Default mode network and the wandering mind.

The respective roles of attentional and default mode networks in our brains has been the subject of numerous MindBlog posts (enter 'default mode' in the search box in the left column). Here is a further installment from Poerio et al.:

Experiences such as mind-wandering illustrate that cognition is not always tethered to events in the here-and-now. Although converging evidence emphasises the default mode network (DMN) in mind-wandering, its precise contribution remains unclear. The DMN comprises cortical regions that are maximally distant from primary sensory and motor cortex, a topological location that may support the stimulus-independence of mind-wandering. The DMN is functionally heterogeneous, comprising regions engaged by memory, social cognition and planning; processes relevant to mind-wandering content. Our study examined the relationships between: (i) individual differences in resting-state DMN connectivity, (ii) performance on memory, social and planning tasks and (iii) variability in spontaneous thought, to investigate whether the DMN is critical to mind-wandering because it supports stimulus-independent cognition, memory retrieval, or both. Individual variation in task performance modulated the functional organization of the DMN: poor external engagement was linked to stronger coupling between medial and dorsal subsystems, while decoupling of the core from the cerebellum predicted reports of detailed memory retrieval. Both patterns predicted off-task future thoughts. Consistent with predictions from component process accounts of mind-wandering, our study suggests a 2-fold involvement of the DMN: (i) it supports experiences that are unrelated to the environment through strong coupling between its sub-systems; (ii) it allows memory representations to form the basis of conscious experience.

The Science of Consciousness

In 1994 I went to the first of what has become an annual gathering, sponsored by the Center for Consciousness Studies of the University of Arizona, of researchers, mystics, and random wackos, all interested in understanding the scientific basis of consciousness. In attending the first few of these conferences I made connections with others in the field, like Daniel Dennett, that motivated me to develop the course notes from a new offering I put together the University of Wisconsin "The Biology of Mind" into a book with the same title. This year's meeting in La Jolla, CA., has the usual mixture of hard science and far-out speculation. Just looking at the titles of the main talks is an interesting read, and I paste in those here:

Plenary Program 

Can Machines Be Conscious?

Sir Roger Penrose, Oxford, 'How can Consciousness Arise within the Laws of Physics?'

Joscha Bach, Harvard, 'Consciousness as a Memory of Coordinating Attention: The Conductor Model of Consciousness'

Hartmut Neven, Google , Quantum AI, 'Possible Roles of Quantum Effects and Subjective Experience in Artificial Intelligence' 

Language and Consciousness

Noam Chomsky, MIT, 'Language and Unconscious Mental Acts' 

Thomas Bever, U Arizona, 'Three Aspects of (Un)conscious Processing in Language and its Normal Use'

Michael J Spivey, UC Merced, 'Language, Consciousness and Embodied Cognition' 

Biophysics 1 - Memory, Spin and Anesthesia

Matthew Fisher, UC Santa Barbara, 'Are We Quantum Computers, or Merely Clever Robots?' 

Travis Craddock, Nova Southeastern U, 'A Unitary Mechanism of Anesthesia?: Altering Collective Oscillations in Microtubules' 

Non-Invasive Brain Stimulation 

Marom Bikson, CCNY/CUNY, 'Non-Invasive Brain Stimulation Devices to Change Thought and Behavior' 

John Allen, Arizona, 'Transcranial Ultrasound, Mood, and Resting State Network Connectivity' 

Marvin Berman, VieLight, 'Integrating Noninvasive Photobiomodulation and Neuromodulation' 

Michael Rohan, Harvard, 'The Effects of Low Field Magnetic Stimulation on Mood and Brain Function' 

Physics, Cosmology and Consciousness

Ivette Fuentes, U Nottingham, 'Gravity in the Quantum Lab' 

Brian Keating, UCSD, 'Conscious Cosmos' 

​James Tagg, Cengine, Penrose Institute, 'Are Human Beings Computers?' 

Music and the Brain

Elaine Chew, Queen Mary University London, 'Mind over Music Perception'

Scott Makeig, UCSD, 'Mind Over Consciousness?'  

Neuroscience and Consciousness 1

Stephen Grossberg, Boston U, 'The Varieties of Brain Resonances and the Conscious Experiences They Support' 

Georg Northoff, U Ottawa, 'Temporo-Spatial Theory of Consciousness' 

Friday, June 9, 2017

Neuroscience and Consciousness 2 - Anomalies

Daniel P. Sheehan, U San Diego, 'It's About Time: Experiments in Consciousness and Retrocausation' 

Peter Fenwick, UC London, 'A Meditation Teacher Who Can 'Transmit' Subjective Light/Energy'​

Lakhmir S. Chawla, George Washington U, 'End-of-Life Brain Activity' 

Biophysics 2 - Memristors in the Brain?

Leon Chua, UCSF, 'Brains are Made of Memristors' 

Jack A. Tuszynski, U Alberta, 'Microtubules as Subcellular Memristors'   

Neuroscience and Consciousness 3

Gentry Patrick, UCSD, 'Destruction as a Means of Remodeling: The Many Roles of Ubiquitin at the Synapse' 

VS Ramachandran, UCSD, 'Embodied Brains and Disembodied Minds' 

Charles F. Stevens, Salk Institute, UCSD, 'The Evolutionary Brain Mechanisms That Underlie Consciousness' 

Saturday, June 10, 2017

Vibrations, Resonance and Consciousness

Anirban Bandyopadhyay, NIMS, Tsukuba, 'Vibrational Frequencies of Biomaterials are the Key to Integration of Information' 

Jiapei Dai, South Central University, China, 'Biophotonic Activities and Transmission in Relation to Consciousness' 

Erik Viirre, UCSD, 'Auditory Vibrations and Frequencies: Sounds in Your Head'   

Eastern Philosophy

Xu Yingjin, Fudan University, China, 'Contemporary Theories of Consciousness and Nishida's notion of 'Basho'' 

Deepak Chopra, Chopra Foundation, 'Mind, Body, and Universe as Human Constructs'  

Origin and Evolution of Life and Consciousness

Bruce Damer, UC Santa Cruz, 'The Origin of Life and Consciousness' 

Alysson R. Muotri, UCSD, 'Cerebral Organoids for Neurodevelopmental and Evolutionary Studie's 

Stuart Hameroff, U Arizona, 'The 'Quantum Pleasure Principle' - Did Life Evolve to Feel Good?'  

A higher-order theory of emotional consciousness

LeDoux and Brown offer an integrated view of emotional and cognitive brain function, in an open source PNAS paper that is a must-read for those interested in first order and higher order theories of consciousness. There is no way I am going to attempt a summary in this blog post, but the simple graphics they provide make it relatively straightforward to step through their arguments. Here are their significance and abstract statements:

Significance

Although emotions, or feelings, are the most significant events in our lives, there has been relatively little contact between theories of emotion and emerging theories of consciousness in cognitive science. In this paper we challenge the conventional view, which argues that emotions are innately programmed in subcortical circuits, and propose instead that emotions are higher-order states instantiated in cortical circuits. What differs in emotional and nonemotional experiences, we argue, is not that one originates subcortically and the other cortically, but instead the kinds of inputs processed by the cortical network. We offer modifications of higher-order theory, a leading theory of consciousness, to allow higher-order theory to account for self-awareness, and then extend this model to account for conscious emotional experiences.

Abstract

Emotional states of consciousness, or what are typically called emotional feelings, are traditionally viewed as being innately programmed in subcortical areas of the brain, and are often treated as different from cognitive states of consciousness, such as those related to the perception of external stimuli. We argue that conscious experiences, regardless of their content, arise from one system in the brain. In this view, what differs in emotional and nonemotional states are the kinds of inputs that are processed by a general cortical network of cognition, a network essential for conscious experiences. Although subcortical circuits are not directly responsible for conscious feelings, they provide nonconscious inputs that coalesce with other kinds of neural signals in the cognitive assembly of conscious emotional experiences. In building the case for this proposal, we defend a modified version of what is known as the higher-order theory of consciousness.

Addendum:

When I passed on the above I was still plowing through the article, the abbreviations and jargon are mind-numbing and a bit of a challenge to my working memory. I thought I would also pass on this comparison of their theory of emotion with other theories,  just before the conclusion to their article, and translate the abbreviations (go to the open source link to pull up references cited in the following clip, which I deleted for this post):

Relation of HOTEC (Higher Order Theory of Emotional Consciousness) to Other Theories of Emotion

A key aspect of our HOTEC is the HOR (Higher Order Representation) of the self; simply put, no self, no emotion. HOROR (Higher Order Representation of a Representation), and especially self-HOROR, make possible a HOT (Higher Order Theory) of emotion in which self-awareness is a key part of the experience. In the case of fear, the awareness that it is you that is in danger is key to the experience of fear. You may also fear that harm will come to others in such a situation but, as argued above, such an experience is only an emotional experience because of your direct or empathic relation to these people.

One advantage of our theory is that the conscious experience of all emotions (basic and secondary), and emotional and nonemotional states of consciousness, are all accounted for by one system (the GNC, General Networks of Cognition). As such, elements of cognitive theories of consciousness by necessity contribute to HOTEC. Included implicitly or explicitly are cognitive processes that are key to other theories of consciousness, such as working memory, attention amplification, and reentrant processing.

Our theory of emotion, which has been in the making since the 1970s, shares some elements with other cognitive theories of emotion, such as those that emphasize processes that give rise to syntactic thoughts, or that appraise, interpret, attribute, and construct emotional experiences. Because these cognitive theories of emotion depend on the rerepresentation of lower-order information, they are higher-order in nature.

Hacking the brain to overcome fear

Schiller does a brief review of work by Koizumi et al., which points to a method for reducing defensive responses without consciously confronting the threatening cues, paving the way for fear-reducing therapies via unconscious processing. The fMRI signals associated with fear conditioned stimuli trained on the first day of the experiment are determined . Then, in the absence of the threatening cues, appearance and growth of the activation pattern representing the conditioned stimulus is paired with a monetary reward in sessions over the next three days. On the fifth day, the defensive response of participants to the threatening cues is significantly reduced, as is amygdala activity. The open source articles give a more complete account. Here is the Koizumi et al. abstract:

Fear conditioning is a fundamentally important and preserved process across species. In humans it is linked to fear-related disorders such as phobias and post-traumatic stress disorder (PTSD). Fear memories can be reduced by counter-conditioning, in which fear conditioned stimuli (CS+s) are repeatedly reinforced with reward or with novel non-threatening stimuli. However, this procedure involves explicit presentations of CS+s, which is itself aversive before fear is successfully reduced. This aversiveness may be a problem when trying to translate such experimental paradigms into clinical settings. It also raises the fundamental question as to whether explicit presentations of feared objects is necessary for fear reduction. Although learning without explicit stimulus presentation has been previously demonstrated, whether fear can be reduced while avoiding explicit exposure to CS+s remains largely unknown. One recently developed approach employs an implicit method to induce learning by reinforcing stimulus-specific neural representations using real-time decoding of multivariate functional magnetic resonance imaging (fMRI) signals in the absence of stimulus presentation; that is, pairing rewards with the occurrences of multi-voxel brain activity patterns matching a specific stimulus (decoded fMRI neurofeedback (DecNef)). It has been shown that participants exhibit perceptual learning for a specific visual stimulus feature through DecNef, without being given any strategy for the induction of specific neural representations, and without awareness of the content of reinforced neural representations. Here we examined whether a similar approach could be applied to counter-conditioning of fear. We show that we can reduce fear towards CS+s by pairing rewards with the activation patterns in visual cortex representing a CS+, while participants remain unaware of the content and purpose of the procedure. This procedure may be an initial step towards novel treatments for fear-related disorders such as phobia and PTSD, via unconscious processing.

Brain changes during hypnosis

Jiang et al. do the most detailed analysis to date of brain changes that are distinctive to people undergoing hypnosis:

Hypnosis has proven clinical utility, yet changes in brain activity underlying the hypnotic state have not yet been fully identified. Previous research suggests that hypnosis is associated with decreased default mode network (DMN) activity and that high hypnotizability is associated with greater functional connectivity between the executive control network (ECN) and the salience network (SN). We used functional magnetic resonance imaging to investigate activity and functional connectivity among these three networks in hypnosis. We selected 57 of 545 healthy subjects with very high or low hypnotizability using two hypnotizability scales. All subjects underwent four conditions in the scanner: rest, memory retrieval, and two different hypnosis experiences guided by standard pre-recorded instructions in counterbalanced order. Seeds for the ECN, SN, and DMN were left and right dorsolateral prefrontal cortex, dorsal anterior cingulate cortex (dACC), and posterior cingulate cortex (PCC), respectively. During hypnosis there was reduced activity in the dACC, increased functional connectivity between the dorsolateral prefrontal cortex (DLPFC;ECN) and the insula in the SN, and reduced connectivity between the ECN (DLPFC) and the DMN (PCC). These changes in neural activity underlie the focused attention, enhanced somatic and emotional control, and lack of self-consciousness that characterizes hypnosis.

The intractability of implicit beliefs

Caoa and Banaji in the Harvard Psychology Dept. introduce their study:

Imagine meeting Jonathan and Elizabeth. One person is a doctor. The other is a nurse. Who is the doctor? Or imagine that an employer is deciding to hire either Colin or Jamaal. A background check will reveal that one person has a violent felony on his record and therefore will not be hired. Who is the violent felon? Before individuating facts are learned, when only gender or race is known, one of two principles can guide beliefs.

The first, which we call the base rate principle, supports the belief that Jonathan is the doctor and Jamaal is the violent felon. If ignoring base rates is considered an error, then one must realize that doctors are more likely to be men than women and people with violent felonies on their record are more likely to be Black than White. In fact, because group membership contains useful information for deciding whether an individual has a certain attribute, stereotypes have been conceptualized as base rates. Moreover, decision theorists have shown that base rates are critical ingredients for making predictions, as neglecting base rates will cause predictions to deviate from what is statistically likely.

Using these base rates, however, is inconsistent with a second principle that we call the fairness principle. By this account, it is morally proper to assume a fair coin, so to speak. Jonathan and Elizabeth are equally likely to be the doctor and Colin and Jamaal are equally likely to have a violent felony on their record. Motivated by egalitarian values, many people believe that base rates cannot and should not be used to make such predictions. In fact, the value of fairness is deeply woven into many legal systems. American courts have rejected the use of base rates to determine guilt, and the European Union has banned gender-based insurance premiums.

In the present work, we assess which principle guides beliefs before individuating facts are learned. Given only information about gender, do beliefs favor Jonathan to be the doctor or both Jonathan and Elizabeth equally to be the doctor? We then assess if the base rate and fairness principles are set aside after individuating facts are learned. Given facts that make abundantly clear who is—and who is not—the doctor, do beliefs align with the facts?

Here is the abstract summarizing their findings:

Meet Jonathan and Elizabeth. One person is a doctor and the other is a nurse. Who is the doctor? When nothing else is known, the base rate principle favors Jonathan to be the doctor and the fairness principle favors both individuals equally. However, when individuating facts reveal who is actually the doctor, base rates and fairness become irrelevant, as the facts make the correct answer clear. In three experiments, explicit and implicit beliefs were measured before and after individuating facts were learned. These facts were either stereotypic (e.g., Jonathan is the doctor, Elizabeth is the nurse) or counterstereotypic (e.g., Elizabeth is the doctor, Jonathan is the nurse). Results showed that before individuating facts were learned, explicit beliefs followed the fairness principle, whereas implicit beliefs followed the base rate principle. After individuating facts were learned, explicit beliefs correctly aligned with stereotypic and counterstereotypic facts. Implicit beliefs, however, were immune to counterstereotypic facts and continued to follow the base rate principle. Having established the robustness and generality of these results, a fourth experiment verified that gender stereotypes played a causal role: when both individuals were male, explicit and implicit beliefs alike correctly converged with individuating facts. Taken together, these experiments demonstrate that explicit beliefs uphold fairness and incorporate obvious and relevant facts, but implicit beliefs uphold base rates and appear relatively impervious to counterstereotypic facts.

Consciousness as the product of carefully balanced chaos.

Tagliafuochi and collaborators have provided more evidence that our experience of consciousness and reality might result from a delicate balance or critical level of connectivity between brain networks in which the brain explores the maximum number of unique pathways to generate meaning. Consciousness slips away if there is too much or too little connectivity. Their abstract:

Loss of cortical integration and changes in the dynamics of electrophysiological brain signals characterize the transition from wakefulness towards unconsciousness. In this study, we arrive at a basic model explaining these observations based on the theory of phase transitions in complex systems. We studied the link between spatial and temporal correlations of large-scale brain activity recorded with functional magnetic resonance imaging during wakefulness, propofol-induced sedation and loss of consciousness and during the subsequent recovery. We observed that during unconsciousness activity in frontothalamic regions exhibited a reduction of long-range temporal correlations and a departure of functional connectivity from anatomical constraints. A model of a system exhibiting a phase transition reproduced our findings, as well as the diminished sensitivity of the cortex to external perturbations during unconsciousness. This framework unifies different observations about brain activity during unconsciousness and predicts that the principles we identified are universal and independent from its causes.

Subliminal learning can nudge future control decisions.

A dichotomy is proposed by most dual-system approaches to cognition (as, for example, in Kahneman's 2011 book "Thinking, fast and slow") in which processes are nonconscious, fast, associative, automatic, rigid, and subjectively effortless, or they are conscious, slow, propositional, controlled, flexible, and effortful. Farooqui and Manly demonstrate a more nuanced reality: unconscious associative learning of subliminal relations. They describe the setup:

In our experiments, participants performed task-switching tests. On each trial, participants saw a colored rectangle that indicated which of two tasks should be performed on the numbers or letter inside it. A couple of seconds before these were presented, one of three subliminal cues appeared: One cue predicted a switch from the prior task, another cue predicted a repetition of the prior task, and a third cue was nonpredictive (and could therefore appear before either type of trial). The cues were not linked to any task set; rather, they predicted the switch/repeat status of the trial, and therefore the participants could use them to make proactive goal-directed changes in the currently active cognitive set.

They found that

Despite participants’ being entirely unaware of subliminal cues in a series of challenging switch tasks, cues predicting switch trials were reliably associated with improved performance. This robust effect was observed across four variants of stimuli and tasks in four independent participant groups.

From their summary abstract:

... This utilization of subliminal information was flexible and adapted to a change in cues predicting task switches and occurred only when switch trials were difficult and effortful. When cues were consciously visible, participants were unable to discern their relevance and could not use them to enhance switch performance. Our results show that unconscious cognition can implicitly use subliminal information in a goal-directed manner for anticipatory control, and they also suggest that subliminal representations may be more conducive to certain forms of associative learning.

The science of mind wandering.

I want to pass on this reference to an Ann. Rev. of Psychology article by Smallwood and Schooler, an extensive review and description of mind wandering, its disengagement from external input, its costs and benefits, its association with medial brain structures of the default mode network, its regulation by more lateral frontal executive control and external attention networks, etc. Here is the abstract, followed by a useful summary graphic:

Conscious experience is fluid; it rarely remains on one topic for an extended period without deviation. Its dynamic nature is illustrated by the experience of mind wandering, in which attention switches from a current task to unrelated thoughts and feelings. Studies exploring the phenomenology of mind wandering highlight the importance of its content and relation to meta-cognition in determining its functional outcomes. Examination of the information-processing demands of the mind-wandering state suggests that it involves perceptual decoupling to escape the constraints of the moment, its content arises from episodic and affective processes, and its regulation relies on executive control. Mind wandering also involves a complex balance of costs and benefits: Its association with various kinds of error underlines its cost, whereas its relationship to creativity and future planning suggest its potential value. Although essential to the stream of consciousness, various strategies may minimize the downsides of mind wandering while maintaining its productive aspects.

Evidence for the default mode network (DMN) as the substrate of the self-generated thought. The DMN is a large-scale brain network defined by the temporal correlation between activity in two core regions on the medial surface of the cortex, known as the posterior cingulate and medial prefrontal cortex. These regions form the core of the DMN (yellow) and interact with subnetworks including the medial temporal lobe subsystem (green) and the dorsal medial subsystem (blue). Meta-analyses using Neurosynth have shown that the core of this system tends to be engaged in self-referential processes, the medial temporal subsystem is engaged by episodic processes, and the dorsal medial subsystem is engaged by social processes. Together, these forms of thought are similar to the content of the self-generated thoughts that often occur during mind wandering, providing important evidence for the involvement of these regions in the mental content that occurs during mind wandering. Studies using experience sampling in conjunction with functional magnetic resonance imaging have shown that these regions show heightened activity during periods of task-unrelated thought (a–c). These brain images show that regions of the core aspects of the DMN exhibited greater activity during periods of task-unrelated thought. Regions: A, dorsal anterior cingulate cortex; B, ventral-medial medial pre-frontal cortex; C, posterior cingulate cortex; D, right temporal-parietal junction; E, dorsal medial prefrontal cortex; F, left rostral-lateral prefrontal cortex.

The signature of consciousness in resting-state brain activity.

I've done a number of posts on attentional or salience versus default mode long-range connectivity networks in our brains (for a review see my lecture.) They correspond roughly to supporting outward task oriented processes versus inward processes such as daydreaming or imagining. Activity in these networks is thought to be a marker of consciousness, but this idea conflicts with observations that long-range functional connectivities persist even after loss of consciousness caused by anesthesia, or in vegetative state patients. This post is to point to recent work by Dehaene and collaborators showing clear difference in the behavior of long-range networks in awake and anesthetized monkeys. Their abstract and statement of significance, followed by a movie showing whole brain connectivity patterns at different time points in the awake monkey.

Significance

What are the origins of resting-state functional connectivity patterns? One dominating view is that they index ongoing cognitive processes. However, this conclusion is in conflict with studies showing that long-range functional connectivity persists after loss of consciousness, possibly reflecting structural connectivity maps. In this work we respond to this question showing that in fact both sources have a clear and separable contribution to resting-state patterns. We show that under anesthesia, the dominating functional configurations have low information capacity and lack negative correlations. Importantly, they are rigid, tied to the anatomical map. Conversely, wakefulness is characterized by the dynamical exploration of a rich, flexible repertoire of functional configurations. These dynamical properties constitute a signature of consciousness.

Abstract

At rest, the brain is traversed by spontaneous functional connectivity patterns. Two hypotheses have been proposed for their origins: they may reflect a continuous stream of ongoing cognitive processes as well as random fluctuations shaped by a fixed anatomical connectivity matrix. Here we show that both sources contribute to the shaping of resting-state networks, yet with distinct contributions during consciousness and anesthesia. We measured dynamical functional connectivity with functional MRI during the resting state in awake and anesthetized monkeys. Under anesthesia, the more frequent functional connectivity patterns inherit the structure of anatomical connectivity, exhibit fewer small-world properties, and lack negative correlations. Conversely, wakefulness is characterized by the sequential exploration of a richer repertoire of functional configurations, often dissimilar to anatomical structure, and comprising positive and negative correlations among brain regions. These results reconcile theories of consciousness with observations of long-range correlation in the anesthetized brain and show that a rich functional dynamics might constitute a signature of consciousness, with potential clinical implications for the detection of awareness in anesthesia and brain-lesioned patients.

Dynamical connectivity matrix - red lines mark positive correlations, and blue lines mark negative correlations.

Subliminal Strengthening

Levy et al. make the interesting observation that presenting subliminal positive age stereotypes to older people has a greater effect than similar explicit interventions:

Negative age stereotypes that older individuals assimilate from their culture predict detrimental outcomes, including worse physical function. We examined, for the first time, whether positive age stereotypes, presented subliminally across multiple sessions in the community, would lead to improved outcomes. Each of 100 older individuals (age = 61–99 years, M = 81) was randomly assigned to an implicit-positive-age-stereotype-intervention group, an explicit-positive-age-stereotype-intervention group, a combined implicit- and explicit-positive-age-stereotype-intervention group, or a control group. Interventions occurred at four 1-week intervals. The implicit intervention strengthened positive age stereotypes, which strengthened positive self-perceptions of aging, which, in turn, improved physical function. The improvement in these outcomes continued for 3 weeks after the last intervention session. Further, negative age stereotypes and negative self-perceptions of aging were weakened. For all outcomes, the implicit intervention’s impact was greater than the explicit intervention’s impact. The physical-function effect of the implicit intervention surpassed a previous study’s 6-month-exercise-intervention’s effect with participants of similar ages. The current study’s findings demonstrate the potential of directing implicit processes toward physical-function enhancement over time.

The study they cite as showing less effect of exercise than subliminal priming used the same standard "Short Physical Performance Battery" to assess changes in physical ability caused by the interventions. This test assesses strength, gait, and balance by examining (a) time to rise from a chair and return to the seated position five times, (b) time to walk 8 feet, and (c) ability to stand with feet together in the side-by-side, semi-tandem, and tandem positions for 10 s. Possible scores range from 0 to 12, with a higher score indicating better physical performance. Older individuals who receive lower scores on this measure have increased risk of disability, nursing-home placement, and mortality.

Information integration without awareness.

I want to point to an excellent review by Christof Koch and colleagues. It contains some useful summary graphics.

•Empirical data suggest that consciousness is not necessary for integration.

•Unconscious integration is nevertheless limited.

•Consciousness enables integrations over extended spatiotemporal windows.

•Consciousness may be needed for novel and high-level semantic integrations.

Information integration and consciousness are closely related, if not interdependent. But, what exactly is the nature of their relation? Which forms of integration require consciousness? Here, we examine the recent experimental literature with respect to perceptual and cognitive integration of spatiotemporal, multisensory, semantic, and novel information. We suggest that, whereas some integrative processes can occur without awareness, their scope is limited to smaller integration windows, to simpler associations, or to ones that were previously acquired consciously. This challenges previous claims that consciousness of some content is necessary for its integration; yet it also suggests that consciousness holds an enabling role in establishing integrative mechanisms that can later operate unconsciously, and in allowing wider-range integration, over bigger semantic, spatiotemporal, and sensory integration windows.

Nonconscious emotions and first impressions - role for conscious awareness

I just came across this interesting article from Davidson and collaborators at Wisconsin:

Emotions can color people’s attitudes toward unrelated objects in the environment. Existing evidence suggests that such emotional coloring is particularly strong when emotion-triggering information escapes conscious awareness. But is emotional reactivity stronger after nonconscious emotional provocation than after conscious emotional provocation, or does conscious processing specifically change the association between emotional reactivity and evaluations of unrelated objects? In this study, we independently indexed emotional reactivity and coloring as a function of emotional-stimulus awareness to disentangle these accounts. Specifically, we recorded skin-conductance responses to spiders and fearful faces, along with subsequent preferences for novel neutral faces during visually aware and unaware states. Fearful faces increased skin-conductance responses comparably in both stimulus-aware and stimulus-unaware conditions. Yet only when visual awareness was precluded did skin-conductance responses to fearful faces predict decreased likability of neutral faces. These findings suggest a regulatory role for conscious awareness in breaking otherwise automatic associations between physiological reactivity and evaluative emotional responses.

Unconscious, not conscious, attitudes predict relationship success.

There has been some recent criticism of 'priming" experiments, in which subliminal presentation, particularly of emotional, stimuli is said to influence the outcome of a decision (see my Nov. 12 post). This is not to be confused with unconscious emotional attitudes, which indeed can be a variance with consciously expressed opinions. McNulty et al. do a nice demonstration of this effect, in showing that 'gut feelings' (implicit attitudes) are a better predictor of success in a marriage than explicit attitudes. They measured explicit and implicit attitudes of newlywed couples toward one another twice a year for 4 years. Over time, the implicit or unaware evaluations of the relationship predicted changes of marital satisfaction, whereas the explicit or conscious evaluations did not.

From their introductory explanation:

The explicit measure was an oft-used semantic differential that asked spouses to report the extent to which they would describe their marriage using 15 pairs of opposing adjectives (e.g., “good” versus “bad,” “satisfied” versus “dissatisfied”). The implicit measure was a version of an associative priming task that required spouses to indicate as quickly as possible the valence of positively and negatively valenced words after being exposed to 300-ms primes of photographs of their partner and various control individuals. An index of spouses’ automatic attitudes was formed by subtracting the time it took them to indicate the valence of the positive words from the time it took them to indicate the valence of the negative words. Both attitude indexes were standardized before analyses. Higher scores on both measures indicate more positive attitudes.

Here is the abstract of the article:

For decades, social psychological theories have posited that the automatic processes captured by implicit measures have implications for social outcomes. Yet few studies have demonstrated any long-term implications of automatic processes, and some scholars have begun to question the relevance and even the validity of these theories. At baseline of our longitudinal study, 135 newlywed couples (270 individuals) completed an explicit measure of their conscious attitudes toward their relationship and an implicit measure of their automatic attitudes toward their partner. They then reported their marital satisfaction every 6 months for the next 4 years. We found no correlation between spouses’ automatic and conscious attitudes, which suggests that spouses were unaware of their automatic attitudes. Further, spouses’ automatic attitudes, not their conscious ones, predicted changes in their marital satisfaction, such that spouses with more positive automatic attitudes were less likely to experience declines in marital satisfaction over time.

The promises of 'priming'

I've done numerous posts noting psychological experiments on the phenomenon of priming, whose practical application is a major component of behavioral economics. Gary Gutting argues that the significance of priming in our real lives, more complex than the controlled parameters of a psychological experiment, may be overblown in claims that priming experiments provide powerful new tools for influencing human behavior. He starts by noting:

The classic priming experiment was one in which college students had been asked to form various sentences from a given set of words. Those in one group were given words that included several associated with older people (like bingo, gray and Florida). Those in a second group were given words with no such associations. After the linguistic exercise, each participant was instructed to leave the building by walking down a hallway. Without letting the participants know what was going on, the experimenters timed their walks down the hall. They found that those in the group given words associated with old people walked significantly slower than those in the other group. The first group had been primed to walk more slowly.

And, after reviewing claims made for the power of priming techniques to alter our behavior, Gutting notes:

...that priming experiments seldom tell us how important priming is in realistic situations. We know that it has striking effects under highly simplified and controlled laboratory conditions, where the subjects are exposed only to the stimuli that the experimenters provide. But it is very difficult to know how significant priming stimuli (thinking about money, large numbers, abstract questions) would be in a real-life, uncontrolled environment, where all sorts of stimuli might be conflicting with one another. Also, there is seldom any reason to think that even a strong priming effect will last very long. As Jonathan Ellis has noted, even Kahneman ignores these points when, after summarizing the walking-like-the-elderly experiment, he says: “Although you surely were not aware of it, reading this paragraph [which contained many words relating to the elderly] primed you as well. If you had needed to stand up to get a glass of water, you would have been slightly slower than usual to rise from your chair . . . ”

These limits are well illustrated by Richard Thaler and Cass Sunstein’s best-selling book, Nudge. The authors begin with excellent discussions of priming and similar experimental results and then put forward numerous public policy proposals, most of them quite sensible, allegedly inspired by these results. But hardly any of their proposals depend on the results of behavioral economics. Their ideas are mostly a matter of common sense or of strategies long practiced in the business world: in giving people options (regarding decisions like retirement plans or organ donations), make the choice you prefer the default option; provide more or less information on a credit card bill depending on whether you want people to pay just the minimum each month; arrange food in a cafeteria or supermarket so the items you want chosen are most accessible. As Benjamin Friedman pointed out in his review of the book, “we don’t need behavioral economics . . . to think such proposals might be helpful.”

Priming experiments remain important sources of information about the details of how our minds work. It’s possible that they might someday yield valuable techniques for modifying real-world behavior. (Here is one promising if very preliminary example.) But for now claims that they have deep philosophical significance or major practical consequences have scant support.

Constructive aspects of mind wandering

I've generally been noting research that documents some negative aspects of mind wandering, for example "A wandering mind is an unhappy mind" and "Better memory with less default mode activity." The other side of the coin, how day dreaming can be constructive, is developed by Kaufman here and here(PDF). He and his coauthors point out that the rewards of mind wandering:

...include self- awareness, creative incubation, improvisation and evaluation, memory consolidation, autobiographical planning, goal driven thought, future planning, retrieval of deeply personal memories, reflective consideration of the meaning of events and experiences, simulating the perspective of another person, evaluating the implications of self and others’ emotional reactions, moral reasoning, and reflective compassion

Kaufman argues for an definition of intelligence moves beyond emphasis on cognitive control, deliberate planning, and decontextualized problem solving, and that includes:

...an individual’s personal goals, and considers both controlled forms of cognition (e.g., working memory, attentional focus, etc.) and spontaneous forms of cognition (e.g., intuition, affect, insight, implicit learning, latent inhibition, and the spontaneous triggering of episodic memories and declarative knowledge) are important potential contributors to that personal adaptation.

Information sharing as a measure of brain consciousness

King et al. make measurements they suggest are a signature of conscious state in awake but noncommunicating patients. I pass on the summary, abstract, and one of their figures (and, the first graphic, thanks to Jean-Rémi King, who offers the unedited PDF of the article here):

Highlights
 • Theories of consciousness link conscious access to global information integration
 • 181 EEG recordings were acquired, including 143 from VS and MCS patients
 • Information sharing across current sources was estimated with a new measure
 • The results suggest that unconscious patients have lower global information sharing

Summary

Neuronal theories of conscious access tentatively relate conscious perception to the integration and global broadcasting of information across distant cortical and thalamic areas. Experiments contrasting visible and invisible stimuli support this view and suggest that global neuronal communication may be detectable using scalp electroencephalography (EEG). However, whether global information sharing across brain areas also provides a specific signature of conscious state in awake but noncommunicating patients remains an active topic of research. We designed a novel measure termed “weighted symbolic mutual information” (wSMI) and applied it to 181 high-density EEG recordings of awake patients recovering from coma and diagnosed in various states of consciousness. The results demonstrate that this measure of information sharing systematically increases with consciousness state, particularly across distant sites. This effect sharply distinguishes patients in vegetative state (VS), minimally conscious state (MCS), and conscious state (CS) and is observed regardless of etiology and delay since insult. The present findings support distributed theories of conscious processing and open up the possibility of an automatic detection of conscious states, which may be particularly important for the diagnosis of awake but noncommunicating patients.

Figure - wSMI Increases with Consciousness, Primarily over Centroposterior Regions(A) The median wSMI that each EEG channel shares with all other channels is depicted for each state of consciousness.(B) 120 pairs formed by 16 clusters of EEG channels are depicted as 3D arcs whose height is proportional to the Euclidian distance separating the two clusters. Line color and thickness are proportional to the mean wSMI shared by the corresponding cluster pair.

Language can boost unseen objects into visual awareness.

From Lupyan et al:

Linguistic labels (e.g., “chair”) seem to activate visual properties of the objects to which they refer. Here we investigated whether language-based activation of visual representations can affect the ability to simply detect the presence of an object. We used continuous flash suppression to suppress visual awareness of familiar objects while they were continuously presented to one eye. Participants made simple detection decisions, indicating whether they saw any image. Hearing a verbal label before the simple detection task changed performance relative to an uninformative cue baseline. Valid labels improved performance relative to no-label baseline trials. Invalid labels decreased performance. Labels affected both sensitivity (d′) and response times. In addition, we found that the effectiveness of labels varied predictably as a function of the match between the shape of the stimulus and the shape denoted by the label. Together, the findings suggest that facilitated detection of invisible objects due to language occurs at a perceptual rather than semantic locus. We hypothesize that when information associated with verbal labels matches stimulus-driven activity, language can provide a boost to perception, propelling an otherwise invisible image into awareness.

A Methods note:

Continuous flash suppression was implemented using anaglyph images: participants wore red/cyan glasses and viewed stereograms containing a high-contrast red mask (∼9° × 9°) and—on object-present trials—a superimposed lower-contrast cyan object (Fig. 1A). Only the object was visible to the right eye and only the mask to the left. The dynamic mask comprised curved line segments, with frames randomly alternating at 10 Hz. Because similarity in spatial properties between stimuli and masks is important for effective suppression of stimuli (72), line segments were used to better mask the curvilinear character of the objects.

(A) Stimulus creation using continuous flash suppression. (B) Basic procedure of experiments 1 and 2.

Unconscious activation of our brains' inhibitory controls.

Hepler and Albarracin have done the interesting experiment of exposing participants in an experiment to subliminally presented inaction (calm) and action (move) words, and then ascertaining that participants were unaware of these primers. They subsequently presented the participants with a Go/No-Go task (press a button if you see an "X", don't press it if you see a "Y") and also measured the P3 component of the event-related brain potential known to index inhibitory control. The subliminally presented inaction (calm) and action (move) words increased inhibitory neural activity whereas the latter set decreased it, relative to a control set of neutral words. Here is the author's summary:

-Event-related potentials were recorded during two go/no-go task with subliminal primes

-Subliminal primes related to general concepts of action, inaction, or were controls.

-Inaction/action primes strengthened/weakened inhibitory control mechanisms (ICMs).

-The primes had never been consciously associated with task responses or goals.

-This is the first demonstration that ICMs can operate completely unconsciously.

Although robust evidence indicates that action initiation can occur unconsciously and unintentionally, the literature on action inhibition suggests that inhibition requires both conscious thought and intentionality. In prior research demonstrating automatic inhibition in response to unconsciously processed stimuli, the unconscious stimuli had previously been consciously associated with an inhibitory response within the context of the experiment, and participants had consciously formed a goal to activate inhibition processes when presented with the stimuli (because task instructions required participants to engage in inhibition when the stimuli occurred). Therefore, prior work suggests that some amount of conscious thought and intentionality are required for inhibitory control. In the present research, we recorded event-related potentials during two go/no-go experiments in which participants were subliminally primed with general action/inaction concepts that had never been consciously associated with task-specific responses. We provide the first demonstration that inhibitory control processes can be modulated completely unconsciously and unintentionally.

Unconscious reading and arithmetic.

Here is a fascinating bit from Sklar et al.:

The modal view in the cognitive and neural sciences holds that consciousness is necessary for abstract, symbolic, and rule-following computations. Hence, semantic processing of multiple-word expressions, and performing of abstract mathematical computations, are widely believed to require consciousness. We report a series of experiments in which we show that multiple-word verbal expressions can be processed outside conscious awareness and that multistep, effortful arithmetic equations can be solved unconsciously. All experiments used Continuous Flash Suppression to render stimuli invisible for relatively long durations (up to 2,000 ms). Where appropriate, unawareness was verified using both objective and subjective measures. The results show that novel word combinations, in the form of expressions that contain semantic violations, become conscious before expressions that do not contain semantic violations, that the more negative a verbal expression is, the more quickly it becomes conscious, and that subliminal arithmetic equations prime their results. These findings call for a significant update of our view of conscious and unconscious processes.

(note:  Continuous Flash Suppression consists of a presentation of a target stimulus to one eye and a simultaneous presentation of rapidly changing masks to the other eye. The rapidly changing masks dominate awareness until the target breaks into consciousness. This suppression may last seconds. To examine arithmetic, another symbolic, rule-following system, the authors moved from a breaking-into-consciousness design to a priming design. They examined the effects of subliminal stimuli on conscious stimuli that follow them, using both subjective and objective measures to verify the subliminality of the primes.)