Electrophysiological auditory measures to identify potential cortical markers of tinnitus.

Tinnitus, or the perception of a sound in the absence of an external acoustic stimulus, is a common condition that cannot yet be objectively diagnosed. Current diagnostic tests of tinnitus consist of case history and behavioral measures that rely on subjective responses. This study examined electrophysiological measures, specifically the auditory late response (ALR), mismatch negativity (MMN), and P300 as potential neural biomarkers of tinnitus in both a tinnitus and non-tinnitus control group while utilizing the pitch-matched tinnitus frequencies as the test stimuli. Results of this study found differences in MMN amplitudes and area under the curve, and in P300 topographic maps between tinnitus and control subjects. The differences in MMN responses across groups suggest that dysfunctional processing of acoustic stimuli located near the tinnitus frequency in individuals with tinnitus manifests as soon as 200 ms after initial onset of the stimulus. In addition, results from a global field power analysis and differences in spatial distributions on topographical maps indicate that deficits persist through higher levels of cortical processing. A secondary goal of this study was to determine if electrophysiological measures correlated with reported tinnitus severity on questionnaires. This analysis indicated that P2 latency was a significant predictor of Tinnitus Reaction Questionnaire, Tinnitus Handicap Inventory, and percent of the time participant's tinnitus was considered bothersome, suggesting that this measure could potentially be used to assess the efficacy of treatment programs for tinnitus.

Crafting Sequences of Sight and Sound: A Behavior Analysis of Filmmaking.

The discipline of film studies often engages in analyses of the functions of filmmakers' decisions in terms of their effects on viewers. Behavior analysis uses a similar, functional-analytic approach toward understanding the relationship between individuals' behavior and the environmental effects that maintain their behavior. Given converging similarities between the two disciplines, a functional analysis of filmmaking is provided, using Skinner (1957)'s Verbal Behavior as a guiding framework. Similar to behavioral conceptualizations of language and speaker-listener verbal episodes, the analysis prioritizes functional explanation of the controlling variables and conditions that underlie the meaning of filmmakers' behavior and behavioral products, rather than solely focusing on their topographical description. Viewers' responses to the audiovisual stimuli of the film are emphasized as key controlling variables, through rules specifying contingency relations as well as through contingency shaping, including when the filmmaker acts as a self-viewer who directly shapes their own behavior. Their responding as a self-viewer during the production and editing of a film is explored as a problem-solving process, similar to other artists who serve as their own audience when creating and editing their behavioral products.

Response Systems, Antagonistic Responses, and the Behavioral Repertoire.

While response systems are often mentioned in the behavioral and physiological literature, an explicit discussion of what response systems are is lacking. Here we argue that response systems can be understood as an interaction between anatomically constrained behavioral topographies occasioned by currently present stimuli and a history of reinforcement. "New" response systems can develop during the lifetime as the organism gains instrumental control of new fine-grained topographies. Within this framework, antagonistic responses compete within each response system based on environmental stimulation, and competition is resolved at the striatum-thalamo-cortical loops level. While response systems can be by definition independent from one another, separate systems are often recruited at the same time to engage in complex responses, which themselves may be selected by reinforcement as functional units.

Intraexperimental development of priming and event related potentials effects with abstract geometrical stimuli.

In the current study we assessed the possibility of developing intraexperimentally behavioral priming and Event Related Potentials (ERP) effects that are often studied with stimuli to which participants typically have a very extensive pre-experimental history, like words. To do so we used abstract geometrical figures in a baseline Lexical Decision Task (LDT), followed by a conditional discrimination-training phase. We then repeated the LDT task to assess the effectiveness of training compared to baseline. We found that participants' reaction time data in the post training LDT session changed, compared to the pre-training LDT session, according to the specific conditional discriminations taught in the training session. Similarly, neural results suggest the presence of an effect due to training that is absent in the baseline neural measures. Moreover, similar effects were also obtained using words. Results point to the possibility that conditional discrimination learning may be sufficient to establish effects that are often considered to be language specific.

A Neuro-Operant Analysis of Mnemonic Recognition.

Historically, the fields of operant selection and recognition memory have not interacted substantially with one another. However, both deal with how behavioral repertoires change over time as a function of environmental stimulation. In this article, we propose neuro-operant interpretations of behavioral phenomena occurring in recognition memory procedures based on (a) the ability to discriminate changes in the strength of responses caused by environmental stimulation and (b) the occasioning of supplementary responses by current stimulation. A neuro-operant interpretation of mnemonic behavior may further the understanding of the phenomena in place and simplify the current taxonomy of learning and memory.

The Challenges of Integrating Behavioral and Neural Data: Bridging and Breaking Boundaries Across Levels of Analysis.

We describe here two approaches introduced by Abrahamsen (1987) that can be used by behavior analysts to interpret neuroscientific data. The first is a "boundary-bridging" approach aimed at understanding the interdisciplinary interactions between the behavioral and the neural levels of analysis while keeping the two domains independent. When presenting the boundary-bridging approach, we describe neuroplasticity, a perspective that describes how changes at the brain level can be understood by examining behavioral factors. In the second part of the paper, we contrast two "boundary-breaking" perspectives: neuropsychology and behavior analytic neuroscience. In neuropsychology, localized brain activation is used to explain behavior. In behavior analytic neuroscience, brain responses are interpreted as behavior. We discuss the conditions under which brain responses can be considered behavior and propose that including brain responses within a behavioral framework may allow carrying out a more sophisticated and temporally detailed behavior analysis.

Conditional discriminations, symmetry, and semantic priming.

Psychologists interested in the study of symbolic behavior have found that people are faster at reporting that two words are related to one another than they are in reporting that two words are not related - an effect called semantic priming. This phenomenon has largely been documented in the context of natural languages using real words as stimuli. The current study asked whether laboratory-generated stimulus-stimulus relations established between arbitrary geometrical shapes would also show the semantic priming effect. Participants learned six conditional relations using a one-to-many training structure (A1-B1, A1-C1, A1-D1, A2-B2, A2-C2, A2-D2) and demonstrated, via accurate performance on tests of derived symmetry, that the trained stimulus functions had become reversible. In a lexical decision task, subjects also demonstrated a priming effect as they displayed faster reaction times to target stimuli when the prime and target came from the same trained or derived conditional relations, compared to the condition in which the prime and target came from different trained or derived conditional relations. These data suggest that laboratory-generated equivalence relations may serve as useful analogues of symbolic behavior. However, the fact that conditional relations training and symmetry alone were sufficient to produce the effect suggests that semantic priming like effects may be the byproduct of simpler stimulus-stimulus relations.

How do we remember traumatic events? Exploring the role of neuromodulation.

The seemingly puzzling datum that behavior decreases after punishing stimulation while individuals are still able to remember traumatic episodes is discussed in relation to dopaminergic and noradrenergic neuromodulation. The described mechanisms may contribute to an understanding of how occurrences of learning reconsolidation yield different outcomes across intra- and extra-therapeutic settings.

Is the N400 effect a neurophysiological index of associative relationships?

The N400 is one of the most widely studied ERP components and has come to be viewed as an index of the semantic processing that relates distinct stimuli. In this study, we examine whether the N400 is sensitive to the associative relationship between distinct stimuli, and not the degree to which the stimuli share semantic features. We used previously established norms to parametrically vary the strength of linguistic association between words within word-pairs, while holding constant their degree of semantic congruency. This manipulation allowed us to compare N400s elicited by unrelated prime-target word-pairs (e.g. mirror-thumb) with N400s generated by related prime-target word-pairs of either moderate (e.g. camera-lens) or high (e.g. cherry-tree) degrees of association. We observed that larger N400 effects occurred for highly associated versus moderately associated pairs despite the fact that no differences in terms of semantic congruency existed between pairs belonging to the highly and moderately associated conditions. These findings demonstrate that the N400 can be modulated by associative relationships quite independently of semantics, and suggest that the N400 effect reflects processes sensitive to the contiguity of distinct elements within one's past experience and not their semantic properties per se.

Neuroscientific measures of covert behavior.

In radical behaviorism, the difference between overt and covert responses does not depend on properties of the behavior but on the sensitivity of the measurement tools employed by the experimenter. Current neuroscientific research utilizes technologies that allow measurement of variables that are undetected by the tools typically used by behavior analysts. Data from a specific neuroscientific technique, event-related potential (ERP), suggest that emission of otherwise covert responses can be indexed and that such covert responses are sensitive to stimulus control and selection by consequences. The P3 ERP effect is proposed as indicative of emission. Moreover, ERP results in semantic priming experiments suggest that operants are sensitive to changes in stimulus control even when they are not emitted (latent responses). Changes in response strength of latent responses as a function of stimulus control can in fact be measured by reaction time data and an ERP dependent variable called the N400 effect. If the interpretations provided in this paper are accurate, an index of covertly emitted operants (P3 effect) constitutes experimental evidence suggesting the validity of a Skinnerian radical behaviorist perspective on behavior. Moreover, in a Skinnerian paradigm, measured fluctuations in the response strength of latent operants as a function of environmental changes (N400 effect) would validate Palmer's (2009) concept of the repertoire.

An Iterated Four-Player Prisoner's Dilemma Game with an External Selecting Agent: A Metacontingency Experiment / El juego del "Dilema del Prisionero" con cuatro participantes y un agente selector externo: un experimento metacontingencia

En esta serie de experimentos utilizamos un juego iterativo del "Dilema del Prisionero" (IPDG por sus siglas en inglés) para examinar el efecto de las metacontingencias sobre los productos agregados del comportamiento interrelacionado de cuatro jugadores. Los resultados del primer experimento muestran que las consecuencias de nivel cultural ("retroalimentación del mercado" en la forma de puntos entregados a todos los jugadores), contingentes con los productos agregados XXX o YYYY aumentaron la frecuencia de esas producciones. En experimentos posteriores, añadimos una condición de línea de base en la cual los jugadores experimentaron solo las contingencias conductuales individuales incorporadas en el juego. Luego impusimos la metacontingencia sobre el producto agregado XXXX, o de forma alternativa sobre YYYY. Después de varias reversiones, descontinuamos la metacontingencia y los jugadores comenzaron a experimentar nuevamente solo las contingencias individuales del juego. En un experimento utilizamos un control para evaluar el efecto de la retroalimentación del mercado de manera independiente de la relación metacontingencial. Los resultados indican que la consecuencia cultural (retroalimentación del mercado) controló la producción de productos agregados incluso cuando su magnitud era mínima, que la relación metacontingencial era necesaria, y que mantenía relaciones en el comportamiento de los individuos que tenían los peores resultados para todos los jugadores.

In these series of experiments we used an iterated prisoners' dilemma game (IPDG) to examine the effect of metacontingencies on aggregate products of the interrelated behavior of four players. Results of the first experiment showed that cultural level consequences ("market feedback" in the form of points delivered to all players) contingent on aggregate products XXXX or YYYY increased the frequency of those productions. In subsequent experiments we added a baseline condition where the players experienced only the individual behavioral contingencies embedded in the game. Then we imposed the metacontingency on the XXXX aggregate product or, alternatively, on YYYY. After several reversals, we discontinued the metacontingency and the players again experienced only the individual contingencies of the game. In one experiment we used a yoked control to assess the effect of market feedback independent from the metacontingency relation. Results indicate that the cultural consequence (market feedback) controlled production of aggregate products even when its magnitude was minimal, that the metacontingency relation was necessary, and that it maintained relations among the behavior of individuals which resulted in the worst individual outcomes for all players.