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Posts Tagged ‘cognitive neuropsychology’

Brain Disease and Creativity

31/05/2012 2 comments

Readers of this blog probably know I’m very interested in creativity. Recently, I came across a very interesting  review paper on artistry in brain disease by Schott.  Even though, many studies focus on the loss of various abilities as result of brain injury or disease, this review is focused on cases where brain disease resulted in enhanced artistic creativity in people with an interest in art or emergence of artistic creativity in art naive patients. Pictures created spontaneously by patient with brain disease sometimes present an excellent opportunity for studying that disease and revealing underlying mechanisms of cerebral dysfunction. It can also provide some useful information about creative processes in the healthy brain.

Dementia and stroke are very common. However, cases of patients who exhibit enhanced artistic output in these and other neurological disorders are rare or very rare. Miller et al. (2000) showed that enhanced artistry is probably more common but it is often under-reported, since new or preserved visual or musical ability was found in 17% of 69 patients with frontotemporal dementia.
In fact, frontotemporal dementia seems to be the brain disease more closely associated with increased creativity. Miller et al. (1996) were the first to report a patient with frontotemporal dementia that had developed new artistic creativity in the face of advancing dementia. A number of papers (Tanabe et al., 1996; Snowden et al., 1996), as well as Miller at al.’s seminal letter in the Lancet published in the same year brought more attention to the subject of preserved or increased artistic creativity in the presence of brain disease. Miller et al. (1996) described a 68-year-old male with a 12-year history of frontotemporal dementia,who, at the age of 56 years, started to paint having had no previous interest in art.

Patients with Alzheimer’s disease have also been reported to exhibit enhance artistic creativity. Professional painter, Danae Chambers, whose dementia started at around the age of 49 years (Fornazzari, 2005) is a striking example. Even though she was diagnosed with Alzheimer’s disease and her MRI scan revealed mild to moderate brain atrophy, there was no effect on her talent and creativity. However, it should be noted that typically during the progression of the disease stylistic changes leading to frank deterioration and eventual cessation of painting have been reported, especially in professional artists (see Crutch and Rossor, 2006).

In the case of autism there have been several cases of even very young autistics who could produce impressive works of art. A famous example is Stephen Wiltshire, who was able to draw astonishingly faithful architectural representations at the age of 7 years (Sacks, 1995).

According to Schott unexpected artistic creativity experienced by many patients has many features that suggest compulsive behaviour. Moreover, emergence of artistry after brain disease reflects innate rather than learned skills.

The brain correlates of emergent artistic creativity are rather obscure. It appears that dysfunction of the anterior temporal lobes is important if not crucial for the production of unexpectedly enhanced artistry, but the findings are often inconsistent. In some cases frontal lobe involvement is present too (Seeley et al., 2008).  Thus creative drive is thought to increase not only with abnormalities of temporal lobe function and ‘release’ of frontal lobe-mediated creativity, but also by involvement of the dopaminergic mesolimbic system (Flaherty, 2005)

One might wonder; is this emergence of artistic talent observed in patients with various brain diseases really creativity?

De Souza et al. (2010) then concluded: ‘The emergence of artistic talent in patients with fvFTLD is explained by the release of involuntary behaviors, rather than by the development of creative thinking’, and also recommended avoiding consideration of ‘pseudo-creative production, or the emergence of “artistic talent”, as a mastered mental production’.

The author, however, disagrees and concludes:

…the notion of pseudo-creation and identification of ‘artistic talent’ create more difficulties than enlightenment; rather, they emphatically confirm the importance of patients’ pictures. The evidence for creativity surely lies in the creation itself rather than in perfusion patterns or psychological tests.

ResearchBlogging.orgSchott, G. (2012). Pictures as a neurological tool: lessons from enhanced and emergent artistry in brain disease Brain, 135 (6), 1947-1963 DOI: 10.1093/brain/awr314

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Distractibility is Reflected in the Structure and Function of the Parietal Cortex

08/05/2011 6 comments

Sustaining attention and blocking goal-irrelevant information is a crucial function in everyday life. Kanai and colleagues combining neuroimaging, self-report judgements and TMS found evidence that indicates that a region of the left superior parietal cortex mediates this function.

The ability to avoid distractibility varies across individuals as measured by the Cognitive Failures Questionnaire (CFQ) (Broadbent et al., 1982). Studies on twins and families have showed that the ability to maintain attention in the presence of distractors is highly heritable (Boomsma, 1998). High degree of heritability suggests that the variability might be mediated by genetic influences on the brain, which may be expressed via variability in brain structure.

This hypothesis was tested by Kanai et al. by scanning 145 healthy adult individuals and obtaining their CFQ scores. They used voxel-based morphometry (VBM) to examine whether distractibility scores predicted brain structure. Their results revealed that the level of an individual’s distractibility in everyday life was predicted by variability in regional grey matter density of the left superior parietal lobe (SPL). Highly distractable individuals had larger grey matter density at the left SPL. This particular region has been implicated in top-down attentional control in previous studies (Mevorach et al., 2009). To examine whether there is a causal relationship between this region and distractibility, Kanai et al. applied transcranial magnetic stimulation (TMS) over the left SPL of the participants while they were performing an attentional capture paradigm. The results of the experiment suggest that the left SPL plays a role in suppressing distraction from task-irrelevant salient distractors in both visual fields.

ResearchBlogging.orgKanai R, Dong MY, Bahrami B, & Rees G (2011). Distractibility in daily life is reflected in the structure and function of human parietal cortex. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31 (18), 6620-6 PMID: 21543590

Boomsma, D. I. (1998). Genetic analysis of cognitive failures (CFQ): a study of dutch adolescent twins and their parents. Eur. J. Pers., 12(5):321-330.

Broadbent, D. E., Cooper, P. F., FitzGerald, P., and Parkes, K. R. (1982). The cognitive failures questionnaire (CFQ) and its correlates. The British journal of clinical psychology / the British Psychological Society, 21 (Pt 1):1-16.

Mevorach, C., Shalev, L., Allen, H. A., and Humphreys, G. W. (2009). The left intraparietal sulcus modulates the selection of low salient stimuli. Journal of cognitive neuroscience, 21(2):303-315.

Walking With Music: Useful Tool for Gait Training in Parkinson’s Disease

20/11/2010 9 comments

Scientists from Canada showed that listening to music during gait training could help patients with Parkinson’s Disease.

Gait disturbances is one of the main characteristics of Parkinson’s Disease (PD). It has been associated with increased risk of falling, diminished mobility, and reduced quality of life. In addition to that, patients with PD have difficulties when it comes to dual tasking; walking and performing a secondary task like talking. This is known as dual task interference and is thought to be associated with the incidents of falling amongst people with PD.

One rehabilitation strategy of PD that seems to be effective includes the use of rhythmic auditory during gait training sessions. de Bruin and colleagues attempted to investigate whether a similar effect would be observed if the cue was a musical piece or “walking song”. They did this by implementing a 13-week home based music and walking program on 11 volunteers with PD. The music used were commercially available songs, unaltered, familiar and enjoyable to individual patients. The tempo of the selected song was matched to each patient’s walking cadence. The control group attended a gait training programme that wasn’t acco

The group of PD patients that underwent a 13 week music programme showed improved gait performance compared to the control group. In particular, marginal improvements were reported in gait velocity, cadence, and stride time. The same patterns of improvements were observed in the dual task condition. Moreover, listening to music during training did not lead to increased falls. This suggests that this practice is safe.

The mechanism that led to these improvements is not fully understood. One possible explanation proposed that music may have enhanced gait performance through increasing the patients’ affective arousal. This is possible as the arousal potential of the music was intentionally high in this study; the pieces were selected based on familiarity and enjoyment. Another explanation suggests that training and listening to music could be seen as a dual tasking condition. Listening to music can be seen as a cognitive demanding task and practising two tasks at the same time (walking and listening to music) allows the improvement of task-coordination skills.

The results of this study indicate that the use of cadence-matched, salient music to accompany walking is a feasible and enjoyable intervention for use amongst patients with mild to moderate PD.

ResearchBlogging.orgde Bruin N, Doan JB, Turnbull G, Suchowersky O, Bonfield S, Hu B, & Brown LA (2010). Walking with music is a safe and viable tool for gait training in Parkinson’s disease: the effect of a 13-week feasibility study on single and dual task walking. Parkinson’s disease, 2010 PMID: 20976086

Tetris as a “cognitive vaccine” against traumatic flashbacks?

11/11/2010 3 comments

Everyone is familiar with Tetris. This simple, but addictive game has been studied quite a few times by researchers (see older post). A group from the University of Oxford investigated whether Tetris could be used as a “cognitive vaccine” against flashback development after trauma exposure. Flashbacks are one of the most persistent symptoms of Post Traumatic Stress Disorder (PTSD).

In a previous study the same group had shown that playing Tetris after viewing traumatic material reduced flashbacks compared to no-task on healthy volunteers.

In their new study they investigated whether other games could have this effect via distraction/enjoyment by conducting two experiments. More specifically, Holmes and colleagues compared the effectiveness of Tetris with Pub Quiz, a general knowledge, verbal computer game. In both experiments, the participants viewed film footage that contained scenes of death and injury. Then a group played Tetris, another Pub Quiz and a third one (control condition) was not give any task. In the first experiment the participants played Tetris or Pub Quiz 30 minutes after being exposed to the traumatic film. In the second there was a gap of 4 hours between the time the videos were presented and the time the tasks were performed.

In both experiments playing Tetris led to a significant reduction in flashbacks compared to no-task control. Pub Quiz in first experiment had the opposite effect and led to an increase of traumatic flashbacks. No such effect was observed when the task was performed 4 hours post-film.

According to the authors this is the first study to provide evidence:

that different computer games have differential effects on the development of flashbacks post-trauma… This was the case despite the games being rated as equally as enjoyable and as of similar difficulty.

The different effects of these games suggest that further research is needed before using computer games as psychological interventions in healthcare, as not all computer games are beneficial – some may even be harmful.

Holmes and colleagues explain this differential pattern of findings via their model of trauma memory formation from cognitive science. According to this theory:

1) Human memory differentiates visual and verbal components
2) Pathological trauma flashbacks consist of sensory, visual images
3) Cognitive science shows that visuospatial cognitive tasks compete for resources with visual images
4) The biology of memory consolidation suggests a 6 hour time frame post-trauma within which memories are malleable
5) Thus, visuospatial cognitive tasks given within 6 hours post-trauma will interfere with visual flashback memory consolidation, and reduce later flashbacks, as demonstrated in our previous study
6) In contrast, verbal tasks post-trauma will not reduce flashbacks as verbal tasks compete with verbal, conceptual processing of the event but not the visual images that make up flashbacks
7) Further, verbal tasks post-trauma will compete with the type of verbal-conceptual processing necessary to make sense of what has happened and from clinical models may serve to increase (rather then reduce) later trauma flashbacks

These findings are quite promising and could lead to a possible development of a computerized “cognitive vaccine” against the development of flashbacks for trauma in the future.

ResearchBlogging.orgHolmes, E., James, E., Kilford, E., & Deeprose, C. (2010). Key Steps in Developing a Cognitive Vaccine against Traumatic Flashbacks: Visuospatial Tetris versus Verbal Pub Quiz PLoS ONE, 5 (11) DOI: 10.1371/journal.pone.0013706

Future Imagining And Episodic Memory

27/08/2010 2 comments

Neuroimaging and lesion studies suggest that imagining the future (i.e. envision future personal experiences) is strongly connected with retrospective memory (i.e. remembering past experiences). Two recent papers published on Neuropsychologia investigated the relationship of retrospective memory and future imagining, as well as their common neural correlates.

Kwan, Carson, Addis, and Rosenbaum (2010) report the case of H.C., a young woman with developmental amnesia associated with bilateral hippocampal loss. Episodic memory seems to depend on hippocampal function (Yancey & Phelps, 2001; Maguire, 2001). Compared to matched controls H.C. was found to be impaired both in tasks requiring past and future event generation. Her performance was similarly deficient in both tasks. According to Kwan and colleagues:

These results indicate that mental time travel can be compromised in hippocampal amnesia, whether acquired in early or later life, possibly as a result of a deficit in reassembling and binding together details of stored information from earlier episodes

Maguire, Vargha-Khadem, and Hassabis (2010) report the cases of two patients (P01 and Jon) with dense amnesia and 50% volume loss in both hippocampi. P01 suffered from adult-acquired amnesia, but unlike previously reported cases was found to be unimpaired at future imagining tasks. The authors suggested that P01 could have been an atypical case, and in order to investigate this they identified another patient with similar neuropsychological profile, Jon. In spite of his dense amnesia, Jon was able to imagine future experiences in a comparable manner to control participants. According to one of the possible explanations proposed by Maguire and colleagues:

Activity in their residual hippocampal tissue supports the ability to imagine new scenarios, and that this is the key feature. Residual hippocampal tissue was active in both patients and in similar circumstances to control participants. Whilst we cannot definitely relate function to these hippocampal activations, we suggest the activations might indicate some preserved hippocampal function which is also sufficient to support their preserved ability to imagine scenarios

ResearchBlogging.orgKwan, D., Carson, N., Addis, D., & Rosenbaum, R. (2010). Deficits in past remembering extend to future imagining in a case of developmental amnesia Neuropsychologia, 48 (11), 3179-3186 DOI: 10.1016/j.neuropsychologia.2010.06.011

Maguire, E., Vargha-Khadem, F., & Hassabis, D. (2010). Imagining fictitious and future experiences: Evidence from developmental amnesia Neuropsychologia, 48 (11), 3187-3192 DOI: 10.1016/j.neuropsychologia.2010.06.037

Behavioural Effects of Early Focal Damage to Prefrontal Cortex

18/04/2010 2 comments

ResearchBlogging.orgAnderson et al. (2007) report a case of a 14 month boy (PF1) who sustained damage to his right inferior dorsolateral prefrontal cortex due to resection of a vascular malformation on day 3 of life. After a successful surgery he exhibit normal behaviour and reached developmental milestones at a normal rate. Also, his performance on various clinical tests was normal, as well as his social and communication skills as rated by his mother. Compared to a sample of healthy controls PF1 was impaired significantly in the regulation of emotion and engagement of attention, specifically in unstructured conditions.
In particular, Anderson et al. (2007) report that:

PF1 showed
markedly high positive affectivity and low restraint
relative to his peers. This was particularly evident
in his intense and positive affective expressions
during free-flowing interactions, his unrestrained
approach of desirable but prohibited stimuli, and to
a lesser extent in his mildly atypical levels of anger
and resistance when physically restrained. Faced
with problem-solving tasks, when most of his peers
displayed affectively neutral expressions and
focused on finding the solutions, PF1 initially
responded with strong and under-regulated positive
emotion that interfered with attentional engagement
on the task at hand.

According to the writers the results of the study provide useful information about the impact that early damage in the prefrontal cortex may have on emotional and cognitive behaviour. I’m looking forward to their future reports on this particular case as the boy grows up.

Anderson SW, Aksan N, Kochanska G, Damasio H, Wisnowski J, & Afifi A (2007). The earliest behavioral expression of focal damage to human prefrontal cortex. Cortex; a journal devoted to the study of the nervous system and behavior, 43 (6), 806-16 PMID: 17710831

Daydreaming as a Disorder?

02/03/2010 6 comments

A few days ago I came across a paper by Schupak and Rosenthal (2008). They report the case of a patient presenting with a long history of excessive daydreaming.
Their patient is a 36 year old successful, educated woman with a long history of excessive and persistent daydreaming, which according to her reports is a cause of distress. What’s really fascinating in this case is the lack of known injury, drug abuse or other disorder. After more than 10 years of therapy, she only found relief from her symptoms when she was prescribed fluvoxamine, an antidepressant drug believed to influence obsessiveness and/or compulsivity. Even though, she used to spend a big part of her free time engaged in daydreaming, she was never disconnected from reality. Growing older, she was forced to hide her excessive daydreaming from colleagues and friends. However, this behaviour didn’t interfere with her education and her career.

The authors do a short review of the existing literature in mind-wandering suggesting that the hypothesis by Mason et al. (2007), according to which “mind-wandering is associated with activity in the default mode network”, could explain their patient’s symptoms. See suggested readings for alternative theories/hypotheses.

Schupak and Rosenthal (2008) conclude:

The subject of the present case study claims to be adjusted to her high level of fantasy proneness. She manages to orchestrate a complex allocation of cognitive and emotional resources toward the competitive requirements of externally- versus internally-driven attentional demands on a daily basis, though at substantial psychological cost. Our question regards the extent to which this case may represent an unrecognized population, i.e., individuals whose mind wandering/daydreaming is experienced as a causative factor in producing psychological distress or functional impairment without meeting criteria for any DSM disorder. The fact that our patient reports a positive response to a medication that influences serotonergic tone may imply neurochemical irregularity

Unfortunately, there is no report on any neuroimaging studies on this specific patient.

Schupak, C. and Rosenthal, J. (2009). Excessive daydreaming: A case history and discussion of mind wandering and high fantasy proneness. Consciousness and Cognition, 18(1):290-292.

Suggested Readings

Burgess, P., Dumontheil, I., and Gilbert, S. (2007). The gateway hypothesis of rostral prefrontal cortex (area 10) function. Trends in Cognitive Sciences, 11(7):290-298.

Gilbert, S. J., Frith, C. D., and Burgess, P. W. (2005). Involvement of rostral prefrontal cortex in selection between stimulus-oriented and stimulus-independent thought. The European journal of neuroscience., 21(5):1423-1431.

Mason, M. F., Norton, M. I., Van Horn, J. D., Wegner, D. M., Grafton, S. T., and Macrae, C. N. (2007). Wandering minds: The default network and stimulus-independent thought. Science, 315(5810):393-395.

Raichle, M. E., MacLeod, A. M., Snyder, A. Z., Powers, W. J., Gusnard, D. A., and Shulman, G. L. (2001). A default mode of brain function. Proceedings of the National Academy of Sciences of the United States of America, 98(2):676-682.

(painting: girl-daydreaming by Anthony Staynes)

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