Age differences in the neural response to emotional distraction during working memory encoding

Age-related declines in attention and working memory (WM) are well documented and may be worsened by the occurrence of distracting information. Emotionally valenced stimuli may have particularly strong distracting effects on cognition. We investigated age-related differences in emotional distraction using task-fMRI. WM performance in older adults was lower for emotional compared with neutral distractors, suggesting a disproportional impairment elicited by emotional task-irrelevant information. Critically, older adults were particularly distracted by task-irrelevant positive information, whereas the opposite pattern was found for younger adults. Age groups differed markedly in the brain response to emotional distractors; younger adults activated posterior cortical regions and the striatum, and older adults activated frontal regions. Also, an age by valence interaction was found for IFG and ACC, suggesting differential modulation of attention to task-relevant emotional information. These results provide new insights into age-related changes in emotional processing and the ability to resolve interference from emotional distraction.     

The relationship between responsiveness to social and monetary rewards and ADHD symptoms

Alterations in reward processing are frequently reported in attention deficit hyperactivity disorder (ADHD). One important factor affecting reward processing is the quality of reward as social and monetary rewards are processed by different neural networks. However, the effect of reward type on reward processing in ADHD has not been extensively studied. Hence, in the current study, an exploratory research was conducted to investigate the effect of reward type (i.e., social or monetary) on different phases of reward processing. We recorded event-related potentials (ERPs) during a spatial attention paradigm in which cues heralded availability and type of the upcoming reward and feedbacks informed about the reward earned. Thirty-nine (19 males) healthy individuals (age range: 19-27 years) participated in the study. ADHD symptoms were assessed by using ADHD self-report scale (ASRS). Our results revealed a consistent negative correlation between the hyperactivity subscale of ASRS and almost all social-feedback related ERPs (P2, P3, and FRN). ERP amplitudes after social feedbacks were less positive for P2 and P3 and more negative for FRN for individuals with greater hyperactivity levels. Our findings suggest that hyporesponsiveness to social feedbacks may be associated with hyperactivity. However, the results have to be confirmed with clinical populations.     

Elaborative feedback: Engaging reward and task-relevant brain regions promotes learning in pseudoword reading aloud

Although much is known about the cognitive and neural basis of establishing letter-sound mappings in learning word forms, relatively little is known about what makes for the most effective feedback during this process. We sought to determine the neural basis by which elaborative feedback (EF), which contains both reward-related and content-specific information, may be more helpful than feedback containing only one kind of information (simple positive feedback, PF) or the other (content feedback, CF) in learning orthography-phonology (spelling-sound) mappings for novel letter strings. Compared to CF, EF activated the ventromedial prefrontal cortex, implicated in reward processing. Compared to PF, EF activated the posterior middle temporal, superior temporal, and supramarginal gyri—regions implicated in orthography-phonology conversion. In the same comparison, EF also activated the left fusiform gyrus/visual word form area—implicated in orthographic processing. Also EF, but not CF or PF, modulated activity in the caudate nucleus. In a postscan questionnaire, EF and PF were rated as more pleasant than CF, suggesting that modulation of the caudate for EF may be due to the coupling of reward and skill content. These findings suggest the enhanced effectiveness of EF may be due to concurrent activation of reward-related and task-relevant brain regions.     

The effects of expected reward on creative problem solving

Creative problem solving involves search processes, and it is known to be hard to motivate. Reward cues have been found to enhance performance across a range of tasks, even when cues are presented subliminally, without being consciously detected. It is uncertain whether motivational processes, such as reward, can influence problem solving. We tested the effect of supraliminal and subliminal reward on participant performance on problem solving that can be solved by deliberate analysis or by insight. Forty-one participants attempted to solve 100 compound remote associate problems. At the beginning of each problem, a potential reward cue (1 or 25 cents) was displayed, either subliminally (17 ms) or supraliminally (100 ms). Participants earned the displayed reward if they solved the problem correctly. Results showed that the higher subliminal reward increased the percentage of problems solved correctly overall. Second, we explored if subliminal rewards preferentially influenced solutions that were achieved via a sudden insight (mostly processed below awareness) or via a deliberate analysis. Participants solved more problems via insight following high subliminal reward when compared with low subliminal reward, and compared with high supraliminal reward, with no corresponding effect on analytic solving. Striatal dopamine (DA) is thought to influence motivation, reinforce behavior, and facilitate cognition. We speculate that subliminal rewards activate the striatal DA system, enhancing the kinds of automatic integrative processes that lead to more creative strategies for problem solving, without increasing the selectivity of attention, which could impede insight.     

Neural response to prosocial scenes relates to subsequent giving behavior in adolescents: A pilot study

Adolescence is characterized by extensive neural development and sensitivity to social context, both of which contribute to engaging in prosocial behaviors. Although it is established that prosocial behaviors are linked to positive outcomes in adulthood, little is known about the neural correlates of adolescents’ prosociality. Identifying whether the brain is differentially responsive to varying types of social input may be important for fostering prosocial behavior. We report pilot results using new stimuli and an ecologically valid donation paradigm indicating (1) brain regions typically recruited during socioemotional processing evinced differential activation when adolescents evaluated prosocial compared with social or noninteractive scenes (N = 20, ages 13–17 years, M_Age = 15.30 years), and (2) individual differences in temporoparietal junction recruitment when viewing others’ prosocial behaviors were related to adolescents’ own charitable giving. These novel findings have significant implications for understanding how the adolescent brain processes prosocial acts and for informing ways to support adolescents to engage in prosocial behaviors in their daily lives.     

Cognitive-behavioral and electrophysiological evidence of the affective consequences of ignoring stimulus representations in working memory

Ignoring visual stimuli in the external environment leads to decreased liking of those items, a phenomenon attributed to the affective consequences of attentional inhibition. Here we investigated the generality of this “distractor devaluation” phenomenon by asking whether ignoring stimuli represented internally within visual working memory has the same affective consequences. In two experiments we presented participants with two or three visual stimuli and then, after the stimuli were no longer visible, provided an attentional cue indicating which item in memory was the target they would have to later recall, and which were task-irrelevant distractors. Participants subsequently judged how much they liked these stimuli. Previously-ignored distractors were consistently rated less favorably than targets, replicating prior findings of distractor devaluation. To gain converging evidence, in Experiment 2, we also examined the electrophysiological processes associated with devaluation by measuring individual differences in attention (N2pc) and working memory (CDA) event-related potentials following the attention cue. Larger amplitude of an N2pc-like component was associated with greater devaluation, suggesting that individuals displaying more effective selection of memory targets—an act aided by distractor inhibition—displayed greater levels of distractor devaluation. Individuals showing a larger post-cue CDA amplitude (but not pre-cue CDA amplitude) also showed greater distractor devaluation, supporting prior evidence that visual working-memory resources have a functional role in effecting devaluation. Together, these findings demonstrate that ignoring working-memory representations has affective consequences, and adds to the growing evidence that the contribution of selective-attention mechanisms to a wide range of human thoughts and behaviors leads to devaluation.     

Neurocognitive mechanisms behind emotional attention: Inverse effects of anodal tDCS over the left and right DLPFC on gaze disengagement from emotional faces

Background

Attention to relevant emotional information in the environment is an important process related to vulnerability and resilience for mood and anxiety disorders. In the present study, the effects of left and right dorsolateral prefrontal cortex (i.e., DLPFC) stimulation on attentional mechanisms of emotional processing were tested and contrasted.

Methods

A sample of 54 healthy participants received 20 min of active and sham anodal transcranial direct current stimulation (i.e., tDCS) either of the left (n = 27) or of the right DLPFC (n = 27) on two separate days. The anode electrode was placed over the left or the right DLPFC, the cathode over the corresponding contra lateral supraorbital area. After each neurostimulation session, participants completed an eye-tracking task assessing direct processes of attentional engagement towards and attentional disengagement away from emotional faces (happy, disgusted, and sad expressions).

Results

Compared to sham, active tDCS over the left DLPFC led to faster gaze disengagement, whereas active tDCS over the right DLPFC led to slower gaze disengagement from emotional faces. Between-group comparisons showed that such inverse change patterns were significantly different and generalized for all types of emotion.

Conclusions

Our findings support a lateralized role of left and right DLPFC activity in enhancing/worsening the top-down regulation of emotional attention processing. These results support the rationale of new therapies for affective disorders aimed to increase the activation of the left over the right DLPFC in combination with attentional control training, and identify specific target attention mechanisms to be trained.

     

How socioemotional setting modulates late-stage conflict resolution processes in the lateral prefrontal cortex

The goal-directed control of behaviour critically depends on emotional regulation and constitutes the basis of mental well-being and social interactions. Within a socioemotional setting, it is necessary to prioritize effectively the relevant emotional information over interfering irrelevant emotional information to orchestrate cognitive resources and achieve appropriate behavior. Currently, it is elusive whether and how different socioemotional stimulus dimensions modulate cognitive control and conflict resolution. Theoretical considerations suggest that interference effects are less detrimental when conflicting emotional information is presented within a “positive socioemotional setting” compared with a “negative socioemotional setting.” Using event-related potentials (ERPs) and source localization methods, we examined the basic system neurophysiological mechanisms and functional neuroanatomical structures associated with interactive effects of different interfering facial, socioemotional stimulus dimensions on conflict resolution. We account for interactive effects of different interfering socioemotional stimulus dimensions on conflict resolution, i.e., we show how the socioemotional valence modulates cognitive control (conflict processing). The data show that conflicts are stronger and more difficult to resolve in a negative emotional task-relevant setting than in a positive emotional task-relevant setting, where incongruent information barely induced conflicts. The degree of emotional conflict critically depends on the contextual emotional valence (positive or negative) in which this conflict occurs. The neurophysiological data show that these modulations were only reflected by late-stage conflict resolution processes associated with the middle (MFG) and superior frontal gyrus (SFG). Attentional selection processes and early-stage conflict monitoring do not seem to be modulated by interactive effects of different interfering socioemotional stimulus dimensions on conflict resolution.     

Dopamine D2 agonist affects visuospatial working memory distractor interference depending on individual differences in baseline working memory span

The interplay of dopaminergic striatal D1–D2 circuits is thought to support working memory (WM) by selectively filtering information that is to be remembered versus information to be ignored. To test this theory, we conducted an experiment in which healthy participants performed a visuospatial working memory (VSWM) task after ingesting the D2-receptor agonist cabergoline (or placebo), in a randomized, double-blinded, crossover design. Results showed greater interference from distractors under cabergoline, particularly for individuals with higher baseline dopamine (indicated by WM span). These findings support computational theories of striatal D1–D2 function during WM encoding and distractor-filtering, and provide new evidence for interactive cortico-striatal systems that support VSWM capacity and their dependence on WM span.     

A flexible and accurate method to estimate the mode and stability of spontaneous coordinated behaviors: The index-of-stability (IS) analysis

Patterns of coordination result from the interaction between (at least) two oscillatory components. This interaction is typically understood by means of two variables: the mode that expresses the shape of the interaction, and the stability that is the robustness of the interaction in this mode. A potent method of investigating coordinated behaviors is to examine the extent to which patterns of coordination arise spontaneously. However, a prominent issue faced by researchers is that, to date, no standard methods exist to fairly assess the stability of spontaneous coordination. In the present study, we introduce a new method called the index-of-stability (IS) analysis. We developed this method from the phase-coupling (PC) analysis that has been traditionally used for examining locomotion–respiration coordinated systems. We compared the extents to which both methods estimate the stability of simulated coordinated behaviors. Computer-generated time series were used to simulate the coordination of two rhythmic components according to a selected mode m:n and a selected degree of stability. The IS analysis was superior to the PC analysis in estimating the stability of spontaneous coordinated behaviors, in three ways: First, the estimation of stability itself was found to be more accurate and more reliable with the IS analysis. Second, the IS analysis is not constrained by the limitations of the PC analysis. Third and last, the IS analysis offers more flexibility, and so can be adapted according to the user’s needs.