Name: Public defence: Laurilyn D. Jones
Start: 2019-09-26
End: 2019-09-26

Trial lecture title: Stimulus Discrimination and Conditional Discrimination.

Th ordinary opponents are:

First opponent: Professor Sigrid S. Glenn, University of North Texas, USA
Second opponent: Professor Robert C. Mellon,Panteion University of Social and Political Sciences, Greece
Leader of the committee: Associate Professor Børge Strømgren, OsloMet, Norway

The leader of the public defence is Professor Per Holth, OsloMet.

The main supervisor is Professor Ingunn Sandaker, OsloMet. The co-supervisor is Dr. Francis Mechner, The Mechner Foundation.

Thesis abstract

Topographic bias and behavioral variability are two fundamental characteristics of the operant class, and are present to some degree in all experimental analysis of behavior, whether measurable or not.

They represent the overlapping effects of multiple extra-experimental contingencies, often drawn from the organism’s biology and history, which interact with the programmed experimental contingencies.

All operant classes have both criterial and noncriterial dimensions, with the criterial ones being those that must occur in order for the programmed consequences to take place, and the noncriterial ones being all other behaviors and aspects of behaviors associated with each operant occurrence.

Bias and variability can affect both criterial and noncriterial aspects of the operant, but their effects are most often visible within the noncriterial ones.

The seven experiments with human participants reported in this thesis used a novel methodology, the revealed operant, that permits the measurement of noncriterial data, thus allowing for an in-depth analysis of both topographic bias and noncriterial variability effects on common behaviors such as drawing and typing.

Findings

Major findings include

an overall bias toward the center of the apparatus in use
a bias toward movement of the hands across the horizontal plane in front of the torso, in particular a preference for moving the hand either right to left or near to far
a bias toward efficiency of motion, even when the movements required were so small as to be almost indistinguishable in effort
high levels of noncriterial variability even when stereotypy would have been equally reinforced, especially variability associated with performance errors
levels of variability correlated with certain measurements of bias, indicating that the two phenomena can interact under certain circumstances.

These findings have implications for current and future behavioral research, as well as for the theory of the operant as a motor program, and theories of automaticity and behavioral variability.