Enhanced Category Tuning Revealed by Intracranial Electroencephalograms in High-Order Human Visual Areas

Privman, Eran; Nir, Yuval; Kramer, Uri; Kipervasser, Svetlana; Andelman, Fani; Neufeld, Miri Y.; Mukamel, Roy; Yeshurun, Yehezkel; Fried, Itzhak; Malach, Rafael

doi:10.1523/jneurosci.4627-06.2007

Cited by 69 publications

(79 citation statements)

References 44 publications

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“…Previous studies using invasive recordings have demonstrated that the BOLD signal correlates positively with the signal power of highfrequency local field potentials (LFPs) measured from both auditory cortex (Mukamel et al, 2005;Nir et al, 2007) and visual cortex (Privman et al, 2007) during movie viewing. In addition, the signal power of low-frequency LFPs correlated negatively with BOLD signal (Mukamel et al, 2005).…”

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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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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“…2, Privman et al, 2007) in which images from four categories were presented pseudo randomly at a rate of one image per second -each presented for 250 ms and followed by a gray screen for an interval of 750 ms. The patients were requested to press a computer mouse button whenever two consecutive pictures were identical and to refrain from pressing in any other case.…”

Section: Stimuli and Taskmentioning

confidence: 99%

“…1 using a particularly large set of intracranial ECoG recordings encompassing thousands of contacts. Such approach offers both high temporal resolution, good cortical localization (Privman et al, 2007) and extensive coverage of cortical areas. Our study consisted of a large cohort of patients (43) all of which performed The models are presented in the framework of three peaks of activations: an early ($100 ms post stimulus presentation) peak localized to early visual areas (EVA), an intermediate peak ($200 ms) localized to high order visual areas (HVA) and finally a late peak ($300 ms) localized to the global work space at the fronto-parietal cortex (GWS).…”

Section: Introductionmentioning

confidence: 99%

Ignition’s glow: Ultra-fast spread of global cortical activity accompanying local “ignitions” in visual cortex during conscious visual perception

Noy

Bickel

Zion-Golumbic

et al. 2015

Consciousness and Cognition

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“…Following Mukamel et al (2005), Sawamura et al (2006), andPrivman et al (2007), we estimated the BOLD response by convolving the population response in the size task (Fig. 3) with a standard canonical hemodynamic response function (Boynton et al, 1996).…”

Section: Simulating Bold Responsementioning

confidence: 99%

Stimulus Similarity-Contingent Neural Adaptation Can Be Time and Cortical Area Dependent

Verhoef¹,

Kayaert²,

Frankó³

et al. 2008

J. Neurosci.

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Repetition of a stimulus results in decreased responses in many cortical areas. This so-called adaptation or repetition suppression has been used in several human functional magnetic resonance imaging studies to deduce the stimulus selectivity of neuronal populations. We tested in macaque monkeys whether the degree of neural adaptation depends on the similarity between the adapter and test stimulus. To manipulate similarity, we varied stimulus size. We recorded the responses of single neurons to different-sized shapes in inferior temporal (IT) and prefrontal cortical (PFC) areas while the animals were engaged in a size or shape discrimination task. The degree of response adaptation in IT decreased with increasing size differences between the adapter and the test stimuli in both tasks, but the dependence of adaptation on the degree of similarity between the adapter and test stimuli was limited mainly to the early phase of the neural response in IT. PFC neurons showed only weak size-contingent repetition effects, despite strong size selectivity observed with the same stimuli. Thus, based on the repetition effects in PFC, one would have erroneously concluded that PFC shows weak or no size selectivity in such tasks. These findings are relevant for the interpretation of functional magnetic resonance adaptation data: they support the conjecture that the degree of adaptation scales with the similarity between adapter and test stimuli. However, they also show that the temporal evolution of adaptation during the course of the response, and differences in the way individual regions react to stimulus repetition, may complicate the inference of neuronal tuning from functional magnetic resonance adaptation.

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Enhanced Category Tuning Revealed by Intracranial Electroencephalograms in High-Order Human Visual Areas

Cited by 69 publications

References 44 publications

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

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

Ignition’s glow: Ultra-fast spread of global cortical activity accompanying local “ignitions” in visual cortex during conscious visual perception

Stimulus Similarity-Contingent Neural Adaptation Can Be Time and Cortical Area Dependent

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