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| Int'l Symposium - Studying the Neural Substrates of Equivalence Classes and Derived Relations |
| Monday, May 30, 2005 |
| 3:00 PM–4:20 PM |
| Boulevard A (2nd floor) |
| Area: EAB; Domain: Basic Research |
| Chair: Lanny Fields (Queens College, City University of New York) |
| Abstract: This symposium focuses on the neural substrates of equivalence class formation, derived relations, emergent relations, and nodal function. In addition to discussions of experimental strategies that can be used to obtain such information, the presentations will also describe empirical findings that illustrate how will evoked potential and fMRI technologies have been used to identify the neural correlates of these emergent performances. One presentation will illustrate how BOLD fMRI procedures have identified patterns of frontal-striatal-thalamic activation while responding to new relations that are derived from conditional discriminations.Another presentation will consider paradigms and measurement strategies that can be used to identify patterns of neural activation that are the substrates of nodal function in equivalence classes. A third presentation will consider how an evoked potential waveform typically associated with semantic processing (N400) is also correlated with equivalence relations. The final presentation will consider the neural substrates of stimulus equivalence and serial learning along with the effects of verbal instruction on these emergent performances and their neural substrates. |
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| Electrophysiological Measures of Derived Stimulus Relations:What Can They Tell Us About Behavior That We Don’t Already Know? |
| DERMOT BARNES-HOLMES (National University of Ireland, Maynooth), Yvonne Barnes-Holmes (National University of Ireland, Maynooth), Ian T. Stewart (National University of Ireland, Galway), Robert Whelan (Anglia Polytechnic University, Cambridge, UK), Simon Dymond (Anglia Polytechnic University, Cambridge, UK) |
| Abstract: The current paper will argue that an important component of the research agenda for Relational Frame Theory involves studying the functional relations that obtain between environmental events and the physiological activity that takes place inside the brain and central nervous system, with a particular focus on human language and cognition. In support of this view, five separate experiments are outlined, which support the argument that there is a clear functional overlap between semantic and derived stimulus relations. Specifically, an evoked potential waveform typically associated with semantic processing (N400) is shown to be differentially sensitive to equivalence versus non-equivalence relations. Experiments 4 and 5 indicate that these reaction time and evoked potential effects are not restricted to traditional lexical decision tasks, but can also be observed using the implicit association test. Furthermore, preliminary evidence suggests that evoked potentials might constitute a more sensitive measure of derived stimulus relations than response time. The results obtained across all five experiments support the view that the study of derived stimulus relations, combined with some of the procedures and measures of cognitive psychology and cognitive neuroscience, may provide an important inroad into the experimental analysis of semantic relations in human language. |
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| Measurement Strategies to Track Neural Substrates of Nodal Function in Equivalence Classes |
| LANNY FIELDS (Queens College, City University of New York) |
| Abstract: When an equivalence class is formed, some stimuli serve as nodes that link together the stimuli in the class. When transitivity probes and equivalence probes are presented, stimuli that were linked by nodes occasion class consistent responding even though the linking nodal stimuli are absent. When equivalence classes are formed, there must be some changes in neural function that are acquired by the nodal stimuli. How can those neural functions of nodal stimuli be measured? Are those neural signatures of nodal function evoked by the stimuli in transitivity probes and equivalence probes? This paper will describe methodological factors that can provide answers to these questions. One strategy should permit the measurement of nodal function after classes have been formed. Another strategy should identify the patterns of neural activation that are acquired by nodal stimuli when a set of unrelated stimuli is transformed into and equivalence class. |
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| Clinical Implications of Integrating Neuroimaging and Stimulus Equivalence Procedures |
| MICHAEL W. SCHLUND (Kennedy Krieger Institute), Michael F. Cataldo (Kennedy Krieger Institute) |
| Abstract: A variety of clinical and neurodevelopmental disorders are characterized by deficits in forming conditional relations that stem from dysfunction in the frontal lobe, striatum and thalamus. Integrating neuroimaging technology and stimulus equivalence (SE) procedures creates the opportunity to (1) map the neurobiology of derived relational responding and (2) map principles of SE and relational frame theory onto frontal-striatal-thalamic regions. As first steps towards these goals, we will present BOLD fMRI data that show how several procedural variables (e.g., task type, stimulus type) modulate frontal-striatal-thalamic activation in humans during derived relational responding. |
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| On Neuroimaging Derived Relations |
| DAVID W. DICKINS (University of Liverpool), Neil Roberts (University of Liverpool), Andrew Mayes (University of Manchester), Daniela Montaldi (University of Manchester), Dermot Barnes-Holmes (National University of Ireland, Maynooth), Yvonne Barnes-Holmes (National University of Ireland, Maynooth) |
| Abstract: Ingenious and seemingly powerful technologies have recently been developed enabling the visualization in some detail of events in the brain concomitant upon the ongoing behavioral performance of a human participant. The good behavioural control and conceptual parsimony characteristic of operant paradigms makes these attractive procedures for advancing the understanding of brain-behaviour relations. A start has been made in such research using two related paradigms - stimulus equivalence and serial learning – in which novel or emergent relations are derived from a baseline set of trained relations. Some published and prospective neuroimaging studies of these and related phenomena will be reviewed. It is argued however that these newly measurable brain events are more than just a new set of dependent variables in relation to which the independent variables familiarly manipulated in the operant laboratory may be explored. Verbal instructions and verbal reports, and chronometric studies, may provide useful adjuncts. We contend that a successful reductionist explanation of such behaviours will require their conceptual dissection into increasingly plausible suites of component processes. The aim is that these may ultimately map on to neural phenomena, which it is expected will be visualized with increasing precision by parallel developments in imaging and related technology. |
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