Representational 'touch' and modulatory 'retouch'-two necessary neurobiological processes in thalamocortical interaction for conscious experience.

Theories of consciousness using neurobiological data or being influenced by these data have been focused either on states of consciousness or contents of consciousness. These theories have occasionally used evidence from psychophysical phenomena where conscious experience is a dependent experimental variable. However, systematic catalog of many such relevant phenomena has not been offered in terms of these theories.

Apical amplification-a cellular mechanism of conscious perception?

We present a theoretical view of the cellular foundations for network-level processes involved in producing our conscious experience. Inputs to apical synapses in layer 1 of a large subset of neocortical cells are summed at an integration zone near the top of their apical trunk. These inputs come from diverse sources and provide a context within which the transmission of information abstracted from sensory input to their basal and perisomatic synapses can be amplified when relevant.

Account of consciousness by Christof Koch: Review and questions.

This review is set to present the gist of the theoretical account of consciousness recently presented by Christof Koch and pose a couple of questions instigated by this account. The expected answers to these questions would hopefully help to advance our understanding of the basic nature of the conscious mind.

BDNF polymorphism in non-veridical decision making and differential effects of rTMS.

Making decisions when an objectively correct option is not obvious, involves different neurobiological mechanisms than "veridical" decision making. The dorsolateral prefrontal cortex (DLPFC) exhibits a distinct pattern of prefrontal activation in non-veridical cognition, but little is known about the role of underlying neurobiological endophenotypes. A functional polymorphism in the brain-derived neurotrophic factor (BDNF) gene, causing a valine (Val) to methionine (Met) amino acid substitution at codon 66, has been shown to be associated with structural and functional changes in DLPFC and affect veridical decision making.

Excess of individual variability of priors prevents successful development of general models.

Perceptual judgments are influenced by a multitude of factors in addition to the perceptual input. Particularly, the widely varying individual neurobiological endophenotypes and individual differences in the propensity for expectation-based illusory percepts make it unlikely that optimality is possible to define and defend by the type of abstract modeling approach criticized by Rahnev & Denison (R&D).

Diminished Risk-Aversion After Right DLPFC Stimulation: Effects of rTMS on a Risky Ball Throwing Task.

Objectives: Several studies on human risk taking and risk aversion have reported the involvement of the dorsolateral prefrontal cortex (DLPFC). Yet, current knowledge of the neural mechanisms of risk-related decision making is not conclusive, mainly relying on studies using non-motor tasks. Here we examine how modulation of DLPFC activity by repetitive transcranial magnetic stimulation (rTMS) affects risk-taking behavior during a motor response task.

Visual masking: Contributions from and comments on Bruce Bridgeman.

When about half a century ago masking research emerged as one of the hot topics in psychophysics, cognitive psychology and psychophysiology, Bruce Bridgeman was among the leaders in this domain. His studies and papers on masking must not be overlooked also today. This article brings to the readers a brief review of Bridgeman's contributions to the field and directly related research from other laboratories, with an eye on the implications for consciousness studies.

Disrupting dorsolateral prefrontal cortex by rTMS reduces the P300 based marker of deception.

Objective: Quite many studies have revealed certain brain-process signatures indicative of subject's deceptive behavior. These signatures are neural correlates of deception. However, much less is known about whether these signatures can be modified by noninvasive brain stimulation techniques representing methods of causal intervention of brain processes and the corresponding behavior.

When expectation confounds iconic memory.

In response to the methodological criticism (Bachmann & Aru, 2015) of the interpretation of their earlier experimental results (Mack, Erol, & Clarke, 2015) Mack, Erol, Clarke, and Bert (2016) presented new results that they interpret again in favor of the stance that an attention-free phenomenal iconic store does not exist. Here we once more question their conclusions. When their subjects were unexpectedly asked to report the letters instead of the post-cued circles in the 101th trial where letters were actually absent, they likely failed to see the empty display area because prior experience with letters in the preceding trials produced expectancy based illusory experience of letter-like objects.

Occipital long-interval paired pulse TMS leads to slow wave components in NREM sleep.

Neural correlates of conscious vs unconscious states can be studied by contrasting EEG markers of brain activity between those two states. Here, a task-free experimental setup was used to study the state dependent effects of occipital transcranial magnetic stimulation (TMS). EEG responses to single and paired pulse TMS with an inter-stimulus-interval (ISI) of 100 ms were investigated under Non-REM (NREM) sleep and wakefulness.

Comments on how Mack et al. (2015) (do not) see iconic memory.

In a recent paper (Mack et al., 2015) the effect of attentional manipulations on partial report performance was investigated. The results were interpreted in favor of the stance that an attention-free phenomenal iconic store does not exist.

Single 5HTR2A-1438 A/G nucleotide polymorphism affects performance in a metacontrast masking task: implications for vulnerability testing and neuromodulation of pyramidal cells.

It is known that 5HTR2A (rs6311) receptors have high concentration in the cortical layer-5 pyramidal neurons and that these receptors play an important role in the modulation of neurocognitive functions. For example, layer-5 pyramidal neurons mediate cellular level integrative interaction of primary sensory afferent signals and top-down signals exerting contextual modulatory influence. It is also known that genetic variability of 5HTR2A is implicated in individual differences in mental processes.

Deception rate in a "lying game": different effects of excitatory repetitive transcranial magnetic stimulation of right and left dorsolateral prefrontal cortex not found with inhibitory stimulation.

Knowing the brain processes involved in lying is the key point in today's deception detection studies. We have previously found that stimulating the dorsolateral prefrontal cortex (DLPFC) with repetitive transcranial magnetic stimulation (rTMS) affects the rate of spontaneous lying in simple behavioural tasks. The main idea of this study was to examine the role of rTMS applied to the DLPFC in the behavioural conditions where subjects were better motivated to lie compared to our earlier studies and where all possible conditions (inhibition of left and right DLPFC with 1-Hz and sham; excitation of left and right DLPFC with 10-Hz and sham) were administered to the same subjects.

Facilitating the right but not left DLPFC by TMS decreases truthfulness of object-naming responses.

Dorsolateral prefrontal cortex (DLPFC) participates in many mental functions involving cognitive control. This also applies to processes underlying deception. Recently it was shown that, compared to the opposite effect found with left-hemisphere 1-Hz repetitive transcranial magnetic stimulation of the DLPFC, right-hemisphere stimulation decreased the propensity to produce untruthful responses in a subsequent task where subjects had freedom to name presented stimulus-objects either veridically or nonveridically.

Perception of successive brief objects as a function of stimulus onset asynchrony: model experiments based on two-stage synchronization of neuronal oscillators.

Recently we introduced a new version of the perceptual retouch model incorporating two interactive binding operations-binding features for objects and binding the bound feature-objects with a large scale oscillatory system that acts as a mediary for the perceptual information to reach consciousness-level representation. The relative level of synchronized firing of the neurons representing the features of an object obtained after the second-stage synchronizing modulation is used as the equivalent of conscious perception of the corresponding object. Here, this model is used for simulating interaction of two successive featured objects as a function of stimulus onset asynchrony (SOA).

Neurobiological mechanisms behind the spatiotemporal illusions of awareness used for advocating prediction or postdiction.

The fact that it takes time for the brain to process information from the changing environment underlies many experimental phenomena of awareness of spatiotemporal events, including a number of astonishing illusions. These phenomena have been explained from the predictive and postdictive theoretical perspectives. Here I describe the most extensively studied phenomena in order to see how well the two perspectives can explain them.

Perceptual retouch theory derived modeling of interactions in the processing of successive visual objects for consciousness: two-stage synchronization of neuronal oscillators.

We introduce a new version of the perceptual retouch model. This model was used for explaining properties of temporal interaction of successive objects in reaching conscious representation. The new model incorporates two interactive binding operations - binding features for objects and binding the bound feature-objects with a large scale oscillatory system that corresponds to perceptual consciousness.