Data Analysis. Memory and Awareness in Fear Conditioning. Delay vs. Trace Conditioning. Discrimination and Reversal. Complex Discriminations

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1 What is Fear Conditioning? Memory and Awareness in Fear Conditioning Information and prediction: Animals use environmental signals to predict the occurrence of biologically significant events. Similar rules apply to learning about pleasant and unpleasant outcomes. Rapid acquisition: Robust learning can occur with as little as a single paired presentation of stimuli. Multiple procedures / forms: In addition to simple relations, humans and laboratory animals can learn a variety of complex conditional and higherorder discriminations. Fred J. Helmstetter Department of Psychology University of Wisconsin Milwaukee Departments of Neurology & Psychiatry Medical College of Wisconsin Model system: Currently one of the most popular preparations for neurobiological studies of memory at the behavioral, systems, and cellular level. Basic element of more complex cognitive phenomena. Implicit and explicit processes: Multiple neural systems encode information simultaneously. Processes are anatomically dissociable. Emotion / affect: Emotional memory reflects central and ANS expression mechanisms. General Imaging parameters: q GE Signa.T / Bruker Medspec.T q Anatomy: SPGR ( axial.mm slices) q fmri: EPI (TR=-sec, TE=ms, FOV=cm) q Resolution:.-.mm in plane Behavioral parameters: q = unique color, shape, and number projected q = transcutaneous AC (-ma,.sec) q GSR, HR & SE in real time q Subjective ratings each block Conditional Stimulus 8 Data Analysis Trace Conditioning Procedure Delay vs. Trace Conditioning Discrimination and } } œ _ À ^ X i h f g Complex Discriminations Subjects: Training: Imaging: N= (9 female), - yrs, right handed. Within-subjects, s of trials each x blocks. =8s, =s, =.s, ITI=s, Trace=s Tesla, TR=s, TE=.msec, FOV=cm, Flip=9deg

2 Delay 8 8 Trace Time of Delay and Trace Period Discrimination ARE Highly Correlated Functional Analysis of Delay Discrimination ( vs ) r =.9 of Trace Discrimination (Trace Periodvs ) of Delay Discrimination ( vs ) Galvanic Skin Response r =. of Trace Discrimination(Trace Periodvs ) Time of Implicit and Explicit Discrimination ARE NOT Highly Correlated Trace Trace Interval of Explicit Discrimination (SE) Delay Discrimination r =. of Explicit Discrimination (SE) Trace Period Discrimination r =.8 of Implicit Discrimination (GSR ) of Implicit Discrimination (GSR ) Distinct trace interval activation A Activation related to forming associations Middle Frontal Gyrus Middle Frontal Gyrus. SupramarginalGyrus. Anterior Cingulate %.. %... SMA Inferior Parietal Lobule. Medial Thalamus. Medial Thalamus %... Frontal Operculum Frontal Operculum Left Right - Left Right -

3 = min %Signal Change N= N= = sec Left Hippocampus.. - % - s - %.. ITI = - 8 sec (shock) Probability. =. sec s - Example Stimulus Seconds Seconds Measures of both explicit and implicit learning show discrimination during both and phases - %. -. Type effect, p>. effect, p>. -. Type X, p< s s s s - - Dorsomedial/Ventral Anterior Thalamus Type effect, p>. effect, p>. Type X, p< Anterior Cingulate Electrodermal Activity. Seconds After Onset Shock Probability Estimation Seconds After Onset 9 8 Change from Baseline (mhos) Probability of Receiving Shock ìì Differences between types in the area under the are driven by evoked responses to the that are larger in amplitude and of longer duration than evoked responses to the - - Response Intensity - Complex Discrimination Left Hippocampus (-. L, -. P, -9.8 I, ml) Unique dimensions of geometric figures served as the or Visual Stimuli Awareness X Type ANOVA performed on revealed a cluster of activation within the left hippocampus Aware %D From Baseline.. Unaware Color Number Shape This cluster was used as a functional mask to sample brain activity associated with the and for Aware and Unaware groups duration: 8 sec; ITI: sec; 8 habituation trials; ; N=/group; levels per dimension;

4 Behavioral Data Imaging Data: versus Cingulate Right Insula SHAPE NUMBER COLOR Expectancy of Receiving Shock s s % Change from baseline 8 8 Cuneus 8 Regions that demonstrate increased responding to the relative to the regardless of category group. These contingency-related effects in sensory and motivational systems are similar to those previously reported. Development of Task Awareness?! Awareness (main effect) R. Middle Frontal Gyrus Awareness x Type L. Primary Somatosensory Cortex Shock Contrast (p <.): images post versus images post Expectancy Contrast (p <.) : Type x Awareness Interaction Post Post

5 Conclusions: q Organisms exposed Pavlovian procedures simultaneously learn the explicit relationships between stimuli, encode the nature of the signaled outcome, and express affective / emotional reactions that do not depend on explicit awareness. q Delay and trace fear conditioning are acquired at similar rates. Activity maps during trace interval periods support a working memory interpretation. MTL regions may contribute to accuracy or timing on trace trials. q Brain activity patterns differ within subjects when comparing the periods before and after explicit contingency awareness. Specifics of MTL contributions to awareness remain unclear. UWM Students: David Bailey David Baruch Dominic Cheng Georgette Gafford David Knight, Ph.D. Ryan Parsons Jennifer Richards Tara Thomas Christine Smith, Ph.D. Other collaborators: Dr. J.J. Kim Yale Dr. A.R. McIntosh Rotman Inst. Dr. S. Rao MCW Dr. E.A. Stein NIDA Dr. R.F. Thompson - USC This work was supported by grants from NIMH, NIDA, and the McDonnell-Pew foundation Implicit Delay Discrimination is Coincident with Awareness Number of Subjects Per Peak Response (umhos). - Aware Implicit Trace Discrimination Occurs After Awareness Number of Subjects Per Peak Response (umhos) Aware