Neural Mechanisms of Positive Mood Induced Modulation of Reality Monitoring

Abstract

This study investigates the neural mechanisms of mood induced modulation of cognition, specifically, on reality monitoring abilities. Reality monitoring is the ability to accurately distinguish the source of self-generated information from externally-presented contextual information. When participants were in a positive mood, compared to a neutral mood, they significantly improved their source memory identification abilities, particularly for self-generated information. However, being in a negative mood had no effect on reality monitoring abilities. Additionally, when participants were in a positive mood state, they showed activation in several regions that predisposed them to perform better at reality monitoring. Specifically, positive mood induced activity within the medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC) was associated with improvements in subsequent identification of self-generated information, and positive mood induced activation within the striatum (putamen) facilitated better identification of externally-presented information. These findings indicate that regions within mPFC, PCC and striatum are sensitive to positive mood-cognition enhancing effects that enable participants to be better prepared for subsequent reality monitoring decision-making.

Neural mechanisms of mood-induced modulation of reality monitoring in schizophrenia

“…Prior research has revealed that both positive mood states and positive rewarding stimuli enhance preparatory activity within the mPFC to facilitate subsequent cognitive performance (Subramaniam et al, 2009; Subramaniam, Faust, et al, 2012; 2016), and that the mPFC supports reality monitoring task performance (better identification of self-generated items) in HC participants (Subramaniam, Luks, et al, 2012; 2016). In our previous fMRI study examining positive mood–cognition interactions, (Subramaniam et al, 2009), the PCC also showed increased activity during a preparation period preceding problem-solving, and was a positive mood-sensitive region that facilitated subsequent problem-solving in HC participants.…”

“…The mPFC/ACC is also a region that is also modulated by positive mood states and positive rewarding stimuli in Healthy Control (HC) participants to facilitate cognitive outcomes (Knutson & Cooper, 2005; Subramaniam, Kounios, Parrish, & Jung-Beeman, 2009; Subramaniam, Faust, Beeman, & Mashal, 2012; 2016). In our previous functional Magnetic Resonance Imaging (fMRI) studies of mood–cognition interactions in HC participants, we found two additional regions within posterior cingulate cortex (PCC) and putamen that showed positive mood-sensitive signals, which also modulated upcoming cognitive performance (Subramaniam et al, 2009; Subramaniam & Vinogradov, 2013; 2016). In general, we expected a positive mood state to modulate a network of regions in HC participants, including prefrontal cortices, PCC, parahippocampal cortices, and basal ganglia, consistent with previous research which has shown recruitment of these regions during positive mood states, and during overall episodic source memory retrieval (Elward et al, 2015).…”

Establishing a causal role for medial prefrontal cortex in reality monitoring

“…We and others have also demonstrated that the mPFC plays a critical function in mediating interactions between mood and higher-order cognition during reality-monitoring (7,12). These prior correlative imaging studies which show that mPFC supports both reality monitoring and mood enhancement underscore the critical need to investigate whether mPFC can causally impact reality monitoring decision-making and mood.…”

“…We have previously demonstrated in our fMRI studies that mPFC activation correlates with improved reality monitoring not only in HC, but also in psychiatric patient populations (i.e., patients with mood and psychotic disorders such as schizophrenia and schizoaffective disorders) (3,7,12). Psychosis typically emerges during excessive pruning of excitatory pathways, leading to hypoactive aberrant networks in the PFC (21,22).…”

“…Reality monitoring is particularly relevant for patients with schizophrenia who suffer from cardinal impairments of the self, which directly contribute to their psychotic symptoms of delusions and hallucinations (indicating their break with reality) (5,6). We and others have recently shown using functional magnetic resonance imaging (fMRI) that the medial prefrontal cortex (mPFC) is a key brain region subserving reality monitoring, which has also been shown to be activated specifically during memory retrieval of self-generated information (i.e., recalling one's own internal thoughts and actions) (3,4,7).…”