fNIRS Grasping Task in Infants

This study aims to investigate the neural mechanisms underlying the development of grasping function in infants aged 3 to 9 months. Specifically, it focuses on brain activity linked to reach-to-grasp movements, the role of maturation in this brain activity, the effect of preterm birth, and brain activity during bimanual toy exploration. The study will recruit 100 infants, including 50 full-term infants and 50 preterm infants (born at less than 36 weeks gestational age). Functional Near-Infrared Spectroscopy (fNIRS) will be used as the brain imaging technique to assess neural activity.

Objectives:

To investigate differences in brain activity during the reach-to-grasp task in 3-9-month-old infants between preterm and full-term infants.

To evaluate differences in the neural correlates of maturation of the reach-to-grasp motor skill.

To investigate differences in laterality index between preterm and full-term infants during bimanual toy exploration.

Method:

Fifty preterm and fifty full-term infants between 3 and 9 months corrected age will be assessed at a single time point. The assessment consists of an fNIRS event-related reach-to-grasp task protocol, where infants are encouraged to reach and grasp a toy, measured using the NSP2 system (NIRx). The task protocol includes 10 repetitions of each reach-to-grasp condition: 5 seconds of left-hand reach-to-grasp, 5 seconds of right-hand reach-to-grasp, and 10 seconds of bimanual toy exploration. A 10-second rest period is implemented between each reach-to-grasp action, and a 30-second rest period is implemented between conditions. Additionally, 5-7 minutes of resting-state fNIRS data will be recorded while infants watch a screensaver-like video to help maintain a resting state.

The fNIRS cap configuration consists of an 8×8 optode array covering the sensorimotor cortex. Cap size is adapted to the infant's head circumference (ranging between 42 and 46 cm), with the optode configuration remaining consistent across all cap sizes.

In addition to the fNIRS assessment, two clinical assessments will be conducted:

Hand Assessment for Infants (HAI): Evaluates hand function in infants. Hammersmith Infant Neurological Examination (HINE): Assesses neurological development.

Inclusion criteria

• 3-9 months old
• can tolerate the fNIRS cap
• performs at least 2 grapsing attempts with one hand within one minute when prompting the hand with a toy

Exclusion criteria

• history of periferal neurological lesion such as plexus brachialis lesion
• presence of epilepsia, congenital brain malformation,
• no informed consent
• severe visual impairments
• syndromal or genetical diseases resulting into developmental delay