Quantitative electroencephalographic amplitude, memory, and cognitive ability in Canadian First Nation adult offenders with and without solvent abuse histories / Michael R. Moland. --

Abstract

Most electroencephalographic (EEG) studies of solvent exposure have involved factory workers chronically exposed to industrial chemicals. Few studies have examined the neurological effects of recreationally abused solvents, and none have explored EEG and solvent abuse in Canadian First Nations people. Measures of EEG amplitude, working memory, cognitive ability, depression, and anxiety were used to compare adult First Nations male offenders (n = 28) with First Nations male university students (n=14). Offenders showed lower absolute theta and alpha amplitudes bilaterally. Compared to university students, they also showed significantly reduced scores on digit-span backward, letter-number sequencing, and a measure of nonverbal cognitive ability. No group differences were found for depression and anxiety. Offenders reporting a history of solvent abuse (n = 10) were also compared to those with no history of solvent abuse (n = 18) and controls (n = 14). Solvent-abusing offenders scored significantly lower than controls on digits forward, digits backward, letter number sequencing, and cognitive ability, while offenders without solvent abuse histories scored lower than controls on letter-number sequencing and cognitive ability. Only digits-forward scores significantly differentiated solving-abusing from non-solving-abusing offenders. On EEG measures, significant group differences were found on absolute alpha amplitudes in eyes-open and letter-number sequencing tasks, with solvent abuse history offenders showing decreased alpha EEG amplitudes compared to non-solvent abusing offenders and controls. The findings suggest that First Nations offenders reporting a history of solvent abuse show evidence of reduced memory performance and reduced cortical EEG functioning compared to non-solvent abusing First Nations offenders and First Nations controls. Participants : 28 First Nations offenders from the Thunder Bay Correctional Centre (in Northwestern Ontario), 14 First Nations controls (Lakehead University Students) and 2 community participants. Correctional inmates as a group reported a wide variety of past drug use involving (mainly) marijuana but also : gasoline, paint, glue, hairspray, barbiturates, opiates, and phencyclidine.