Prospective Motor Control in Infancy Is Related to Inhibition and Working Memory
By Janna M. Gottwald
Executive functions are processes that help us to focus on what is important, to remember things, and to plan our daily activities. Finding early markers of executive functioning could help researchers develop interventions for children with impaired executive functioning (Diamond, 2013), but early executive functioning and its emergence in infancy are not yet sufficiently understood.
In a recent study, my collaborators and I tested the hypothesis that executive control in infancy is grounded in the physical ability of infants to move their bodies—also called motor control. We believed these domains were related based on theories of embodied cognition, which suggests that thought is rooted in our abilities to physically interact with the world (Marshall, 2016; Thelen, Schöner, Scheier, & Smith, 2001).
Executive functions deal with choosing, enacting, and sustaining of actions (Barkley, 2012). Prospective motor control is concerned with adapting actions to goals and the environment (Gottwald et al., 2016). Both prospective motor control and executive functioning deal with the ability to plan and control actions to reach goals. However, they address action control on different levels: at a relatively lower (motor) level and on a higher (cognitive) level.
The body shapes the mind – Taking the idea of an embodied cognition seriously means regarding executive functions as emerging from our own bodily interactions with the environment. Here we do not test this theory directly, but we test an implication of the theory.
If executive functions emerge from prospective motor control, we should find a correlation between the developing ability to plan and control motor actions and executive functions at the age of 18 months, the earliest point at which executive functions can be reliably tested (Garon, Smith, & Bryson, 2014).
Seventy 18-month-olds (78% were included in the final sample) visited the Child and Baby Lab at Uppsala University, Sweden and took part in four different tasks: One task measuring prospective motor control and three tasks measuring early executive functioning:
- In the prospective motor control task, the infants had to reach for a small toy and place it in boxes that differed in size and distance to the toy. We measured their speed at the beginning of their reaches. Being quick and at the same time successful (i.e., to succeed in reaching and grasping the toy and placing it in a cylinder subsequently) indicated high prospective motor control.
- In the behavioral inhibition task, we placed a glittering wand in front of the infants while telling them not to touch it. We waited for 30 seconds and measured the time until they could not resist anymore and touched this attractive toy. This is difficult for children this age – consequently, mean waiting time was only 7 seconds.
- In the working memory task, the infants had to search for a toy that was hidden in a little drawer. We demonstratively hid the toy in one of the four drawers, covered the drawer with cloth and waited for 5 seconds until the infant was allowed to search for the toy. We repeated this task three more times with different locations and gave points for the number of trials the infants needed to find the toy.
- In the complex inhibition task, the child had to inhibit a dominant response in favor of subdominant action. The task was to retrieve a shiny plastic duck from a box. The duck was visible through a window, but in order to get the toy, the infant had to open the window first (subdominant action) and then reach for the attractive toy (dominant action). The opening of the box was done by pulling a knob. This task turned out to be too difficult for the infants – they often reached for the duck directly, without first opening the window.
Results demonstrated that the infants with higher prospective motor control were better in the tasks requiring behavioral inhibition and working memory than the infants with lower prospective motor control. In other words: The quicker the infants were in the motor task, the better they were in restraining themselves from grabbing an attractive toy and the better they were remembering a hidden toy’s location after a delay. The complex inhibition measure was not related to any of the other measures, suggesting that it was not adequately measuring the same executive functioning construct.
These results demonstrate that executive functions are related to prospective motor control. We suggest that executive functions are grounded in the developing ability to plan and control motor actions in infancy. To put it differently, the ability to plan reaching movements is associated with higher-order cognitive control. This study is the first demonstrating that low-level motor control is related to higher-order executive functions.
Janna M. Gottwald recently defended her thesis about motor and cognitive development in infancy at Uppsala University, Sweden. She is now doing a postdoc in personality and clinical psychology at the International Psychoanalytic University Berlin, Germany.
Gottwald, J. M., Achermann, S., Marciszko, C., Lindskog, M., & Gredebäck, G. (2016). An embodied account of early executive function development: Prospective motor control in infancy is related to inhibition and working memory. Psychological Science. doi: 10.1177/0956797616667447
Barkley, R. A. (2012). Executive Functions: What They Are, How They Work, and Why They Evolved. New York: Guilford.
Diamond, A. (2013). Executive Functions. Annual Review of Clinical Psychology, 64, 135–168. http://doi.org/10.1146/annurev-psych-113011-143750.
Garon, N., Smith, I. M., & Bryson, S. E. (2014). A novel executive function battery for preschoolers: Sensitivity to age differences. Child Neuropsychology: A Journal on Normal and Abnormal Development in Childhood and Adolescence, 20(6), 713–736. http://doi.org/10.1080/09297049.2013.857650
Gottwald, J. M., de Bortoli Vizioli, A., Lindskog, M., Nyström, P., Ekberg, T. L., von Hofsten, C., & Gredebäck, G. (2016). Infants prospectively control reaching based on the difficulty of future actions - To what extent can infants’ multiple step actions be explained by Fitts’ law? Accepted for publication in Developmental Psychology.
Marshall, P. J. (2016). Embodiment and human development. Child Development Perspectives. http://doi.org/doi: 10.1111/cdep.12190
Thelen, E., Schöner, G., Scheier, C., & Smith, L. B. (2001). The dynamics of embodiment: A field theory of infant perseverative reaching. Behavioral and Brain Sciences, 24(1), 1–86. http://doi.org/10.1017/S0140525X01003910