Experimental Studies of Complex Human Behavior

Stimulus equivalence has been one of the most prominent areas of research in the field of behavioural analysis for a long time. This research tradition began with a series of experiments carried out by Murray Sidman and his colleagues in the 1970s. Terms such as reflexivity, symmetry and transitivity were later imported from mathematical set theory and used to define the phenomenon of stimulus equivalence. In this connection, it is useful to see the phenomenon as meaning that stimuli within a class of stimuli are interchangeable in the sense that they mean the same to the individual.

To sum up, part of the main point is that, after a small number of stimuli relations have been established, many relations will emerge that have not been directly established via programmed reinforcers.

Stimulus equivalence is a behavioural analysis approach to the study of what is called cognitive skills, and its research questions will often overlap with those studied in the field of cognitive psychology. Although the starting point for this type of research was of a more applied nature, most subsequent studies conducted in the area of stimulus equivalence have been basic research studies. However, in recent years many applied research studies have been carried out that have demonstrated how productive this approach can be in establishing various skills in normal children and children with autism as well as statistics skills in university students.

The Experimental Studies of Complex Human Behaviour (ESCHB) lab conducts both basic and applied research as well as translational research. The experiments carried out cover a broad spectrum of research questions and human subjects. They include experiments in areas such as attention, memory and problem-solving, and both children and adults, as well as patients with aphasia and dementia, take part as test subjects.

We work on a broad range of research questions at all times, but they all have to do with variables that are relevant to how stimuli influences human behaviour. In the examples below, you will find information about some of our projects.

Training Structures and Stimulus Equivalence

Different arrangements or training structures can be used to train the conditions for testing for stimulus equivalence. The objective of this research project is to study the effects of different training structures as regards the number of trials in relation to a set criterion (95 percent correct responses) and how this influences responses in relation to stimulus equivalence. The project is based on several previous experiments carried out both internationally and in the ESCHB lab.

Sorting or Categorisation and Stimulus Equivalence

The research question in this project is whether there is a connection between how the test subjects categorise the stimuli presented during the experiment and how they respond to the stimulus equivalence tests. This is part of a series of experiments that has been going on for a long time at the ESCHB lab.

Delayed Matching-To-Sample and Dementia

The objective of these projects has been (and remains) to study the variables that influence what has traditionally been called short-term memory, and also to study whether it is possible to train dementia patients to remember the link between different stimuli when the interval between two stimuli is gradually increased.

Stimulus Equivalence, Transfer of Functions and Preference Testing

The research question in this project is whether it is possible to influence people's preferences for neutral stimuli or objects. This is done by means of conditional discrimination training, stimulus equivalence tests, and establishing a function for a stimulus in an equivalence class. We then look at whether this function passes to all stimuli in that class and whether this will influence the choice of a neutral stimulus afterwards. This type of experiment, in which this is linked to stimulus equivalence and transfer of functions to people's subsequent choices, is an area in which little research has been done.

We cooperate with partners at several universities in Brazil, the USA and the UK.