Quantitative EEG Findings in Convicted Murderers

Abstract

In this study we examined the QEEGs of convicted murderers
(n = 73) living on death row, referred by attorneys, and compared
them to a control group (n = 23) referred for neuropsychological evaluation by physicians, attorneys, or a State Vocational Rehabilitation
Department. The individuals living on death row committed murders during robberies, drug deals, rapes, and crimes of passion. They all had
suspected or known histories of traumatic brain injury; some had comorbidities of schizophrenia, depression, and other psychiatric diagnoses. The individuals in the control group had a history of head trauma resulting primarily from motor vehicle accidents; a few had the comorbidity of depression. The murderers were randomly divided into two separate groups for comparisons with the control group. Coherence (within broad-band alpha) scores were calculated between all scalp electrode sites and fast-fourier spectral analyses were performed for each channel for two QEEG samples of at least 60 seconds (after artifact removal) recorded during eyes-closed. Spatial principal components derived from the mean peak-to-peak magnitude were calculated for several bands of EEG and submitted to 2 x 2 (death penalty x handedness) ANOVAs. Murderers had reduced mean peak-to-peak magnitude across all bands similar to that seen in broad spectrum EEG studies of aging. At anterior regions murderers had reduced high theta and high alpha suggesting impaired attention. There was significantly higher coherence in controls in the alpha range between and among central and posterior sites. These findings are used to support the theory that time on death row facilitates “cognitive aging.”