We make fast, ballistic eye movements called saccades more often than our heart beats. Although every saccade causes a large movement of the image environment on retina, we never perceive this motion. This aspect perceptual stability is referred to as saccadic suppression: reduction visual sensitivity around time saccades. Here, investigated neural basis phenomenon with extracellular recordings from awake, behaving monkeys in middle temporal, medial superior ventral intraparietal, and...

Transcranial electrical stimulation (tES) is a promising therapeutic tool for range of neurological diseases. Understanding how the small currents used in tES spread across scalp and penetrate brain will be important rational design therapies. Alternating applied transcranially above visual cortex induce perception flashes light (phosphenes). This makes system useful model to study tES. One hypothesis that generates phosphenes by direct underneath transcranial electrode. Here, we provide...

The visual system adapts to its environment. Some adaptive changes are detrimental-perception is no longer veridical. Others beneficial-the ability discriminate two stimuli improves. latter may reflect the system's zoom-in on currently relevant properties of We studied neural basis in middle temporal area (MT) macaque monkey cortex. Our data show that brief adaptation a moving stimulus reduces magnitude responses and width speed tuning curves. Comparable with what has recently been reported...

When cartoonists use speed lines—also called motion streaks—to suggest the of a stationary object, they form to imply motion. The goal this study was investigate mechanisms that mediate percept implied in human visual cortex. In an adaptation functional imaging paradigm we presented Glass patterns that, just like lines, but do not on average contain coherent energy. We found selective these complex, lateral occipital complex (LOC), and earlier areas. both local orientation features global...

A car driving through the fog appears to move more slowly than one on a clear and sunny day. In laboratory, this observation has been confirmed as pronounced reduction of perceived speed caused by in contrast. We measured influence contrast cells middle temporal area (MT) macaque, which hypothesized underlie perception speed. The responsiveness tuning these was pervasive highly regular. As expected, most responded less at low More importantly, preferred shifted lower speeds contrasts....

Transcranial alternating current stimulation (tACS) is used in clinical applications and basic neuroscience research. Although its behavioral effects are evident from prior reports, understanding of the mechanisms that underlie these limited. We motion perception, a percept with relatively well known properties underlying neural to investigate tACS mechanisms. Healthy human volunteers showed surprising improvement sensitivity when visual stimuli were paired 10 Hz tACS. In addition, reduced...

We previously showed that brief application of 2 mA (peak-to-peak) transcranial currents alternating at 10 Hz significantly reduces motion adaptation in humans. This is but one many behavioral studies showing weak applied to the scalp modulate neural processing. Transcranial stimulation has been shown improve perception, learning, and a range clinical symptoms. Few studies, however, have measured consequences current stimulation. capitalized on strong link between perception activity middle...

Eagleman and Sejnowski ([1][1]) showed that the flash-lag effect ([2][2], [3][3])—a visual illusion in which two objects physically at same location appear to be offset because of differing motion trajectories—cannot explained by latency correction ([4][4]) or differential latencies

Eye-position signals (EPS) are found throughout the primate visual system and thought to provide a mechanism for representing spatial locations in manner that is robust changes eye position. It remains unknown, however, whether cortical EPS (also known as "gain fields") have necessary temporal characteristics fulfill their purported computational roles. To quantify these EPS, we combined single-unit recordings four dorsal areas of behaving rhesus macaques (lateral intraparietal area, ventral...

Recent stimulus history, or adaptation, can alter neuronal response properties. Adaptation effects have been characterized in a number of visually responsive structures, from the retina to higher visual cortex. However, it remains unclear whether adaptation across stages system take similar form particular sensory event. This is because studies typically probe single structure cortical area, using ensemble chosen provide potent drive cells interest. Here we adopt an alternative approach and...