According to recent functional magnetic resonance imaging (fMRI) studies, spectators of a movie may share similar spatiotemporal patterns of brain activity. We aimed to extend these findings of intersubject correlation to temporally accurate single-trial magnetoencephalography (MEG). A silent 15-min black-and-white movie was shown to eight subjects twice. We adopted a spatial filtering model and estimated its parameter values by using multi-set canonical correlation analysis (M-CCA) so that the intersubject correlation was maximized. The procedure resulted in multiple (mutually uncorrelated) time-courses with statistically significant intersubject correlations at frequencies below 10 Hz; the maximum correlation was 0.28 ± 0.075 in the ≤1 Hz band. Moreover, the 24-Hz frame rate elicited steady-state responses with statistically significant intersubject correlations up to 0.29 ± 0.12. To assess the brain origin of the across-subjects correlated signals, the time-courses were correlated with minimum-norm source current estimates (MNEs) projected to the cortex. The time series implied across-subjects synchronous activity in the early visual, posterior and inferior parietal, lateral temporo-occipital, and motor cortices, and in the superior temporal sulcus (STS) bilaterally. These findings demonstrate the capability of the proposed methodology to uncover cortical MEG signatures from single-trial signals that are consistent across spectators of a movie.

Transcranial magnetic stimulation (TMS) is a non-invasive tool to perturb brain activity. In TMS studies, the stimulation intensity (SI) is commonly normalized to the resting motor threshold (rMT) that produces muscle responses in 50% of stimulations applied to the motor cortex (M1). Since rMT is influenced by spinal excitability and coil-to-cortex distance, responses recorded from the cortex, instead of a peripheral muscle, could provide a more accurate marker for cortical excitability. Combining TMS with electroencephalography (EEG) enables the measurement of brain-wide cortical reactivity to TMS. We quantified TMS-induced changes in oscillatory power and the phase of EEG with event-related spectral perturbation (ERSP) and inter-trial coherence (ITC). We studied the SI-dependency of ERSP and ITC responses by stimulating the dominant M1 of ten healthy volunteers using single-pulse TMS with 150 pulses at 60%, 80%, 100%, and 120% of rMT. We found SI-dependent ERSP and ITC responses in M1, most notably with the wide-band (8-70 Hz) early ITC responses averaged 20-60 ms after TMS. With approximately linear SI-dependence, the early ITC response was consistent between SIs (intraclass correlation = 0.78, ). Our results reveal the potential of oscillatory EEG responses, in place of rMT, as a measure of the cortical excitability threshold in M1.

ABSTRACT.Purpose: To assess three novel digital fundus cameras for diabetic retinopathy (DR) screening. Methods: Digital colour and red-free retinal imaging (Topcon TRC 50 IA, Canon CR6À45NM, and MediTell) was used to capture 427 images of 70 diabetes patients and control subjects. The images were graded for DR by three readers in a randomized and masked manner using a modified Early Treatment Diabetic Retinopathy Study classification. The reference standard was based on mydriatic ophthalmoscopy and colour and red-free images. Results: Digital 50 red-free imaging had sensitivity of 97.7%, two-field 50 colour imaging 94.0%, and two-field 45 colour imaging sensitivity of 88.9%. The specificity of these imaging modalities was 98.9À100%, and ungradeable images represented 1.2À1.6%. The hand-held digital colour videocamera (MediTell) showed a sensitivity of 6.9% and ungradeable images represented 92.3% Conclusion: Digital 50 red-free and two-field 50 or 45 colour imaging were suitable for DR screening, whereas the hand-held digital videocamera did not fulfil the needs of DR screening.

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.,

ABSTRACT.Purpose: To determine the concentration of group IIA phospholipase A 2 (GIIAPLA 2 ) in tears of patients with ocular rosacea, and to compare it with GIIAPLA 2 concentration in tears of age-matched healthy controls. Methods: The GIIAPLA 2 concentration in tears was measured with a timeresolved fluoroimmunoassay in 21 patients with ocular rosacea (mean age 55.6±9.2 years) and in 21 normal subjects (mean age 53.4±8.2 years). Conjunctival brush cytology was carried out and eosinophils, neutrophils, lymphocytes, squamous epithelial cells, columnar epithelial cells, metaplastic changes and goblet cells were calculated separately. Results: The GIIAPLA 2 concentration in tears was statistically significantly lower in patients with ocular rosacea (31.0±18.4 mg/ml, p=0.0099) and, more specifically, in patients who had dry eye (25.8±15.1 mg/ml, p=0.0034), compared to that in normal controls. There was no correlation between the GIIAPLA 2 content of tears and the conjunctival cells collected by the brush cytology. Conclusion: The tears of patients with dry eye symptoms due to ocular rosacea have decreased GIIAPLA 2 content. The pathogenic importance of this finding is discussed.

Results indicate reduced flow at the time of DH and increased flow after resorption.

Cup reversal seemed to be an independent protective factor for progression of glaucoma.

No difference in peripapillary retinal blood flow between progressive and stable ExG could be found.