The short and long of it: neural correlates of temporal-order memory for autobiographical events

Previous functional neuroimaging studies of temporal-order memory have investigated memory for laboratory stimuli that are causally unrelated and poor in sensory detail. In contrast, the present functional magnetic resonance imaging (fMRI) study investigated temporal-order memory for autobiographical events that were causally interconnected and rich in sensory detail. Participants took photographs at many campus locations over a period of several hours, and the following day they were scanned while making temporal-order judgments to pairs of photographs from different locations. By manipulating the temporal lag between the two locations in each trial, we compared the neural correlates associated with reconstruction processes, which we hypothesized depended on recollection and contribute mainly to short lags, and distance processes, which we hypothesized to depend on familiarity and contribute mainly to longer lags. Consistent with our hypotheses, parametric fMRI analyses linked shorter lags to activations in regions previously associated with recollection (left prefrontal, parahippocampal, precuneus, and visual cortices), and longer lags with regions previously associated with familiarity (right prefrontal cortex). The hemispheric asymmetry in prefrontal cortex activity fits very well with evidence and theories regarding the contributions of the left versus right prefrontal cortex to memory (recollection vs. familiarity processes) and cognition (systematic vs. heuristic processes). In sum, using a novel photo-paradigm, this study provided the first evidence regarding the neural correlates of temporal-order for autobiographical events

Neurocognitive Mechanisms of Fear Conditioning and Vulnerability to Anxiety

A commentary on Fear-conditioning mechanisms associated with trait vulnerability to anxiety in human

Component Neural Systems for the Creation of Emotional Memories during Free Viewing of a Complex, Real-World Event

To investigate the neural systems that contribute to the formation of complex, self-relevant emotional memories, dedicated fans of rival college basketball teams watched a competitive game while undergoing functional magnetic resonance imaging (fMRI). During a subsequent recognition memory task, participants were shown video clips depicting plays of the game, stemming either from previously-viewed game segments (targets) or from non-viewed portions of the same game (foils). After an old–new judgment, participants provided emotional valence and intensity ratings of the clips. A data driven approach was first used to decompose the fMRI signal acquired during free viewing of the game into spatially independent components. Correlations were then calculated between the identified components and post-scanning emotion ratings for successfully encoded targets. Two components were correlated with intensity ratings, including temporal lobe regions implicated in memory and emotional functions, such as the hippocampus and amygdala, as well as a midline fronto-cingulo-parietal network implicated in social cognition and self-relevant processing. These data were supported by a general linear model analysis, which revealed additional valence effects in fronto-striatal-insular regions when plays were divided into positive and negative events according to the fan's perspective. Overall, these findings contribute to our understanding of how emotional factors impact distributed neural systems to successfully encode dynamic, personally-relevant event sequences

Human Fear Conditioning Conducted in Full Immersion 3-Dimensional Virtual Reality

Fear conditioning is a widely used paradigm in non-human animal research to investigate the neural mechanisms underlying fear and anxiety. A major challenge in conducting conditioning studies in humans is the ability to strongly manipulate or simulate the environmental contexts that are associated with conditioned emotional behaviors. In this regard, virtual reality (VR) technology is a promising tool. Yet, adapting this technology to meet experimental constraints requires special accommodations. Here we address the methodological issues involved when conducting fear conditioning in a fully immersive 6-sided VR environment and present fear conditioning data

Dominance, Politics, and Physiology: Voters' Testosterone Changes on the Night of the 2008 United States Presidential Election

BACKGROUND: Political elections are dominance competitions. When men win a dominance competition, their testosterone levels rise or remain stable to resist a circadian decline; and when they lose, their testosterone levels fall. However, it is unknown whether this pattern of testosterone change extends beyond interpersonal competitions to the vicarious experience of winning or losing in the context of political elections. Women's testosterone responses to dominance competition outcomes are understudied, and to date, a clear pattern of testosterone changes in response to winning and losing dominance competitions has not emerged. METHODOLOGY/PRINCIPAL FINDINGS: The present study investigated voters' testosterone responses to the outcome of the 2008 United States Presidential election. 183 participants provided multiple saliva samples before and after the winner was announced on Election Night. The results show that male Barack Obama voters (winners) had stable post-outcome testosterone levels, whereas testosterone levels dropped in male John McCain and Robert Barr voters (losers). There were no significant effects in female voters. CONCLUSIONS/SIGNIFICANCE: The findings indicate that male voters exhibit biological responses to the realignment of a country's dominance hierarchy as if they participated in an interpersonal dominance contest

Effects of induced moods on economic choices

Emotions can shape decision processes by altering valuation signals, risk perception, and strategic orientation. Although multiple theories posit a role for affective processes in mediating the influence of frames on decision making, empirical studies have yet to demonstrate that manipulated affect modulates framing phenomena. The present study asked whether induced affective states alter gambling propensity and the influence of frames on decision making. In a between-subjects design, we induced mood (happy, sad, or neutral) in subjects (N=91) via films that were interleaved with the framing task. Happy mood induction increased gambling and apparently accentuated framing effects compared to sad mood induction, although the effect on framing could have resulted from the fact that the increased tendency to gamble made the framing measure more sensitive. Happy mood induction increased gambling, but not framing magnitude, compared to neutral mood induction. Subjects experiencing a sad mood induction did not exhibit behavioral differences from those experiencing a neutral mood. For those subjects who experienced the happy mood induction, both gambling propensity and framing magnitude were positively correlated with the magnitude of the change in their mood valence. We discuss the broader implications of mood effects on real-world economic decisions

Hemodynamic signals of mixed messages during a social exchange

The present study used functional magnetic resonance imaging (fMRI) to characterize hemodynamic activation patterns recruited when participants view mixed social communicative messages during a common interpersonal exchange. Mixed messages were defined as conflicting sequences of biological motion and facial affect signals that are unexpected within a particular social context (for example, observing the reception of a gift). Across four social vignettes, valenced facial expressions were crossed with rejecting and accepting gestures in a virtual avatar responding to presentation of a gift from the participant. Results indicate that conflicting facial affect and gesture activated superior temporal sulcus, a region implicated in expectancy violations, as well as inferior frontal gyrus and putamen. Scenarios conveying rejection differentially activated the insula and putamen, regions implicated in embodied cognition and motivated learning, as well as frontoparietal cortex. Characterizing how meaning is inferred from integration of conflicting nonverbal communicative cues is essential to understand nuances and complexities of human exchange