PROFILE Profile of Peter H. Schiller n a windowless laboratory on the sixth program in psychology at Clark University floor of the Brain and Cognitive Sci- in Worcester, Massachusetts. Under the Iences Institute of Massachusetts tutelage of psychologist Morton Weiner, Institute of Technology (MIT), neu- Schiller studied the phenomenon of sub- roscientist Peter Schiller lines up visual liminal perception, helping to debunk the stimuli on a computer screen. The stimuli then-rife myth of extrasensory perception are pairs of cues flashed side-by-side, such by demonstrating that subliminal cues as horizontal and vertical lines, upright could trigger neurobiological processes and inverted triangles, and the words “car” underlying certain behaviors, such as and “his.” As Schiller flashes the stimuli people making a bee line to buy soda in on his monitor, a volunteer observes them movie halls when the message “Drink through a stereoscope, which presents one Coca Cola” was briefly flashed between cue in a pair to one eye and the other cue movie frames (1). to the other eye. The volunteer identifies While at Clark University, Schiller the stimuli in order: a cross, the Star of spent his summers at the Austen Riggs David, and the word “chairs.” Then, the Center, an institution for psychotherapy, stereoscope displays groups of dots, some in Stockbridge, Massachusetts, where of which are shifted in position. To the he met George Klein, a professor of volunteer, the shifting dots appear deeper psychology at New York University. At than the rest. Through such experiments the center, Schiller and Klein conducted aimed at identifying people’s ability to experiments on the development of combine visual cues and perceive depth, visual interference in children. Working Schiller, who was elected to the National with more than 200 grade-school and Academy of Sciences in 2007, hopes to Peter H. Schiller uses random-dot stereograms (on college children, Schiller found that visual determine the brain regions involved in wall) to study depth perception. interference, which thwarts people’s binocular integration and depth percep- ability to identify a color when its name tion. The findings from those studies could institute then located in Florida. At the is printed in a different color, wanes help pinpoint the precise time frame Yerkes Laboratory, where he joined his with age (2). when corrective interventions can best father months later, the adolescent Schil- Back at Clark University, Schiller help stereoblind people perceive depth. ler helped his father carry out experi- studied the basis of optical illusions. Beyond uncovering the neurobiological ments in animal behavior. Those early “Illusions are far more complicated than basis of vision, Schiller’s goal is to help forays into brain science research sowed people think, largely because they could restore sight to the blind someday. the seeds of Schiller’s future scientific be generated in the retina or in various Born in Berlin shortly before World War accomplishments. brain regions,” Schiller says. To deter- II, Schiller moved to Budapest, Hungary in Two years later, following the death of mine where in the visual system illusions 1934, when his father, a research psychol- his father, Schiller went to Charleston, occur, Schiller had to present visual ogist, returned to his homeland after a South Carolina to live with his father’s stimuli to experimental subjects in two postdoctoral stint at the University of physician-friend James Anliker. With ways: to each eye separately and to both Berlin. A German-speaking transplant in Anliker’s help, Schiller got a job in the eyes at once. To accomplish this, Schiller Budapest, Schiller at first struggled to anatomy department at Charleston Medi- fashioned an optical tool called a five- memorize Hungarian poems in grammar cal School, where his chores ranged from field tachistoscope. The instrument school but soon mastered his mother feeding monkeys in the animal facility helped reveal that many illusions, such tongue, devouring Hungarian translations to cleaning up after medical students dis- as the Ebbinghaus illusion, in which of Jules Verne’s science-fiction books. secting cadavers. A meeting with Schiller’s identical circles appear different when Schiller’s boyhood years bear testimony to color-blind high-school English teacher surrounded by circles of different sizes, his budding scientific temperament. At piqued Schiller’s early interest in vision. occur in the brain’s visual cortex rather the age of 12, he found a ball lost during “When Mr. Gibbs told me he was pulled than in the retina. play by using an identical one to retrace the over by a cop for running a red light that Extending his findings on illusions, path to where the lost ball lay hidden. As he had presumed was green, I became Schiller trained his new tool on a phe- a teenager, he cobbled together a Morse intrigued—even more so when I learned nomenon called masking, which reduces code-based communication system to ex- that color blindness is more common the visibility of an object shown to people change surreptitious messages with his among males than females,” Schiller says. milliseconds before a second object, cousin, whom he was sometimes forbidden known as a “masking” object, is shown. to see. When he was not devising science- Eye on Vision Vision researchers knew that masking based ploys for play, Schiller spent starlit Schiller struggles to pinpoint the precise could arise from differences in brightness, nights in his uncle’s hilltop backyard with point when he embarked on his decades- pattern, and contrast related to the two a map of the sky, gazing at constellations. long career in vision research, but his objects, but where in the visual system Growing up in war-torn Hungary, undergraduate studies in psychology at masking originates was a mystery. Schil- Schiller witnessed the ravages wrought by Duke University are a good starting point. ler’s tachistoscope helped answer that the Russian invasion of Budapest. Facing As an undergraduate, Schiller studied the question (3). “We found that brightness bleak prospects for a scientific career in ability of fish to see colors, his first formal a harsh political climate, Schiller’s father attempt to study vision scientifically. fled the country in 1947 for the United After graduating from Duke University, This is a Profile of a recently elected member of the Na- States, where he worked as a researcher at Schiller spent a year in Germany on mil- tional Academy of Sciences to accompany the member’s the Yerkes Laboratory, a primate research itary duty before enrolling in a graduate Inaugural Article on page 17087 in issue 40 of volume 107. www.pnas.org/cgi/doi/10.1073/pnas.1101955108 PNAS Early Edition | 1of3 Downloaded by guest on October 2, 2021 masking occurred only when both visual ments by virtue of high-frequency bursts responding to rises and drops in the stimuli were presented to the same eye, that rapidly contract the muscle; the amount of light. Objects absorb and re- suggesting that it occurred in the retina, duration of the burst defines the ampli- flect different wavelengths of light, alter- whereas pattern masking and metacon- tude of the saccade,” Schiller says. “That ing the number of photons of light enter- trast masking occurred even when dif- work led to a basic understanding of how ing eyes trained on them. The ON/OFF ferent stimuli were presented to the two the brain’s oculomotor complex drives the system, Schiller found, helps the eyes eyes, suggesting that it occurred in the eyes,” he adds. perceive changes in light intensity (8). brain,” Schiller says. Schiller parlayed Soon thereafter, another brain structure “We did experiments that selectively these wide-ranging studies into a PhD driving the eyes became the focus of blocked one channel and found that the ’ “ degree in psychology from Clark Univer- Schiller s interest. Dubbed the superior ON channel responds to light increment, ” sity in 1962. colliculus, this many-layered nub of whereas the OFF channel responds to brain tissue serves as a source of saccades ” MIT-Bound light decrement, Schiller says. Those in primates. Schiller found that macaques seemingly mundane findings underlie After a brief interlude of clinical work without a superior colliculus were slow to revelatory “Aha!” moments when applied with mentally ill patients at Worcester execute saccades, whereas macaques to real-world scenarios. Thanks to the State Hospital, Schiller began angling for with lesions in the frontal eye field had OFF channel, people can read print, postdoctoral research opportunities. trouble selecting targets in a visual scene. which usually contains dark characters Hans-Lukas Teuber, then recently ap- Removing both regions scotched all sac- on a light background; reading dark pointed chair of the psychology depart- cades (5). These findings helped lay the ment at MIT, invited Schiller to perform foundation for an overarching scheme for characters in succession signals light “ decrement to the retina. Thanks to the postdoctoral research on the mechanism the neural control of saccades (6): There fi of visual masking in the brain. There, are two brain systems involved in gener- ON channel, a sh in the ocean can spot Schiller mastered a method for recording ating saccades. One helps select targets its predator in murky waters through the ’ electrical activity from individual brain in the visual scene to which the eyes light bouncing off the predator s body; fl cells in cats and monkeys by using varnish- must be directed, and the other gener- the re ection signals light increment to “ coated tungsten microelectrodes that ates saccades to sudden visual cues,” the retina. The ON/OFF system is helped shed light on the mechanism of Schiller says. crucial for survival for virtually every brightness masking. Later, in partnership species, except maybe for largely noctur- with MIT psychologist Steven Chorover, Midgets, Parasols, and Toggle Switches nal animals,” Schiller says.