Difficulty sensitivity replaces reward sensitivity during adolescence: Task-related fMRI and functional connectivity during self-regulative learning choices.

AIM: We examined age-related differences in valuation and cognitive control circuits during value-based decision-making. METHODS: 13-year-olds (N = 25) and 17-year-olds (N = 22) made a metacognitive choice to be tested or not on an upcoming learning task, based on reward and difficulty associated with word-pairs. To investigate whether these determinants of subjective value are differently processed at different ages, we performed region-of-interest(ROI)-based analyses of task-related and functional connectivity data. RESULTS: We observed age-related differences in responsiveness of valuation structures (amygdala, ventral striatum, ventromedial prefrontal cortex) and caudate nucleus, with activity modulated by reward in 13-year-olds, while in 17-year-olds activity being responsive to difficulty. These accompanied age-related differences in functional connectivity between medial prefrontal and striatal/amygdala seeds. DISCUSSION: These results are in line with current views that sensitivity changes for reward and difficulty during adolescence are the result of a maturational switch in effort-related signalling in the cognitive control circuit, which increasingly regulates value-signalling structures.

Age-related differences in task-induced brain activation is not task specific: Multivariate pattern generalization between metacognition, cognition and perception.

Adolescence is associated with widespread maturation of brain structures and functional connectivity profiles that shift from local to more distributed and better integrated networks, which are active during a variety of cognitive tasks. Nevertheless, the approach to examine task-induced developmental brain changes is function-specific, leaving the question open whether functional maturation is specific to the particular cognitive demands of the task used, or generalizes across different tasks. In the present study we examine the hypothesis that functional brain maturation is driven by global changes in how the brain handles cognitive demands. Multivariate pattern classification analysis (MVPA) was used to examine whether age discriminative task-induced activation patterns generalize across a wide range of information processing levels. 25 young (13-years old) and 22 old (17-years old) adolescents performed three conceptually different tasks of metacognition, cognition and visual processing. MVPA applied within each task indicated that task-induced brain activation is consistent and reliably different between ages 13 and 17. These age-discriminative activation patterns proved to be common across the different tasks used, despite the differences in cognitive demands and brain structures engaged by each of the three tasks. MVP classifiers trained to detect age-discriminative patterns in brain activation during one task were significantly able to decode age from brain activation maps during execution of other tasks with accuracies between 63 and 75%. The results emphasize that age-specific characteristics of task-induced brain activation have to be understood at the level of brain-wide networks that show maturational changes in their organization and processing efficacy during adolescence.

Reverse inference of memory retrieval processes underlying metacognitive monitoring of learning using multivariate pattern analysis.

Monitoring of learning is only accurate at some time after learning. It is thought that immediate monitoring is based on working memory, whereas later monitoring requires re-activation of stored items, yielding accurate judgements. Such interpretations are difficult to test because they require reverse inference, which presupposes specificity of brain activity for the hidden cognitive processes. We investigated whether multivariate pattern classification can provide this specificity. We used a word recall task to create single trial examples of immediate and long term retrieval and trained a learning algorithm to discriminate them. Next, participants performed a similar task involving monitoring instead of recall. The recall-trained classifier recognized the retrieval patterns underlying immediate and long term monitoring and classified delayed monitoring examples as long-term retrieval. This result demonstrates the feasibility of decoding cognitive processes, instead of their content.

Enhanced perceptual responses during visual processing of facial stimuli in young socially anxious individuals.

The present study investigated whether social anxiety modulates the processing of facial expressions. Event-related potentials were recorded during an oddball task in young adults reporting high or low levels of social anxiety as evaluated by the Liebowitz Social Anxiety Scale. Repeated pictures of faces with a neutral expression were infrequently replaced by pictures of the same face displaying happiness, anger, fear or disgust. For all participants, response latencies were shorter in detecting faces expressing disgust and happiness as compared to fear or anger. Low social anxiety individuals evoked enhanced P1 in response to angry faces as compared to other stimuli while high socially anxious participants displayed enlarged P1 for all emotional stimuli as compared to neutral ones, and general higher amplitudes as compared to non-anxious individuals. Conversely, the face-specific N170 and the task-related decision P3b were not influenced by social anxiety. These results suggest increased pre-attentive detection of facial cues in socially anxious individuals and are discussed within the framework of recent models of anxiety.

Sex differences on emotional processing are modulated by subclinical levels of alexithymia and depression: a preliminary assessment using event-related potentials.

Several studies have suggested that women are more sensitive than men to emotions in general. Event-related potential (ERP) studies have demonstrated N2 and P3b modulations, suggesting that women allocate more attentional resources to emotions than men do. However, the exact origin of this emotional modulation by sex is still a matter of debate. We wondered whether these sex differences might be due to some specific personality traits of women and men. Thirty participants (15 males and 15 females) were selected so that there were no sex differences on alexithymia, or depression and anxiety scales. The participants were asked to complete a "modified emotional" oddball task, in which they had to detect deviant stimuli among frequent neutral ones as quickly as possible. Behavioral performance, N2 and P3b ERP data were analyzed. When personality factors were controlled for, the sex differences on N2 and P3b components of the ERPs disappeared. Moreover, linear regression analyses showed that alexithymia was much better than sex at predicting the N2 latencies, while depression was the best factor for predicting the P3b latency. These results suggest that personality factors should be taken into account when sex differences on emotional processing are investigated.

Appetitive vs. defensive responses to emotional cues. Autonomic measures and brain oscillation modulation.

The present study explored the effect of the subjective evaluation and the individual differences related to BIS and BAS (Behavioural Inhibition and Activation System) on autonomic measures and brain oscillations, in response to appetitive and aversive emotional stimuli. Multiple measures were recorded, such as psychophysiological (skin conductance response, heart rate, and electromyography) and frequency bands (delta, theta, alpha, and gamma), during viewing IAPS figures, that varied in terms of pleasantness (appetitive vs. aversive) and arousing power (high vs. low intensity). Both BIS and BAS measures were significant in modulating behavioural, autonomic and brain oscillations responses. Withdrawal (BIS system) and appetitive (BAS system) behaviour showed opposite patterns of responses by the subjects. Also, frontal cortical site response was more significant than other sites. Nevertheless, no specific lateralization effect was found as a function of BIS/BAS dichotomy. Moreover, autonomic variables and frequency band modulations were found to be effected by valence and arousal rating per se, with an increased response for high arousing and negative or positive stimuli in comparison with low arousing and neutral stimuli. The effects of subjective evaluation and individual differences were discussed at light of coping activity model of emotion comprehension.

BIS/BAS, cortical oscillations and coherence in response to emotional cues.

The present study explored the effect of the individual differences related to BIS and BAS (Behavioural Inhibition and Activation System) on brain oscillations, in response to appetitive and aversive emotional stimuli. EEG cortical measures (delta, theta, alpha, and gamma) were recorded, during viewing IAPS figures, that varied in terms of pleasantness and arousal. Withdrawal (BIS system) and appetitive (BAS system) behaviour showed opposite patterns of subjective responses. Also, a specific frontal network was found to be responsive to the relevance of emotional cues. Moreover an increased response for high arousing (negative and positive) stimuli in comparison with low arousing and neutral stimuli was found within the left and right frontal areas. Specifically delta and theta band have a significant role in monitoring the attentional significance of emotions. Finally, the effects of subjective evaluation and individual differences were discussed at light of the two-dimensional model of emotion processing, that is the valence and the arousing power of emotional cues.