Immediate effect of quadri-pulse stimulation on human brain microstructures and functions.

It remains unclear whether repetitive stimulation of a single brain area immediately alters brain microstructure. Thus, we investigated the immediate changes in human brain microstructures following repetitive extrinsic excitation of the left primary motor cortex (M1) through quadri-pulse stimulation (QPS). Sixteen right-handed healthy adults underwent excitatory (QPS5) and inhibitory (QPS50) QPS.

Neural Mechanisms of Feedback Processing and Regulation Recalibration During Neurofeedback Training.

The acquisition of new skills is facilitated by providing individuals with feedback that reflects their performance. This process creates a closed loop that involves feedback processing and regulation recalibration to promote effective training. Functional magnetic resonance imaging (fMRI)-based neurofeedback is unique in applying this principle by delivering direct feedback on the self-regulation of brain activity.

Prediction of Alpha Power Using Multiple Subjective Measures and Autonomic Responses.

Alpha oscillations are associated with various cognitive functions. However, the determinants of alpha power variation remain ambiguous, primarily due to its inconsistent associations with autonomic responses and subjective states under different experimental conditions. To thoroughly examine the correlations between alpha power variation and these factors, we implemented a range of experimental conditions, encompassing attentional and emotional tasks, as well as a resting-state.

Internal State Estimation via Physiological Data and Their Modulation by Environmental Context during Social Activity.

Understanding individuals' internal cognitive states during group interactions is crucial for enhancing group dynamics and communication. This study investigated internal states by analyzing physiological data-EEG, electrocardiography, and pupil size-collected from high school students during group discussions. Using a data-driven clustering method, we identified four distinct internal states, each corresponding to the different power distributions in the four frequency bands of EEG activity.

Decoding time-resolved neural representations of orientation ensemble perception.

The visual system can compute summary statistics of several visual elements at a glance. Numerous studies have shown that an ensemble of different visual features can be perceived over 50-200 ms; however, the time point at which the visual system forms an accurate ensemble representation associated with an individual's perception remains unclear. This is mainly because most previous studies have not fully addressed time-resolved neural representations that occur during ensemble perception, particularly lacking quantification of the representational strength of ensembles and their correlation with behavior.

The relationship between alpha power and heart rate variability commonly seen in various mental states.

The extensive exploration of the correlation between electroencephalogram (EEG) and heart rate variability (HRV) has yielded inconsistent outcomes, largely attributable to variations in the tasks employed in the studies. The direct relationship between EEG and HRV is further complicated by alpha power, which is susceptible to influences such as mental fatigue and sleepiness. This research endeavors to examine the brain-heart interplay typically observed during periods of music listening and rest.

Theoretical and Technical Issues Concerning the Measurement of Alpha Frequency and the Application of Signal Detection Theory: Comment on Buergers and Noppeney (2022).

Classical and recent evidence has suggested that alpha oscillations play a critical role in temporally discriminating or binding successively presented items. Challenging this view, Buergers and Noppeney [Buergers, S., & Noppeney, U.

Macromolecular tissue volume mapping of lateral geniculate nucleus subdivisions in living human brains.

The lateral geniculate nucleus (LGN) is a key thalamic nucleus in the visual system, which has an important function in relaying retinal visual input to the visual cortex. The human LGN is composed mainly of magnocellular (M) and parvocellular (P) subdivisions, each of which has different stimulus selectivity in neural response properties. Previous studies have discussed the potential relationship between LGN subdivisions and visual disorders based on psychophysical data on specific types of visual stimuli.

Can enhancement and suppression concurrently guide attention? An assessment at the individual level.

Background: Although people can pay attention to targets while ignoring distractors, previous research suggests that target enhancement and distractor suppression work separately and independently. Here, we sought to replicate previous findings and re-establish their independence.

Methods: We employed an internet-based psychological experiment.

Building a decoder of perceptual decisions from microsaccades and pupil size.

Many studies have reported neural correlates of visual awareness across several brain regions, including the sensory, parietal, and frontal areas. In most of these studies, participants were instructed to explicitly report their perceptual experience through a button press or verbal report. It is conceivable, however, that explicit reporting itself may trigger specific neural responses that can confound the direct examination of the neural correlates of visual awareness.

Frequency- and phase-dependent effects of auditory entrainment on attentional blink.

Attentional blink (AB) is the impaired detection of a second target (T2) after a first target has been identified. In this paper, we investigated the functional roles of alpha and theta oscillations on AB by determining how much preceding rhythmic auditory stimulation affected the performance of AB. Healthy young adults participated in the experiment online.

Microstructural Properties of Human Brain Revealed by Fractional Anisotropy Can Predict the After-Effect of Intermittent Theta Burst Stimulation.

Intermittent theta burst stimulation (iTBS) delivered by transcranial magnetic stimulation (TMS) produces a long-term potentiation-like after-effect useful for investigations of cortical function and of potential therapeutic value. However, the iTBS after-effect over the primary motor cortex (M1) as measured by changes in motor evoked potential (MEP) amplitude exhibits a largely unexplained variability across individuals. Here, we present evidence that individual differences in white matter (WM) and gray matter (GM) microstructural properties revealed by fractional anisotropy (FA) predict the magnitude of the iTBS-induced after-effect over M1.

V1 Projection Zone Signals in Human Macular Degeneration Depend on Task Despite Absence of Visual Stimulus.

Identifying the plastic and stable components of the visual cortex after retinal loss is an important topic in visual neuroscience and neuro-ophthalmology. Humans with juvenile macular degeneration (JMD) show significant blood-oxygen-level-dependent (BOLD) responses in the primary visual area (V1) lesion projection zone (LPZ), despite the absence of the feedforward signals from the degenerated retina. Our previous study reported that V1 LPZ responds to full-field visual stimuli during the one-back task (OBT), not during passive viewing, suggesting the involvement of task-related feedback signals.

Atypical spatial frequency dependence of visual metacognition among schizophrenia patients.

Although altered early stages of visual processing have been reported among schizophrenia patients, how such atypical visual processing may affect higher-level cognition remains largely unknown. Here we tested the hypothesis that metacognitive performance may be atypically modulated by spatial frequency (SF) of visual stimuli among individuals with schizophrenia, given their altered magnocellular function. To study the effect of SF on metacognitive performance, we asked patients and controls to perform a visual detection task on gratings with different SFs and report confidence, and analyzed the data using the signal detection theoretic measure meta-d'.

Inter-individual Differences in Occipital Alpha Oscillations Correlate with White Matter Tissue Properties of the Optic Radiation.

Neural oscillations at ∼10 Hz, called alpha oscillations, are one of the most prominent components of neural oscillations in the human brain. In recent years, characteristics (power/frequency/phase) of occipital alpha oscillations have been correlated with various perceptual phenomena. However, the relationship between inter-individual differences in alpha oscillatory characteristics and the properties of the underlying brain structures, such as white matter pathways, is unclear.

Threat Anticipation in Pulvinar and in Superficial Layers of Primary Visual Cortex (V1). Evidence from Layer-Specific Ultra-High Field 7T fMRI.

The perceptual system gives priority to threat-relevant signals with survival value. In addition to the processing initiated by sensory inputs of threat signals, prioritization of threat signals may also include processes related to threat anticipation. These neural mechanisms remain largely unknown.

Microstructural properties of the vertical occipital fasciculus explain the variability in human stereoacuity.

Stereopsis is a fundamental visual function that has been studied extensively. However, it is not clear why depth discrimination (stereoacuity) varies more significantly among people than other modalities. Previous studies have reported the involvement of both dorsal and ventral visual areas in stereopsis, implying that not only neural computations in cortical areas but also the anatomical properties of white matter tracts connecting those areas can impact stereopsis.

A non-invasive, quantitative study of broadband spectral responses in human visual cortex.

Currently, non-invasive methods for studying the human brain do not routinely and reliably measure spike-rate-dependent signals, independent of responses such as hemodynamic coupling (fMRI) and subthreshold neuronal synchrony (oscillations and event-related potentials). In contrast, invasive methods-microelectrode recordings and electrocorticography (ECoG)-have recently measured broadband power elevation in field potentials (~50-200 Hz) as a proxy for locally averaged spike rates. Here, we sought to detect and quantify stimulus-related broadband responses using magnetoencephalography (MEG).

[Modulation of Metacognition with Decoded Neurofeedback].

Humans often assess their confidence in their own perception, e.g., feeling "confident" or "certain" of having seen a friend, or feeling "uncertain" about whether the phone rang.

Illusory Jitter Perceived at the Frequency of Alpha Oscillations.

Neural oscillations, such as alpha (8-13 Hz), beta (13-30 Hz), and gamma (30-100 Hz), are widespread across cortical areas, and their possible functional roles include feature binding [1], neuronal communication [2, 3], and memory [1, 4]. The most prominent signal among these neural oscillations is the alpha oscillation. Although accumulating evidence suggests that alpha oscillations correlate with various aspects of visual processing [5-18], the number of studies proving their causal contribution in visual perception is limited [11, 16-18].