Association for Behavior Analysis International

The observability of behavior depends on the resolution of adopted instrumentation. Consistently, in the past 15 years Behavior Analysts have been incorporating in their experimental and theoretical analyses data collected via measurement tools traditionally used in other fields (e.g. Neuroscience.) As behavior shifts rapidly in response to changing environments, tools like Eye Tracking and Electroencephalography (EEG) can capture behavior otherwise below the threshold of observability. Moreover, other tools like Transcranial Magnetic Stimulation (TMS) and Transcranial Alternating Current Stimulation (TACS) allow experimenting with the elements of the Neurobehavioral movement cycle. The talks in this symposium will cover recent experimental and theoretical advances made possible by the adoption of these technologies, and each of the tools described will be introduced propaedeutically in a short preliminary overview. The described data will be also interpreted in relation to potential future developments in the fields of Brain Computer Interfaces (BCIs) and Brain to Brain Interfaces (BBIs.)

Paired associative stimulation (PAS) is an experimental paradigm used to induce plasticity in the human motor cortex. It involves repetitive stimulation of the peripheral nerve along with transcranial magnetic stimulation (TMS) of the cortex. PAS leads to a long-term increase in corticospinal excitability within the primary motor cortex (M1), akin to processes associated with long-term potentiation (LTP). The debate over whether LTP and long-term depression of cortical synaptic strength influence behaviors remains ongoing. To address this, we conducted a study to assess whether behavior is affected when PAS is synchronized or desynchronized with sensory signals associated with behavior. In our behavioral task, participants were required to abduct their right index finger upon hearing a beep. The study design employed the AB method, with an asynchronous condition followed by a synchronous condition. TMS was precisely timed to coincide with the arrival of the sensory signal at the M1. Our experimental results demonstrated an increase in motor evoked potentials, a reduction in reaction time, and an increase in maximal velocity during the synchronous condition. These findings suggest that behavior can be modulated by PAS, whether it is synchronized or desynchronized with sensory signals related to the behavior.

Some experiments have trained only two stimulus classes when testing for stimulus equivalence class formation (SECF). An unfortunate outcome of having only two comparison stimuli is that this can lead to the choice response being under rejection control and not selection control. Therefore, some researchers have added a third comparison stimulus, a “null” stimulus, to hinder rejection control without training three classes. The present experiment aims to investigate the effect the "null" stimulus has (1) on SECF, (2) in a sorting test, and (3) on eye movements. Eight adult participants are trained in a matching-to-sample procedure in two conditions: one in which two 3-member stimulus classes are trained and tested, and one condition in which two 7-member stimulus classes are trained and tested. All participants are exposed to both conditions, half in the opposite order. Each condition contains a pre- and post-sorting of stimuli, including null stimuli. Eye movements during the MTS procedure are measured. Preliminary results show that larger classes reduce SECF, if the trained classes are sorted correctly, the “null” stimuli are sorted as one class. Fixation time to incorrect and “null” stimuli are similar in training, and there is a higher fixation time to correct comparison stimuli when participants respond correctly in the test and the opposite when they respond incorrectly.

Event-Related Potentials (ERPs) are a subtype of Electroencephalography that captures moment-to-moment neural activity. ERP research, similarly to most neuroimaging, has been constrained to rigid experimental protocols based on discrete trial procedures. Here we propose research that is free of discrete trial constraints and is entirely driven by participants. Gathering neural responses in an unconstrained free operant procedure may allow examining how a brain response may look like in more natural unconstrained self-paced conditions without abandoning the rigor of a laboratory setting. Here we show that the traditional interpretation of some neural effects may have to be revised, as the anterior P3 effect can be shown to be present with highly repeated stimuli in a VR5 compared to a FR5 schedule. This experiment merges two fruitful lines of research that have so far been isolated from one another and creates a semi-naturalistic approach to measuring ERPs featuring a high degree of ecological validity.