Predicting stimulus‐rate sensitivity of human somatosensory fMRI signals with MEG

Nangini, Cathy; Hlushchuk, Yevhen; Hari, Riitta

doi:10.1002/hbm.20787

Cited by 10 publications

(10 citation statements)

References 37 publications

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“…We have demonstrated earlier [ 34 ] that one of the reasons for this apparent discrepancy is the traditional way in which electrophysiological and hemodynamic signals are compared. Typically, the peak amplitudes of MEG or EEG responses to individual stimuli within a block are compared with the peak or mean fMRI signal in response to the entire block.…”

Section: Discussionmentioning

confidence: 99%

Stimulus-Rate Sensitivity Discerns Area 3b of the Human Primary Somatosensory Cortex

et al. 2015

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Previous studies have shown that the hemodynamic response of the primary somatosensory cortex (SI) to electrical median nerve stimulation doubles in strength when the stimulus rate (SR) increases from 1 to 5 Hz. Here we investigated whether such sensitivity to SR is homogenous within the functionally different subareas of the SI cortex, and whether SR sensitivity would help discern area 3b among the other SI subareas. We acquired 3-tesla functional magnetic resonance imaging (fMRI) data from nine healthy adults who received pneumotactile stimuli in 25-s blocks to three right-hand fingers, either at 1, 4, or 10 Hz. The main contrast (all stimulations pooled vs. baseline), applied to the whole brain, first limited the search to the whole SI cortex. The conjunction of SR-sensitive contrasts [4 Hz − 1 Hz] > 0 and [10 Hz − 1 Hz] > 0 ([4Hz − 1Hz] + [10Hz − 1Hz] > 0), applied to the SI cluster, then revealed an anterior-ventral subcluster that reacted more strongly to both 10-Hz and 4-Hz stimuli than to the 1-Hz stimuli. No other SR-sensitive clusters were found at the group-level in the whole-brain analysis. The site of the SR-sensitive SI subcluster corresponds to the canonical position of area 3b; such differentiation was also possible at the individual level in 5 out of 9 subjects. Thus the SR sensitivity of the BOLD response appears to discern area 3b among other subareas of the human SI cortex.

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Section: Discussionmentioning

confidence: 99%

Stimulus-Rate Sensitivity Discerns Area 3b of the Human Primary Somatosensory Cortex

et al. 2015

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“…An electrophysiologically more plausible representation of the neuronal activity, containing an initial transient component followed by a lower‐amplitude sustained component, gave a better prediction of real fMRI signals from primary somatosensory cortex (SI) than did the boxcar when simultaneously fit for different stimulus durations 60 . The use of actual MEG data to represent the neuronal correlates of the fMRI signal was subsequently verified for SI signals for different stimulus rates, 61 in line with monkey and rat electrophysiological measures used to predict the time‐course of hemodynamic signals 62–64 …”

Section: Principles Of Megmentioning

confidence: 97%

The brain in time: insights from neuromagnetic recordings

Hari

Parkkonen

Nangini

2010

Annals of the New York Academy of Sciences

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The millisecond time resolution of magnetoencephalography (MEG) is instrumental for investigating the brain basis of sensory processing, motor planning, cognition, and social interaction. We review the basic principles, recent progress, and future potential of MEG in noninvasive tracking of human brain activity. Cortical activation sequences from tens to hundreds of milliseconds can be followed during, e.g., perception, motor action, imitation, and language processing by recording both spontaneous and evoked brain signals. Moreover, tagging of sensory input can be used to reveal neuronal mechanisms of binaural interaction and perception of ambiguous images. The results support the emerging ideas of multiple, hierarchically organized temporal scales in human brain function. Instrumentation and data analysis methods are rapidly progressing, enabling attempts to decode the four-dimensional spatiotemporal signal patterns to reveal correlates of behavior and mental contents.

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“…Overall, MEG and fMRI signals display a relatively good spatial agreement in low-level sensory projection areas (e.g. Moradi et al, 2003;Brookes et al, 2005;Nangini et al, 2009;Stevenson et al, 2011) whereas the MEG and fMRI spatial patterns often differ during cognitive tasks (e.g. more than 15 mm in various regions as shown by Liljestr€ om et al, 2009; more than 10 mm outside occipital cortex; Vartiainen et al, 2011).…”

Section: Neurophysiological Differences Between Meg and Fmrimentioning

confidence: 99%

Consistency and similarity of MEG- and fMRI-signal time courses during movie viewing

et al. 2018

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Movie viewing allows human perception and cognition to be studied in complex, real-life-like situations in a brain-imaging laboratory. Previous studies with functional magnetic resonance imaging (fMRI) and with magneto-and electroencephalography (MEG and EEG) have demonstrated consistent temporal dynamics of brain activity across movie viewers. However, little is known about the similarities and differences of fMRI and MEG or EEG dynamics during such naturalistic situations.We thus compared MEG and fMRI responses to the same 15-min black-and-white movie in the same eight subjects who watched the movie twice during both MEG and fMRI recordings. We analyzed intra-and intersubject voxel-wise correlations within each imaging modality as well as the correlation of the MEG envelopes and fMRI signals. The fMRI signals showed voxel-wise within-and between-subjects correlations up to r ¼ 0.66 and r ¼ 0.37, respectively, whereas these correlations were clearly weaker for the envelopes of band-pass filtered (7 frequency bands below 100 Hz) MEG signals (within-subjects correlation r < 0.14 and between-subjects r < 0.05). Direct MEG-fMRI voxel-wise correlations were unreliable. Notably, applying a spatial-filtering approach to the MEG data uncovered consistent canonical variates that showed considerably stronger (up to r ¼ 0.25) betweensubjects correlations than the univariate voxel-wise analysis. Furthermore, the envelopes of the time courses of these variates up to about 10 Hz showed association with fMRI signals in a general linear model. Similarities between envelopes of MEG canonical variates and fMRI voxel time-courses were seen mostly in occipital, but also in temporal and frontal brain regions, whereas intra-and intersubject correlations for MEG and fMRI separately were strongest only in the occipital areas.In contrast to the conventional univariate analysis, the spatial-filtering approach was able to uncover associations between the MEG envelopes and fMRI time courses, shedding light on the similarities of hemodynamic and electromagnetic brain activities during movie viewing. IntroductionA practical and ecologically valid approach to probe the neural underpinnings of perception and social cognition is to use movies as stimuli in neuroimaging experiments. Mimicking everyday situations around us, movies can provoke a wide spectrum of sensory, social, and emotional percepts that may be difficult to elicit using the highly controlled repetitive stimuli typically employed in conventional brain-imaging experiments. Despite the apparent complexity and unrestrained nature of movies, consistent and synchronized brain activity patterns across movie viewers have been demonstrated with functional magnetic resonance imaging (fMRI; e.g. Hasson et al.,

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Predicting stimulus‐rate sensitivity of human somatosensory fMRI signals with MEG

Cited by 10 publications

References 37 publications

Stimulus-Rate Sensitivity Discerns Area 3b of the Human Primary Somatosensory Cortex

Stimulus-Rate Sensitivity Discerns Area 3b of the Human Primary Somatosensory Cortex

The brain in time: insights from neuromagnetic recordings

Consistency and similarity of MEG- and fMRI-signal time courses during movie viewing

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