Recognizing a Mother's Voice in the Persistent Vegetative State

Abstract

We studied an 8-year-old boy after a near-drowning left him in a vegetative state (VS) for 4 years before the study. Findings fulfilled all clinical criteria for the diagnosis of VS. The purpose of this study was to investigate whether there was significant differential activation of the brain in response to hearing his mother's voice compared with the voices of unknown women. The data were assessed using quantitative electric tomography (QEEGt), a technique that combines anatomical information of the brain by MRI with EEG patterns to estimate the sources of the EEG within the brain. We found significant differences for EEG frequencies from 14-58 Hz, with a peak at 33.2 Hz (gamma band). The 3D reconstruction showed that these statistical differences were localized in the lateral and posterior regions of the left hemisphere. No significant differences were found between unknown women vs. basal conditions. These results demonstrate recognition of the mother's voice and indicate high-level residual linguistic processing in a patient meeting clinical criteria for VS. These findings launch new ethical and practical implications for the management of VS patients.

Finding a way in: A review and practical evaluation of fMRI and EEG for detection and assessment in disorders of consciousness

“…This finding was Page 9 replicated by Perrin et al (2006) in 3 out of 5 VS patients, all 6 MCS patients, 4 LIS patients, and 5 healthy controls. Machado et al (2007) observed oscillatory changes in the gamma band in a boy in VS when he listened to his mother's voice, but not when the same words were spoken by unfamiliar women. In the only substantial group study of emotion in DOC, Kotchoubey et al (2009) examined patients' ERP responses to woeful exclamations as oddball stimuli in a series of joyful stimuli (single words in which only the prosody determined the emotion).…”

Effects of familiar voices on brain activity

“…For example, a study conducted on an 8-year-old boy who nearly drowned and was left in a vegetative state for 4 years prior to the study demonstrated that there were significant differential activations in EEG frequencies at 14-58 Hz, with specific brain activity at 33.2 Hz (gamma band) to the sound of his mother's voice when compared with the voices of unfamiliar women. 20 An additional study analyzed electrophysiological data on how newborns process their mother's voice compared with the voice of a stranger and found that exposure to one's maternal voice elicited early language-relevant processing, whereas the stranger's voice elicited more voice- specific responses. 21 In an experiment examining eventrelated potentials to audio of a subject's own name (SON) recorded by a familiar voice vs. an unknown voice that was recorded by an unfamiliar person, the SON elicited large response amplitudes during the later phase of a novel P3 (after 300 ms).…”

“…Additionally, for subsequent analyses, the b band (13-30 Hz) was divided into its two respective portions: b1 band (13-20 Hz) and b2 band (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Subsequent comparisons examining the content ratios within the four sites (F3, F4, C3 and C4) revealed a significant increase in brain activity while listening to a familiar voice (a mother's voice) specifically in the b1 band at the F4 site (Fig.…”

“…As previously suggested by others, firstly, it may be easier to focus on the contents of a story while listening to a familiar person's voice vs. a stranger's voice. 20 Secondly, it seems that the brain may be activated by things that are not directly related to the contents of the fairy tale, for example, thoughts about their family, and events that may have occurred among their family members, such as recalling a memory connecting their family to the fairy tale.…”

TCD Diastolic Velocity Decay and Pulsatility Index Increment in PVS Cases

“…They showed no evidence of gestural or verbal communication, no ability to follow commands, and no visual pursuit, or purposeful motor behavior, fulfilling PVS diagnostic criteria. [2][3][4][5][6][7][8][9][10] Auditory, visual, motor, oromotor, communication, and arousal processes were assessed in all cases by the JFK scale, 22 ranging from 3 and 6 points.…”