neurodudes

This study provides fMRI evidence that, after forgetting some memories, the brain has to work less hard.

(more…)

Entrepreneur-turned-cognitive neuroscientist Jeff Hawkins is distributing a “research release” of their experimental code base implementing his idea of hierarchical temporal memory described in his book, “On Intelligence”. Hawkins drew inspiration for the model from his own reading about the structure and function of the human neocortex and believes that it represents the foundation for developing intelligent machines.

Jeff explains this surprising move to open source the code for the Numenta Platform for Intelligent Computing (NuPIC) on the Numenta web site:

Why are we making NuPIC available now?

We have been contacted by dozens of researchers and scientists who are excited about HTM and by our work at Numenta. These people are anxious to work on HTM, are willing to be pioneers, and are willing to accept the uncertainty associated with a new technology. We are making our tools available so that these sophisticated developers can start building a community around HTM technology. NuPIC has been under development for 18 months, is pretty solid, and is well documented – including several examples to make it easy to get started – so we’re ready to open up to more developers, even while knowing that we do not yet have benchmarking data, and we cannot make guarantees about applicability to specific problems.

Here’s why Hawkins thinks that HTMs are new.

We have been covering Hawkins’ work for a while now. See these previous posts for more background info.

Neurodudes is actively soliciting code reviews of the newly released software. Is NuPIC the next big thing, or are you left feeling cold? Post your thoughts yourself using the instructions on the right-hand column, or let us know at contactus -AT- neurodudes.com!

Postdoctoral/research scientist positions are available in the inter-disciplinary group of Dmitri Chklovskii at the new Janelia Farm Research Campus of the Howard Hughes Medical Institute located in the suburbs of Washington, D.C. Candidates are expected to have a PhD in neuroscience, physics, computer science or electrical engineering. Most of the work is theoretical or computational and is done in collaboration with several experimental laboratories. Successful applicants will work on projects centered on neuronal circuits such as high-throughput reconstruction of wiring diagrams as well as combining structural and physiological data to infer circuit function. Salary will be commensurate with qualifications. For more information about research directions in the group please see: http://www.hhmi.org/research/groupleaders/chklovskii.html
Interested applicants should send their CV and a statement of research interests to mitya (at) janelia.hhmi.org, and arrange for three recommendation letters to be emailed to me.

The October 6th issue of Science is a special issue devoted to computational neuroscience. From the introduction to the special issue:

Computational neuroscience is now a mature field of research. In areas ranging from molecules to the highest brain functions, scientists use mathematical models and computer simulations to study and predict the behavior of the nervous system. Simulations are essential because the present experimental systems are too complex to allow collection of all the data. Modeling has become so powerful these days that there is no longer a one-way flow of scientific information. There is considerable intellectual exchange between modelers and experimentalists. The results produced in the simulation lab often lead to testable predictions and thus challenge other researchers to design new experiments or reanalyze their data as they try to confirm or falsify the hypotheses put forward. For this issue of Science, we invited leading computational neuroscientists, each of whom works at a different organizational level, to review the latest attempts of mathematical and computational modeling and to give us an outlook on what the future might hold in store.

Of particular interest is a review article by Randall O’Reilly on biologically based computational models. He focuses on models of the pre-frontal cortex.

Transcranial magnetic stimulation (TMS) is a popular technology for stimulating human cortical neurons, due to its safety, noninvasiveness, and efficacy. A TMS device is just a little coil of wire, through which 10,000 Amps of current is cranked during a period of only a few hundred microseconds; the resultant rapidly-changing magnetic field induces eddy currents in the brain. Depending on the protocol used, TMS can drive/inhibit a region of cortex corresponding to roughly a cubic centimeter or two, and is being explored for the treatment of depression, the reduction of auditory hallucinations during schizophrenia, and the alleviation of tinnitus and migraines. Thousands of papers on medicine and psychology have been written using this tool.

Yet the device itself is expensive and rare — they can run from $20,000 to $50,000 or even more, despite the fact that they are, in essence, a coil, a switch, a bank of capacitors, and a power supply. Much of the art lies in making the devices safe and fail-proof. Is it possible to hack/engineer a system that is safe, fault-tolerant, efficacious, and inexpensive? And furthermore, can we facilitate a community that will devise such devices, and share information about protocols and approaches to brain hacking?

This past August at Foo Camp, a hackers’ conference in Northern California, a group of people got together and set out to do just that. We are designing a safe, noninvasive, modular, and “open source” brain stimulator that will open up the field of circuit modulation to a wider audience. Members of the group include therapists and mental health professionals, engineers, programmers, and others interested in either the development of such devices, or the sharing of information on this front. Key to the design is safety — we want to make sure that the devices we create are as safe as devices on the market. Also, all the information is released under the Creative Commons “Attribution and Sharealike” license. This is a new model for “open source” medical device development — which may move it beyond the domain of simply creating “cool toys,” and to creating real devices.

You can find out more information, or contribute to the project, or learn from the project, at
http://transcenmentalism.org/OpenStim/

-Ed

Intelligent Life 2006 | From A to Zzzzz

Introducing CX717, a drug being developed by Cortex Pharmaceuticals of Irvine, California. It’s the first of what promises to be many aimed at detaching people from the daily routine of eight hours each for work, rest and play.

Tests conducted on rhesus monkeys last year suggest that CX717 can wire users to remain awake for 36 hours without the jitters, euphoria and eventual crash that come after mega-doses of caffeine or amphetamines. Further down the line are even more radical compounds—stimulants that can wipe out sleep for several days at a stretch, and pills that deliver a whole night’s shut-eye in two hours.

More information about the ampakine CX717 can be found here. We previously mentioned the delay match-to-sample performance improvement of monkeys on CX717.

Last year, the Redwood Center for Theoretical Neuroscience moved from the Redwood Neuroscience Institute in Meno Park to the Helen Wills Neuroscience Institute at Berkeley. In October they held a symposium with several interesting speakers presenting on various topics within Theoretical Neuroscience.

The videos are now online for your perusal, or you can buy a DVD of the whole symposium for a paltry $5.

• Horace Barlow, Cambridge University: The Roles of Theory, Commonsense, and Guesswork in Neuroscience
• Dan Kersten, University of Minnesota: Human Object Perception: Theory, Psychophysics & Imaging
• Sue Becker, McMaster University: The role of the hippocampus in memory, contextual gating, stress and depression
• Florentin Worgotter, University of Goettingen: Learning in Neurons and Robots
• Panel Discussion: The Role and Future Prospects for Math/Computational Theories in Neuroscience
• David Heeger, New York University: What fMRI Can Tell Us about How Visual Cortex Works
• Kevan Martin, ETH/UNI Zurich: Canonical Circuits for Neocortex
• Terry Sejnowski, Salk Institute: Dendritic Darwinism
• Jeff Hawkins, Numenta: Prospects and Problems of Cortical Theory

A forthcoming issue of the journal Neuroscience is devoted to an examination of multidisciplinary approaches to the study of working memory within the field of Cognitive Neuroscience. Although the issue will not be released until late April, a detailed press release is available from the University of Washington at St. Louis.

From the article:

“Multidisciplinary research within cognitive neuroscience has established itself as a promising approach to answering the question of how the mind emerges from the working of the brain” [...] “One of the fields that has gained substantially by successfully combining the theoretical frameworks, methodologies, empirical results and insights of the varied disciplines within cognitive neuroscience, is the study of working memory”

It goes on to describe a “pyramid approach” to multidisciplinary work in this area, which chiefly involves the merging of cognitive psychology, computational science, neuroscience, and cognitive neuropsychiatry.

What gives humans the unique ability to construct novel sentences from the building blocks of language? A recent article in Behavioral and Brain Sciences proposes a “neural blackboard architecture” is capable of just this.

From the article (doi: 10.1017/S0140525X06009022):

“This paper aims to show that neural “blackboard” architectures can provide an adequate theoretical basis for a neural instantiation of combinatorial cognitive structures. [...] We also discuss the similarities between the neural blackboard architecture of sentence structure and neural blackboard architectures of combinatorial structures in visual cognition and visual working memory [...]”

As with all main articles in Behavioral and Brain Sciences, this one is followed by extensive comment and criticism from colleagues, and finally a reply by the authors. This provides a very deep look at the article and the issues surrounding it.

An older, but freely available, version of the article is available here.

“Scans of brain activity, published online in the journal Nature Neuroscience, indicate that the brain can actually get into the ‘right frame of mind’ to store new information and that we perform at our best if the brain is active not only at the moment we get new information but also in the seconds before.
….
Tests showed that the brain’s electrical activity differed after the cue question and before the word was presented and this was linked to whether the subject would remember or forget the word in a later unexpected memory test. If the electrical activity maintained a high level over frontal parts of the scalp just before the word was shown, then it was likely that the subject would remember the word up to 50 minutes later – and after doing a series of other word tests. On the other hand, if the voltage was lower, the subjects were less likely to remember the word.”

(from the press release)

Leun J. Otten, Richard N. A. Henson & Michael D. Rugg. State-related and item-related neural correlates of successful memory encoding. Nature Neuroscience 5, 1339 – 1344 (2002). Published online: 28 October 2002; doi:10.1038/nn967