Neuroethics Aside, In Search of the Spotless Mind

 

No, fly me, fly me, far as pole from pole;
Rise Alps between us! and whole oceans roll!
Ah, come not, write not, think not once of me,
Nor share one pang of all I felt for thee.
Thy oaths I quit, thy memory resign;
Forget, renounce me, hate whate'er was mine.
Fair eyes, and tempting looks (which yet I view!)
Long lov'd, ador'd ideas, all adieu!

Alexander Pope’s 1717 poem Eloisa to Abelard describes Eloisa’s wish to escape the suffering of separation from her lover Abelard through the ablation of her memories, a theme more recently featured in the film Eternal Sunshine of the Spotless Mind, the title of which is taken from Pope’s poem:

How happy is the blameless vestal's lot!
The world forgetting, by the world forgot.
Eternal sunshine of the spotless mind!
Each pray'r accepted, and each wish resign'd

While for Eloisa, however, the attainment of a spotless mind remained unrealised, our increasing understanding of the neural substrates of memory and pharmacological developments mean memory suppression is becoming a tangible reality. While therapeutic benefits for this are easily imaginable, the treatment of post-traumatic stress disorder (PTSD) comes quickly to mind, ethical quandaries over this do not follow far behind. These are explored in a recent comment piece in Nature by Adam Kolber. Central to criticism of the notion of pharmacological altering memories are that this could alter an individual’s very sense of themselves. We are all, of course, the sum of all our experiences, both the good and those which we are less keen to recall. Kolber goes on to conclude these arguments don’t stand up, and that the potential for such great therapeutic benefits outweigh the concerns.

While the concept is fascinating and the ethical implications certain to be argued over for a long time to come, it is worth placing all these things in the context of our current understanding of how memory could be augmented in this way. Great insights into this are provided by a review article by Stephen Maren appearing in the journal Neuron.

The review focuses on fear memories and the contemporary shift in research  from the historically prevalent concentration on their elicitation to new work looking at their suppression and expurgation. From this research a number of candidate drugs and techniques have been shown to have the potential to alter fear memories:

• Exposure therapy has been shown to be successful in reducing the fear associated with traumatic memories by eliciting trauma related memories in a non-threatening environment, breaking the contingency between the memory and the fearful response. Pertinent to the ethical debate around memory suppression is the fact that this techniques does not seek to ablate the episodic memory, but to reduce the harmful responses elicited by it.

• The drug propranolol  has also been shown to help people suffering from PTSD. Combining the recativation of traumatic memories with the administration of the propranolol led to dampened fear related physiological responses a week later.

•  Another  potential intervention aiming to erase rather than simply suppress the memory utilises the fact that following an event, the memory for it is not immediately and objectively stamped into our minds, but undergoes a period of consolidation, rendering the memory vulnerable.  It is known that this consolidatory process can be disrupted through the administration of protein synthesis inhibitors such as anisomycin and puromycin soon after learning in animal models. In addition it has also been shown that these effects can been seen not just during initial consolidation but also after subsequent retrieval.

Great progress in our understanding of how memories can be suppressed have already led to therapeutic improvements. The exiting prospect of using what has been learned form protein synthesis inhibition in people soon after experiencing a traumatic incident to protect against future related mental illness is also a tantalising prospect. The day may not be too far away where the liberation afforded by Eloisa's spotless mind may no longer be a dream, but a reality with real potential to make a positive contribution to psychiatric care.



Maren S (2011). Seeking a spotless mind: extinction, deconsolidation, and erasure of fear memory. Neuron, 70 (5), 830-45 PMID: 21658578

Dealing With Angry Customers? Misanthropy Might Help

The affective state of a person can have a profound influence on a multitude of cognitive processes. In memory, for example, there are high levels of mood congruence, that is, the induction of a positive affective state will lead to the recollection of more happy memories. The converse of this is also the case, with people suffering from depression more likely to show a bias for negative memories, congruent with their affective state. A recent study published in the journal Motivation and Emotion has shown that the affective state of employees has an important bearing on how they cope with abusive customers.

Dealing with customers can be tough. The character Dante in Kevin Smith’s film Clerks (pictured above) faces many, somewhat surreal, challenges in negotiating a hopelessly elongated shift in a convenience store, despite the fact he's not even supposed to be there. Charlie Brooker, in a recent column for the Guardian also described an encounter he had with a particularly vile customer while working in a shop:

'I vividly recall one guy who sloped in wearing a loose pair of tracksuit trousers, absentmindedly playing with his own bollocks as he entered. He stood at the counter, scanning the display behind me and obliviously juggling his goolies – at one point literally reaching inside to re-arrange his collection – and then wiped his nose with the back of his hand, sucked the slime off it, pointed at an item he was interested in and said: "Show me that." Moments later he started an argument about how much it cost, demanded a discount, and, when I refused, called me an arsehole and knocked a load of boxes off a shelf by the door as he left.'

How well service sector employees cope with these kinds of challenges, it has been found, has a lot to do with affective state. Using a large sample of call centre workers, a group who report they field calls from aggressive customers on a daily basis, showed that, as would be expected, customer aggression lead to increased job tension, reduced job satisfaction and leaving more workers wanting to quit. Importantly, though, this was found to be the case more so for workers high in positive affect.

This finding might seem the inverse of what might be intuitively expected, that workers with a positive disposition are better able to brush of negative interactions with customers, but in reality, the opposite seems to be true. It is suggested this may be because the lack of reciprocity in the interaction between the positive employee and the aggressive customer is judged as highly unfair, leading them to attach more significance and negativity to the encounter. If this is the case, it may just be that a misanthropic disposition is the way to go when dealing with difficult customers.

Goussinsky, R. (2011). Does customer aggression more strongly affect happy employees? The moderating role of positive affectivity and extraversion. Motivation and Emotion : 10.1007/s11031-011-9215-z

This does that...

While this beautifully balanced satirical news piece claiming gay scientists have identified a Christian gene is delightfully humorous, it also taps a recurring theme in neuroscience, that there are easily attributable causal links between a bit of brain or DNA and behaviour. This is well exemplified by the modulation of memory where the idea of a ‘memory store’ which translates into an actual brain region where memories are banked is simply fanciful. The reality is that there are several functional loops involving dopaminergic midbrain areas for rewarding memories or the amygdala for emotional ones which along with the hippocampus and other regions dictate the encoding and consolidation of memories through processes yet to be fully elucidated. This is the reality across neuroscience, and any claim 'there’s a brain area for that' is a gross oversimplification. 

Autobiographical Memory Deficits in Depression Mirrored in Literature

‘Our civilisation is in a middle stage, scarcely beast, in that it is no longer guided by instinct, scarcely human in that it is not yet wholly guided by reason.’

This is the quotation Joseph LeDoux chose to cite at the beginning of his book The Emotional Brain. It comes from the novel Sister Carrie by Theodore Dreiser, and while the quotation well illustrates the sometimes enigmatic role emotion has in shaping our behaviour and thoughts, the novel itself and the literary movement of naturalism to which it belongs provides a metaphor for a more specific example of the influence emotion can have.

Naturalism is a movement within literature pioneered by Dreiser as well as other writers such as John Steinbeck and Upton Sinclair at the beginning of the twentieth century. Central to naturalism are characters not defined ethically, such as with Scrooge’s Christmas moral epiphany in Charles Dickens’ A Christmas Carol, but by their perseverance in navigating through an unremittingly grim industrial world. In Dreiser’s novel, the main character Carrie sacrifices her integrity to at first survive and then elevate herself socially against a backdrop of the harsh economic realities of industrialised Chicago. The relentless drudgery portrayed in naturalist writing provides a sharp contrast to the specific points of morality integral to characterisation elsewhere, and this can be seen to mirror the expression of autobiographical memory in people with and without depression.

Autobiographical memory is a form of episodic memory specifically for events in a person’s life. These are normally very specific and crisply defined, for example I remember when I got my first car, it was my 17^th birthday, and I was so excited... This is in contrast to the more opaque and over-generalised autobiographical memories that are commonly reported by people suffering from depression, for example I used to drive to work every day. This focus on category and repeated events in people with depression mirrors neatly with the themes of continuous and unrelenting endeavour within the depressing situations presented in naturalist novels.

While these patterns in autobiographical memory have been shown to be symptomatic of depression, recently published research by Willem Kuyken and Tim Dalgleish adds to evidence indicating over-generalisation in autobiographical memory may provide a risk factor for the development of depression in young people. The paper reports two studies which show well established risk factors for depression correlate with the generation of categorical autobiographical memories in response to negative cues in young people between the ages of 14 and 18.

In their first study, the authors report that higher scores on the personality dimension of neuroticism, a known risk factor for depression, correlated with over-generalised autobiographical memories. This, however, was largely mediated by depressive symptomology assessed using the Beck Depression Inventory. The second study provided more concrete evidence for a direct link between risk factors for depression and over-generalised autobiographical memories. They used two samples of previously depressed young people and never depressed young people, utilising the fact that depression has high levels of recurrence, meaning that having previously suffered from depression provides a significant risk factor for depression. Using structured interviews rather than written questionnaires as in the first study, it transpired that the young people who were previously depressed where more likely to report categorical autobiographical memories in response to negative cues.

Taken together, these findings suggest young people at risk of depression display autobiographical memory deficits in response to negative, but not positive cues. This is important as it suggests one intuitive explanation for this pattern of memory effects associated with depression, as it may be blocking recall of specific memories serves to protect against the elicitation of damaging negative associations.

Whilst this poses many questions for the future, not least how effective teaching strategies for cognitive control and emotional regulation might be as clinical interventions, it seems clear that over-generalisation is a key component of depression, something reflected in literature.

Kuyken W, & Dalgleish T (2011). Overgeneral autobiographical memory in adolescents at risk for depression. Memory, 1-10 PMID: 21400355

To begin...

Hello and welcome to my new blog on all things memory, and hopefully some other interesting things too. Inspired by the many fantastic science blogs I've read for years, I have finally decided to give it a go myself. I aim to use this blog mainly to write about new research relevant to my own work which looks and how emotion and reward can modulate memory. Since I am new to this, comments/advise/searing criticism would be greatly appreciated.