In the current study, the neuropsychological score “TotCor_Fw” (i.e., total number of correctly performed forward trials) from the visual span test was also identified as one of the key variables contributing to the classification of AUD individuals from controls by the RF model. On the other hand, parametric group comparison of neuropsychological variables (Table 5) revealed that the AUD group performed poorly in both “TotCor_Fw” and “Span_Fw” (i.e., span of recalled items during forward trials), compared to controls. Interestingly, these two variables tapping short-term memory performance were also found to be significant in our previous classification studies with the same sample of participants [63,85]. Furthermore, there is a strong literature support for memory deficits in individuals with chronic AUD [118,119,120,121], and some of the deficits linger even after prolonged abstinence [37]. It is also worth noting that in our previous structural MRI study on the same groups of subjects, we found that the AUD group showed lower volumes in prefrontal cortex and left hippocampus, which were associated with poorer visuospatial memory performance [54]. Furthermore, in another study on the same
