White matter fiber compromise contributes differentially to attention and emotion processing impairment in alcoholism, HIV-infection, and their comorbidity

► A substantial proportion of individuals with HIV have comorbid conditions, notably alcohol abuse. ► Alcoholism (ALC) and HIV were associated with compromise in emotion and attention processes. ► In HIV, uncinate fiber compromise correlated with enhanced interference from negative emotion. ► In ALC and ALC+HIV, poorer callosal integrity was related to enhanced emotional interference. ► Fiber integrity in ALC and HIV has functional relevance for emotion and attention processing.