Engineering Psychology · UTSIC
A pair of grey safety goggles with the lenses replaced by liquid crystal cells. The cells are mounted in place with small screws. An electrical cord emerges from the right side of the goggles The long cord is terminated with one silver coloured three-pin connector.
Accession Number: 2024.ep.26
Liquid-Crystal Tachistoscope; Visual Occlusion Glasses
Primary Materials: Plastic, Glass
A white label on the right side of the goggles includes the following identification number:
Goggles: Height = 7 cm, Width =17cm, Length= 8; The cord is ~4.5m long.
This is a hand-built set of goggles featuring two cholesteric liquid crystal cells. When linked to a controlling circuit and power supply (notably this early unit), it selectively blocks vision as a current is applied to one or both cells, creating a white, opaque field. When the current ceases, the cells return to the transparent state.
The system was originally used to quantify the attentional workload of various tasks. It has since been used in many fields including research in visual perception, neuroscience, sports psychology/training, ergonomic evaluation of interfaces, and more.
This artifact is in good cosmetic condition. The transparent material of the goggle has become tacky and slightly yellowed. The sheathing on the cable is slightly dirty. One of the cells is cloudier than the other.
Associated Instruments:
Dr. Paul Milgram; Organization for Applied Scientific Research of the Dutch National Defence Research Organisation.
Date of Manufacture: c. mid 1980s.
This item was among a small collection of items related to the development of the PLATO visual occlusion goggles donated to the collection by Dr. Paul Milgram on September 11, 2024.
John W. Senders, Kristofferson A. B., Levison W. H., Dietrich C. W., Ward J. L. (1967). The attentional demand of automobile driving. Highway Research Record, 195, 15–32. (Archived March 5. 2025).
Paul Milgram and R Van der Horst. “Alternating-Field Stereoscopic Displays Using Light-Scattering Liquid Crystal Spectacles.” Displays 7, no. 2 (1986): 67–72.
The PLATO (Portable Liquid crystal Apparatus for Tachistoscopic Occlusion) system was developed beginning around 1981 by Professor Paul Milgram. The system is an experimental tool that permits the time controlled occlusion of one or both of a subject’s eyes. The system has various applications, including research in visual perception, neuroscience, sports psychology/training, ergonomic evaluation of interfaces, etc., in addition to its original goal for quantifying the attentional workload of various tasks.
Visual occlusion was pioneered by Dr. John Senders and collaborators in the 1960’s (cited and linked above). Milgram completed his PhD under Senders at UofT in 1980. During his post-doc research, he focused on driving tasks, as Senders had done. This research was done while working at the Institute for Perception of the Dutch Organization for Applied Scientific Research (subsequently TNO Human Factors) in Soesterberg, the Netherlands
At that point, visual occlusion research relied on head mounted mechanical visors, first developed by Senders, to periodically block vision. While at TNO, Milgram developed a goggle-based system using cholesteric liquid crystals to block vision. This was proposed as an alternative to existing twisted-nematic liquid crystal devices and PLZT ceramic-based shutters. In addition to the need for light polarising layers, which significantly reduced the intensity of light transmitted, the former had a relatively slow refresh rate while the latter required very high voltages.
This is prototype version of the system is mentioned in Milgram and Van der Horst 1986. It follows this earlier pair of prototype spectacles, and precedes the production versions of the system.
Milgram returned to Toronto in 1986 to take a faculty position at the Department of Industrial Engineering (currently Mechanical and Industrial Engineering) of the University of Toronto. In 1990, in Toronto, he founded Translucent Technologies Inc., which continues to develop and sell the PLATO system worldwide.
- Donated to UTSIC