1. Procedural Learning among HIV+ and HIV- individuals with Substance Dependence R. Gonzalez, J. Jacobus, J.W. Rodriguez, E.H. Fakhoury, E.M. Martin

2. Taxonomy of Memory Systems Cohen & Squire, 1980; Squire & Knowlton, 1994; Squire & Zola, 1996

3. Brief Background HIV is associated with striatal damage Substance use affects striatal systems Striatum is critical for procedural learning Procedural learning in HIV & substance use –A. Martin et al., (1993) –Kalechstein et al., (1998) –Van Gorp et al., (1999) –Waldrop et al., (2001)

4. PL Measures Pursuit Rotor (PR) Trace star seeing only mirror image –Go quickly, stay inside lines –4 trial blocks, 2 trials each –DV = time to complete Follow light around circle –55 rpm –4 trial blocks, 2 20s trials each –DV = seconds on target Mirror Tracing (MT) Weather Prediction (WP) Try to guess “sun” or “rain” based on cards –Participants are not told probability structure –4 trial blocks, 50 cards each

5. Performance on PL Tasks Performance Indices | General Deficit (Main Effect) | PL Deficit (Group X Time) | # Errors Time (Trial Blocks) Performance Control Group Clinical Group Learning

6. Hypotheses HIV+ participants: –poorer performance, overall, on measures of PL General Deficit –less improvement in performance over time on PL tasks PL Deficit More severe substance use: –poorer performance overall and with poorer PL Interaction between HIV and substance use

7. Participants 79 adults with history of cocaine and/or heroin dependence –HIV- : n = 33 –HIV+: n = 46 Negative u-tox & alcohol breath test No cocaine or heroin use in last 7 days No current abuse or dependence for EtOH and other drugs No history of severe thought disorder or unmedicated bipolar disorder No history of significant loss of consciousness or neurological problems

8. Demographics Psychiatric & Medical

9. Substance Use Parameters

10. Analyses Three separate repeated-measures ANOVA –Between factor = same for all three analyses HIV, KMSK –Within factor = performance across PL task trial blocks PR: Block 1, Block 2, Block 3, Block 4 MT: Block 1, Block 2, Block 3, Block 4 WP: Block 1, Block 2, Block 3, Block 4 –All interactions examined

11. Summary of Results Mirror Tracing HIV Main Effect: Hedges ES = 0.65, 95%CI [0.20, 1.11] Significant 3-way interactions

12. PR Interaction Effect KMSK PR change HIV – HIV + n = 33n = 46 R 2 =.16, p =.02 R 2 =.03, p =.24 ↑ improvement in PR was associated with history of ↑ severe drug use [only for HIV- subjects]

13. MT Interaction Effect HIV – HIV + n = 33n = 46 R 2 =.12, p =.05 R 2 =.03, p =.26 KMSK MT change ↑ improvement in MT was associated with history of ↑ severe drug use [only for HIV- subjects] KMSK

14. Summary HIV+ subjects generally performed worse, overall, on PL tasks –Significant differences on Mirror Tracing –Evidence suggests general deficit History of substance use severity and HIV serostatus interacted to affect procedural learning

15. Possible Explanations Supersensitivity of striatal dopamine receptors –Process disrupted by HIV HIV+ participants fairly “healthy” Control group consisted of individuals with substance dependence Amount of striatal damage not sufficient for functional deficits HIV deficits are “spotty” affecting multiple systems

16. Acknowledgements NIDA –F32 DA018522 (RG) –R01 DA12828 (EMM) University of Illinois Chicago, Dept. of Psychiatry HIV & Addictions Neuroscience –Eileen Martin, PhD –Jasmin Vassileva, PhD –Pyrai Vaughn –Elizabeth Walczak –Leslie Ladd –Sarah Wicks