An important new meta-analysis of brain imaging research came out this week in JAMA Psychiatry, “Identification of a Common Neurobiological Substrate for Mental Illness” which highlights the importance of the insula and anterior cingultate in healthy brain function.
Neuroscientist News provides an effective overview of the results that came out of Amit Etkin’s lab at Stanford. I’ll then add in two caveats about the characterization of the deficits and the assumed biological causation that are needed in interpreting these results. Or, to be blunt, that social causes related to how we deal with mental illness in our modern societies have as much potential to explain these common biological differences, since it’s one of the main things that these patients share in common.
But first the overview.
We tried to ask a basic question that hasn’t been asked: Is there any common biological basis for mental illness?
To address that question, he and his colleagues pooled data from 193 separate studies containing, in all, magnetic-resonance images of the brains of 7,381 patients falling into six diagnostic categories: schizophrenia, bipolar disorder, major depression, addiction, obsessive-compulsive disorder and a cluster of related anxiety disorders.
Comparing the images with those from 8,511 healthy control subjects, the research team identified three separate brain structures, several centimeters apart from one another, with a diminished volume of gray matter, the brain tissue that serves to process information.
These structures — the left and right anterior insula and the dorsal anterior cingulate — are known to be parts of a larger network in the brain whose component parts tend to fire in synchrony. This network is associated with higher-level executive functions such as concentrating in the face of distractions, multitasking or task-switching, planning and decision-making, and inhibition of counterproductive impulses.
Gray matter loss in the three brain structures was similar across patients with different psychiatric conditions, the researchers found.
The abstract to the JAMA Psychiatry paper makes this same point:
Based on the voxel-based morphometry meta-analysis of 193 studies comprising 15 892 individuals across 6 diverse diagnostic groups (schizophrenia, bipolar disorder, depression, addiction, obsessive-compulsive disorder, and anxiety), we found that gray matter loss converged across diagnoses in 3 regions: the dorsal anterior cingulate, right insula, and left insula.
By contrast, there were few diagnosis-specific effects, distinguishing only schizophrenia and depression from other diagnoses. In the parallel follow-up analyses of the 3 independent healthy participant data sets, we found that the common gray matter loss regions formed a tightly interconnected network during tasks and at resting and that lower gray matter in this network was associated with poor executive functioning.
So what is executive function in the eyes of Etkin? What is going on with these parts of the brain?
These structures can be viewed as the alarm bell of the brain, Etkin said. “They work together, signaling to other brain regions when reality deviates from expectations — that something important and unpredicted has happened, or something important has failed to happen.” That signaling guides future behavior in directions more likely to obtain desired results…
Among healthy people, gray-matter volume in the right and left anterior insula and the dorsal anterior cingulate correlated with performance on classic tests of executive function. Such a test might involve, for example, asking the test-taker to note the color of the word “blue,” displayed in a color other than blue, after seeing it briefly flashed on a screen.
Executive function always sounds to me, well, so executive. Like it’s a little capitalist dude there in your brain, telling you how to maximize profits and climb the corporate ladder. In other words, it’s a culturally-infused view of brain areas that we still don’t understand well. We know these areas are linked to social and emotional regulation, sense of self, coordination of behavior and integration of information, and the ability to make judgment calls.
I want to focus in on one line quoted earlier: “These structures — the left and right anterior insula and the dorsal anterior cingulate — are known to be parts of a larger network in the brain whose component parts tend to fire in synchrony.” Mental illness disrupts high-level synchrony between the brain and the world. This is the very stuff of social life. Social regulation and coordinated interaction with the world is key to how humans are humans.
Neuroscientist News points to a potential biological cause for the identified biological problem, highlighting a 2013 genetic study whose punchline is Common Genetic Factors Found in 5 Mental Disorders. You need to read a bit further into that research (like just to the bottom of the news article) to get to statements such as “causal factors haven’t yet been pinpointed” and “each of these genetic associations individually can account for only a small amount of risk for mental illness.”
For those of you interested in a more in-depth consideration of how genetics relates to mental illness, I recommend Kendler’s 2013 paper What psychiatric genetics has taught us about the nature of psychiatric illness and what is left to learn. As Kendler says elsewhere, “The impact of individual genes on risk for psychiatric illness is small, often nonspecific, and embedded in complex causal pathways. The phrase “a gene for” and the preformationist concept of gene action that underlies it are inappropriate for psychiatric disorders.”
But there is a specific and robust cause that can have a direct impact on brain function, particularly in the areas that Etkin and his colleagues have identified: How society deals with mental illness.
An alternative view is that societal reactions drive these patterns in the brain; that the lives of mental health patients become disorganized because of what happens through treatment (or lack thereof), the loss of social roles, and the inability to mesh with a capitalist and regulatory society. In other words, these common losses in brain grey matter can happen because of common societal causes.
The case for schizophrenia is clear. Caribbean people who move to the UK suffer much higher rates of schizophrenia than expected. And cross-culturally there are dramatically different ways of dealing with schizophrenia, such that symptoms can be less adverse in places like Chennai, India. But this biosocial view is not the type of approach being promoted by the Research Domain Criteria from the National Institutes of Mental Health, which views mental illness as biological.
One issue is that we don’t have good assessments that could link the type of problems in brain function identified by Etkin with the sorts of social causes that we know make a tremendous impact on people’s lives and their ability to effectively handle social regulation and coordinated interaction with a wider social world. By developing this approach, which could look more closely at how brain function interacts with daily function within the context of people’s lives, we might get closer to understanding what might be causing common patterns in mental illness and what we might do about as a society.
Very interesting blog – don’t even know where to begin! I’m so excited that I’ve found this site and can finally some of my ideas with others (and also, to learn from others).
Michael Tomasello brilliantly argues that human cognition is NOT ABOUT discovering some ‘objective truth’ in the world, that is, the human mind is not about seeing things “as they objectively are”. Far more soberly, he rightly emphasizes that human “reason” is about JUSTIFYING OUR REASON for acting as we do, or did, or why we should pursue a certain course of action. By positioning human cognition in this way, Tomasello reconciles human thought with human feeling (even if his analysis is a bit too cognitive for my liking) which, from the perspective of evolution, has EVERYTHING to do with enhancing survivability.
If human thought is used, or deposed, for the purpose of justifying ourselves, why is this? The only realistic reason for this behavior is to ‘gain recognition’ in the eyes of our interlocutor, so that ‘shared intentionality’ can be achieved. Tomasellos analysis is 3rd person, and as such, doesn’t offer much in the way of what we can do to counter these effects. On the other hand, the first person approach of modern relational and interpersonal psychotherapeutic theory offers a lot of useful insights; the 1st person phenomenology that we experience when we find ourselves girded to defend something we think or an assertion we’ve made that ‘needs to be defended’ needs to be handled in a way similar to the way therapists approach their experience with patients. Or is this ‘asking too much’?
Why do people who suffer trauma feel and think as they do? For instance, why does a person who experiences chronic long term bullying seem to feel the PRESENCE of the bully’s voice, or way of being, in his present mental functioning? From the perspective of Tomasellos theory, the answer is simple: the sense of self and identity is BUILT from social processes, so that any state we find ourselves in, whether one of fantasy or initiative to act, is BORNE from the motivational systems activated during social interactions. Put differently, the intentional states of past interlocutors “exist within us” as motivational drives; for the traumatized, the experience of shame or the way they orient to the world has everything to do with the way the perpetrator related with them; the perpetrators voice, feeling, and intention (the way they were seen) echoes from within, as it were, as a presence that ‘oversees’ and guides their functioning. In less pathological contexts, the way we think, feel, and the manner in which we assert ourselves often implies the presence of others (what we casually call ‘culture’ or ‘society) whom we’ve been earlier influenced by.
So, how should we understand the human self? Here’s my theory. Over evolution, human beings have evolved minds/self’s that are constructed on top of, and out of, life-preserving processes that have nothing to do with kindness, shame, or love. The idea of homeostasis ‘taking precedence’ to the viability of our ‘sense of self’ has been amply demonstrated by contemporary traumatology, in particular. It’s not unusual that we haven’t noticed the reality of a ‘self’ that is contingently reliant on the viability of a body; after all, no one knew we had something called an ‘immune system’ until scientists interested in mysterious illnesses discovered such a mechanism in the body which ‘protected’ the integrity of individuals cells.
When interpersonal experience, particularly shame, but also anxiety and depression, persists for too long, lower brain stem nuclei (in the PAG) interrupt social awareness by flooding the brain with endogenous opiates; by doing so, it depresses blood flow to higher cortical regions – the area where the psychological conflict is being created – and preferentially activates the dorsal branch of the vagus nerve complex which keeps heart rate slow and breathing shallow.
This is the beginning of post-traumatic stress symptomology: when the body automatically circumvents conscious attachment to external objects by ‘dulling’ consciousness, the person is left, unbeknownst to itself, in a state very different from the one it has hitherto operated from. The complication is not so much the trauma of a severe emotional response, but the fact that the body NEEDED to intervene; psychopathology TENDS to result when dissociation kicks in, because the mind, left to itself, has been unable to regulate bodily arousal via consciousness.
Nevertheless, what traumatology shows is that the body TAKES OVER the activities of the mind when the activities of the mind cross a certain threshold. After that, the mind tends to oscillate between hyperarousal and hypoarousal, over-activation of the HPA axis, increased vigilance (via noradrenergic and dopamine pathways) to external and internal stimuli, and back again to a hypoaroused state when the body again ‘turns off’ frontal lobe areas (particularly the dorsolateral PFC) and leaves the mind ‘foggy’, but metabolically speaking, this is a useful situation in terms of the survivability of the organism. Stress is costly. Down-regulating metabolic processes in the brain responsible for ‘connection’ and ‘meaning’ helps the body concentrate its energies on the heath of the various life-sustaining processes.
This evidence indicates something even more important: the brain stem is ALWAYS ‘evaluating’ the world, or the way the world affects us, by BIASING, via feelings (think Damasio’s somatic marker hypothesis) how we should understand the world we experience. Neurologically, it probably starts with the amygdala ‘picking up’ what we ourselves have felt (via self-monitoring processes in the brain, probably centralized in the temporal lobe and cingulate areas) in the past, and through the amygdala (and it’s meaningful appraisal of ‘objects’) activates bodily events that become ‘interpreted’ in our moment of acting as demanding ‘this course of action’. This is what Damasio means, I think, when he stresses the input of the body: the body ‘limits’, ‘constrains’ and ultimately DISSOCIATES from awareness ways of being, thinking, or speaking, that are likely to elicit undesirable reactions from others (and thus, affects in ourselves). This is basically object-relations. This is the implication of Tomasellos shared intentionality hypothesis, one that is totally consistent with modern relational psychoanalytical theory: human beings are ALWAYS relating their behavior to some imagined, social/culture ‘referent’; this does not require knowing, it is just there, present in all our meaning-making with the world. This works to ‘enhance survivability’ by enhancing cooperation between individuals.
What this ultimately reveals is two things: our sense of self is an illusion, but more important, our sense of self is an emergent property of social processes. On a deeper level, feelings like joy, coherence, awe – none of this would be possible were it not for the I-Thou dialectic of shared experiences. Though perhaps, I should better describe our behavior, particularly in a capitalistic, competitive, and slightly chauvinistic culture, as being predominantly I-it, because these two ways of relating, from an ethical perspective, implies to two very different ways of self-regulation, and in particular, biases how we interpret our behavior in social situations.
I-It and I-thou (to borrow Bubers terms) is necessary if we want to understand why we act the way we do – thus, I can see no way of ‘making a better world’ without adopting, and eventually CONVENTIONALIZING, a theoretical understanding of human functioning in social situations.
So why did my sister and I fight? I came into the conversation experiencing an affective need that biased my attention to expect a certain response from my sister. Because of our close relationship, I derive a certain support and succor from our conversations. When I went up to her, explaining why I didn’t go to a cousins house (it was raining) she replied “I don’t see any rain”, with a tad bit of wryness and affective distance in her voice, I felt dismissed. The mismatch between our states, what was happening in her mind (preparing for work), her eating her meal, didn’t enter my mind. Had I ‘taken in’ this contextualizing information, I would’ve been more attentive to the dissociative process – my own state of my mind, itself re-enforced by my personal history and biological patterns – and so prevented what happened next. I rose my voice and asked her “why are you replying like that”, “like what” she responds; like me, she’s ‘hyper-focused’ by her present emotional state, preparations for the day, and no doubt, anticipation to show off her new haircut at work, to treat the “perturbation” of my probing inquiry as ‘ridiculous’. Like-minds see situations similarly. If i were in a similar state, I would’ve appreciated her remark that I was putting ‘too much’ in to what she said, and yet, there really was something dismissive, contrary, and instigatory in her response. Not being able to let, let alone to communicate to her what I was feeling, the conversation devolved into an argument about “her not being attentive” to the way she was functioning (this being something we’re both interested in) and her accusing me of being overly demanding in communication (which, to an extent, is understandable).
What arguments like this teach me is how our minds become deposed by our body, in particular, how the excitement we feel when we experience the pleasure of assertion, propels us to ‘follow’ through, to complete “our reason” for acting. What this is also teaches me is how emotion – in particular, the EXCITATION of emotion, serves not rational, objective purposes (as we believe when we’re acting), but rather, the PERSONAL NEEDS of one party seeking to ‘convince’ another party of THEIR REASON FOR ACTING.
The inevitable conclusion from this line of thinking is that one cannot speak rationally if emotions grow too great, because one cannot recursively ‘check in’ on one’s present state of feeling (and the way this feeling dissociates thought). As emotion grows, it swallows up more and more mental space, forcing cognition to ‘follow the path’ of ‘defending the self’, and steering it away from the dual awareness needed to keep track of what is happening between oneself and the other in the moments of communication. To borrow a term from the psychoanalyst Philip Bromberg, a healthy mind needs to ‘stand in the spaces’, to simultaneously attend to one’s own core needs and at the same time, be attuned to the affective cues expressed in the other. The ‘complexity’ in communication, as the science of interpersonal neurobiology has paid much attention to, is the way the other party’s communicative displays AFFECT right brain embodied process; thinkers such as Schore, Siegel, Ogden, as well as Bromberg, locate intelligent awareness of “how am I being affected” to the process of paying attention to the way your body feels in the process of interaction. A fundamental principle of all this is, I hope, should be apparent: we are not in control of how we respond; furthermore, our bodies are biased by evolutionary history (specific motivational needs and the aversions ignited when they aren’t met) to be activated and aroused by control parameters – signals – that drive our organism forward, to increase complexity.
The implications of the dissociation theory of mental functioning are huge: we need not just mindfulness (a hub of awareness) but an understanding that our minds – or self – is constantly being undermined by non-conscious implicit relational knowing (not to mention the other stuff studied by cognitive psychology, such as in the work of Daniel Kahneman) at all times. What needs to be cultivated is a SKEPTICISM of our motivations; a willingness and an interest to explore the reasons for our acting a certain way – what sort of emotions are being avoided, for example, by acting this way? I believe we need to emphasize systems processes in our educational system, such as having a class on ‘systems’ or ‘self-organization’, such as the continuity in contingency between the big bang, galaxies, solar systems, planets, eco-systems, life forms, and yes, social processes and intrapsychic functioning, so that people will come to consider their behavior by instinct with reference to the influence of the past as well as context on their present feelings. Mindfulness by itself is insufficient. The social-basis of the self and its need to be understood require left-brain understanding. The human self, and human happiness, DEPENDS on HOW WE understand ourselves, as well as how we are willing to be with others. Unless the ecology of human experience is conventionalized, mindfulness will be experienced as ‘optional’, as opposed to a responsibility that comes with being embedded in a system that provokes non-conscious processes that in turn organize consciousness.
I find this very interesting because there are so many mental illnesses within the world and people wonder why they are the way they are. There are so many chemicals within the brain that can affect someones health but i feel that no chemical within a human can be perfect amount to keep it “normal”. I also do not agree with how the current world treats others with mental illnesses they are often isolated and put down by the rest of society for something that is beyond their control. Even in the past we had inhuman treatments that were considered okay, such as electroshock treatment that was previous used back within the early 1900’s. What is to say 50 years from now our current methods of treatment for mentally ill wont be considered inhumane also?