Fast vigilance decrement in closed head injury patients as reflected by the mismatch negativity (MMN)

Abstract

Event-related potentials (ERPs) were measured from 24 chronic closed head injury (CHI) patients and 18 age- and education-matched controls. The oddball paradigm was applied while subjects were watching a silent movie. The standard (p=0.8) sound of 75 ms duration had a basic frequency of 500 Hz with harmonic partials of 1000 Hz and 1500 Hz, whereas these frequencies for the pitch deviant were each 10% higher. The frequencies of the duration deviant matched with those of the standard but was 25 ms in duration. The MMN (mismatch negativity), generated by the brain's automatic auditory change-detector mechanism, was elicited by both deviants. No significant differences in the MMN latency or amplitude for either pitch or duration deviants were found between the groups. However, the MMN amplitude for the pitch deviant decreased in the patient group during the experiment considerably faster than in controls, suggesting a faster vigilance decrement in the patients.

Electrophysiological evidence for pre-attention information processing improvement in patients with central hemiplegic after peripheral nerve rewiring: a pilot study

“…Compared with healthy normal control participants, the amplitudes of MMN were significantly lower in CNI patients, both before and after PNR surgery. Consistent with the present findings, MMN decreases also occurs in brain injury and stroke patients 11 , 27 , 28 . For example, Ilvonen et al .…”

“…Similarly, a study by Kaipio et al . 28 also showed changes in MMN amplitude in closed head injury and stroke patients. There was evidence that changes in MMN were correlated with the recovery of speech comprehension in aphasic stroke patients 11 .…”

Preattentive Sensory Processing as Indexed by the MMN and P3a Brain Responses is Associated with Cognitive and Psychosocial Functioning in Healthy Adults

“…Indeed, the mismatch response is evoked regardless of whether subjects are even remotely aware of subtle task-irrelevant deviant stimuli in the environment. In this context, it is striking that welldefined MMN waveforms can be obtained from fetuses using magnetoencephalography (Draganova et al, 2005), as well as from sleeping infants (Huotilainen et al, 2003;Cheour-Luhtanen et al, 1996;Alho, Sainio, Sajaniemi, Reinikainen, & Näätänen, 1990) and adults (Sabri & Campbell, 2002;Nashida et al, 2000), patients with severe brain injuries (Kaipio et al, 2001;Woods, Knight, & Scabini, 1993), and even comatose individuals who ultimately regain consciousness (Morlet, Bouchet, & Fischer, 2000;Fischer et al, 1999;Kane et al, 1996). Because MMN occurs even in the absence of conscious and effortful attention, it appears to index a preattentive form of sensory memory (Näätänen, 1992) that may ''govern'' some higher order physiological and behavioral cognitive operations in normal subjects (Tiitinen, May, Reinikainen, & Näätänen, 1994).…”