Better Than Conscious? The Brain, the Psyche, Behavior, and Institutions

The title of this chapter is deliberately provocative. Intuitively, many will be inclined to see conscious control of mental process as a good thing. Yet control comes at a high price. The consciously not directly controlled, automatic, parallel processing of information is not only much faster, it also handles much more information, and it does so in a qualitatively different manner. This different mental machinery is not adequate for all tasks. The human ability to consciously deliberate has evolved for good reason. But on many more tasks than one might think at first sight, intuitive decision-making, or at least an intuitive component in a more complex mental process, does indeed improve performance. This chapter presents the issue, offers concepts to understand it, discusses the effects in terms of problem solving capacity, contrasts norms for saying when this is a good thing, and points to scientific and real world audiences for this work.

Separate cortical stages in amodal completion revealed by functional magnetic resonance adaptation : research article

Background Objects in our environment are often partly occluded, yet we effortlessly perceive them as whole and complete. This phenomenon is called visual amodal completion. Psychophysical investigations suggest that the process of completion starts from a representation of the (visible) physical features of the stimulus and ends with a completed representation of the stimulus. The goal of our study was to investigate both stages of the completion process by localizing both brain regions involved in processing the physical features of the stimulus as well as brain regions representing the completed stimulus. Results Using fMRI adaptation we reveal clearly distinct regions in the visual cortex of humans involved in processing of amodal completion: early visual cortex - presumably V1 - processes the local contour information of the stimulus whereas regions in the inferior temporal cortex represent the completed shape. Furthermore, our data suggest that at the level of inferior temporal cortex information regarding the original local contour information is not preserved but replaced by the representation of the amodally completed percept. Conclusion These findings provide neuroimaging evidence for a multiple step theory of amodal completion and further insights into the neuronal correlates of visual perception

Meditation increases the depth of information processing

During meditation, practitioners are required to center their attention on a specific object for extended periods of time. When their thoughts get diverted, they learn to quickly disengage from the distracter. We hypothesized that learning to respond to the dual demand of engaging attention on specific objects and disengaging quickly from distracters enhances the efficiency by which meditation practitioners can allocate attention. We tested this hypothesis in a global-to-local task while measuring electroencephalographic activity from a group of eight highly trained Buddhist monks and nuns and a group of eight age and education matched controls with no previous meditation experience. Specifically, we investigated the effect of attentional training on the global precedence effect, i.e., faster detection of targets on a global than on a local level. We expected to find a reduced global precedence effect in meditation practitioners but not in controls, reflecting that meditators can more quickly disengage their attention from the dominant global level. Analysis of reaction times confirmed this prediction. To investigate the underlying changes in brain activity and their time course, we analyzed event-related potentials. Meditators showed an enhanced ability to select the respective target level, as reflected by enhanced processing of target level information. In contrast with control group, which showed a local target selection effect only in the P1 and a global target selection effect in the P3 component, meditators showed effects of local information processing in the P1, N2, and P3 and of global processing for the N1, N2, and P3. Thus, meditators seem to display enhanced depth of processing. In addition, meditation altered the uptake of information such that meditators selected target level information earlier in the processing sequence than controls. In a longitudinal experiment, we could replicate the behavioral effects, suggesting that meditation modulates attention already after a 4-day meditation retreat. Together, these results suggest that practicing meditation enhances the speed with which attention can be allocated and relocated, thus increasing the depth of information processing and reducing response latency

Thalamocortical synchronization and cognition: implications for schizophrenia?

Cognitive deficits are a core dysfunction in schizophrenia. In this issue of Neuron, Parnaudeau et al. (2013) investigated synchronization in thalamocortical pathways in an animal model to address the disconnection between brain regions as a mechanism for working memory impairments in the disorder.implicated dysfunctional neural oscillations in the explanation of cognitive deficits and certain clinical symptoms of schizophrenia. Specifically, we will focus on findings that have examined neural oscillations during 1) perceptual processing, 2) working memory and executive processes and 3) spontaneous activity. The importance of the development of paradigms suitable for human and animal models is discussed as well as the search for mechanistic explanation for oscillatory dysfunctions

The ongoing search for the neuronal correlate of consciousness

A few decades ago the search for the neuronal correlates of consciousness was considered both technically intractable and philosophically questionable. Searching for a material substrate of phenomena accessible only from the first-person perspective appeared to be epistemically problematic. But the development of non-invasive imaging technologies and the availability of intracranial recordings from patients alleviated the imminent technical problems. Progress in the analysis of the connectome of the brain, and the introduction of multisite recordings from the cerebral cortex of animals led to a revision of concepts in the field of cognitive neuroscience, emphasizing principles of distributed processing in recurrent networks with non-linear dynamics, self-organization, and coding in high-dimensional-state space. These advances, together with the growing evidence for epigenetic shaping of brain functions by socio-cultural influences, pave the way for novel theories that attempt to bridge the gap between neuronal processes and subjective states

Neural synchrony in cortical networks : history, concept and current status

Following the discovery of context-dependent synchronization of oscillatory neuronal responses in the visual system, the role of neural synchrony in cortical networks has been expanded to provide a general mechanism for the coordination of distributed neural activity patterns. In the current paper, we present an update of the status of this hypothesis through summarizing recent results from our laboratory that suggest important new insights regarding the mechanisms, function and relevance of this phenomenon. In the first part, we present recent results derived from animal experiments and mathematical simulations that provide novel explanations and mechanisms for zero and nero-zero phase lag synchronization. In the second part, we shall discuss the role of neural synchrony for expectancy during perceptual organization and its role in conscious experience. This will be followed by evidence that indicates that in addition to supporting conscious cognition, neural synchrony is abnormal in major brain disorders, such as schizophrenia and autism spectrum disorders. We conclude this paper with suggestions for further research as well as with critical issues that need to be addressed in future studies

State or content of consciousness? : A reply to Valdas Noreika

An attempt is made to distinguish between brain states required to support consciousness and the neuronal underpinnings of conscious versus non-conscious processing in an awake, attentive brain, respectively. It is argued that brain states supporting consciousness are characterised by high dimensional dynamics exhibiting a high degree of complexity, implying that conscious states are graded. Different mechanisms determine whether signals are processed at the conscious or subconscious level. Thus, there is no unique neuronal correlate of consciousness

Membrane resonance enables stable and robust gamma oscillations

Neuronal mechanisms underlying beta/gamma oscillations (20-80 Hz) are not completely understood. Here, we show that in vivo beta/gamma oscillations in the cat visual cortex sometimes exhibit remarkably stable frequency even when inputs fluctuate dramatically. Enhanced frequency stability is associated with stronger oscillations measured in individual units and larger power in the local field potential. Simulations of neuronal circuitry demonstrate that membrane properties of inhibitory interneurons strongly determine the characteristics of emergent oscillations. Exploration of networks containing either integrator or resonator inhibitory interneurons revealed that: (i) Resonance, as opposed to integration, promotes robust oscillations with large power and stable frequency via a mechanism called RING (Resonance INduced Gamma); resonance favors synchronization by reducing phase delays between interneurons and imposes bounds on oscillation cycle duration; (ii) Stability of frequency and robustness of the oscillation also depend on the relative timing of excitatory and inhibitory volleys within the oscillation cycle; (iii) RING can reproduce characteristics of both Pyramidal INterneuron Gamma (PING) and INterneuron Gamma (ING), transcending such classifications; (iv) In RING, robust gamma oscillations are promoted by slow but are impaired by fast inputs. Results suggest that interneuronal membrane resonance can be an important ingredient for generation of robust gamma oscillations having stable frequency

Progress toward an understanding of cortical computation

The additional data, perspectives, questions, and criticisms contributed by the commentaries strengthen our view that local cortical processors coordinate their activity with the context in which it occurs using contextual fields and synchronized population codes. We therefore predict that whereas the specialization of function has been the keynote of this century the coordination of function will be the keynote of the next