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Functional magnetic resonance imaging (fMRI) is currently the mainstay of neuroimaging in cognitive neuroscience. Advances in scanner technology, image acquisition protocols, experimental design, and analysis methods promise to push forward [...]

Author(s): Stelios M. Smirnakis (corresponding author) [1, 2]; Alyssa A. Brewer [3]; Michael C. Schmid [1]; Andreas S. Tolias [1]; Almut Schüz [1]; Mark Augath [1]; Werner Inhoffen [4]; Brian [...]

A Correction to this paper has been published: https://doi.org/10.1038/s41586-020-03068-9., Author(s): Juan F. Ramirez-Villegas [sup.1] [sup.2] [sup.8] , Michel Besserve [sup.1] [sup.3] , Yusuke Murayama [sup.1] [sup.4] , Henry C. Evrard [sup.1] [sup.4] [sup.5] [sup.6] , Axel Oeltermann [sup.1] , [...]

Author(s): Nikos K. Logothetis (corresponding author); Jon Pauls; Mark Augath; Torsten Trinath; Axel Oeltermann Since its inception [1, 2, 3, 4, 5] BOLD fMRI has generated interest not only as [...]

The competition for perceptual dominance during binocular rivalry occurs between the two stimuli in the eyes rather than between the eyes themselves. The perceptual changes caused by quickly alternating rival stimuli between the two eyes is similar to the temporal dynamic of stationary objects. There is a single phase of dominance for multiple changes in the stimuli. Thus, binocular rivalry is a general multistable phenomena.

Interaction between binocular neurons during various visual pathways produces binocular rivalry in monkeys. A quantitative analysis of various responses reveal that a distinct level of cells exhibits distinct responses to rivalrous and congruent stimuli. Analysis of perception-associated modulation in visual cortical areas V1, V2 and V4 of monkeys indicates that the V4 visual cortex area exhibits patterns of suppression and dominance of one stimulus.

The hippocampus has a major role in encoding and consolidating long-term memories, and undergoes plastic changes during sleep1. These changes require precise homeostatic control by subcortical neuromodulatory structures2. The underlying mechanisms of this phenomenon, however, remain unknown. Here, using multi-structure recordings in macaque monkeys, we show that the brainstem transiently modulates hippocampal network events through phasic pontine waves known as pontogeniculooccipital waves (PGO waves). Two physiologically distinct types of PGO wave appear to occur sequentially, selectively influencing high-frequency ripples and low-frequency theta events, respectively. The two types of PGO wave are associated with opposite hippocampal spike-field coupling, prompting periods of high neural synchrony of neural populations during periods of ripple and theta instances. The coupling between PGO waves and ripples, classically associated with distinct sleep stages, supports the notion that a global coordination mechanism of hippocampal sleep dynamics by cholinergic pontine transients may promote systems and synaptic memory consolidation as well as synaptic homeostasis. Studies using multi-structure recordings in macaque monkeys show that distinct phasic pontogeniculooccipital waves modulate hippocampal network events similar to those that underlie the learning and formation of memories during sleep. [ABSTRACT FROM AUTHOR]

In primates, including man, the color-opponent and broad-band channels involved in vision begin in the retina of the eye, and continue to the brain through several different neural stations. Research from single cells has shown that the ganglia (nerve cells in the retina that comprise the color component) have small receptive fields, respond for prolonged periods of time, and receive inputs from different spatially segregated cells, known as cones. The broad-band cells have large receptive fields, respond for short periods of time, and receive impulses from cones that are not separated. The visual capacities of rhesus monkeys were examined before and after disrupting areas of the brain (where the various channels are located) with small lesions. It was shown that the color-opponent channels are necessary for the processing of color and texture, the discrimination of fine patterns, and seeing objects in three dimensions. The broad-band channels are essential for perception of motion. Neither of the channels is involved in the discrimination of brightness, the processing of coarse shapes, and contrast sensitivity. These studies have increased the understanding of vision, and can lead to applications in the treatment of various medical problems relating to vision. (Consumer Summary produced by Reliance Medical Information, Inc.)

Author(s): Asif A. Ghazanfar (corresponding author); Nikos K. Logothetis The perception of human speech can be enhanced by a combination of auditory and visual signals [1, 2]. Animals sometimes accompany [...]