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. Author manuscript; available in PMC: 2016 Oct 3.
Published in final edited form as: J Cogn Neurosci. 2016 Mar 11;28(7):1024–1038. doi: 10.1162/jocn_a_00953

Figure 5. Post-change percentage of perseverative errors by abused substance type group for S-R sets.

Figure 5

We categorized participants according to substance dependence history as follows: no history (control), no stimulant dependence (alcohol or opiate dependence; “No Stims”), or stimulant and alcohol dependence (stimulants; “Stims”). Overall nonparametric comparison of the three groups indicated a significant difference in the percentage of perseverative errors for the FAMILIAR set (magenta), χ2(3)=11.67, p=0.009. The groups did not differ in terms of the percentage of perseverative errors for the NOVEL set (yellow), χ2(3)=4.86, p=0.182. Post-hoc tests corrected for multiple comparisons (p=0.025) demonstrated that, compared to controls, participants with a history of stimulant dependence committed a higher percentage of perseverative errors for both the FAMILIAR set (z=2.69, p=0.007) and the NOVEL set (z=2.07, p=0.038). In contrast, participants with no history of stimulant dependence committed a higher percentage of perseverative errors when compared to controls only in the FAMILIAR set (z=2.60, p=0.009), not in the NOVEL set (z=2.69, p=0.342).