March 2022: Error-signaling in the Developing Brain

Overview and Purpose

One of a human being’s most potent learning mechanisms is the ability to adapt and adjust from mistakes. Errors provide the brain powerful signals, but do these error signals change from task to task or is there a common error system in the brain? Using functional MRI (fMRI), we can see which parts of the brain change signals during a mistake.

In adults, studies have found that there is a core set of multiple brain regions that respond to mistakes across different tasks. The brain regions involved in errors for adults have also been shown to be important for other control-demanding activities, such as starting a task or doing a harder-relative-to-easier task (Neta et al., 2015).

Does error processing in children look similar to error processing in adults? To answer this question, Roe and colleagues (2021) examined error signals in the brains of children across three different tasks performed in an MRI scanner. The results indicated a great deal of overlap between children and adults in error signaling across the three tasks, and error-related signals in the developing brain overlapped well with adult error processing. The one notable group difference was in the lateral frontal cortex, which is a brain region related to errors in adults but which in this analysis was not consistently used by children. It could be that these lateral frontal regions relate to the better performance shown by adults than children on most tasks.

Study Methods

The main purpose of Roe and colleague’s study was to examine via fMRI the consistency of error processing across different tasks in children. To do this, the authors pooled data across multiple studies, including one dataset collected by the Texas Center for Learning Disabilities. A total of 232 kids ages 8-17 years participated across the different research collections. The researchers took pictures of each child’s brain while they performed at least one of three tasks. To be a part of this analysis, the child had to make at least one mistake on one of the tasks. The three fMRI tasks used in this analysis were reading comprehension (where children judged the sensibility of simple sentences; n=119), response inhibition (where children tried to stop a prepotent response; n=218), and a cognitive flexibility task (where children had to sort targets by color or shape; n=95).

To study error signals, authors compared activation in the brain when the child got a test question correct and when they got a test question wrong. They looked at error signaling in each task separately, but were most interested in the consistency across different tasks and the similarities to adult error activity. They also examined how the number of mistakes a child made affected their error signalling, and whether age consistently related to error-related brain activity across tasks.

Key Findings

1. Consistent with adults, many of the brain’s control regions are active during mistakes

Nineteen brain regions had significant error-related activity during all three tasks, including many important control-related regions of the brain. Additional regions overlapped between children and adults across two tasks. When the authors calculated the distance between these hubs of error activity in children and the previous literature’s reports of adult error-related brain activity, they found that the only adult error regions that were not within 2 cm of a child region were in the lateral frontal cortex. There was no consistent three-task overlap of error signal regions with task accuracy. There were many two-task overlap regions that correlated with accuracy, again in control-related regions. Error signals were larger in these regions when task accuracy was higher.

2. Lateral frontal regions were not consistently engaged

Lateral frontal brain regions, while engaged significantly by children during the tasks overall, did not show consistent error-related signals. This result was a substantial difference from the published literature on adult error processing. At the individual task level, children seemed to activate the lateral frontal regions for errors in the cognitive flexibility (switching) task, but this finding was not consistent across the three tasks. Maturation of lateral frontal cortex may be prolonged or this area of the brain may relate to a different aspect of error processing than the more consistent regions found by Roe and colleagues.

3. Age effects were task-specific

Each task had significant changes in error processing over time, but the brain regions that changed over age were not consistent across the three tasks, indicating that age-related error processing changes were task-specific. Nearly all error-related regions across all three tasks showed greater brain activity for mistakes than for correct trials, which is consistent with the adult pattern. Thus, in addition to children demonstrating similar error-related locations in the brain as adults, the pattern of activity was also similar over age. Age-related changes were more task-specific, likely relating to changes in individual task accuracy rather than reflecting a consistent maturational change. The error-related brain processing network appears largely in place by middle childhood, suggesting that age-related differences in task performance may relate to how other brain regions receive information from this error network.

Conclusions, Implications, and Future Directions

Children have multiple brain regions that consistently respond to mistakes across tasks. These brain patterns look highly similar to what is seen in adults except in the lateral frontal cortex. Future studies should examine brain activity after a mistake to see what children do to compensate for mistakes, as well as studying the age trajectory of error signaling in the lateral frontal cortex and its relation to successful task performance.

Future studies could also examine the role of feedback in children’s error processing, as the mistakes in the current study occurred without any indication of correct or incorrect performance. Similarly, response time effects were not studied­. As people sometimes slow down to be more accurate in some tasks, exmaining these effects might be worthwhile. Finally, it is important to study how children with a mental health challenge, such as attention-deficit/hyperactivity disorder (ADHD), engage the brain during mistakes (e.g., Plessen et al., 2016).

Mistakes are a key learning tool for the developing brain. This study suggests a robust, consistent set of brain regions process errors in a manner similar to that seen in adults, with the exception of the slow-to-mature lateral frontal cortex.

References

Neta, M., Miezin, F. M., Nelson, S. M., Dubis, J. W., Dosenbach, N. U. F., Schlaggar, B. L., & Petersen, S. E. (2015, January 7). Spatial and temporal characteristics of error-related activity in the human brain. Journal of Neuroscience. 35(1), 253–266. https://doi.org/10.1523/JNEUROSCI.1313-14.2015

Plessen, K. J., Allen, E. A., Eichele, H., van Wageningen, H., Høvik, M. F., Sørensen, L., Worren, M. K., Hugdahl, K., & Eichele, T. (2016, March 1). Reduced error signalling in medication-naive children with ADHD: Associations with behavioural variability and post-error adaptations. Journal of Psychiatry & Neuroscience. 41(2), 77–87. https://doi.org/10.1503/jpn.140353