A nice cautionary discussion of how to interpret the results of multiple-way ANOVAs that yield unexpected interactions.
Bishop Blog
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He uses non-invasive stimulation to phase cancel the tremor. The stimulation mirrors but is opposite phase of the motor cortex oscillation. Reduces tremor by ~40% Brittain et al 2013
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Charlie Schroeder shows us the laminar profile of oscillations in cortex. Different strengths for different frequency bands in different cortical layers. Attention phase-synchronizes oscillations across layers facilitating communication between them. See Lakatos et al (2005) J. Neurophys.
Circuits from different thalamic nuclei to cortex, one broad and modulatory, the other narrow and specific, may regulate oscillatory entrainment.
New Neuron paper shows cortical entrainment that matches periodic sensory inputs; phase depended on the attended frequency content., enhancing attended representations. Lakatos et al 2013
Entrainment may explain cocktail party effect. Low frequency phase and high gamma power track attended speech. Zion Golumbic et al
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Follow @MIllerLabMIT on Twitter for updates from the Cognitive Rhythms Conference @ MIT today. See #CRC2013
http://cogrhythms.bu.edu/conference.htm -
Zara Bergstrom, Jon Simons and crew show that people can beat EEG tests of guilt detection by suppressing the guilty memories. Research calls into question reliability of such tests.
http://www.cam.ac.uk/research/news/people-can-beat-guilt-detection-tests-by-suppressing-incriminating-memories -
If you are interested in cognition, brain rhythms, and, especially, brain rhythms and cognition, this is the place to be.
http://cogrhythms.bu.edu/conference.htmThe Rhythmic Dynamics and Cognition Conference is a two-day event sponsored by the Cognitive Rhythms Collaborative (CRC). The program will be held at the Brain Building (Building 46) on the MIT campus (Room 3002) and will include lectures, a reception, and a poster session.
Speakers include:
- Pascal Fries, (Ernst Strungmann Institute (ESI), Frankfurt)
- Elizabeth Buffalo (Emery University)
- Charlie Schroeder (Nathan Kline Institute)
- Peter Brown (University College London)
- Fiona Le Beau (Newcastle University)
- Earl Miller (MIT)
- Charlie Wilson (University of Texas, San Antonio)
- Peter Uhlhaas (University of Glasgow)
- Christa van Dort (Mass. General Hospital)
- Markus Siegal (University of Tubingen)
- Robert Knight (UC Berkely)
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It was recently reported that low-voltage, non-invasive brain stimulation improves mathematical abilities. Does it? Here’s a cautionary discussion:
Does Brain Stimulation Make You Better at Maths? -
Visual attention modulates several aspects of neural coding. There is an increase in firing rate and changes in temporal dynamics: a reduction of neural variance and noise correlation as well as changes in oscillatory synchronization. The authors used glutamatergic receptor activation, combined with neurophysiological recording to show that the NMDA receptor is responsible for attention -related changes in neural temporal dynamics but not for increases in firing rate. Thus, different neurophysiological mechanisms that underlie attention can be dissociated at the receptor level. This supports the hypothesis that attention is mediated in part by the temporal dynamics of neural activity, not merely changes in the firing rate of neurons, and that the changes temporal dynamics are not simply a byproduct of changes in firing rate.
Herrero et al (2013) NeuronFor a further discussion of the role of temporal dynamics in attention see:
Miller, E.K. and Buschman, T.J. (2013) Cortical circuits for the control of attention. Current Opinion in Neurobiology. 23:216–222 View PDF »Buschman, T.J. and Miller, E.K. (2007) Top-down versus bottom-up control of attention in the prefrontal and posterior parietal cortices. Science. 315: 1860-1862 . View PDF »
Buschman, T.J. and Miller, E.K. (2009) Serial, covert, shifts of attention during visual search are reflected by the frontal eye fields and correlated with population oscillations. Neuron, 63: 386-396. View PDF »
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This paper uses EEG to examine the timecourse of synchronization patterns across the brain during a simple cognitive task. First, there was low frequency (delta) synchrony, which may reflect global, long-range synchronization and may help organize the higher frequency synchrony that followed. Then, there was higher frequency (gamma) synchrony, which may reflect reorganization of local circuits for bottom-up processing of sensory inputs. Finally, there was beta synchrony, which may reflect the final stage of top-down processing in the task. Gamma and beta synchronization has been shown to be correlated with bottom-up vs top-down cortical processing (Buschman and Miller, 2007; Chanes et al, 2013; Ibos et al, 2013). This study identifies and confirms some of the proposed mechanisms of global information integration in the brain.
Brazdil et al (2013)For further reading:
Buschman, T.J. and Miller, E.K. (2007) Top-down versus bottom-up control of attention in the prefrontal and posterior parietal cortices. Science. 315: 1860-1862 The Scientist’s “Hot Paper” for October 2009. View PDF »Chanes et al (2013) Journal of Neuroscience
Ibos et al (2013) Journal of Neuroscience
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For years, neurophysiologists have observed that many neurons in higher-level cortex have “weird” properties. They activate across a wide range of seemingly unrelated conditions and thus don’t seem to fit into the traditional view of brain function in which each neuron has a single function or message. They were often considered a “complicating nuisance” at best or dismissed at worst. It turns out that these mixed selectivity neurons may be the most critical for complex behavior and cognition. They greatly expand the brain’s computational power.
Read MIT press release: Complex brain function depends on flexibility
The paper:
Rigotti, M., Barak, O., Warden, M.R., Wang, X., Daw, N.D., Miller, E.K., & Fusi, S. (2013) The importance of mixed selectivity in complex cognitive tasks. Nature View PDF doi:10.1038/nature12160