Summary: Older children have stronger neural responses to rewards over punishments later in the afternoon. In younger children, this pattern is reversed.
Source: Binghamton University
Older children respond more strongly to rewarding experiences and less strongly to negative experiences later in the day, which may lead to poor decision-making at night, according to research from Binghamton University, State University of New York.
“When children transition into adolescence, they begin to chase rewards/pleasing experiences more and respond to losses/punishment less. How responsive someone is to rewards varies depending on time of day because of circadian rhythms,” said Aliona Tsypes, a graduate student in psychology at Binghamton University. “So we wanted to see how time of day might affect reward responsiveness in children and how this might vary depending on their age. This is important to better understand (and prevent) teenage risk-taking, particularly because the rates of psychological problems increase dramatically during one’s transition to adolescence. This is also important for us and other researchers who study reward to know, to make sure we consider the timing of our study sessions as a potentially influential factor.”
Tsypes and Brandon Gibb, professor of psychology and director of the Mood Disorders Institute at Binghamton University, recruited 188 healthy children between the ages of 7 and 11 and had them complete a commonly used simple guessing task on a computer. In this task, they see two doors on the screen and guess which one has money behind it. Each time they guess correctly, they win 50 cents and each time they are incorrect, they lose 25 cents. During the task, the researchers measured children’s brain activity using electroencephalography (EEG) to examine neural responses to wins and losses.
“One way to objectively assess someone’s responsiveness to reward and loss is to measure their brain activity while they play a computer game during which they receive feedback about winning or losing money,” said Gibb. “In our study, we were primarily interested in how these responses to gains versus losses may differ throughout the day in children.”
The researchers found that older children had stronger neural responses to rewards/pleasing experiences than losses/punishments later in the day (after around 5:15 p.m.), whereas younger children showed the reverse pattern. These findings suggest that early adolescents might experience greater urges to engage in rewarding/pleasing experiences, even if such experiences are unhealthy or dangerous, later in the day.
“Heightened reward responsiveness in early adolescents later in the day may contribute to greater risk for making poor decisions in the evenings (e.g., choosing to engage in risky behaviors),” said Gibb. “This may help to explain why adolescence is a period of increased risk for developing psychopathology and substance use problems.”
Credit: Binghamton University.
“If there are times during which children who approach adolescence are particularly responsive to rewards and particularly unresponsive to losses/punishment, these might be important times to particularly watch out for, to prevent dangerous behaviors,” said Tsypes.
Tsypes continues to study reward-related processes, particularly as they relate to suicidal and self-harming thoughts and behaviors (STBs). She hopes to better understand the influences of circadian rhythms on reward and how this affects the risk for STBs.
“It is important to note that time-of-day effects are not strictly circadian, so future research should also examine additional relevant variables with a circadian rhythm (e.g., cortisol) to better distinguish reward-related processes from other cyclic processes within the human nervous system,” said Tsypes.
Time of Day Differences in Neural Reward Responsiveness in Children
The Reward Positivity (∆RewP) event‐related potential (ERP), generally quantified as the difference between neural responsiveness to monetary gains (RewP‐Gain) and losses (RewP‐Loss) is commonly used as an index of neural reward responsiveness. Despite the popularity of this ERP component in studies of reward processing, knowledge about the role of state‐related influences on the ∆RewP is limited. The present study examined whether ∆RewP amplitudes may differ based on when during the day they are assessed and whether age or sex would moderate this link. Participants were 188 children between the ages of 7 and 11 (47.3% female) without a lifetime history of a major depressive disorder or any anxiety disorder recruited from the community. Children completed the Doors task during which continuous electroencephalography was recorded to isolate the ∆RewP. To better isolate this ERP component from other temporally or spatially overlapping ERPs, we used temporospatial principal component analysis. We found that time of day (ToD) differences in the ∆RewP amplitude varied based on children’s age. Specifically, older, compared to younger, children exhibited stronger responses to gains versus losses between 11:15 a.m. and 12:30 p.m. and after around 5:15 p.m. Further, these age‐related differences appeared to be driven specifically by older children’s reduced neural responsiveness to losses. The findings have methodological implications by highlighting the importance of accounting for the ToD at which ∆RewP‐focused study sessions are conducted as well as for demographic characteristics of the participants, such as their age.