A group of scientists have been working on a less complex variety of string theory. Instead of dealing with theoretical physics, their research, involving a touch screen, aims to prove the perceptual and cognitive capabilities of animals, pigeons in particular. Tests of such human abilities have relied on patterned string tasks whereby one string is attached to a reward, while another is not. In this experiment, pigeons got fed by pulling the correct string in a virtual environment by pecking on a touch screen.

The research team is composed of Edward A. Wasserman, Professor of Experimental Psychology, University of Iowa, with Yasuo Nagasaka, Leyre Castro and Stephen J. Brzykcy. They believe there may be special merits to this technological environment. Hundreds of testing set ups were undertaken. The numerous repetitions would have been difficult to conduct with conventional manual methods that have been used on other bird species and several mammals.

The most difficult test is the Crossed String task

The pigeons faced a 15-in LCD monitor located behind an 5-wire AccuTouch resistive touch screen from Elo TouchSystems. The monitor is advertised to be good for 35 million finger touches. They didn?t say how many pigeon pecks it could survive. Its 4H coversheet hardness rating should have protected it from scratches from the birds? beaks.

Elographics, now Elo TouchSystems, was founded by Bill Cowell and Sam Hurst, while working out of a basement in the 1970?s, They soon obtained a patent for the separator dot which became the transparent technology known as AccuTouch. As the company grew over the years, their screens have been put to the test by humans and recently by pigeons.

Decades old, second generation AccuTouch touch screen with the proprietary "T pattern" for linearization, which eliminated hand-soldered diodes around the edge.

Pecks to the touch screen were processed by a serial controller board outside the box. The AccuTouch 2218 Combo ? Dual Serial/USB ? Controller offers EIA 232E (Serial RS-232), DCE configuration. 8 data bits, 1 stop bit, no parity, full duplex and RTS/CTS handshaking.

The pigeons were rewarded with food pellets via a rotary dispenser through a vinyl tube into a food dish located in the center of the rear wall opposite the touch screen. The pellet dispenser was controlled by a digital I/O interface board. Each experimental chamber was controlled by an Apple iMac computer. The programs used in the experiments were developed in MatLab with Psychtoolbox-3 extensions.

Dr. Wasserman has been a ‘go to’ expert in comparative cognition. In his recent series of testing, the birds were offered a choice of acting on multiple virtual strings which were distinctively different from one another. This author questioned if color was the deciding factor in the pigeons? choice. However, Dr. Wasserman said that color and spatial position of each string was randomly associated with the full and empty bowl. The response ‘buttons’ where the pigeons were to touch the screen, however, were identical.

By pecking one of the buttons, the bird had to select the string ‘attached’ to the image which indicated a full food bowl to reel the bowl in and cause the pellets to drop. A black image attached to the other string was used to indicate an empty bowl.

The pigeons were ‘trained’ how peck the screen to achieve a reward before progressing to the string related assignments. At first, the strings were arranged in patterns that were perpendicular and non-perpendicular. The hardest test came when the strings were crossed. Until given more intense training, the pigeons did not effectively transfer their virtual string-pulling behavior from their previous successes with the simpler patterns. Eventually, their percentage of correct responses increased.

The research group stated that, ?We therefore believe that our virtual patterned-string task represents a promising innovation in comparative and developmental psychology. It may permit expanded exploration of other species and variables which would otherwise be unlikely because of inadequacies of conventional string task methodology or sensorimotor limitations."