Sex differences in the neural underpinnings of social and monetary incentive processing during adolescence

The brain’s reward system undergoes major changes during adolescence, and an increased reactivity to social and nonsocial incentives has been described as a typical feature during this transitional period. Little is known whether there are sex differences in the brain’s responsiveness to social or monetary incentives during adolescence. The aim of this event-related potential (ERP) study was to compare the neurophysiological underpinnings of monetary and social incentive processing in adolescent boys versus girls. During ERP recording, 38 adolescents (21 females, 17 males; 13–18 years) completed an incentive delay task comprising (a) a reward versus punishment condition and (b) social versus monetary incentives. The stimulus-preceding negativity (SPN) was recorded during anticipation of reward and punishment, and the feedback P3 (fP3) along with the feedback-related negativity (FRN) after reward/punishment delivery. During anticipation of social punishment, adolescent boys compared with girls exhibited a reduced SPN. After delivery, male adolescents exhibited higher fP3 amplitudes to monetary compared with social incentives, whereas fP3 amplitudes in girls were comparable across incentive types. Moreover, whereas in boys fP3 responses were higher in rewards than in punishment trials, no such difference was evident in girls. The results indicate that adolescent boys show a reduced neural responsivity in the prospect of social punishment. Moreover, the findings imply that, once the incentive is obtained, adolescent boys attribute a relatively enhanced motivational significance to monetary incentives and show a relative hyposensitivity to punishment. The findings might contribute to our understanding of sex-specific vulnerabilities to problem behaviors related to incentive processing during adolescence.     

Orthographic learning in children with isolated and combined reading and spelling deficits

Dissociations between reading and spelling problems are likely to be associated with different underlying cognitive deficits, and with different deficits in orthographic learning. In order to understand these differences, the current study examined orthographic learning using a printed-word learning paradigm. Children (4th grade) with isolated reading, isolated spelling and combined reading and spelling problems were compared to children with age appropriate reading and spelling skills on their performance during learning novel words and symbols (non-verbal control condition), and during immediate and delayed reading and spelling recall tasks. No group differences occurred in the non-verbal control condition. In the verbal condition, initial learning was intact in all groups, but differences occurred during recall tasks. Children with reading fluency deficits showed slower reading times, while children with spelling deficits were less accurate, both in reading and spelling recall. Children with isolated spelling problems showed no difficulties in immediate spelling recall, but had problems in remembering the spellings 2 hours later. The results suggest that different orthographic learning deficits underlie reading fluency and spelling problems: Children with isolated reading fluency deficits have no difficulties in building-up orthographic representations, but access to these representations is slowed down while children with isolated spelling deficits have problems in storing precise orthographic representations in long-term memory.