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Posts Tagged ‘cognition’

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)

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:

Ode To The Brain

03/12/2011 1 comment

The Symphony of Science is a musical project of John D Boswell, designed to deliver scientific knowledge and philosophy in musical form. The project owes its existence in large measure to the classic PBS Series Cosmos, by Carl Sagan, Ann Druyan, and Steve Soter, as well as all the other featured figures and visuals. Continuation of the videos relies on generous support from fans and followers.

Read more about the project here.

Here’s one of my favourites, “Ode To The Brain”.

Investigating the Anatomical Relationship Between Primary Sensory and Prefrontal Cortices in the Human Brain

11/10/2011 1 comment

People experience the world in slightly different ways. Philosophers have been writing about this for years and, recently, studies using psychophysics and neuroimaging provide further support for this. A classic example is the way we perceive visual illusions; there is variability in the responses of people about the extent they experience various illusions. Schwarzkopf et al. (2010) showed that inter-individual differences in the surface area of V1 predict individual differences in conscious perception, such as how big something looks.

A study by Chen et al. that was published on the  JoN used a novel approach that combined non-invasive cortical functional mapping with whole-brain voxel-based morphometric analyses to investigate the anatomical relationship between the functionally mapped visual cortices and other cortical structures in healthy humans. Chen et al. found an interesting correlation between the size of V1 and primary auditory cortex. This relationship could be explained in terms of our everyday multisensory experience of the world. However, the size of those areas was anticorrelated with the size of the anterior prefrontal cortex (aPFC), the frontopolar part of the frontal cortex. In a few words, individuals with larger primary visual cortex had larger primary auditory cortex but smaller aPFC. This anticorrelation was only found for the primary sensory cortices and not for other visual cortices (e.g. V2, V3).

According to Chen et al.

…while one might expect a positive correlation between the whole-brain gray matter volume and the volume of its components, instead we found a striking anticorrelation for primary visual cortex: individuals with larger brains tended to have smaller primary visual cortices. In contrast, anterior prefrontal cortex was the single most enlarged region in a larger brain.

The aPFC is a particularly fascinating area. Apart from having many names (anterior PFC, the frontal pole, frontopolar cortex, rostral prefrontal cortex, BA 10…), aPFC is larger relative to the rest of the brain (Semendeferi et al., 2001) and is significantly different in humans compared to other primates (Semendeferi et al., 2001), suggesting that this region may contribute to the unique human behaviour. Furthermore, it is one of the last brain areas to mature in humans (Dumontheil et al., 2008) and has been recently identified as the region with the greatest relative prediction power about brain maturity over development (Dosenbach et al., 2011). Evidence from previous studies suggest that this particular area has a role in higher-order cognitive functions (including prospective memory)

The pairing between the expansion of anterior prefrontal cortex and the contraction of primary sensory cortices reflects a common ground for the formation of anatomically and phylogenetically remote cortical regions, and suggests the existence of a reciprocal link between high-order cognition and low-level sensation.

Future studies will attempt to further investigate this relationship and examine what the effects of these structural differences are on function and performance on various tests thought to tap on those areas.

ResearchBlogging.orgSong C, Schwarzkopf DS, Kanai R, & Rees G (2011). Reciprocal anatomical relationship between primary sensory and prefrontal cortices in the human brain. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31 (26), 9472-80 PMID: 21715612

Schwarzkopf DS, Song C, & Rees G (2011). The surface area of human V1 predicts the subjective experience of object size. Nature neuroscience, 14 (1), 28-30 PMID: 21131954

Coren S, & Porac C (1987). Individual differences in visual-geometric illusions: predictions from measures of spatial cognitive abilities. Perception & psychophysics, 41 (3), 211-9 PMID: 3575080

Dumontheil I, Burgess PW, & Blakemore SJ (2008). Development of rostral prefrontal cortex and cognitive and behavioural disorders. Developmental medicine and child neurology, 50 (3), 168-81 PMID: 18190537

Semendeferi, K., Armstrong, E., Schleicher, A., Zilles, K., & Van Hoesen, G. W. (2001). Prefrontal cortex in humans and apes: a comparative study of area 10 American journal of physical anthropology, 3 (114), 224-241

Dosenbach NU, Nardos B, Cohen AL, Fair DA, Power JD, Church JA, Nelson SM, Wig GS, Vogel AC, Lessov-Schlaggar CN, Barnes KA, Dubis JW, Feczko E, Coalson RS, Pruett JR Jr, Barch DM, Petersen SE, & Schlaggar BL (2010). Prediction of individual brain maturity using fMRI. Science (New York, N.Y.), 329 (5997), 1358-61 PMID: 20829489

Art in the Eye of the Beholder: Preliminary Evidence?

08/03/2011 3 comments

Yellow, Red, Blue by Wassily Kandinsky

Does monocular viewing affect judgement of art? According to a 2008 paper by Finney and Heilman it does. The two researchers from the University of Florida inspired by previous studies investigating the effect of monocular viewing on performance on visual-spatial and verbal memory tasks, attempted to see what the results would be in the case of Art.

 

In particular, they recruited 8 right-eye dominant subjects (6 men and 2 women) with college education and asked them to view monocularly on a colour computer screen 10 painting with the right eye and another 10 with the left. None of the subjects was familiar with the presented paintings. Overall, each subject viewed 5 abstract expressionist and 5 impressionist paintings with each eye. Then they rated on a 1 to 10 scale four qualities of the paintings: representation (=how well the subject of the painting was rendered), aesthetics (how beautiful the painting appeared), novelty (=newness and originality of the painting), and closure (=completeness of the composition). Each quality was defined for each subject.

Monocular viewing had significant effects only in paintings in the abstract expressionist style. Impressionist paintings yielded no differences. The authors attributed this to the more concrete nature of impressionist works. Abstract expressionist paintings were rated more novel when viewed with the left eye. Moreover, the researchers found a trend for rating paintings as having more closure when they were viewed with the right eye than with the left.

The left eye primarily projects to the right superior colliculus and activation of this colliculus activates the right hemisphere’s attentional systems. The authors suggest that the results of the study provide evidence for the role of the right hemisphere in creativity and novelty processing. This seems consistent with previous research on patients with brain lesions and neuroimaging studies that have associated global processing and creativity with the right hemisphere*.

The small number of participants, however, means that the effects observed in this study must be seen with caution. Hopefully, someone will try to replicate these results involving a bigger sample in the near future.

*but also see Lindell (2010)

ResearchBlogging.orgFinney, G., & Heilman, K. (2008). Art in the Eye of the Beholder: The Perception of Art During Monocular Viewing Cognitive and Behavioral Neurology, 21 (1), 5-7 DOI: 10.1097/WNN.0b013e3181684fe0

Cognitive Stimulation Can Increase Creativity

06/10/2010 3 comments

Creativity plays a big part in most areas of everyday life. Sternberg and Lubart (1996) define creativity as the ability to produce work that is original, useful and, generative. Psychologists usually measure creativity with the Alternative Uses (AU) task. In this particular test individuals are asked to list as many possible uses for a common item. It is thought to test divergent thinking, a thought process associated with creativity and problem solving. The AU task has been shown to activate especially frontal areas of the brain. More specifically, Carlsson and colleagues (2000) found that the AU compared to a verbal fluency task was associated with stronger level of activity of the anterior prefrontal cortex (PFC). The same area was found to be activated during divergent thinking problems (Goel & Vartanian, 2005) and in creative story generation (Howard-Jones et al., 2005). Other brain areas that have been found to play a role in creativity include posterior brain areas like the anterior supramarginal gyrus

Fink and colleagues scanned 31 healthy participants while they were performing one non-creative control task and three creative tasks (the AU and two variations of it). In one of those variations, the incubation condition (AUinc) the researchers administered the AU task and instructed participants to reflect on their own ideas or responses they gave during the performance of the respective test item in the simple AU condition. The final task was the cognitive stimulation condition (AUstim). In this condition the participants were asked to do the AU task but were also exposed to other people’s ideas.

The AU conditions differed significantly with respect to the originality of generated ideas. In particular the highest originality was observed when the participants when exposed to other people’s idea (AUstim), followed by the incubation task (AUinc). These findings suggest that cognitive stimulation via the exposure to other people’s ideas has beneficial effects on creative cognition. At the neurophysiological level, the main differences in activations between the experimental tasks were found in posterior, especially temporo-parietal brain regions. More specifically the generation of original ideas was associated with more activation in the (anterior) supramarginal gyrus and stronger widespread deactivation in the inferior parietal cortex (around the angular gyri), especially in the right hemisphere.

Reflecting on own ideas (AUinc) compared to the simple AU condition was accompanied by higher activation in the bilateral cingulate cortex (or less deactivation, respectively), and lower activation in regions of the bilateral occipital cortex, the latter probably reflecting the stronger attentional focus to the visual input in the AU compared to the AUinc condition. The stimulation with external ideas (AUstim), yielding the strongest increase in originality compared to AU, was also associated with stronger activation (less deactivation) in the cingulate gyrus, now extending to the precuneus bilaterally. The latter contrast also revealed additional activation clusters in the right temporo-parietal cortex (including portions of the middle temporal, angular, and supramarginal gyri) and in medial orbitofrontal regions, with both clusters displaying less deactivation in the AUstim compared to the AU condition.

Interestingly, the contrasts between the two different intervention conditions (AUinc vs. AUstim) did not reveal any significant activation clusters, even though those two conditions produced different behavioural results.
According to the authors:

we may conclude that the interventions effects – though resulting in different behavioral results – appear to be rather unspecific with respect to brain function. However, this finding could also reflect the possibility that both creativity interventions provoke fairly similar psychological and neural processes during the idea generation period. Both interventions require participants to actively attend to and to process stimulus-related information which was in the one case self-generated (AUinc) and in the other case produced by other people (AUstim).

The findings of this study suggest that creative cognition can be improved effectively by cognitive stimulation and techniques (e.g. brainstorming). Furthermore, these effects are also apparent at the level of the brain. It would be very interesting to see similar studies in the future that attempt to employ more complex, ecologically valid creativity tasks.

ResearchBlogging.orgFink A, Grabner RH, Gebauer D, Reishofer G, Koschutnig K, & Ebner F (2010). Enhancing creativity by means of cognitive stimulation: evidence from an fMRI study. NeuroImage, 52 (4), 1687-95 PMID: 20561898

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

Sleep and Brain Connectivity

01/12/2009 2 comments

Massimini et al. (2005) attempted to study sleep and cortical connectivity by combining two different methods, TMS and EEG.

The abstract is below:

“When we fall asleep, consciousness fades yet the brain remains active. Why is this so? To investigate whether changes in cortical information transmission
play a role, we used transcranial magnetic stimulation together with highdensity electroencephalography and asked how the activation of one cortical area (the premotor area) is transmitted to the rest of the brain. During quiet
wakefulness, an initial response (È15 milliseconds) at the stimulation site was followed by a sequence of waves that moved to connected cortical areas several centimeters away. During non–rapid eye movement sleep, the initial
response was stronger but was rapidly extinguished and did not propagate beyond the stimulation site. Thus, the fading of consciousness during certain
stages of sleep may be related to a breakdown in cortical effective connectivity.”

Read the original study here (pdf).

How Does Your Memory Work?

While I was searching for Prof E. Warrington’s publications, I came across this interesting documentary on memory, which was originally broadcast by BBC2.

You can find a short description and the video below:

You might think that your memory is there to help you remember facts, such as birthdays or shopping lists. If so, you would be very wrong. The ability to travel back in time in your mind is, perhaps, your most remarkable ability, and develops over your lifespan. Horizon takes viewers on an extraordinary journey into the human memory. From the woman who is having her most traumatic memories wiped by a pill, to the man with no memory, this film reveals how these remarkable human stories are transforming our understanding of this unique human ability. The findings reveal the startling truth that everyone is little more than their own memory.

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