24 maart 2008

Duckus Dentatus

How does Your hippocampus separates one duck from another ?
Using very fine resolution fMRI these guys found out.. read about it in Science.
Pattern Separation in the Human Hippocampal CA3 and Dentate Gyrus Arnold Bakker,1 C. Brock Kirwan,2 Michael Miller,3 Craig E. L. Stark1,4* Pattern separation, the process of transforming similar representations or memories into highly dissimilar, nonoverlapping representations, is a key component of many functions ascribed to the hippocampus. Computational models have stressed the role of the hippocampus and, in particular, the dentate gyrus and its projections into the CA3 subregion in pattern separation. We used high-resolution (1.5-millimeter isotropic voxels) functional magnetic resonance imaging to measure brain activity during incidental memory encoding. Although activity consistent with a bias toward pattern completion was observed in CA1, the subiculum, and the entorhinal and parahippocampal cortices, activity consistent with a strong bias toward pattern separation was observed in, and limited to, the CA3/dentate gyrus. These results provide compelling evidence of a key role of the human CA3/dentate gyrus in pattern separation. Science 319, 1640 (2008);

Working memory: do not forget to work

But first read about it here. Maybe equipped with this knowledge You will be able to beat the chimp...
Synaptic Theory of Working Memory Gianluigi Mongillo, Omri Barak, Misha Tsodyks Science 319, 1543 (2008); It is usually assumed that enhanced spiking activity in the form of persistent reverberation for several seconds is the neural correlate of working memory. Here, we propose that working memory is sustained by calcium-mediated synaptic facilitation in the recurrent connections of neocortical networks. In this account, the presynaptic residual calcium is used as a buffer that is loaded, refreshed, and read out by spiking activity. Because of the long time constants of calcium kinetics, the refresh rate can be low, resulting in a mechanism that is metabolically efficient and robust. The duration and stability of working memory can be regulated by modulating the spontaneous activity in the network. Thanks to my good friend Dr Paul V. for pointing this one out.
Muy obrigado !
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PS One must be subscribed to Science in order to gain acces to the complete article. The links allow You acces to the abstract.

22 maart 2008

Best Visual illusions of the Year contest

Why does adding blur (removing high spatial frequenties) induces the illusion of movement ? Discover it here

The Magic of consciousness

A faboulous program... wish i could be there ! The 11th annual meeting of the Association for the Scientific Study of Consciousness took place between June 22nd and June 25th, 2007, in Las Vegas. We would like to thank all conference participants, symposium and plenary speakers for their excellent contributions. This is the archived site for the conference meeting.

Band of blogs

Ponzi illusion: engages only the ventral visual stream

You cannot fool a good hand !

17 maart 2008

Curbing EBM

Curbsite is not Your mom's simple search engine. It is a true EBM device that understands natural (english) language. Type in Your question and You get a wealth of EBM based clinical knowledge delivered right at Your internet doorstep. Blows me away !! (and it's free !) Sign up NOW !

15 maart 2008

Brain on Jazz

Dedicated to my favorite Jazz Musician and very good friend Dr. Peter DB

Study Illuminates Brain Activity During Jazz Improvisation

Without the ability to create and improvise, the unique and complex forms of art, music, and literature would be impossible, and recent studies have begun to use these artistic endeavors as tools for peering deeper into the brain. The experience of music in particular has become a target for researchers, although most have focused on the brain patterns of individuals listening to music, not creating it. Late last month, research appearing in the Public Library of Science (PLoS) One provided insight into the creative process by studying the minds of professional musicians asked to both play music by memory and generate an improvised melody. The study was authored by Dr. Charles Limb, an assistant professor at the Johns Hopkins University School of Medicine (and a trained jazz saxophonist), and Dr. Allen Braun of the National Institute on Deafness and Other Communication Disorders. Both have been involved in previous studies on the affects of music and language on the brain, and they designed a special plastic keyboard that could be held and played by someone inside of an fMRI machine. Six professional jazz pianists served as the study's subjects, and each took a turn playing the keyboard while undergoing an fMRI scan. They were given four tasks that would highlight differences in how their brains functioned while playing a song from memory versus improvising. Initially, each pianist played a basic C major scale using quarter notes. Then, in an easy improvisational exercise, they created a tune using the notes in the C scale, once again restricted to quarter notes. Next, they played a blues melody that they had memorized in advance while listening with headphones to a pre-recorded accompaniment. Finally, with the jazz accompaniment still playing, the pianists were given free reign to improvise their own melody. The researchers found that the dorsolateral prefrontal cortex, an area involved in planning and self-monitoring, became less active during improvisational playing, and this may be an crucial factor in these musicians' reduced inhibition and in their ability to form new creations and use novel techniques without planning ahead. Heightened activity was also observed in the medial prefrontal cortex, an area associated with self-expression, and this finding relates to earlier research conducted by Dr. Braun. In a 2001 study on language production, he reported that activity in the medial prefrontal cortex was associated with recollections of autobiographical information. In their current research, Dr. Limb and Dr. Braun note that jazz musicians use a personal style when playing and that jazz improvisation has been described as autobiographical. These patterns of brain activation and deactivation were consistent whether the pianist was engaged in the simple improvisational exercise or the more complex one, an indication that changes in brain activity were caused by the act of improvising and not by the difficulty of the task. As professionals, all of these musicians had a well-developed ability to improvise, and these results cannot be generalized to the general public. However, the researchers suggest that these same patterns of brain activity may occur during other situations. Future research should investigate patterns of brain activation in people engaged in other artistic activities, like drawing and writing, and in non-artistic activities that still require use of improvisational skills, such as conversing with others or problem-solving. More information on how the brain functions during creative activities adds to our understanding of brain functioning in general, and continued research may yield a more comprehensive understanding of the roles played by different regions of the brain.

DBMBMB: Derics Bownds Mind Boggling Mind Blog

Data formats

EEG data formats can often contribute quite heavily to the confusion soup. Filter them out with the help of this website