Metacognition and emotion - How accurate perception of own biases relates to positive feelings and hedonic capacity.

Metacognition refers to awareness of one's own cognitive processes, including examining own biases and decision making. Metacognitive self (MCS), defined as accuracy in perception of own biases, is associated with pro-health behaviors and desire for feedback, including negative information. Two studies investigated MCS in relation to emotion and hedonic capacity. First, in a longitudinal study of college students, MCS measure was stable over time, and correlated with feelings of love and joy. In the second study, MCS, mood, and hedonic capacity ratings were collected prior to evaluating stimuli for pleasure from engagement during an fMRI. Higher MCS was associated with greater hedonic capacity and increased signal in cortical areas involved in self-reflection and decision making. Our findings implicate self-awareness of biases as a cognitive process supporting positive emotional state and hedonic capacity. Future studies should explore how MCS relates to changes in mood and vulnerability to mood disorders.

Correction to: Mapping anticipatory anhedonia: an fMRI study.

The image of the Figure 2b in Figure 2 in the published article was incorrect and the authors would like to correct them. The original article has been corrected.

Mapping anticipatory anhedonia: an fMRI study.

Anhedonia-broadly defined as loss of interest and/or an inability to experience pleasure-is an important feature of several psychiatric disorders. Research into the clinical presentation and neurobiology of this symptom has identified components related to motivation, learning, anticipation, and experience of pleasure as important constructs that inform therapeutic interventions. The experimental study of anhedonia is largely based on incentive processing paradigms, most often with monetary rewards, though studies have also used pleasantness ratings of various stimuli. However, linking an individual's own system of reinforcers and ability to enjoy them with anhedonia and neural activity remains comparatively under-explored. A previous study of participants with major depressive disorder (MDD) and healthy controls found that activity word ratings correlated with measures of anhedonia, depression, and motivation. The present study collected functional magnetic resonance imaging (fMRI) images in healthy controls while they rated activity words and pictures showing activities in order to identify networks differentially responsive to subjective decisions about the appetitive value of activities. The study sought to measure individually-relevant hedonic capacity as demonstrated by correlations between task measures and anticipatory anhedonia ratings. Ratings of potential pleasure were associated with neural activity in areas previously identified as relevant to pleasure and reward processing, such as anterior and posterior cingulate, middle frontal areas, and dorsal and ventral striatum. Although the study included only healthy controls, the results demonstrate a link between anhedonia measures, behavior, and brain responses and also test a paradigm that could be used to study anhedonia in clinical populations.

Effects of Ketamine on Brain Activity During Emotional Processing: Differential Findings in Depressed Versus Healthy Control Participants.

BACKGROUND: In the search for novel treatments for depression, ketamine has emerged as a unique agent with rapid antidepressant effects. Experimental tasks involving emotional processing can be used during functional magnetic resonance imaging scanning to investigate ketamine's effects on brain function in major depressive disorder (MDD). This study examined ketamine's effects on functional magnetic resonance imaging activity during an emotional processing task. METHODS: A total of 33 individuals with treatment-resistant MDD and 24 healthy control participants (HCs) took part in this double-blind, placebo-controlled crossover study. Participants received ketamine and placebo infusions 2 weeks apart, and functional magnetic resonance imaging scans were conducted at baseline and 2 days after each infusion. Blood oxygen level-dependent signal was measured during an emotional processing task, and a linear mixed-effects model was used to analyze differences in activation among group, drug, and task-specific factors. RESULTS: A group-by-drug interaction was observed in several brain regions, including a right frontal cluster extending into the anterior cingulate cortex and insula. Participants with MDD had greater activity than HCs after placebo infusion but showed lower activity after ketamine infusion, which was similar to the activity in HCs after placebo. A group-by-drug-by-task condition interaction was also found, which showed further differences that varied between implicit and explicit emotional conditions. CONCLUSIONS: The main results indicate that ketamine had differential effects on brain activity in participants with MDD versus HCs. The pattern of activation in participants with MDD after ketamine infusion resembled the activation in HCs after placebo infusion, suggesting a normalization of function during emotional processing. The findings contribute to a better understanding of ketamine's actions in the brain.

Ketamine normalizes brain activity during emotionally valenced attentional processing in depression.

Background: An urgent need exists for faster-acting pharmacological treatments in major depressive disorder (MDD). The glutamatergic modulator ketamine has been shown to have rapid antidepressant effects, but much remains unknown about its mechanism of action. Functional MRI (fMRI) can be used to investigate how ketamine impacts brain activity during cognitive and emotional processing. Methods: This double-blind, placebo-controlled, crossover study of 33 unmedicated participants with MDD and 26 healthy controls (HCs) examined how ketamine affected fMRI activation during an attentional bias dot probe task with emotional face stimuli across multiple time points. A whole brain analysis was conducted to find regions with differential activation associated with group, drug session, or dot probe task-specific factors (emotional valence and congruency of stimuli). Results: A drug session by group interaction was observed in several brain regions, such that ketamine had opposite effects on brain activation in MDD versus HC participants. Additionally, there was a similar finding related to emotional valence (a drug session by group by emotion interaction) in a large cluster in the anterior cingulate and medial frontal cortex. Conclusions: The findings show a pattern of brain activity in MDD participants following ketamine infusion that is similar to activity observed in HCs after placebo. This suggests that ketamine may act as an antidepressant by normalizing brain function during emotionally valenced attentional processing. Clinical trial: NCT#00088699: https://www.clinicaltrials.gov/ct2/show/NCT00088699.

Altered interaction with environmental reinforcers in major depressive disorder: Relationship to anhedonia.

Anhedonia-defined as loss of interest or pleasure-is one of two core symptoms of major depressive disorder (MDD). Anhedonia may involve decreased enjoyment of potentially rewarding activities and decreased motivation to engage in such activities. Increased engagement with reinforcers-activities with the potential to be positive experiences-is a frequent target of cognitive-behavioral therapies. Nevertheless, how environmental reinforcers are perceived, and how decisions to approach or avoid them are made by individuals with MDD, is largely unknown. We developed an experimental Behavioral Approach Motivation Paradigm to study how activities are evaluated and approached in MDD. Twenty-one MDD participants and 23 healthy controls performed an experimental task that rated activity words for their hedonic value, then engaged in an approach-avoidance joystick task with each individual's unique set of 'liked' and 'disliked' activity words. A negative correlation was observed between anhedonia and the number of 'liked' activities across participants. No significant difference between approach and avoidance behavior was found in direct comparisons between healthy controls and MDD participants; however, weaker avoidance and greater approach toward 'disliked' activities was found in MDD participants. This suggests negative bias in selecting environmental opportunities, potentially further compromising access to hedonic experiences in MDD.