Conflict and control in cortical responses to inconsistent emotional signals in a face-word Stroop.

Social communication is fraught with ambiguity. Negotiating the social world requires interpreting the affective signals we receive and often selecting between channels of conflicting affective information. The affective face-word Stroop (AFWS) provides an experimental paradigm which may identify cognitive-affective control mechanisms underpinning essential social-affective skills. Initial functional magnetic resonance imaging (fMRI) study of the AFWS identified right amygdala as driving this affective conflict and left rostral anterior cingulate cortex (rACC) as the locus of conflict control. We employed electroencephalogram (EEG) and eLORETA source localization to investigate the timing, location, and sequence of control processes when responding to affective conflict generated during the AFWS. However we designated affective word as the response target and affective face as the distractor to maximize conflict and control effects. Reaction times showed slowed responses in high vs. low control conditions, corresponding to a Rabbitt type control effect rather than the previously observed Grattan effect. Control related activation occurred in right rACC 96-118 ms post-stimulus, corresponding to the resolution of the P1 peak in the Visual Evoked Potential (VEP). Face distractors elicit right hemisphere control, while word distractors elicit left hemisphere control. Low control trials require rapid "booting up" control resources observable through VEPs. Incongruent trial activity in right fusiform face area is suppressed 118-156 ms post stimulus corresponding to onset and development of the N170 VEP component. Results are consistent with a predicted sequence of rapid early amygdala activation by affective conflict, then rACC inhibition of amygdala decreasing facilitation of affective face processing (however, amygdala activity is not observable with EEG).

New directions in hypnosis research: strategies for advancing the cognitive and clinical neuroscience of hypnosis.

This article summarizes key advances in hypnosis research during the past two decades, including (i) clinical research supporting the efficacy of hypnosis for managing a number of clinical symptoms and conditions, (ii) research supporting the role of various divisions in the anterior cingulate and prefrontal cortices in hypnotic responding, and (iii) an emerging finding that high hypnotic suggestibility is associated with atypical brain connectivity profiles. Key recommendations for a research agenda for the next decade include the recommendations that (i) laboratory hypnosis researchers should strongly consider how they assess hypnotic suggestibility in their studies, (ii) inclusion of study participants who score in the middle range of hypnotic suggestibility, and (iii) use of expanding research designs that more clearly delineate the roles of inductions and specific suggestions. Finally, we make two specific suggestions for helping to move the field forward including (i) the use of data sharing and (ii) redirecting resources away from contrasting state and nonstate positions toward studying (a) the efficacy of hypnotic treatments for clinical conditions influenced by central nervous system processes and (b) the neurophysiological underpinnings of hypnotic phenomena. As we learn more about the neurophysiological mechanisms underlying hypnosis and suggestion, we will strengthen our knowledge of both basic brain functions and a host of different psychological functions.

Inhibition of retrieval in hypnotic amnesia: dissociation by upper-alpha gating.

Hypnotic amnesia is a functional dissociation from awareness during which information from specific neural processes is unavailable to consciousness. We test the proposal that changes in topographic patterns of cortical oscillations in upper-alpha (10-12 Hz) band selectively inhibit the recall of memories during hypnotic amnesia by blocking availability of locally processed information at specific points in retrieval. Participants were prescreened for high or low hypnotic susceptibility. Following hypnotic induction, participants were presented with a series of 60 face stimuli and were required to identify affective expressions. Participants received a suggestion for amnesia for these faces. They were then presented with a set of 30 old and 30 new faces and identified each as old or new. Amnesia suggestion was lifted and recall tested using the remaining 30 old faces and another 30 new faces. Exact Low Resolution Brain Electromagnetic Tomography source analyses are reported for 64 channel event-related electroencephalogram recorded from highs showing reversible amnesia to old faces. For high-susceptible participants, the amnesia suggestion significantly increased old faces wrongly identified while for low-susceptible participants amnesia suggestion increased the new faces wrongly identified. There were no differences between high- and low-susceptible participants following reversal of the suggestion. For previously seen faces which were wrongly identified, compared to new faces correctly identified, (late) evoked upper-alpha is significantly higher in right BA7 in a region implicated in top-down executive control to assist recall of visual information. Lagged nonlinear connectivity between cortical sources in upper-alpha in the same condition showed significantly increased connectivity between right BA34 (parahippocampal gyrus) and right BAs 7, 20 and 22. Integration between these regions is essential for recall of recent faces. During amnesia, spatial and temporal coordination of upper-alpha appears to suppress integrated functioning of these regions (hence recall). These patterns were absent after reversal of amnesia suggestion.

Hypnotic induction is followed by state-like changes in the organization of EEG functional connectivity in the theta and beta frequency bands in high-hypnotically susceptible individuals.

Altered state theories of hypnosis posit that a qualitatively distinct state of mental processing, which emerges in those with high hypnotic susceptibility following a hypnotic induction, enables the generation of anomalous experiences in response to specific hypnotic suggestions. If so then such a state should be observable as a discrete pattern of changes to functional connectivity (shared information) between brain regions following a hypnotic induction in high but not low hypnotically susceptible participants. Twenty-eight channel EEG was recorded from 12 high susceptible (highs) and 11 low susceptible (lows) participants with their eyes closed prior to and following a standard hypnotic induction. The EEG was used to provide a measure of functional connectivity using both coherence (COH) and the imaginary component of coherence (iCOH), which is insensitive to the effects of volume conduction. COH and iCOH were calculated between all electrode pairs for the frequency bands: delta (0.1-3.9 Hz), theta (4-7.9 Hz) alpha (8-12.9 Hz), beta1 (13-19.9 Hz), beta2 (20-29.9 Hz) and gamma (30-45 Hz). The results showed that there was an increase in theta iCOH from the pre-hypnosis to hypnosis condition in highs but not lows with a large proportion of significant links being focused on a central-parietal hub. There was also a decrease in beta1 iCOH from the pre-hypnosis to hypnosis condition with a focus on a fronto-central and an occipital hub that was greater in high compared to low susceptibles. There were no significant differences for COH or for spectral band amplitude in any frequency band. The results are interpreted as indicating that the hypnotic induction elicited a qualitative change in the organization of specific control systems within the brain for high as compared to low susceptible participants. This change in the functional organization of neural networks is a plausible indicator of the much theorized "hypnotic-state."

Neurosurgery and consciousness: historical sketch and future possibilities.

Neurosurgery has played an important role in the development of neuroscience and the science of consciousness. In this paper, the authors reflect on some of the historical contributions of neurosurgeons to the science of consciousness and discuss the ways in which clinical neurosurgery can contribute to the science of consciousness in the 21st century. An approach to the "hard problem" is proposed based on the principles of psychophysics, and the opportunities offered by intracranial recording and stimulation in patients capable of reporting changes in subjective experience are discussed. Such an approach will allow the systematic study and description of the bridging relationships between neurobiology and conscious experience.

Using structural equation modeling to examine McCollough Effects (orientation-contingent color aftereffects): influence of dissociative experiences and age on illusory aftereffects.

Conventional accounts of the McCollough Effect (ME) have focused on strictly bottom-up processing accounts of the phenomenon, most commonly involving the fatiguing of orientation-selective neurons; although association-learning mechanisms have also gained acceptance. These lower order accounts do not take into account higher order variables related to key personality traits and/or associated cognitive control processes. This article reports the use of confirmatory factor analysis and follow-up structural equation style regressions that model MEs and also the part played by the personality trait of dissociation. After considering the relative impact of age and dissociative processes, the article concludes that trait dissociation is positively associated with reports of MEs.

Hypnotizability, eating behaviors, attitudes, and concerns: a literature survey.

The literature suggests that aspects of hypnotizability may be involved in the etiology and maintenance of self-defeating eating. However, interpretation of the published research findings has been complicated by the use of instruments that appear to have measured different or, at best, only related facets of the underlying constructs. This article reports relationships between weight, shape, dietary concerns, hypnotizability, dissociative capacity, and fantasy proneness. Implications for a key role for hypnosis in the treatment of eating behaviors, attitudes, and concerns are discussed.

Changes in mismatch negativity across pre-hypnosis, hypnosis and post-hypnosis conditions distinguish high from low hypnotic susceptibility groups.

The role of alterations in mismatch negativity (MMN) in hypnosis was examined by recording MMN of the auditory ERP at frontal (F3, Fz, and F4) and mastoid (M1 and M2) placements. Frontal MMN is believed to reflect activity in right anterior cortical generators, whereas MMN at mastoid leads reflects generators located bilaterally in the temporal auditory cortex. MMN recordings were obtained in 11 low and 12 high hypnotically susceptible participants in three successive blocks; pre-hypnosis, hypnosis and post-hypnosis. Frontal (but not temporal) MMN showed a significant quadratic trend across testing conditions. It increased during hypnosis and then dropped post-hypnosis for both susceptibility groups. Linear trends for frontal and temporal MMN showed directly opposite patterns of change in the interaction between hypnotic susceptibility and testing blocks. Frontal MMN built up linearly over the test blocks in high relative to low susceptibility participants. Temporal MMN showed the reverse pattern and increased linearly across test conditions in those with low relative to high hypnotic susceptibility.

Psychobiology of altered states of consciousness.

The article reviews the current knowledge regarding altered states of consciousness (ASC) (a) occurring spontaneously, (b) evoked by physical and physiological stimulation, (c) induced by psychological means, and (d) caused by diseases. The emphasis is laid on psychological and neurobiological approaches. The phenomenological analysis of the multiple ASC resulted in 4 dimensions by which they can be characterized: activation, awareness span, self-awareness, and sensory dynamics. The neurophysiological approach revealed that the different states of consciousness are mainly brought about by a compromised brain structure, transient changes in brain dynamics (disconnectivity), and neurochemical and metabolic processes. Besides these severe alterations, environmental stimuli, mental practices, and techniques of self-control can also temporarily alter brain functioning and conscious experience.

An empirical test of Woody and Bowers's dissociated-control theory of hypnosis.

Woody and Bowers's dissociated-control theory predicts impaired performance on tasks indexing frontally mediated supervisory attentional functions during hypnosis, especially for high susceptibles. This prediction is tested using Stroop task behavioral performance to measure aspects of anterior-mediated supervisory attentional function. All measures of anterior-mediated attentional functions significantly declined during hypnosis. Interactions be-tween susceptibility and hypnosis condition showed specific changes among hypnotized high susceptibles. Total Stroop errors (failures of attentional suppression) were significantly higher in hypnosis for high, but not low, susceptibles. Tellegen's experiential mental set was highest for hypnotized highs. Use of rehearsal strategy (instrumental set) decreased significantly in hypnosis but more so for highs than lows. Results suggest that "absorption" in hypnosis may be a consequence of dissociated anterior attentional control. It is proposed that dissociated control emerges from the functional disconnection of left dorsolateral prefrontal cortex and anterior cingulate cortex.

Weak platelet agonists and U46619 induce apoptosis-like events in platelets, in the absence of phosphatidylserine exposure.

Platelets express apoptotic markers during storage, while aging and after stimulation with strong agonists thrombin and collagen. It is unknown if the weak agonists ADP and epinephrine or U46619, a thromboxane analog, induce the expression of apoptotic markers in platelets. To answer this question, we measured phosphatidylserine exposure, gelsolin cleavage and decrease in membrane mitochondrial potential after stimulation with these agonists. No phosphatidylserine exposure was evident, however, gelsolin cleavage and a platelet population with a decreased membrane mitochondrial potential appeared, suggesting that in platelets selective agonists can induce apoptosis in the absence of phosphatidylserine exposure. Interestingly, costimulation by thrombin plus collagen together with each of the other agonists increased the phosphatidylserine exposure induced by strong agonists. These findings may be of importance in platelet activation and apoptosis under pathophysiological conditions where multiple effectors are involved.