fMRI Response During Figural Memory Task Performance in College Drinkers [pre-print]

Rationale: 18-25-year-olds show the highest rates of alcohol use disorders (AUD) and heavy drinking, which may have critical neurocognitive implications. Regions subserving memory may be particularly susceptible to alcohol-related impairments. Objective: We used blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to examine the neural correlates of visual encoding and recognition among heavy drinking college students. We predicted that heavy drinkers would show worse memory performance and increased frontal/parietal activation and decreased hippocampal response during encoding. Methods: Participants were 23 heavy drinkers and 33 demographically matched light drinkers, ages 18-20, characterized using quantity/frequency of drinking and AUD diagnosis. Participants performed a figural encoding and recognition task during fMRI. BOLD response during encoding was modeled based on whether each stimulus was subsequently recognized or forgotten (i.e., correct vs. incorrect encoding). Results: There were no group differences in behavioral performance. Compared to light drinkers, heavy drinkers showed: 1) greater BOLD response during correct encoding in right hippocampus/medial temporal, right dorsolateral prefrontal, left inferior frontal, and bilateral posterior parietal cortices; 2) less left inferior frontal activation and greater bilateral precuneus deactivation during incorrect encoding; and 3) less bilateral insula response during correct recognition (clusters \u3e10,233ul, p Conclusions: This is the first investigation of the neural substrates of figural memory among heavy drinking older adolescents. Heavy drinkers demonstrated compensatory hyperactivation of memory-related areas during correct encoding, greater deactivation of default mode regions during incorrect encoding, and reduced recognition-related response. Results could suggest use of different encoding and recognition strategies among heavy drinkers

Relationships between reward sensitivity, risk-taking and family history of alcoholism during an interactive competitive fMRI task.

Individuals with a positive family history for alcoholism (FHP) have shown differences from family-history-negative (FHN) individuals in the neural correlates of reward processing. FHP, compared to FHN individuals, demonstrate relatively diminished ventral striatal activation during anticipation of monetary rewards, and the degree of ventral striatal activation shows an inverse correlation with specific impulsivity measures in alcohol-dependent individuals. Rewards in socially interactive contexts relate importantly to addictive propensities, yet have not been examined with respect to how their neural underpinnings relate to impulsivity-related measures. Here we describe impulsivity measures in FHN and FHP individuals as they relate to a socially interactive functional magnetic resonance imaging (fMRI) task.Forty FHP and 29 FHN subjects without histories of Axis-I disorders completed a socially interactive Domino task during functional magnetic resonance imaging and completed self-report and behavioral impulsivity-related assessments.FHP compared to FHN individuals showed higher scores (p = .004) on one impulsivity-related factor relating to both compulsivity (Padua Inventory) and reward/punishment sensitivity (Sensitivity to Punishment/Sensitivity to Reward Questionnaire). Multiple regression analysis within a reward-related network revealed a correlation between risk-taking (involving another impulsivity-related factor, the Balloon Analog Risk Task (BART)) and right ventral striatum activation under reward >punishment contrast (p<0.05 FWE corrected) in the social task.Behavioral risk-taking scores may be more closely associated with neural correlates of reward responsiveness in socially interactive contexts than are FH status or impulsivity-related self-report measures. These findings suggest that risk-taking assessments be examined further in socially interactive settings relevant to addictive behaviors

Risk indices by group (Family History Positive and Family History Negative) over time in to game.

<p>Risk Index was derived by dividing number of non-match choices by number of total choices when non-match and match choices were available to the player. FHP (a) and FHN (b) data are plotted by minute into game with standard error (averaged for all games for all subjects). No significant differences were found between groups. There was a significant main effect of time across groups (F = 9.58, df = 3, 201, p<.0001).</p

Domino game task.

<p>Domino Game Paradigm. The upper panel describes the 4 intervals that comprise each round of the game: Decision Making, Ready, Anticipation to Outcome and Response to Outcome. The latter is the main focus of this study, thus it is highlighted in gray. The duration of each interval and the command (i.e. event) that starts it are described in the bolded arrows below. The lower panel depicts the Domino Game sequence and corresponding consequences. At the beginning of each game the player (participant scanned) gets 12 playing chips and his/her goal is dispose of all 12 within 4 minutes. A constant opponent’s chip (in this example 6∶5, shown enlarged in the yellow ellipsoid) to which the player matches one chip in each round of the game, is displayed in the upper left corner of the screen throughout the game. Each round starts with the player instructed to decide what chip he/she will play next by the command ‘Choose’ (Decision-making interval). Then the player is instructed to move the cursor to this chip (Ready interval). The chip can either match the opponent’s (i.e. have one of the numbers match those on the opponent’s chip, upper row, 5∶1 in this example) or not (lower row: 3∶3; note that this is a later round in the same game). After placing the selected chip face down next to the opponent’s, he/she awaits the opponent’s response (Anticipation of Outcome interval). The opponent can either challenge the player’s choice (‘Show’) or not (‘No-Show’). Based on the player’s choice and the opponent’s response there are four possible consequences for each round (Response to Outcome interval): Show Match (overt gain); No-Show Match (relative loss, as the player could have been rewarded if challenged); Show Non-Match (overt loss) and No-Show Non-Match (relative gain, as the player could have been punished if challenged).</p

Subject Debriefing after Domino Game.

<p>FHN = family history negative, FHP = family history positive.</p><p>Domino debriefing scores as Likert scale responses (1–5) to statements regarding salience of gains and losses during game play.</p

Subject Demographics.

<p>M = male, F = female.</p><p>Demographics for FHN, FHP, and total sample used in the study.</p

Correlation of Impulsivity-related Factor 5 (Behavorial Risk-Taking) scores with neural activation under the reward-punishment contrast across all subjects.

<p><b>A</b>. Threshold was set at p<0.05 FWE for voxels within the reward network mask. Statistical parametric F-maps (sagittal, coronal and axial) of the Reward-Punishment contrast for multiple regression against Factor 5 - “Behavioral Risk-Taking”. Crosshairs overlaid on brain slices are at the voxel of peak correlation (MNI coordinates: x,y,z = 12,4,–8). Bottom panel depicts individual factor scores vs. individual peak cluster activation at this voxel. <b>B</b>. Linear regression plot at the voxel of peak correlation between reward-punishment BOLD activity in the right ventral caudate and Factor-5 score for each subject.</p