Selective Cortical Mapping of Biological Motion Processing in Young Infants

Abstract

How specialized is the infant brain for perceiving the facial and manual movements displayed by others? Although there is evidence for a network of regions that process biological motion in adults--including individuated responses to the perception of differing facial and manual movements--how this cortical specialization develops remains unknown. We used functional near-infrared spectroscopy [Lloyd-Fox, S., Blasi, A., & Elwell, C. Illuminating the developing brain: The past, present and future of functional near-infrared spectroscopy. Neuroscience and Biobehavioral Reviews, 34, 269-284, 2010] to investigate the ability of 5-month-old infants to process differing biological movements. Infants watched videos of adult actors moving their hands, their mouth, or their eyes, all in contrast to nonbiological mechanical movements, while hemodynamic responses were recorded over the their frontal and temporal cortices. We observed different regions of the frontal and temporal cortex that responded to these biological movements and different patterns of cortical activation according to the type of movement watched. From an early age, our brains selectively respond to biologically relevant movements, and further, selective patterns of regional specification to different cues occur within what may correspond to a developing "social brain" network. These findings illuminate hitherto undocumented maps of selective cortical activation to biological motion processing in the early postnatal development of the human brain.

Coregistering functional near-infrared spectroscopy with underlying cortical areas in infants

“…During Session 1 the infants participated in an fNIRS study at CBCD using the UCL-fNIRS system 37 and custom built CBCD-fNIRS headgear (used in previously published work 3,4,19 ). The CBCD fNIRS headgear houses three arrays to form up to 33 channels.…”

“…Measurements are then taken in relation to head size and external landmarks such as the nasion/ear for each individual. 19 The first type of design—based on a proportional 10 to 20 system—makes the assumptions that the cortical regions in the developing brain do not change location in relation to external landmarks or proportional changes in head size as the individual ages, and that it does not matter whether the source-detector distances, and, therefore, the depth of measurement differ across infants. Generally, the cap is changed according to head size within one age group, thus the source-detector distances may vary across infants.…”

The emergence of cerebral specialization for the human voice over the first months of life

“…Interestingly, and perhaps related to these functional findings, the anatomy of the left STS appears to develop more slowly than the right over the first 4 months of life (Leroy et al, 2011), and there is continued asymmetry in the anatomical structure of the STS region into adulthood (Ochiai et al, 2004;van Essen et al, 2005). The STS region has also been associated with the perception of speech-like mouth movements in infants (Lloyd-Fox, Blasi, Everdell, Elwell, & Johnson, 2011) and adults (Pelphrey, Morris, Michelich, Allison, & McCarthy, 2005) and silent lip reading (Calvert et al, 1997). Furthermore, this anterior STS region activation does not arise in response to the perception of nonspeech-like mouth movements (Calvert et al, 1997) such as facial gurning (i.e., twitching or closed-mouth gestures), suggesting that this region of the temporal cortex is particularly sensitive to voice-associated visual cues.…”

Localization of Hemodynamic Responses to Simple Visual Stimulation: An fNIRS Study

“…Briefly, this has included using flashing LEDs, reversing checkerboards, static and motion-inducing stimuli, illusory percepts, and infant studies using videos of face, hand, and mouth movements. [7][8][9][10][11][12][13] Results from such studies have established parallels with data from imaging techniques.Although vision-related fNIRS research has been very active, there is limited information available about how much cortical tissue is activated outside of primary visual cortex (V1) locations as reflected by the distribution of hemodynamic parameters with systematic mapping. Furthermore, mapping of scalp distributions has not been used with luminancematched and controlled stimulation.…”