1. Stop! But How? Multiple Inhibitory Processes in 5- and 6-year-olds Christopher H. Chatham1, Katharine A. Blackwell2, Melody Wiseheart3 & Yuko Munakata4
1Brown University 2Salem College 3York University 4University of Colorado Boulder
Inhibition Is Critical to
Cognitive Control
Everyday situations require us to stop inappropriate actions:
Stop paying attention to the radio so we can focus on driving
Stop reaching for a slice of cake so we can adhere to a diet
Task Switching
Override a prepotent response
3D card sort task: match first by shape, then by color, then by size (12 trials each).
Children categorically switch (near perfect on both post-switch blocks) or perseverate (continue sorting by shape on both postswitch blocks) (Blackwell et al., 2009; Deák, 2003)
Switchers Better at
Selective Stopping Only
Switchers (n = 19) were slightly older (M = 6.3 years) than perseverators (n=28, M = 6.0 years; t(45) = 2.5, p < .05) so age was controlled.
Switchers and perseverators were equally fast to stop a single action (F < 1)
Switchers were faster to stop one action while continuing another (F(1,38) = 6.8, p = .01), regardless of cueing.
Discussion
Switchers showed an advantage at selective stopping only, not global stopping.
This contrasts a switcher disadvantage at global stopping observed in other stop signal tasks (Blackwell et al., under review).
Complexity of primary task (simple reaction vs. choice reaction) may influence children’s stopping efficiency.
Switchers showed advantage at selective stopping, but not expected reduced interference found in adults.
Theories of inhibitory control should consider developmental changes in stopping efficiency for insight into how inhibitory pathways function and interact.
Inhibition May Involve
Multiple Processes
Two paths may be global vs. selective (Aron & Verbruggen, 2008)
Inhibition
Stop a single action
One banana appears; press button to get banana for monkey, unless the banana turns brown.
Global inhibition
stops all responses
uses hyperdirect route from prefrontal cortex (PFC) to subthalamic nucleus
used when we “freeze” (e.g., stop reaching for slice of cake)
Selective inhibition
stops some responses but not others
uses indirect route from PFC through basal ganglia to subthalamic nucleus
used when we substitute actions (e.g., stop fiddling the the radio to steer the car)
Switchers Still Have Go-Hand Stopping Interference Cost
Adults using a selective stopping mechanism show less stopping-interference cost: still-going response (e.g., to yellow banana) is not slowed as much as when a global stopping mechanism is used (Aron & Verbruggen, 2008).
Switchers and perseverators have same stopping-interference cost (F < 1)
References
Aron, A. R., & Verbruggen, F. (2008). Stop the presses: Dissociating a selective from a global mechanism for stopping. Psychological Science, 19,
Blackwell, K. A., Cepeda. N. J., & Munakata, Y. (2009). When simple things are meaningful: Working memory strength predicts children’s cognitive flexibility. JECP, 103,
Blackwell, K. A., Chatham, C. H., Wiseheart, M., & Munakata, Y. (under review). A developmental window into trade-offs in executive function: The case of task switching versus response inhibition in 6-year-olds.
Deák, G. O. (2003). The development of cognitive flexibility and language abilities. In R. Kail (Ed.). Advances in child development and behavior (Vol. 31, pp. 271–327). San Diego: Academic Press.
Stop one action while continuing another
Two bananas appear; press two buttons simultaneously to get both bananas
If one turns brown, don’t press that button but do press the other to get the yellow banana
How Do Distinct Inhibition
Pathways Develop?
Acknowledgements
This research was supported by NIH (RO1 HD37163 and P50-MH079485)
Thanks to: Wolfgang Pauli and members of the Cognitive Development Center at CU Boulder.
Global and selective stopping investigated in 5- and 6-year olds
Relations of each compared to task-switching
Switchers may be using a different process for stopping one action while continuing another than adults use.
Contact
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