Cortical Resonance Frequencies Emerge from Network Size and Connectivity→

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Neural oscillations occur within a wide frequency range with different brain regions exhibiting resonance-like characteristics at specific points in the spectrum. At the microscopic scale, single neurons possess intrinsic oscillatory properties, such that is not yet known whether cortical resonance is consequential to neural oscillations or an emergent property of the networks that interconnect them. Using a network model of loosely-coupled Wilson-Cowan oscillators to simulate a patch of cortical sheet, we demonstrate that the size of the activated network is inversely related to its resonance frequency. Further analysis of the parameter space indicated that the number of excitatory and inhibitory connections, as well as the average transmission delay between units, determined the resonance frequency. The model predicted that if an activated network within the visual cortex increased in size, the resonance frequency of the network would decrease. We tested this prediction experimentally using the steady-state visual evoked potential where we stimulated the visual cortex with different size stimuli at a range of driving frequencies. We demonstrate that the frequency corresponding to peak steady-state response inversely correlated with the size of the network. We conclude that although individual neurons possess resonance properties, oscillatory activity at the macroscopic level is strongly influenced by network interactions, and that the steady-state response can be used to investigate functional networks.

Database of more than 10,000 3D object scans→

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Cool idea, public domain.

We have created a dataset of more than ten thousand 3D scans of real objects. To create the dataset, we recruited 70 operators, equipped them with consumer-grade mobile 3D scanning setups, and paid them to scan objects in their environments. The operators scanned objects of their choosing, outside the laboratory and without direct supervision by computer vision professionals. The result is a large and diverse collection of object scans: from shoes, mugs, and toys to grand pianos, construction vehicles, and large outdoor sculptures. We worked with an attorney to ensure that data acquisition did not violate privacy constraints. The acquired data was irrevocably placed in the public domain and is available freely.

Human Superior Temporal Gyrus Organization of Spectrotemporal Modulation Tuning Derived from Speech Stimuli→

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The human superior temporal gyrus (STG) is critical for speech perception, yet the organization of spectrotemporal processing of speech within the STG is not well understood. Here, to characterize the spatial organization of spectrotemporal processing of speech across human STG, we use high-density cortical surface field potential recordings while participants listened to natural continuous speech. While synthetic broad-band stimuli did not yield sustained activation of the STG, spectrotemporal receptive fields could be reconstructed from vigorous responses to speech stimuli. We find that the human STG displays a robust anterior–posterior spatial distribution of spectrotemporal tuning in which the posterior STG is tuned for temporally fast varying speech sounds that have relatively constant energy across the frequency axis (low spectral modulation) while the anterior STG is tuned for temporally slow varying speech sounds that have a high degree of spectral variation across the frequency axis (high spectral modulation). This work illustrates organization of spectrotemporal processing in the human STG, and illuminates processing of ethologically relevant speech signals in a region of the brain specialized for speech perception.

Corrective lenses for tight head coils (practiCalffMRI)→

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Nice.

Most labs have plastic goggles for correcting a subject's vision in the MRI...

These goggles work pretty well for a standard sized head coil, such as the 12-channel TIM coil on my Siemens Trio. But for a tighter fitting coil, such as the 32-channel head coil, there is simply no way to cram a subject wearing goggles into the space available. For a start the goggles' frame prevents the subject's nose from penetrating the appropriate gap in the front of the coil.

A simple solution is to relocate the corrective lenses on the outer surface of the head coil. All that's required is a different way to hold the lenses in place

Left Superior temporal gyrus is coupled to attended speech in a cocktail-party auditory scene→

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Interesting low frequency (delta) results here.

Using a continuous listening task, we evaluated the coupling between the listener's cortical activity and the temporal envelopes of different sounds in a multitalker auditory scene using magnetoencephalography and corticovocal coherence analysis. Neuromagnetic signals were recorded from 20 right-handed healthy adult humans who listened to five different recorded stories (attended speech streams), one without any multitalker background (No noise) and four mixed with a “cocktail party” multitalker background noise at four signal-to-noise ratios (5, 0, −5, and −10 dB) to produce speech-in-noise mixtures, here referred to as Global scene. Coherence analysis revealed that the modulations of the attended speech stream, presented without multitalker background, were coupled at ∼0.5 Hz to the activity of both superior temporal gyri, whereas the modulations at 4–8 Hz were coupled to the activity of the right supratemporal auditory cortex. In cocktail party conditions, with the multitalker background noise, the coupling was at both frequencies stronger for the attended speech stream than for the unattended Multitalker background. The coupling strengths decreased as the Multitalker background increased. During the cocktail party conditions, the ∼0.5 Hz coupling became left-hemisphere dominant, compared with bilateral coupling without the multitalker background, whereas the 4–8 Hz coupling remained right-hemisphere lateralized in both conditions. The brain activity was not coupled to the multitalker background or to its individual talkers. The results highlight the key role of listener's left superior temporal gyri in extracting the slow ∼0.5 Hz modulations, likely reflecting the attended speech stream within a multitalker auditory scene.

Dorothy Bishop on "ghost variables" and why researchers need to understand poker→

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Good reminder (and a good analogy) from Dorothy Bishop on reporting all variables we test:

Quite simply p-values are only interpretable if you have the full context: if you pull out the 'significant' variables and pretend you did not test the others, you will be fooling yourself - and other people - by mistaking chance fluctuations for genuine effects.

You don’t need more free time→

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As I discovered in a study that I published with my colleague Chaeyoon Lim in the journal Sociological Science, it’s not just that we have a shortage of free time; it’s also that our free time, in order to be satisfying, often must align with that of our friends and loved ones. We face a problem, in other words, of coordination. Work-life balance is not something that you can solve on your own.

 

Open data and the social contract of scientific publishing→

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We owe the effectiveness of the scientic enterprise in large part to the social contract under which sci- entists publish their ndings in such a way that they may be con rmed or refuted and receive credit for their work in return. Because of the limitations of the printed page, data have been largely left out of this arrange- ment. We have grown accustomed to reading papers in which tables, figures, and statistics summarize the underlying data, but the data themselves are unavailable. There are exceptions, such as DNA sequences, for which there exist specialized public repositories that authors are required to use. But the vast majority of data types do not have such repositories.

Movement for fair open access at Cognition→

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A worthy request.

With you as cosignatory I would like to write the Cognition Editorial Board, asking them to request the 5 components of Fair Open Access publishing listed below. No demands or ultimatums will be issued at this point - only a request. If you agree to this I'll send you exactly one email (no more) that contains a final draft letter and will ask you to give a thumbs up or thumbs down to your participation. In the meantime, I'm encouraging everyone to continue supporting and contributing to Cognition: It's the creation of our collective research dollars, time, and efforts.

Turn-taking in human communication – Origins and implications for language processing→

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Looks to be an interesting article from Stephen Levinson.

Most language usage is interactive, involving rapid turn-taking. The turn-taking system has a number of striking properties: turns are short and responses are remarkably rapid, but turns are of varying length and often of very complex construction such that the underlying cognitive processing is highly compressed. Although neglected in cognitive science, the system has deep implications for language processing and acquisition that are only now becoming clear. Appearing earlier in ontogeny than linguistic competence, it is also found across all the major primate clades. This suggests a possible phylogenetic continuity, which may provide key insights into language evolution.

Surviving as an underrepresented minority scientist in a majority environment→

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Very informative read.

After I arrived at Duke in 1998, I was inducted into many initiatives to help diversify the scientific workforce, including the push for women in science. I wondered, as a man, what did I know about women? But there was an assumption that a person of an underrepresented minority background knew more of what was needed for any minority to succeed, including women in science, relative to white males. There may be some truth to this, but certainly not an absolute truth. I began to realize that as a young professor at Duke University, and within the scientific community generally, I was being unintentionally asked to take on two jobs: 1) be the best scientist I could be, as expected of everyone else; and 2) help cure society’s racial disease, unlike everyone else. After two years, I made the conscious decision that I could not do both jobs well at the same time. I decided on job 1, to pursue being the best scientist I could be, and only taking on those few tasks for job 2 in which I felt I could make the biggest impact.