Archive

Posts Tagged ‘science’

Do older adults benefit from videogames?

Brain training games claim to boost your mental skills. But while practicing a game might make you better at it, research in young people has shown it doesn’t improve how well you perform other cognitive tasks in everyday life. Now a new study suggests the case may be different for adults above the age of 60. Researchers at the University of California have designed a driving game called NeuroRacer. In this Nature Video, we see how the game can improve an older player’s short-term memory and attention, skills which decline with age.

Read the original research paper here:http://dx.doi.org/10.1038/nature12486 (from Nature)

Advertisements

LOL cats and Neuroscience?

31/01/2013 1 comment

I never expected to see this. Using LOL cats to describe a new study? The result is surprisingly good. Maybe I’m slightly biased because I love cats.

Here’s the abstract of the newly published (31/01) Nature paper in case you want to learn more:

Stroking of the skin produces pleasant sensations that can occur during social interactions with conspecifics, such as grooming1. Despite numerous physiological studies (reviewed in ref. 2), molecularly defined sensory neurons that detect pleasant stroking of hairy skin3, 4 in vivo have not been reported. Previously, we identified a rare population of unmyelinated sensory neurons in mice that express the G-protein-coupled receptor MRGPRB4 (refs 5, 6). These neurons exclusively innervate hairy skin with large terminal arborizations7 that resemble the receptive fields of C-tactile (CT) afferents in humans8. Unlike other molecularly defined mechanosensory C-fibre subtypes9, 10, MRGPRB4+ neurons could not be detectably activated by sensory stimulation of the skin ex vivo. Therefore, we developed a preparation for calcium imaging in the spinal projections of these neurons during stimulation of the periphery in intact mice. Here we show that MRGPRB4+ neurons are activated by massage-like stroking of hairy skin, but not by noxious punctate mechanical stimulation. By contrast, a different population of C fibres expressing MRGPRD11 was activated by pinching but not by stroking, consistent with previous physiological and behavioural data10, 12. Pharmacogenetic activation of Mrgprb4-expressing neurons in freely behaving mice promoted conditioned place preference13, indicating that such activation is positively reinforcing and/or anxiolytic. These data open the way to understanding the function of MRGPRB4 neurons during natural behaviours, and provide a general approach to the functional characterization of genetically identified subsets of somatosensory neurons in vivo.

You can read the paper here (paywall alert).

PS: LOL cats seem to be popular in academia lately. Remember the LOLcat dissertation?

Cake Is Better Than Sex: The Case of Asexuality

10/07/2012 5 comments

Recently, a “new” sexual orientation has started getting attention in the media, asexuality (or nonsexuality) (e.g., see recent article on the Metro)

But what is asexuality? No, we are not talking about the asexual reproduction of invertebrates and other lower-level vertebrates. Unfortunately, there is only a limited number of studies on asexuality. In fact, some psychologists still doubt its existence or see it as sexual dysfunction. In the UK about 1% of the population self-identify as asexual (Bogaert, 2004). A few definitions have been given for asexuality: Storms (1980) defines asexuality as the absence of sexual orientation. This is similar to the definition given by Bogaert (2004), who describes asexuality as the lack of basic attraction towards others. The definition adopted by the largest international online community of asexual individuals, the Asexual Visibility and Education Network (AVEN) is broader than the ones mentioned above. AVEN defines asexuality as the lack of sexual attraction. A quick look at the forums at AVEN reveals that there is a great level of variability between individuals who self-identify as asexuals. Some are characterised by a lack of romantic orientation, as well as sexual attraction. Other, however, experience romantic attraction and identify as hetero-romantic (romantically attracted to people from the opposite sex), homo-romantic asexuals (romantically attracted to people from the same sex), or bi-romantic asexuals (attracted to individuals from both sexes).

Orientation or… disorder?

Could some of the people who self-identify as asexual individuals have some hormonal imbalance or a disorder behind their lack of sexual attraction?

Some initial findings show that asexuality is not associated with higher rates of psychopathology (Brotto et al., 2010). However, a subset might fit the criteria for Schizoid Personality Disorder. Asexuality seems to be more common among adults with autism spectrum disorder (ASD) (Gilmour et al., 2012).

A recent study by Brotto & Yule (2011)  challenged the view that asexuality should be characterised as a sexual dysfunction. They did this by comparing genital (vaginal pulse amplitude; VPA) and subjective sexual arousal in asexual and non-asexual women.

Thirty-eight women between the ages of 19 and 55 years (10 heterosexual, 10 bisexual, 11 homosexual, and 7 asexual) viewed neutral and erotic audiovisual stimuli while VPA and self-reported sexual arousal and affect were measured. There were no significant group differences in the increased VPA and self-reported sexual arousal response to the erotic film between the groups. Asexuals showed significantly less positive affect, sensuality-sexual attraction, and self-reported autonomic arousal to the erotic film compared to the other groups; however, there were no group differences in negative affect or anxiety. Genital-subjective sexual arousal concordance was significantly positive for the asexual women and non-significant for the other three groups, suggesting higher levels of interoceptive awareness among asexuals. Taken together, the findings suggest normal subjective and physiological sexual arousal capacity in asexual women and challenge the view that asexuality should be characterized as a sexual dysfunction. (Brotto & Yule, 2011)

Is asexuality a new orientation?

In a sex obsessed society  the idea of individuals who don’t experience sexual attraction sounds alien. However, there is evidence from early studies by Kinsey (1948) that a small percentage of the population, a category he called “X” exhibited behaviour consistent with modern definitions of asexuality. The first known publication focused on asexuality was by Johnson in 1977. So, the answer is probably no. It was probably always around but it was the internet that gave asexual individuals the chance to meet others like them from all over the world.

Some theories suggest that asexuality is a product of modern society. In particular, Przybylo (2011) views asexuality as:

“both a product of and reaction against our sexusocial, disoriented postmodern here and now. This article also addresses the question of whether or not, and on what terms, asexuality may be considered a resistance against sexusociety”

References

Bogaert A.F. (2004) Asexuality: Its Prevalence and Associated Factors in a National Probability Sample. Journal of Sex Research, 41, 279-287

Brotto, L. A., Knudson, G., Inskip, J., Rhodes, K., & Erskine, Y. (2010). Asexuality: A mixed methods approach. Archives of Sexual Behavior, 39, 599-618.

Brotto, L. A., & Yule, M. A. (2011). Physiological and Subjective Sexual Arousal in Self-Identified Asexual Women, Archives of Sexual Behavior, 40, 699-712

Gilmour, L., Schalomon, P. M., and Smith, V. (2012). Sexuality in a community based sample of adults with autism spectrum disorder. Research in Autism Spectrum Disorders, 6(1):313-318.

Johnson, M. T. (1977). Asexual and Autoerotic Women: Two invisible groups. in ed. Gorchros H.L. and Gochros J.S. The Sexually Oppressed. New York: Associated Press.

Kinsey, Alfred C. (1948). Sexual Behavior in the Human Male. W.B. Saunders.

Przybylo, E. (2011) Crisis and safety: The asexual in sexusociety. Sexualities, 14, 444-461.

Storms, M. D. (1980). Theories of sexual orientation. Journal of Personality and Social Psychology, 38, 783–792.

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

Eye Movements as an Objective Measurement of Mind Wandering

26/03/2012 3 comments

We spent a lot of time mind wandering. Cognitive neuroscience has recently started investigating this phenomenon. However, the subjective nature of mind wandering makes capturing and measuring it exceptionally difficult. As a result, there is still no way to objectively measure mind wandering. In the majority of published studies researchers ask participants at random intervals how focused they are on a given task. Uzzaman and Joordens in a recently published paper explored the use of eye movements as an objective measure of mind wandering while participants performed a reading task.

Eye movements are thought to reflect (to some degree) cognitive processes (for a brief overview of eye movement research, see the Scholarpedia entry). Uzzaman et al. study was based on an earlier paper by Reichle, Reineberg, and Schooler (2010) who suggested that eye movements may provide an objective measure of mind wandering. Reichle et al. investigated this hypothesis by comparing the fixation-duration during mind wandering and normal reading episodes. The results were very encouraging and suggested that the participants’ eye movements became progressively decoupled from the ongoing task (i.e., text processing) during mind wandering episodes.

Uzzaman et al. used a reading task coupled with a self-classified probe-caught mind wandering paradigm to obtain a subjective account of mind wandering episodes. They recruited 30 participants who were explicitly informed of the definition of mind wandering episodes prior to the start of the experiment and were instructed that they would be asked to report their mind state at random intervals. The authors defined explicitly mind wandering “as reading without text comprehension, or thinking about anything other than the text on hand”. They also provided several examples to make sure the participants fully understood the concept.

The participants read sixteen pages of “War and Peace” by Tolstoy on a computer screen while their eye movements were tracked and recorded. Randomly every 2–3 min, a probe would appear on top of the text asking what was the mind state of the participants at this specific point. Participants would have to answer to continue the experiment. On average participants received 10 probes in total, in which mind wandering was reported on 49% of them.

The eye movement behaviours of the participants were categorised into mind wandering or reading conditions, based on their self-reports. This analysis was conducted for the 5 s time interval preceding the probe for reading and wandering conditions within each participant. Nine pairs of eye movement variables were analysed (e.g., count of blinks, fixations, saccades, fixation duration, within-word regression count), which displayed different degrees of sensitivity to mind wandering.

Statistical differences were found in two of the eye movement variables, run count and  within-word regression count. Run count was defined as the “the total number of runs, where a run is two consecutive fixations within the same interest-area” and  within-word regression count as “the sum of all fixation durations from when the word was first fixated upon, till the last fixation”.  

Specifically, there were fewer within-word regressions for periods before mind wandering episodes compared to periods before reading reports (z = −2.305, p = 0.021). Also, the total run count was also lower during mind wandering episodes (z = −1.997, p = 0.046). In addition, fixation count, saccade count and total number of saccades within the interest-area were lower during mind wandering reports, although these variables fell slightly short of the conventional significance criterion (all z < −1.755,p > 0.079).

During comprehensive reading all the words were being cognitively processed deeply and effort was put forth. On the contrary, a different pattern was observed during mind wandering episodes, as it was suggested by the lower number and duration of within-word regressions that shows that the  text was not being processed deeply, and as a result limited lexical information was being extracted. As a result, reading became less effortful and more automatic.

The current study revealed a correlation between subjective reports of mind wandering, and objective ocular behaviour. These findings could be further exploited in future studies and lead to the development of algorithms that would mathematically predict the likelihood of mind wandering based on eye movements. Such a development might provide valuable insights into the neural correlates of mind wandering.
ResearchBlogging.orgUzzaman, S., & Joordens, S. (2011). The eyes know what you are thinking: Eye movements as an objective measure of mind wandering Consciousness and Cognition, 20 (4), 1882-1886 DOI: 10.1016/j.concog.2011.09.010

Reichle ED, Reineberg AE, & Schooler JW (2010). Eye movements during mindless reading. Psychological science, 21 (9), 1300-10 PMID: 20679524

Music and the Brain: Depression and Creativity Symposium

22/01/2012 8 comments

If you’re following this blog, you probably know that I’m very interested in creativity. I was delighted to find this video on YouTube and decided to share it with you:

Kay Redfield Jamison, professor of psychiatry and behavioral sciences and co-director of the Johns Hopkins Mood Disorders Center at the Johns Hopkins University School of Medicine, convened a discussion of the effects of depression on creativity. Joining Jamison were two distinguished colleagues from the fields of neurology and neuropsychiatry, Dr. Terence Ketter and Dr. Peter Whybrow. The Music and the Brain series is co-sponsored by the Library’s Music Division and Science, Technology and Business Division, in cooperation with the Dana Foundation.

The “Depression and Creativity” symposium marks the bicentennial of the birth of German composer Felix Mendelssohn (1809-1847), who died after a severe depression following the death of his sister, Fanny Mendelssohn Hensel, also a gifted composer.

One of the nation’s most influential writers on creativity and the mind, Kay Redfield Jamison is a noted authority on bipolar disorder. She is the co-author of the standard medical text on manic-depressive illness and author of “Touched with Fire,” “An Unquiet Mind,” “Night Falls Fast” and “Exuberance: The Vital Emotion.”

Dr. Terence Ketter is known for extensive clinical work with exceptionally creative individuals and a strong interest in the relationship of creativity and madness. He is professor of psychiatry and behavioral sciences and chief of the Bipolar Disorders Clinic at Stanford University School of Medicine.

Dr. Peter Whybrow, an authority on depression and manic-depressive disease, is director of the Semel Institute for Neuroscience and Human Behavior at the University of California, Los Angeles (UCLA). He is also the Judson Braun Distinguished Professor and executive chair of the Department of Psychiatry and Biobehavioral Sciences at the David Geffen School of Medicine at UCLA. (description take from here).

And here’s the video:

domestic diva, M.D.

my mother raised the perfect housewife...then I went to med school

The Courgette Cooperation

A personal take on food and cooking and anything related

poetsinironedsuits

you're just an idea away...

Nou Stuff

another cognitive neuroscience/psychology blog...

%d bloggers like this: