The Miller Lab @ MIT

  • Gorillas Agree: Human Frontal Cortex is Nothing Special

    Miller Lab
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    The human prefrontal cortex may not be special in terms of its size relative to other primates, but it is still a pretty special.
    http://blogs.scientificamerican.com/beautiful-minds/2013/05/16/gorillas-agree-human-frontal-cortex-is-nothing-special/?utm_source=feedly

    Want to know what it does?  Here’s a start:
    Miller, E.K. and Cohen, J.D. (2001) An integrative theory of prefrontal cortex function. Annual Review of Neuroscience, 24:167-202.  Designated a Current Classic by Thomson Scientific as among the most cited papers in Neuroscience and Behavior. View PDF »

  • Watch 32 discordant metronomes achieve synchrony in a matter of minutes

    Miller Lab
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    The title says it all.  Oscillations are useful for all sorts of things.
    Synchrony in 32 metronomes

  • Top-down vs bottom-up processing boosted by stimulating human frontal cortex at beta vs gamma frequencies

    Miller Lab

    A number of laboratories have been suggesting that top-down vs bottom-up attention signals may be transmitted across the cortex via neural synchronization at beta vs gamma frequencies, respectively (Buschman and Miller, 2007; Bosman et al, 2012; Gregoriou et al, 2009, see review by Wang 2010).  Chanes et al (2013) tested this by entraining the human frontal cortex at those frequencies.  This produced the predicted top-down vs bottom-up effects on behavior: Beta modulated (top-down) response criterion whereas gamma modulated (bottom-up) perceptual sensitivity.  This supports observations that different frequencies of neural synchrony support feedback vs feedforward cortical processing.  It also shows how neural synchrony supports multiplexing of function: Activity from the same neurons has different functional outcomes depending on their rhythmic dynamics.
    Chanes et al (2013)

    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 »

    G.G. Gregoriou, S.J. Gotts, H. Zhou, R. Desimone (2009) High-frequency, long-range coupling between prefrontal and visual cortex during attention Science, 324 (2009), pp. 1207–1210.

    C.A. Bosman, J.-M. Schoffelen, N. Brunet, R. Oostenveld, A.M. Bastos, T. Womelsdorf, B. Rubehn, T. Stieglitz, P. De Weerd, P. Fries (2012) Attentional stimulus selection through selective synchronization between monkey visual areas. Neuron, 75 (2012), pp. 875–888

    X.-J. Wang (2010) Neurophysiological and computational principles of cortical rhythms in cognition.  Physiol. Rev., 90 (2010), pp. 1195–1268

  • Best Visual Illusion of The Year Contest 2013

    Miller Lab
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    Personally, my favorite is the 3rd prize winner: Look at Boston as if you are a giant with eyes 200 yards apart.
    http://illusionoftheyear.com/

  • Neural structures underlying set-shifting

    Miller Lab

    A nice review of the brain areas and neural mechanisms underlying attention and set-shifting.
    http://www.sciencedirect.com/science/article/pii/S0166432813002453

  • Lessons of an amnesiac

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    MIT neuroscientist Suzanne Corkin, author of the new book “Permanent Present Tense,” tells of her nearly five decades studying a man whose memory loss transformed science.

    In the Boston Globe Sunday magazine

  • Congratulations to new HHMI investigators Moore and Diesseroth

    Miller Lab

    Tirin Moore and Karl Deisseroth named Howard Hughes Medical Institute Investigators.  Congrats to both.

    The Miller Lab is proud to be in the same scientific family as Tirin. “Pappa” Charlie Gross must be also be proud.  See: Neurotree

  • Robust Gamma Coherence between Macaque V1 and V2 by Dynamic Frequency Matching

    Miller Lab

    Rhythmic synchrony between neurons has been suggested as a mechanism for establishing communication channels between neurons.  However, this hypothesis has been criticized because of observations that the exact frequency of gamma oscillations bounces around too much to provide a stable communication channel.  (BTW, it doesn’t seem to bother anyone that single neuron activity also bounces around).

    In this study, Roberts et al record from V1 and V2 simultaneously while presenting gratings of varying contrast.  Even though the gamma frequencies changed with stimulus contrast and fluctuated over time, coherence remained stable between V1 and V2.   Thus, rhythmic synchrony can provide a stable channel for neural communication.
    http://www.cell.com/neuron/abstract/S0896-6273(13)00227-4?utm_source=feedly

    For further reading on the role of rhythmic synchrony in neural communication 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., Denovellis, E.L., Diogo, C., Bullock, D. and Miller, E.K. (2012) Synchronous oscillatory neural ensembles for rules in the prefrontal cortex. Neuron, 76: 838-846.  View PDF

  • A Functional Hierarchy within the Parietofrontal Network in Stimulus Selection and Attention Control

    Miller Lab

    Ibos et al examined the relative roles of the frontal eye fields (FEF) and lateral intraparietal area (LIP) in bottom-up vs top-down selection.  They found that intrinsic salience (bottom-up) was signaled in LIP before the FEF whereas extrinsic salience (top-down) was signaled in FEF before LIP.  The authors conclude that bottom-up vs top-down control of attention predominates in the parietal vs frontal cortex, respectively.
    http://www.jneurosci.org/content/33/19/8359.abstract

    As noted by the authors, this is highly consistent with our lab’s observations that attention signals for bottom-up capture by stimulus salience (pop-out) vs top-down search originate from parietal vs frontal cortex, respectively.
    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 »

    We also showed that rhythmicity of frontal cortical top-down signals may control the periodic shifts of attention during visual search that leads to eventual selection of a target:
    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 »

  • Neural Limits to Representing Objects Still within View

    Miller Lab

    Our very limited ability to hold multiple thoughts in mind is apparent to anyone who has tried to talk on the phone and email at the same time.  Traditionally, this is thought of as a limitation in the capacity of working memory, the “mental scratchpad” used to keep important information “online” after it is no longer available.  However, Ed Vogel and crew show that the bottleneck is not in working memory per se but instead present during processing of visual stimuli while they are still visible.  Thus, the bottleneck is not (just) in memory but also in the processing of sensory inputs.  In other words, capacity limitations seem to be a fundamental limit in neural processing related to consciousness in general, not a unique byproduct of working memory.
    http://www.jneurosci.org/content/33/19/8257.abstract

    As noted by the authors, this is consistent with our finding that when capacity is exceeded, information is lost in a bottom-up fashion during initial processing of visual stimuli:
    Buschman,T.J., Siegel, M., Roy, J.E. and Miller, E.K. (2011) Neural substrates of cognitive capacity limitations. Proceedings of the National Academy of Sciences. 108(27):11252-5. View PDF »