iv) working memory that retains information for consciousness, (v) stimulus at or above threshold level, and (vi) neural-network proto-experiences (PEs) that are superposed SEs embedded in a neural-network. Attention and the ability to report are not necessary for phenomenal consciousness. The neural source for the arousal system is the ascending reticular activating system in the brain stem, which brings the thalamocortical neural networks to wakeful state as a baseline for consciousness to occur. Reentrant interactions among neural populations bind stimulus attributes (such as location and features) and entail consciousness. Attention could be the results of reentry and competitive interactions, and modulates the stimulus related feed forward signal and consciousness. The ‘sources’ of attention may be thalamic reticular nucleus for bottom-up or frontal cortex for top-down direction. The ‘target’ of visual attention is ‘V4/V8/VO’ for Red-Green (R-G) channel. The neural correlates of the psychophysical entity R-G channel appear to be ‘V4/V8/VO’-neural-network (retina → LGN ↔ V1 ↔ V2 ↔ ‘V4/V8/VO’, and areas for attention, memory, and wakefulness). The psychophysical Red-Green Channel, its neurophysiological correlates V4/V8/VO-neural-network, and related experience (such as redness) are integrated. The dual-aspect-dual-mode PE-SE framework (Vimal, J Integr Neurosci 7:49–73, 2008) was used to address the explanatory gap problem of materialism. Neural-network and related SEs are the results of the co-evolution and co-development of the material aspect (mass, charge, spin, force, quanta, and space-time) and the mental aspect of fundamental particles (strings or elementary particles (fermions and bosons)). Their mental aspects are considered as the carriers of superposed multiple possible experiences (SEs/PEs) in unexpressed form. These possibilities are actualized when neural-networks are formed via neural Darwinism, and a specific SE is selected by a matching process when the necessary ingredients of consciousness/SE are satisfied. A simple experimental design is suggested to address the necessary and sufficient attributes of consciousness. (shrink)

Schizophrenia is a worldwide, prevalent disorder with a multifactorial but highly genetic aetiology. A constant prevalence rate in the face of reduced fecundity has caused some to argue that an evolutionary advantage exists in unaffected relatives. Here, I critique this adaptationist approach, and review – and find wanting – Crow's “speciation” hypothesis. In keeping with available biological and psychological evidence, I propose an alternative theory of the origins of this disorder. Schizophrenia is a disorder of the social brain, and it (...) exists as a costly trade-off in the evolution of complex social cognition. Paleoanthropological and comparative primate research suggests that hominids evolved complex cortical interconnectivity (in particular, frontotemporal and frontoparietal circuits) to regulate social cognition and the intellectual demands of group living. I suggest that the ontogenetic mechanism underlying this cerebral adaptation was sequential hypermorphosis and that it rendered the hominid brain vulnerable to genetic and environmental insults. I argue that changes in genes regulating the timing of neurodevelopment occurred prior to the migration of Homo sapiens out of Africa 100,000–150,000 years ago, giving rise to the schizotypal spectrum. While some individuals within this spectrum may have exhibited unusual creativity and iconoclasm, this phenotype was not necessarily adaptive in reproductive terms. However, because the disorder shared a common genetic basis with the evolving circuitry of the social brain, it persisted. Thus schizophrenia emerged as a costly trade-off in the evolution of complex social cognition. Key Words: cortical connectivity; evolution; heterochrony; metarepresentation; primates; psychiatry; schizophrenia; social brain; social cognition. (shrink)

Source preference in which equally distributed risks may be valued differently has been receiving increasing attention. Using subjects recruited in Berkeley, Fox and Tversky demonstrate a familiarity bias in source preference—betting on a less than even-chance event based on San Francisco temperature is valued more than betting on a better than even-chance event based on Istanbul temperature. Neophobia is associated with the amygdala which is GABA-rich and is known to be modulated by benzodiazepines as anxiolytic agents that enhance the activity (...) of the GABAA receptor in processing anxiety and fear. This leads to our hypothesis that familiarity bias in decision making may be explained by polymorphic variations in this receptor mediated by anxiety regulation in the amygdala. In two companion studies involving Beijing-based subjects, we examine 10 single nucleotide polymorphisms of GABRB2 and find 7 SNPs each showing negative association between familiarity bias—preference for betting on parity of Beijing temperature over Tokyo temperature—and having at least one minor allele. In an imaging genetics study of a subsample of subjects based on the SNP with the most balanced allelic distribution, we find that subjects’ familiarity bias in terms of risk aversion towards bets on the parity of the temperature of 20 Chinese cities is negatively associated with their post-scanning familiarity ratings of the cities only for those with no minor allele in this SNP. Moreover, familiarity bias is positively associated with activation in the right amygdala along with the brain’s attention networks. Overall, our findings help discriminate between ambiguity aversion and familiarity bias in source preference and supports our gene–brain–behavior hypothesis of GABAergic modulation of amygdala activation in response to familiarity towards the source of uncertainty. (shrink)

How are attention and consciousness related? Can we learn what the contents of someone’s consciousness are if we know the targets of their attention? What can we learn about the contents of consciousness if we know the targets of attention? Although introspection might suggest that attention and consciousness are intimately connected, a good body of recent findings in cognitive psychology and cognitive neuroscience brings compelling reasons to believe that they are two separate and independent processes. This paper attempts to bring (...) attention and consciousness back together to make the study of attentional distributions an essential ingredient for the study of the contents of consciousness. My proposal has two main components. First, I introduce a framework for systematizing the relations between attention in its different forms and consciousness in its different forms. Although philosophers and cognitive scientists have repeatedly highlighted the importance of such systematization, most details are still to be worked out. Here I take an initial stab at this project based on the notion of degrees of informational enhancement. Second, I introduce the notion of vicarious attention to account for a kind of additional processing benefit that comes for free when attention is allocated to a target. I then propose that this kind of processing must also be considered when mapping attention targets into contents of consciousness. (shrink)

The review first discusses componential explanations of automaticity, which specify non/automaticity features (e.g., un/controlled, un/conscious, non/efficient, fast/slow) and their interrelations. Reframing these features as factors that influence processes (e.g., goals, attention, and time) broadens the range of factors that can be considered (e.g., adding stimulus intensity and representational quality). The evidence reviewed challenges the view of a perfect coherence among goals, attention, and consciousness, and supports the alternative view that (a) these and other factors influence the quality of representations in (...) an additive way (e.g., little time can be compensated by extra attention or extra stimulus intensity) and that (b) a first threshold of this quality is required for unconscious processing and a second threshold for conscious processing. The review closes with a discussion of causal explanations of automaticity, which specify factors involved in automatization such as repetition and complexity, and a discussion of mechanistic explanations, which specify the low-level processes underlying automatization. (shrink)

Probabilistic realism and syntactical positivism were two among outdated theories that Feigl criticised on account of their semantical poverty. In this paper, I argue that a refined version of probabilistic realism, which relies on what Feigl specified as the pragmatic description of the symbolic behaviour of scientists’ estimations and foresight, is defendable. This version of statistical realism does not need to make the plausibility of realist thesis dependent on the conventional acceptance of a constructed semantic metalanguage. I shall rely on (...) the Prediction Error Minimisation theory to support my probabilistic version of realism with a scientifically-informed and naturalistically plausible statistical account of the theories-world relationship which has a pragmatic ring to it. (shrink)

How can we explain our capacity to think about particulars in our external environment? Many philosophers have answered this question in terms of a sophisticated conception of space and time and the movement of objects therein. A more recent reaction against this view sought to explain this capacity solely in terms of perceptual mechanisms of object individuation. Neither explanation remains fully satisfactory. This book argues for a more desirable middle ground in terms of a pragmatist approach to demonstrative thought, where (...) this capacity is explained through graded practical knowledge of objects. This view allows us to do justice to important insights put forward by both positions criticized in the book, while avoiding their potential shortcomings. It also paves the way to a more pragmatist approach to the theory of mental representation, where the notion of practical knowledge is allowed to play a central role in our cognitive life. Finally, it shows how practical knowledge may be firmly rooted in neurobiological processes and mechanisms that conform to what the empirical sciences tell us about the mind. (shrink)

Deep Brain Stimulation (DBS) is a relatively new, experimental treatment for patients suffering from treatment-refractory Obsessive Compulsive Disorder (OCD). The effects of treatment are typically assessed with psychopathological scales that measure the amount of symptoms. However, clinical experience indicates that the effects of DBS are not limited to symptoms only: patients for instance report changes in perception, feeling stronger and more confident, and doing things unreflectively. Our aim is to get a better overview of the whole variety of changes that (...) OCD patients experience during DBS treatment. For that purpose we conducted in-depth, semi-structured interviews with 18 OCD patients. In this paper, we present the results from this qualitative study.We list the changes grouped in four domains: with regard to (a) person, (b) (social) world, (c)characteristics of person-world interactions, and (d) existential stance. We subsequently provide an interpretation of these results. In particular, we suggest that many of these changes can be seen as different expressions of the same process; namely that the experience of anxiety and tension gives way to an increased basic trust and increased reliance on one’s abilities. We then discuss the clinical implications of our findings, especially with regard to properly informing patients of what they can expect from treatment, the usefulness of including CBT in treatment, and the limitations of current measures of treatment success. We end by making several concrete suggestions for further research. (shrink)

Attention and adaptation are both mechanisms that optimize visual performance. Attention optimizes performance by increasing contrast sensitivity for and neural response to attended stimuli while decreasing them for unattended stimuli; adaptation optimizes performance by increasing contrast sensitivity for and neural response to changing stimuli while decreasing them for unchanging stimuli. We investigated whether and how the adaptation state and the attentional effect on contrast sensitivity interact. We measured contrast sensitivity with an orientation-discrimination task, in two adaptation conditions—adapt to 0% or (...) 100% contrast—in focused, distributed, and withdrawn attentional conditions. We used threshold and asymptotic performance to index the magnitude of the attentional effect—enhancement or impairment in contrast sensitivity—before and after adapting to high-contrast stimuli. The results show that attention and adaptation affect the contrast psychometric function in a similar but opposite way: Attention increases stimulus salience, whereas adaptation reduces stimulus salience. An interesting finding is that the adaptation state does not modulate the magnitude of the attentional effect. This suggests that attention affects the normalized signal once the effect of contrast adaptation has taken place and that these two mechanisms act separately to change contrast sensitivity. Attention can overcome adaptation to restore contrast sensitivity. (shrink)

This paper aims to clarify the relationship between consciousness and attention through theoretical considerations about evolution. Specifically, we will argue that the empirical findings on attention and the basic considerations concerning the evolution of the different forms of attention demonstrate that consciousness and attention must be dissociated regardless of which definition of these terms one uses. To the best of our knowledge, no extant view on the relationship between consciousness and attention has this advantage. Because of this characteristic, this paper (...) presents a principled and neutral way to settle debates concerning the relationship between consciousness and attention, without falling into disputes about the meaning of these terms. A decisive conclusion of this approach is that extreme views on the relationship between consciousness and attention must be rejected, including identity and full dissociation views. There is an overlap between the two within conscious attention, but developing a full understanding of this mechanism requires further empirical investigations. (shrink)

Attention has a role in much of perception, thought, and action. On the erotetic theory, the functional role of attention is a matter of the relationship between questions and what counts as answers to those questions. Questions encode the completion conditions of tasks for cognitive control purposes, and degrees of attention are degrees of sensitivity to the occurrence of answers. Questions and answers are representational contents given precise characterizations using tools from formal semantics, though attention does not depend on language. (...) The erotetic theory proposes an integrated account of attention in cognitive control and of attentional focus in perception. The functional role of attentional focus on objects, properties, and locations has to do with picking out something that corresponds to what a task is ‘about’. The erotetic theory of attention opens new avenues in theorizing about the relationship between attention, representational content, phenomenal character, and practical reason. A novel representationalist account of salience is proposed. The theory also provides an account of distraction that suggests when distraction is a defect in practical reasoning. (shrink)

Mechanisms of selective attention are vital for coherent perception and action. Recent advances in cognitive neuroscience have yielded key insights into the relationship between neural mechanisms of attention and eye movements, and the role of frontal and parietal brain regions as sources of attentional control. Here we explore the growing contribution of reversible neurodisruption techniques, including transcranial magnetic stimulation and microelectrode stimulation, to the cognitive neuroscience of spatial attention. These approaches permit unique causal inferences concerning the relationship between neural processes (...) and behaviour, and have revealed fundamental mechanisms of attention in the human and animal brain. We conclude by suggesting that further advances in the neuroscience of attention will be facilitated by the combination of neurodisruption techniques with established neuroimaging methods. (shrink)

Prominent models of attentional control assert a dichotomy between top-down and bottom-up control, with the former determined by current selection goals and the latter determined by physical salience. This theoretical dichotomy, however, fails to explain a growing number of cases in which neither current goals nor physical salience can account for strong selection biases. For example, equally salient stimuli associated with reward can capture attention, even when this contradicts current selection goals. Thus, although 'top-down' sources of bias are sometimes defined (...) as those that are not due to physical salience, this conception conflates distinct - and sometimes contradictory - sources of selection bias. We describe an alternative framework, in which past selection history is integrated with current goals and physical salience to shape an integrated priority map. (shrink)

Event-related potential studies have attempted to discover the processes that underlie conscious visual perception by contrasting ERPs produced by stimuli that are consciously perceived with those that are not. Variability of the proposed ERP correlates of consciousness is considerable: the earliest proposed ERP correlate of consciousness coincides with sensory processes and the last one marks postperceptual processes. A negative difference wave called visual awareness negativity , typically observed around 200 ms after stimulus onset in occipitotemporal sites, gains strong support for (...) reflecting the processes that correlate with, and possibly enable, aware visual perception. Research suggests that the early parts of conscious processing can proceed independently of top-down attention, although top-down attention may modulate visual processing even before consciousness. Evidence implies that the contents of consciousness are provided by interactions in the ventral stream, but indispensable contributions from dorsal regions influence already low-level visual responses. (shrink)

The last decade has seen great progress in the study of the nature of crossmodal links in exogenous and endogenous spatial attention . Exogenous spatial cuing studies of human crossmodal attention and multisensory integration. In C. Spence, & J. Driver , Crossmodal space and crossmodal attention . Oxford, UK: Oxford University Press.], for a recent review). A growing body of research now highlights the existence of robust crossmodal links between auditory, visual, and tactile spatial attention. However, until recently, studies of (...) exogenous and endogenous attention have proceeded relatively independently. In daily life, however, these two forms of attentional orienting continuously compete for the control of our attentional resources, and ultimately, our awareness. It is therefore critical to try and understand how exogenous and endogenous attention interact in both the unimodal context of the laboratory and the multisensory contexts that are more representative of everyday life. To date, progress in understanding the interaction between these two forms of orienting has primarily come from unimodal studies of visual attention. We therefore start by summarizing what has been learned from this large body of empirical research, before going on to review more recent studies that have started to investigate the interaction between endogenous and exogenous orienting in a multisensory setting. We also discuss the evidence suggesting that exogenous spatial orienting is not truly automatic, at least when assessed in a crossmodal context. Several possible models describing the interaction between endogenous and exogenous orienting are outlined and then evaluated in terms of the extant data. (shrink)

Observers can learn the locations where salient distractors appear frequently to reduce potential interference. The effect that observers appear to learn the spatial distribution of salient but task-irrelevant distractors in the visual environment to reduce the interference caused by such distractors was referred to as ‘statistical learning of distractor locations’. Emerging studies agreed that the observed reduction of distractor interference is largely attributable to better suppression of distractor in frequent locations, however, concerning how this spatial distractor suppression is implemented within (...) the functional architecture of search guidance, and how the learned suppression is processed in the brain to reduce the interference, remains debated and poorly understood. The line of studies of the current dissertation, therefore, explores the cognitive and neural mechanism underlying spatial distractor suppression based on statistical learning. Using psychophysical experiments, the first two studies examined a series of potentially ‘confounding’ factors that might lead to different theoretical conclusions concerning the locus of learned spatial distractor suppression in different studies. We found that irrespective of whether a salient singleton distractor is more likely to occur at multiple locations within a subregion of the display or at a specific location, observers are both likely to adopt the priority-map-based suppression strategy and dimension-based suppression strategy to reduce interference of distractor in the frequent region. Notably, a critical factor determining which strategy is adopted is whether the distractor and non-distractor items swap colors randomly across trials: without color swapping, observers are more likely to acquire a dimension-based suppression; with color swapping, they prefer to develop a priority-map-based suppression in the first beginning, and potentially shift to dimension-based suppression later with the course of learning. The third study employed functional magnetic resonance imaging techniques with the distractor-location learning paradigm with two types of distractors defined in either the same- or different- visual dimension relative to the target. We disclosed that statistical learning of distractor locations involves suppression down to the level of the early visual cortex to reduce distractor interference, potential different neural mechanisms of spatial distractor suppression between distractors defined in a different and the same dimension to the target. With different-dimension distractors, higher-level, dimension-specific filtering mechanisms plays a role to reduce the interference; with same-dimension distractors, interference reduction relies on cutting down lower-level sensory signals. (shrink)