Toward an electrocortical biomarker of cognition for newborn infants
Joseph R Isler1, Amanda R Tarullo, Philip G Grieve
1Department of Pediatrics, Columbia University, New York, NY 10032, USA. jri2101@columbia.edu
Insights
Wavelet analysis of brain activity in newborns shows more robust detection of stimulus change than traditional event-related potentials (ERPs). This method may offer a clinically useful test for early cortical function in infants.
Area of Science:
- Neuroscience
- Developmental Neuroscience
- Cognitive Neuroscience
Background:
- Mismatch negativity (MMN) using event-related potentials (ERPs) was the first electrophysiological method to assess cognitive processing in newborns.
- Initial predictions of MMN's clinical utility for identifying infants at risk for developmental deficits have not been fully realized.
Purpose of the Study:
- To investigate if wavelet analysis of power in the MMN paradigm provides more robust markers of brain response to stimulus change in sleeping newborn infants compared to ERP-derived MMN.
- To explore the presence of theta, beta, and gamma band oscillations in neonates during auditory change detection.
Main Methods:
- Utilized the mismatch negativity (MMN) paradigm in sleeping newborn infants.
- Employed wavelet analysis to assess power spectrum changes in response to auditory stimuli (frequent vs. infrequent/unpredictable tones).
- Analyzed electrophysiological data from multiple scalp locations across various latencies and frequencies.
Main Results:
- Found increased wavelet power in response to unpredictable and infrequent tones compared to frequent tones, even when ERP-derived MMN was absent.
- Observed elevated theta band power at middle and late latencies (200-600 ms), suggesting early presence of working memory-related rhythms.
- Detected increased beta and gamma band power at late latency (500 ms) for infrequent/unpredictable tones, indicating the presence of adult-like cognitive oscillations in neonates.
Conclusions:
- Wavelet-derived measures of brain activity offer a more sensitive approach to detecting auditory change in newborns than traditional ERP-derived MMN.
- The findings suggest that frequency-dependent measures, like wavelet power, can potentially serve as clinically useful indicators of cortical function in the early postnatal period.
- Neocortical theta, beta, and gamma rhythms associated with cognitive functions like working memory appear to be present at birth.
Abstract:
The event-related potential (ERP) effect of mismatch negativity (MMN) was the first electrophysiological probe to evaluate cognitive processing (change detection) in newborn infants. Initial studies of MMN predicted clinical utility for this measure in identification of infants at risk for developmental cognitive deficits. These predictions have not been realized. We hypothesized that in sleeping newborn infants, measures derived from wavelet assessment of power in the MMN paradigm would be more robust markers of the brain's response to stimulus change than the ERP-derived MMN. Consistent with this premise, we found increased power in response to unpredictable and infrequent tones compared to frequent tones. These increases were present at multiple locations on the scalp over a range of latencies and frequencies and occurred even in the absence of an ERP-derived MMN. There were two predominant effects. First, theta band power was elevated at middle and late latencies (200 to 600 ms), suggesting that neocortical theta rhythms that subserve working memory in adults are present at birth. Second, late latency (500 ms) increased power to the unpredictable and infrequent tones was observed in the beta and gamma bands, suggesting that oscillations involved in adult cognition are also present in the neonate. These findings support the expectation that frequency dependent measures, such as wavelet power, will improve the prospects for a clinically useful test of cortical function early in the postnatal period.
