Integrating Nursing and Bioengineering Expertise in Research: Use of Optical Imaging to Uncover Neural Correlates of Adult Risk Decisions

Monday, 30 July 2012: 11:10 AM

Mary A. Cazzell, RN, PhD1
Hanli Liu, PhD2
Lin Li, MS2
Sonal Patel, MS2
(1)College of Nursing, The University of Texas at Arlington, Arlington, TX
(2)Department of Bioengineering, The University of Texas at Arlington, Arlington, TX

Learning Objective 1: identify the contributory roles of dorsolateral prefrontal cortex activation and suppression in risk seeking or risk avoidance among male and female adults.

Learning Objective 2: explain how research collaboration between disciplines contribute to study rigor and power, statistical and clinical significance, innovative use of existing technology, and future research opportunities.

Purpose: Across the lifespan, the degree of prefrontal cortex (PFC) maturity or decline influences executive cognitive functions. Adults are expected to demonstrate mature decision-making skills, impulse control, and delay of gratification. Purposes are: (1) find prefrontal correlates of wins and losses during voluntary and involuntary risk decisions in a baseline population of adults, presumed to have PFC maturity; (2) identify gender differences in neural correlates of wins versus losses; and (3) demonstrate feasibility of optical imaging in risk decision research.

 Methods: In this correlational blocked design, functional near-infrared spectroscopy (fNIRS) was used to examine oxygenated hemoglobin (HbO) changes in the PFC of 40 right-handed healthy adults (23 males), ages 25 to 44 years, while performing voluntary and involuntary risk decision tasks from the Balloon Analogue Risk Task (BART). A fiber-optic array with 28 light-emitting diode (LED) fibers was placed in a rectangular configuration across participants’ foreheads; fNIRS signals were acquired during risk tasks. Gender differences in behavioral and hemodynamic data were analyzed using analysis of variance (ANOVA), paired samples t-tests, and linear mixed model analyses.

 Results: No PFC activation was noted during involuntary decisions, but strong PFC activation during voluntary wins and losses was seen in total sample. Losses in females were significantly associated with bilateral dorsal lateral PFC (DLPFC) activation; females demonstrated risk aversion. Males exhibited suppressed right DLPFC activation correlating to reduced inhibitory control. Study achieved strong power (0.9) and BART exhibited adequate reliability.

 Conclusion: Adult males decided to risk earnings and suffered more losses than females; females tried to avoid losses. The feasibility and convenience of fNIRS technology, the psychometric rigor of BART, the strong study power to examine gender differences in risk decisions, and the successful collaboration between disciplines will be extended to lifespan risk decision research of “normal” and “clinical" populations.