Behavior Analysis on the Mov(i)e with 16-millimeter Film

Historians’ Corner contributed by Dr. Andy Lattal

Andy Lattal
West Virginia University
Cambridge Center for Behavioral Studies, Member, Board of Directors

What do the Normandy Invasion and B. F. Skinner’s ping-pong playing pigeons have in common? If you said that they both happened during the Second World War you would be only partially correct. In addition to their temporal proximity in history, images of both events were recorded and preserved on 16-millimeter (mm) film.

Credit for discovering how to capture and preserve moving visual images is shared among several late 19^th century inventors, including, as first among equals in the eyes of many, Louis Le Prince in England, followed by the Luminaire brothers, Auguste and Louis, of France and Thomas Edison of the United States (see Fischer, 2023; Most of the earliest film was 35-mm wide, like your parents or grandparents old still camera, or about so ————————– wide.

This width became popular with Hollywood “moving picture” makers because its large size allowed images filmed with it to be projected sharply onto screens located at a distance from the projector. Both cameras and film, however, were large, bulky and expensive. The cameras precluded mobility and spontaneous use. Over 100 years ago, in 1923, the Eastman Kodak Company introduced 16 mm film, cameras, and projectors that were an immediate hit because they were relatively inexpensive, mobile, and could be used without laborious set up. It also was safer because instead of using highly flammable cellulose nitrate, its base was noncombustible acetate plastic (Wallace, undated). Sixteen millimeters is like so: ————

Although largely replaced by other technologies, 16-mm film remains the medium of choice of several smaller- and Avant-Garde film directors on the east and west coasts of the United States (Girish, 2023).

There were a number of 16-mm films made of Skinner’s experiments for Project Pelican, in which pigeons were trained to keep a bomb centered on its target as part of a World War II research program sponsored by the U. S. Navy (see Skinner, 1960; also Figure 1). All of these films, as well as famous images of his pigeons playing ping pong are an important part of Skinner’s legacy to our discipline. These images, some available on the B. F. Skinner Foundation website, “bring to life” aspects of behavior that cannot be captured by words, graphs, or even photographs because they provide a permanent record of what the organism is actually doing in real time.

Figure 1. Device for tracking head movements of a pigeon designed for Skinner’s Pigeon in a Pelican project.

The humble 16-mm film’s contributions to behavior analysis, however, did not end with Skinner’s lab movies. One can only speculate that perhaps Skinner’s filming of other activities resulted in rolls of 16-mm film left about the lab that in turn led some clever, tinkering lab type or types to come up with what follows based on that 16-mmm film-rich environment in which that person or persons found themselves.

Variable-interval and variable-ratio schedules require reinforcer availability to be spaced unevenly in time from one another. One way of doing this, someone discovered probably in the late 1940s or early 1950s, was to place holes unevenly in a length of 16-mm film and then making the length into a continuous loop by glueing the ends together. The loop then was placed in a reader, like that shown in Figure 2, that allowed it to be fed through a sprocket, identical to that found on 16-mm film projectors, at a constant speed (for variable-interval schedules) or to be moved a fixed length with each response (for variable-ratio schedules). Attached to the top of the reader was a microswitch that was mechanically held in the inoperative position by the portion of the tape without a hole. When a hole aligned with the switch, the switch arm fell into the hole. This sent a signal to other programming modules that made a reinforcer available following the next response. This method of programming VI and VR schedules was the standard in operant labs for many years, until the digital computer allowed intervals and response numbers to be programmed with a few lines of code.

Figure 2. A device for programming a variable-interval or variable-ratio schedule. See text for construction and operation details.

One problem with using actual film for these VI and VR “tapes,” as they came to be called, was that they became brittle and cracked over time. The solution was to use, instead of the actual film, a strip of film leader, shown in Figure 3. So that a movie film would start at the beginning when the projector was turned on, the film was preceded by a long strip of this film leader that was threaded through the projector. The leader was more malleable and less prone to crack or split, but otherwise identical to the film itself. Film leader VI tapes constructed in the 1960s remain intact today.

Figure 3. A roll of Kodak 16 mm film leader that was used to construct “tapes” that arranged reinforcers according to variable-interval or variable-ratio schedules.

Variable-interval or -ratio schedules were constructed by placing the holes in the tape irregularly. This often was done by calculating the number of holes needed in a given length of film to obtain the desired average interreinforcer interval or response count. The holes then were placed (punched with a paper hole punch) by “eyeballing” their location relative to one another, some closer together and others further apart. Perhaps the most famous placement of the holes for creating a VI schedule was accomplished by the so-called “Harvard golden tape” described by Catania and Reynolds (1968) as one

The 16-mm tape thus played an instrumental role in not only recording some of the most important demonstration of the power of a science of behavior, but also in establishing the place of that science in the world of ideas and of applications.

References