Posts tagged creativity

Autism and white Matter/Myelination: the opposite of creativty/psychosis phenotype?

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A new paper by Ben Bashat et al extends their earlier findings that had found that there was accelerated maturation of white matter in children with Autism. In this new paper they use Tract Based Spatial statistics (TBSS) to determine the white matter integrity of children (age around 3 years) with Autism as compared to normal controls. Of course they used Diffusion tensor Imaging to find out Fractional anisotropy and other measures of white matter integrity.

Essentially they found that in some regions/tracts there was greater Fractional Anisotropy (FA) as compared to controls. These regions/tracts were genu and body of the corpus callosum (CC), left superior longitudinal fasciculus (SLF) and right and left cingulum (Cg). They also found that in areas of high FA there was corresponding decrease in Radial diffusivity (Dr). What this essentially means, to my naive mind, is that greater conductance or speed of action potential in axons would primarily be due to enhanced myelination which reduces leakage or lateral flow of AP.

I’ll like to contrast the results with an earlier study I had blogged about regarding creativity, psychopathology and white matter mylienation connection. As per that study an inverse relation was found between people high on creativity (divergent type) and Fractional anisotropy in frontal regions, i’e there was low FA. Also importantly there was increased Dr (radial diffusivity) in the same regions and thus the conclusion was that there was reduced myelination in those areas which meant reduced signal transmission speed and more signal leak . It is notable that that study too used DTI and Tract based Spatial statistics (TBSS) analysis method to arrive at their conclusions.

Regular readers of this blog will know my fanaticism for Autism and Psychosis as opposites on a continuum theory. This new paper nicely fits in with my last post linking creativity/psychosis and white matter/myelination, I had as much surmised that Autism would show the opposite effect and have high FA and decreased Dr. It is heartening to note when such a relation is found and reported- goes to show the strength and ability to make predictions of the theory.

However, I would also like to point out and highlight that I believe Autistic spectrum is characterized by another type of ability – the savantic intelligence– that may be directly due to this white matter /excess myelination effect. Perhaps the signals travel so fast that decisions are made locally without the time available to get other far-0off regions involved- thus giving attention to details but inability to link disparate regions and ideas.

Weinstein, M., Ben-Sira, L., Levy, Y., Zachor, D., Itzhak, E., Artzi, M., Tarrasch, R., Eksteine, P., Hendler, T., & Bashat, D. (2010). Abnormal white matter integrity in young children with autism Human Brain Mapping DOI: 10.1002/hbm.21042
Ben Bashat, D., Kronfeld-Duenias, V., Zachor, D., Ekstein, P., Hendler, T., Tarrasch, R., Even, A., Levy, Y., & Ben Sira, L. (2007). Accelerated maturation of white matter in young children with autism: A high b value DWI study NeuroImage, 37 (1), 40-47 DOI: 10.1016/j.neuroimage.2007.04.060
Jung, R., Grazioplene, R., Caprihan, A., Chavez, R., & Haier, R. (2010). White Matter Integrity, Creativity, and Psychopathology: Disentangling Constructs with Diffusion Tensor Imaging PLoS ONE, 5 (3) DOI: 10.1371/journal.pone.0009818

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More brains and bonkers connection: thinking out of a broken box

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We have covered many studies linking creativity with Psychosis and this new study by Manzano et al provides further corroborating evidence.

Dopamine has been linked with psychosis and is now also being increasingly being linked with creativity, especially divergent creativity and thinking style.

Divergent thinking is influenced by dopaminergic function. Reuter [6] found a correlation between divergent thinking (the Inventiveness battery of the Berliner Intelligenz Struktur Test) and polymorphisms of the dopamine D2 receptor gene–DRD2 TAQ IA. Higher creativity scores were observed in carriers of the A1 allele. This polymorphism is unrelated to general intelligence [7], [8], which suggests that it is more specifically related to Glr (“long-term storage and retrieval”). This finding is in line with functional imaging research showing the D2 system to be involved in attentional set shifting and response flexibility, which are important components of divergent thinking [9]. Furthermore, the finding indicates that divergent thinking is related to regional differences in D2 densities, since the DRD2 TAQ IA polymorphism has been shown to modulate D2 binding potential (D2BP) in both striatal [10] and extrastriatal regions [11].

Divergent thinking is traditionally measured using alternate uses test, for eg., in which a familiar object like brick is provided and subjects asked to name novel use for that object. The responses are marked for creativity as per the follwoing criterion:

  • Fluency–the number of valid responses;
  • Originality–how frequent the participant’s responses were among the responses of the rest of the sample;
  • Flexibility–the number of semantic categories produced;
  • Switching–the number of shifts between semantic categories;
  • and Elaboration–how extensive each response is (if the task involves producing more than single words)

The main findings of the study was that dopamine D2 binding potential (D2BP) receptor density in thalamus correlated negatively with divergent thinking and creativity scores. Here is how the authors interpret the results:

Based on the current findings, we suggest that a lower D2BP in the thalamus may be one factor that facilitates performance on divergent thinking tasks. The thalamus contains the highest levels of dopamine D2 receptors out of all extrastriatal brain regions [33], [45]. Decreased D2BP in the thalamus has been suggested, firstly, to lower thalamic gating thresholds, resulting in decreased filtering and autoregulation of information flow [31] and, secondly, to increase excitation of cortical regions through decreased inhibition of prefrontal pyramidal neurons [46], [47], [48]. The decreased prefrontal signal-to-noise ratio may place networks of cortical neurons in a more labile state, allowing them to more easily switch between representations and process multiple stimuli across a wider association range [49]. This state, which we hereforth will refer to as the “creative bias”, could benefit performance on tasks that involve continuous generation and (re-)combination of mental representations and switching between mind-sets. The creative bias could also explain why the different measures of divergent task performance correlate: A decreased signal-to-noise ratio in thalamus would decrease information gating and possibly increase fluency; decreased signal-to-noise ratio in cortical regions should better enable flexibility and switching between representations; similarly, the associative range should be widened and selectivity should be decreased which might spur originality and elaboration.

Besides carrying benefits related to fluency and switching, the decreased signal-to-noise ratio associated with the creative bias should be disadvantageous in relation to tasks that require high levels of selective attention. Some support for this prediction can be taken from Dorfman [50] who showed that the greater a person’s divergent thinking scores, the slower his or her reaction times were on a negative priming task requiring the inhibition of interfering information. Furthermore, the creative bias may also bring a risk of excessive excitatory signals from the thalamus overwhelming cortical neurotransmission, with ensuing cognitive disorganization and positive symptoms [30]. It is thus tempting to suggest that dopaminergic modulation of neurotransmission mediated through dopamine D2-receptors could be one of the mechanisms which associate creativity with positive psychotic symptoms. Interestingly, positive symptoms are not necessarily related to problems in executive function, at least not to the same extent as negative symptoms [51], which indicates that in the creative individual “blind variation” might be affected without a concomitant decline in “selective retention”. It can be speculated that aberrant thalamic function may promote unusual associations, as well as improved performance on divergent thinking tests in healthy individuals, in the absence of the detrimental effects typically associated with psychiatric disorders. In other words, thinking outside the box might be facilitated by having a somewhat less intact box.

In plain English speak, the same decreased signal-to-noise ratio in perfrontal regions that gives rise to creativity also gives rise to proneness to psychosis. The more the noise that is introduced the greater the chances that the ideas generated by ‘blind variation’ are more creative; if the ‘selective retention’ procedure is also defective or loosened to an extent, it may result in psychopathology and psychosis, while if intact it leads to creativity. Thus while one factor , that of loosening of associations, flexibility and set switching is common to both psychosis and creativity, the defects in selective retention may be the crucial factor that distinguishes brains from bonkers.

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de Manzano, ?., Cervenka, S., Karabanov, A., Farde, L., & Ullén, F. (2010). Thinking Outside a Less Intact Box: Thalamic Dopamine D2 Receptor Densities Are Negatively Related to Psychometric Creativity in Healthy Individuals PLoS ONE, 5 (5) DOI: 10.1371/journal.pone.0010670

The Creativity-dopamine (b)linkage: more brains and bonkers connections

rh?zom?ng Cam?ra?Obscura pl?ats . .
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Creativity is certainly different from intelligence; it is usually gauged as the ability to make novel and useful unique contributions to a field. Creativity itself is not a unified construct but can be broken into convergent creativity (involving more focused approach) and divergent creativity (involving more widening and loosening of associations).

It has been evident for quite some time that there is a connection between insanity (especially bipolar/schizophrenia spectrum) and creativity , especially as evidenced by the creative bent of schizotypal people. See for example this article covering a recent study that looks at exactly the same issue. However, most of these studies rely on a unitary construct of creativity that does not do full justice to the correlations that could be found if convergent and divergent creativity was distinguished and effect of intelligence was factored out. The new study by Hommel, B. does just that.

Schizophrenia/psychosis as many will know from their elementary neuroscience knowledge is associated with dopamine dysfunction; specifically it is believed that high baseline dopamine levels are there in schizophrenics/psychotics. So it was not unreasonable for Hommel et al to hypothesize that dopamine should have some relation with creativity possible higher dopamine associated with high creativity. However, dopamine has shown an inverse U relation for many other factors and thus they were cautious and tried to fit both linear and quadratic graphs to their data. But we are moving ahead of ourselves. Before they could find the underlying relation between dopamine and creativity, they had to measure these things accurately.

They measured dopamine using Eye Blink Rate (EBR): that is how many time you blink in a minute. For creativity , they measured Convergent Creativity using a remote association task (don’t go by the name …the task has only one answer and measures convergent thinking) . for eg. a subject is given three words (say time, hair, stretch) and have to come up with a word that is commonly related to all three (answer: long) . this reliably measures creativity but of he convergent type. For Divergent thinking , they administered the Alternate Uses task (AUT),a task that requires one tocome up with novel uses of everyday objects like brick, toothpaste etc. The responses to AUT were further coded for fluency (how easily one could come up with alternatives measured by total no. of responses) , flexibility(the number of different categories used or how remote the mind wandered) and elaboration (the level of detail surrounding the use). They also measured fluid intelligence using Raven’s progressive matrices.

They then conducted experiments (administered the tests to subjects) , collected data and analyzed the results. The main findings of interest to us is that they found a inverse u shaped relation between dopamine (EBR) and flexibility dimension fo divergent thinking. This effect was present even when the effect of intelligence was factored out. thus both low dopamine, as well as too much dopamine is detrimental to flexible divergent thinking/creativity and schizotypals , placed precariously between normals and psychotics are best placed to be the most creative as they presumably have the optimum dopamine levels. the authors also argue that schizophrenics dopamine levels should not be brought down indiscreetly by using anti-psychotics (which reduce dopamine levels) but they should be brought in the optimum range of dopamine functioning. this obviously has immense importance and treatment implications. No wonder creative people feel stiffed when on anti-psychotics- their dopamine levels are being brought down way too much.

The other interesting finding was that dopamine (EBR) was negatively ad linearly related to convergent thinking. Thus, it is evident that convergent creativity and divergent creativity are different constructs and while dopamine has a complex quadratic relationship with divergent thinking, that with convergent thinking is linear though not very comforting. It seems that as dopamine levels increase the ability to narrow focus diminishes and this would be concordant with other studies linking dopamine to ADHD for example.

Overall, a view of how brains and bonkers are two sides of the same coin is emerging and it is exciting to note that many previous inconsistencies in literature around this issue may have to do with not differentiating and decomposing creativity into its many components and not looking for inverse u shaped effects.

Chermahini SA, & Hommel B (2010). The (b)link between creativity and dopamine: Spontaneous eye blink rates predict and dissociate divergent and convergent thinking. Cognition PMID: 20334856

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Creativity-psychosis linkage via reduced white matter /myelination
I have been following, and am passionate about, the positive psychology movement for quite some time, but was surprised to discover that there was something called positive neuroscience also in place. I recently came across this new scientist article about the research paper of Rex Jung et al and was pleased to discover that Jung was working on the frontier of applying latest in neuroscience research to Positive brain states and substrates like that involved in creativity.

The article is in PLOSOne, an open access journal and is lucidly written , so you should go and read it now. I’ll anyway like to summarize their study results. First a bit of background about creativity psychopathology linkage.

Some research reports positive correlations between various definitions of creativity and a diagnosis of psychopathology [1], [2], [3], [4]. Other studies report that psychopathology is rarely, if ever, associated with creative insight, capacity, or productivity [5]. When artists are studied more carefully, certain personality characteristics appear to reside upon a continuum of both normal behavior and psychopathology. For example, creative expression in the visual arts and poetry has been linked with the overlapping personality traits of schizotypy and Openness to Experience (Openness), and particularly to self-reports of “unusual experiences” and “unconventional nonconformity”, but not the “introvertive anhedonia” characteristic of schizophrenia [6].

This is inline with what we have been covering at mouse trap regarding association of creativity with the psychotic spectrum especially the creativity that is artistic or revolutionary in nature rather than scientific and methodical in nature. This is how the authors distinguish between types of creativity inline with my views that one type of creativity is autistic (cognitive) in nature while the other is psychotic (emotional) and these are on a continuum.

First, there does not exist one “creativity”; rather, this construct is hypothesized to reside upon a continuum between cognitive (i.e., scientific) and emotional (i.e., artistic) behavioral domains [41], [42]. Thus, when comparing scientists and artists directly, researchers have found lower lifetime rates of psychopathology for: 1) scientists compared to artists, 2) natural scientists compared to social scientists, 3) nonfiction writers compared to fiction writers and poets, and 4) formal artists compared to “expressive” artists [3], [4], [43]. These findings have led researchers to hypothesize a hierarchical structure of creativity across disciplines [42], which echoes the notions of “paradigmatic” (i.e., a fundamental model of events) versus “revolutionary” (i.e., rejection of doctrines) approaches as applied to the sciences [44]. The benefits of working within the lines of a given field appear to be lower levels of psychopathology; alternately, individuals with lower levels of psychopathology may be attracted to such endeavors. Similarly, there is increasing evidence that the cost of “revolutionary” approaches to creative endeavors, whether it is in the arts or sciences, may be associated with increased levels of psychopathology although, again, causative links are weak at best.

So that fits in with broader creativity/ psychopathology linkage, but to get back to the current study the authors had already established earlier that performance on Divergent Thinking (DT) (a measure of creativity) “exhibited significant inverse relationships with both cortical thickness in frontal lobe regions and metabolite concentration of N-acetyl-aspartate (NAA) in the anterior cingulate cortex in normal young subjects “. Thus, some theoretical relationship between creativity and underlying brain circuitry in the frontal reagion was available a priori. Also, research by other researchers has already established that ” Both schizophrenic and bipolar patients have been shown to have reduced fractional anisotropy (FA) in the anterior thalamic radiation [12], [13] and uncinate fasciculus [14] within frontal brain regions. Similarly, reduced FA was observed within the uncinate fasciculus of a cohort with schizotypal personality disorder, providing strong support for the hypothesis that similar neural phenotypes may not result in full-blown clinical symptoms [15]. Finally, in normal subjects, the Neuroregulin-1 (NRG1) single nucleotide polymorphisms (SNP’s) SNP8NRG243177 and SNP8NRG221533 were found to predict lower FA in the left anterior thalamic radiation [16]. As NRG1 has been found to predict higher risk of schizophrenia [17], [18] and bipolar disorder [19], and is linked with axonal myelination and migration [20], these authors hypothesize a mechanistic link between NRG1 within the anterior thalamic radiation and risk for psychotic disorders [16].”

Thus, from the above it is easy to see that there should be a inverse relationship between Fractional Anisotropy (a construct related to myelination of axons) in the frontal regions and creativity if one assumes that creativity and psychopathology are related and are on one end of a continuum. And this inverse relationship between creativity and FA is exactly what they found:

Our results suggest a convergence between a cognitive measure of divergent thinking, a personality measure of Openness, and a white matter integrity measure within the inferior frontal lobes. We found that normal young subjects with lower levels of FA within predominantly left inferior frontal white matter (i.e., regions overlapping the uncinate fasciculus and anterior thalamic radiation) scored higher on the CCI; similarly subjects with lower levels of FA within the right frontal white matter (i.e., regions overlapping the uncinate fasciculus and anterior thalamic radiation) scored higher on self-reported measures of Openness. These two regions of white matter overlap with those reported by other researchers who found lower FA in both schizophrenia and bipolar disorder [13], [14], [30].

They could also nail the reduced FA to reduced myelination as radial diffusion was affected more than axial diffusion. As reduced myelination has been shown as a diatheisis for psychosis, this fits in with previous research linking risk factors common to psychosis and creativity.

Whereas more neural resources are often associated with higher intellectual capacity in a parieto-frontal network of brain regions [39], studies in DT appear to suggest that less is often better in a different network of brain regions, particularly fronto-cingulate-subcortical networks linked via white matter loops [40].

One can speculate that frontal region, more concerned with executive control , when with reduced activity or functional connectivity , may not inhibit the other brain regions that much, and may thus lead to flowering of inherent creativity and cross-talk amongst different brain regions. On the other hand too much white matter/ gray matter in this region may lead to too much control and leave little room for flexibility and creativity.

However, while lower FA is commonly seen in diseases where both cognition and white matter integrity are impaired (e.g., Traumatic Brain Injury, Schizophrenia, Alzheimer’s disease) [45], [46], [47], evidence is accumulating that higher FA in particular brain regions may also be associated with clinical disorders including post-traumatic stress disorder [48], obsessive-compulsive disorder [49], panic disorder [50], synaesthesia [51], and Williams syndrome [52].

It is interesting to note that enhanced FA is associated with clinical disorder of Williams syndrome, which is associated with Autism; on the other end of continuum, reduced FA in particular brain region is associated with psychosis proneness, thus providing another convergent linkage of autism and psychosis as opposites.

Jung, R., Grazioplene, R., Caprihan, A., Chavez, R., & Haier, R. (2010). White Matter Integrity, Creativity, and Psychopathology: Disentangling Constructs with Diffusion Tensor Imaging PLoS ONE, 5 (3) DOI: 10.1371/journal.pone.0009818

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