Neural systems subserving valence and arousal during the experience of induced emotions.

The circumplex model of affect construes all emotions as linear combinations of 2 independent neurophysiological dimensions, valence and arousal. We used functional magnetic resonance imaging to identify the neural networks subserving valence and arousal, and we assessed, in 10 participants, the associations of the BOLD (blood oxygen level-dependent) response, an indirect index of neural activity, with ratings of valence and arousal during the emotional experiences induced by the presentation of evocative sentences. Unpleasant emotional experience was associated with increased BOLD signal intensities in the supplementary motor, anterior midcingulate, right dorsolateral prefrontal, occipito-temporal, inferior parietal, and cerebellar cortices. Highly arousing emotions were associated with increased BOLD signal intensities in the left thalamus, globus pallidus, caudate, parahippocampal gyrus, amygdala, premotor cortex, and cerebellar vermis. Separate analyses using a finite impulse response model confirmed these results and revealed that pleasant emotions engaged an additional network that included the midbrain, ventral striatum, and caudate nucleus, all portions of a reward circuit. These findings suggest the existence of distinct networks subserving the valence and arousal dimensions of emotions, with midline and medial temporal lobe structures mediating arousal and dorsal cortical areas and mesolimbic pathways mediating valence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure of positive but not negative emotional valence to enhance memory in schizophrenia.

Abnormalities in the integration of emotion and cognition have long been considered hallmark characteristics of schizophrenia. Study authors used a well-established emotional memory model from the neuroscience literature to assess the facilitative impact of emotional valence of information on long-term memory consolidation in schizophrenia. Participants with schizophrenia (n=33) indicated somewhat higher levels of emotional intensity in response to emotional images than did healthy (n=28) participants. However, when recognition memory was tested 24 hr later, schizophrenia participants did not show enhancement of memory for positive images as was found in healthy participants. Their memory enhancement for negative images did not differ from that of healthy participants. Correlations between self-reported physical and social anhedonia were significantly inversely correlated with intensity ratings of positive stimuli during the encoding phase for healthy participants but were negligible for schizophrenia participants. These results suggest a failure to adequately integrate positive emotional experience in memory consolidation processes in schizophrenia participants, despite appropriate initial response to positive stimuli, which may contribute to symptoms such as anhedonia by reducing the long-term impact of positive experiences in motivating hedonic behavior in day-to-day life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Allocation of spatial attention to emotional stimuli depends upon arousal and not valence.

Attentional allocation to emotional stimuli is often proposed to be driven by valence and in particular by negativity. However, many negative stimuli are also arousing leaving the question whether valence or arousal accounts for this effect. The authors examined whether the valence or the arousal level of emotional stimuli influences the allocation of spatial attention using a modified spatial cueing task. Participants responded to targets that were preceded by cues consisting of emotional pictures varying on arousal and valence. Response latencies showed that disengagement of spatial attention was slower for stimuli high in arousal than for stimuli low in arousal. The effect was independent of the valence of the pictures and not gender-specific. The findings support the idea that arousal affects the allocation of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of emotional valence and arousal upon memory trade-offs with aging.

Attention can be attracted faster by emotional relative to neutral information, and memory also can be strengthened for that emotional information. However, within visual scenes, often there is an advantage in memory for central emotional portions at the expense of memory for peripheral background information, called an emotion-induced memory trade-off. The authors examined how aging impacts the trade-off by manipulating valence (positive, negative) and arousal (low, high) of a central emotional item within a neutral background scene and testing memory for item and background components separately. They also assessed memory after 2 study–test delay intervals, to investigate age differences in the trade-off over time. Results revealed similar patterns of performance between groups after a short study–test delay, with both age groups showing robust memory trade-offs. After a longer delay, young and older adults showed enhanced memory for emotional items but at a cost to memory for background information only for young adults in negative arousing scenes. These results emphasize that attention and consolidation stage processes interact to shape how emotional memory is constructed in young and older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experiencing activation: Energetic arousal and tense arousal are not mixtures of valence and activation.

R. E. Thayer (1989) proposed 2 types of activation: energetic arousal (awake-tired) and tense arousal (tense-calm). This view has been challenged by claims that energetic arousal and tense arousal are mixtures of valence and a single activation dimension. The authors present a direct test of this hypothesis by computing the correlation between the residuals of energetic arousal and tense arousal after removing the shared variance with valence. Whereas the valence activation hypothesis predicts a strong positive correlation between the 2 residuals, the authors found that it was not significantly different from 0. This finding reaffirms the view of energetic arousal and tense arousal as 2 distinct types of activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The moderating effects of stimulus valence and arousal on memory suppression.

This study examined the separate and combined effects of stimulus valence and arousal on retrieval inhibition. Participants performed Anderson and Green's (2001) memory suppression task with stimuli varying across dimensions of valence and arousal. Memory was tested through free and cued recall as well as speeded recognition. Results showed that both stimulus valence and arousal influenced the extent to which participants successfully inhibited retrieval, but not in the ways anticipated. Specifically, the strongest inhibition effects were for highly arousing, pleasant words. In addition, unpleasant stimuli that were suppressed were better recalled during both cued and free-recall tasks than pleasant stimuli that were suppressed. Across all tests of memory performance, there were no significant differences between the experimental conditions for highly arousing, unpleasant words. The implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relation between event processing and the duration of emotional experience.

An emotional experience can last for only a couple of seconds up to several hours or even longer. In the present study, we examine to which extent covert intrapersonal actions (cognitions both related and unrelated to the emotion-eliciting stimulus) as well as overt interpersonal actions (social sharing) account for this variability in emotion duration. Participants were asked to report the duration of their anger, sadness, joy, and gratitude episodes on a daily basis during five days. Furthermore, information was collected with regard to their cognitions during the episodes and their social sharing behavior. Discrete-time survival analyses revealed that for three of the four emotions under study, stimulus-related cognitions with the same valence as the emotion lead to a prolongation of the episode; in contrast, both stimulus-related and stimulus-unrelated cognitions with a valence opposite to the emotion lead to a shortening. Finally, for the four emotions under study, social sharing was associated with a prolongation. The findings are discussed in terms of a possible process basis underlying the time dynamics of negative as well as positive emotions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Diagnostic differences in social anhedonia: A longitudinal study of schizophrenia and major depressive disorder.

This study examined the hypothesis that, in schizophrenia, elevated trait social anhedonia (SA) is a stable individual difference, whereas in depression, increased SA is a reflection of a current clinical state that will diminish with recovery. Differences in trait Negative Affect (NA) and Positive Affect (PA) were also examined. Individuals with schizophrenia (n?=?55) and depression (n?=?34) were evaluated at baseline during hospitalization and compared with nonpsychiatric control participants (n?=?41). Participants were assessed again at a 1-year follow-up. At baseline, compared with control participants, individuals with schizophrenia and depression were both characterized by elevated SA, greater NA, and lower PA. In schizophrenic individuals, elevated SA remained stable over the follow-up. However, in recovered depressed patients, SA declined over the follow-up period. Group differences remained in NA and PA over the 1-year follow-up. These results support the view that elevated SA is enduring in schizophrenia but that elevated SA is transiently related to clinical status in depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in the sensitivity to appetitive and aversive arousal across adulthood.

In 2 cross-sectional studies, the authors examined age-related differences in the evaluation of emotional stimuli in 2 community samples, with participants ranging in age from young to older adulthood (18–81 years old). Pictures of the International Affective Picture System were used in Study 1, and written verbs were used in Study 2. Participants rated these stimuli along the 2 major affective dimensions of hedonic valence and emotional arousal, thus yielding a 2-dimensional affective space for each participant. Young adults showed the expected pattern of 2 distinct clusters of stimuli in this space, representing increasing pleasantness (appetitive activation) and unpleasantness (aversive activation) with increasing emotional arousal. In contrast, for older adults, emotional valence and arousal ratings were linearly related: Low-arousing stimuli were rated as most pleasant, and high-arousing stimuli were rated as most unpleasant. When regressed on age, these changes revealed a gradual decrease of appetitive activation (i.e., the relationship between pleasure and arousal) across adulthood and a linear increase in aversive activation (i.e., the relationship between displeasure and arousal). These results extend previous work on emotional development, adding information as to the role of emotional intensity for affective experience in different age groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age and emotional experience during mutual reminiscing.

In the present article, the authors examined age differences in the emotional experiences involved in talking about past events. In Study 1, 129 adults in an experience-sampling study reported whether they were engaged in mutual reminiscing and their concurrent positive and negative emotion. Their experiences of positive and negative emotion during mutual reminiscing were compared with emotional experience during other social activities. Age was associated with increasing positive emotion during mutual reminiscing. In Study 2 (n=132), the authors examined emotions during reminiscing for specific positive and negative events. In this case, age was associated with improved emotional experiences but only during reminiscing about positive experiences. Findings are discussed in terms of socioemotional selectivity theory and the literature on reminiscence and life review. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How emotional auditory stimuli modulate time perception.

Emotional and neutral sounds rated for valence and arousal were used to investigate the influence of emotions on timing in reproduction and verbal estimation tasks with durations from 2 s to 6 s. Results revealed an effect of emotion on temporal judgment, with emotional stimuli judged to be longer than neutral ones for a similar arousal level. Within scalar expectancy theory (J. Gibbon, R. Church, & W. Meck, 1984), this suggests that emotion-induced activation generates an increase in pacemaker rate, leading to a longer perceived duration. A further exploration of self-assessed emotional dimensions showed an effect of valence and arousal. Negative sounds were judged to be longer than positive ones, indicating that negative stimuli generate a greater increase of activation. High-arousing stimuli were perceived to be shorter than low-arousing ones. Consistent with attentional models of timing, this seems to reflect a decrease of attention devoted to time, leading to a shorter perceived duration. These effects, robust across the 2 tasks, are limited to short intervals and overall suggest that both activation and attentional processes modulate the timing of emotional events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Startle Modulation During Conscious Emotion Regulation Is Arousal-Dependent.

Conscious regulation of negative emotion has been shown to affect human eyeblink startle responses, but whether these results depend on modulation of arousal- or valence-based processes is unknown. The authors presented participants with negative, neutral, and positive pictures and directed them to enhance, maintain, and suppress emotional responses. On emotional picture trials, startle responses decreased as a function of cue in the following order: enhance > maintain > suppress. Analysis of negative and positive picture trials separately revealed similar patterns of startle modulation by emotion regulation. There were no effects of emotion regulation on neutral trials. Results indicate that arousal, not valence, may be critical to startle modulation via conscious emotion regulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of BOTOX injections on emotional experience.

Although it was proposed over a century ago that feedback from facial expressions influence emotional experience, tests of this hypothesis have been equivocal. Here we directly tested this facial feedback hypothesis (FFH) by comparing the impact on self-reported emotional experience of BOTOX injections (which paralyze muscles of facial expression) and a control Restylane injection (which is a cosmetic filler that does not affect facial muscles). When examined alone, BOTOX participants showed no pre- to posttreatment changes in emotional responses to our most positive and negative video clips. Between-groups comparisons, however, showed that relative to controls, BOTOX participants exhibited an overall significant decrease in the strength of emotional experience. This result was attributable to (a) a pre- versus postdecrease in responses to mildly positive clips in the BOTOX group and (b) an unexpected increase in responses to negative clips in the Restylane control group. These data suggest that feedback from facial expressions is not necessary for emotional experience, but may influence emotional experience in some circumstances. These findings point to specific directions for future work clarifying the expression-experience relationship. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemispheric perception of emotional valence from facial expressions.

The authors previously reported that normal subjects are better at discriminating happy from neutral faces when the happy face is located to the viewer's right of the neutral face; conversely, discrimination of sad from neutral faces is better when the sad face is shown to the left, supporting a role for the left hemisphere in processing positive valence and for the right hemisphere in processing negative valence. Here, the authors extend this same task to subjects with unilateral cerebral damage (31 right, 28 left). Subjects with right damage performed worse when discriminating sad faces shown on the left, consistent with the prior findings. However, subjects with either left or right damage actually performed superior to normal controls when discriminating happy faces shown on the left. The authors suggest that perception of negative valence relies preferentially on the right hemisphere, whereas perception of positive valence relies on both left and right hemispheres. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Understanding the emotional aspects of escalation of commitment: The role of negative affect.

Despite the importance of understanding the emotional aspects of organizational decision making, prior research has paid scant attention to the role of emotion in escalation of commitment. This article attempts to fill this gap by examining the relationship between negative affect and escalation of commitment. Results showed that regardless of whether negative affect was measured as a dispositional trait (Neuroticism) in Studies 1 and 2 or as a transient mood state in Study 3, it was negatively correlated with escalation tendency when one was personally responsible for a prior decision. This pattern of results is consistent with the predictions derived from the coping perspective, suggesting that people seek to escape from the unpleasant emotions that are associated with escalation situations. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Gender differences in acute alcohol effects on self-regulation of arousal in response to emotional and alcohol-related picture cues.

Basic mechanisms through which men and women self-regulate arousal have received little attention in human experimental addiction research, although stress-response-dampening and craving theories suggest an important role of emotional arousal in motivating alcohol use. This study examined gender differences in the effects of acute alcohol intoxication on psychophysiological and self-reported arousal in response to emotionally negative, positive, and neutral, and alcohol-related, picture cues. Thirty-six social drinkers (16 women) were randomly assigned to an alcohol, placebo, or control beverage group and exposed to picture cues every 10 s (0.1 Hz presentation frequency). Psychophysiological arousal was assessed via a 0.1-Hz heart rate variability (HRV) index. A statistically significant beverage group-by-gender interaction effect on psychophysiological, but not self-reported, arousal was found. The 0.1-Hz HRV responses to picture cues were suppressed by alcohol only in men. This gender-specific suppression pattern did not differ significantly across picture cue types. There were no significant gender differences in the placebo or control group. Greater dampening of arousal by alcohol intoxication in men, compared with women, may contribute to men’s greater tendency to use alcohol to cope with stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and emotional memory: The co-occurrence of neurophysiological and behavioral positivity effects.

The positivity effect is a trend for adults to increasingly process positive and/or decreasingly process negative information compared with other information with advancing age. The positivity effect has been observed with behavioral measures, such as in attention and memory tests, and with measures of neurophysiological activity, such as in amygdala activation and the late positive potential (LPP). In this study, it was investigated whether these behavioral and neurophysiological positivity effects co-occur. The electroencephalogram of younger (19–26 years) and older (65–82 years) adults was recorded while they encoded unpleasant, neutral, and pleasant pictures for retrieval in free and cued recall tests. Positivity effects occurred in the late LPP amplitude (700–1,000 ms) and in the free recall test, with negativity biases in younger adults and no biases in older adults. The occurrence of a valence bias in the LPP was substantially but nonsignificantly correlated with the occurrence of a similar valence bias in memory in the older adults. In conclusion, neurophysiological and behavioral positivity effects appear to co-occur, a finding that awaits expansion using different neurophysiological and behavioral measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrophysiological correlates of emotional responding in schizophrenia.

People with schizophrenia consistently report normal levels of pleasant emotion when exposed to evocative stimuli, suggesting intact consummatory pleasure. However, little is known about the neural correlates and time course of emotion in schizophrenia. This study used a well-validated affective picture viewing task that elicits a characteristic pattern of event-related potentials (ERPs) from early to later processing stages (i.e., P1, P2, P3, and late positive potentials [LPPs]). Thirty-eight stabilized outpatients with schizophrenia and 36 healthy controls viewed standardized pleasant, unpleasant, and neutral pictures while ERPs were recorded and subsequently rated their emotional responses to the stimuli. Patients and controls responded to the pictures similarly in terms of their valence ratings, as well as the initial ERP components (P1, P2, and P3). However, at the later LPP component (500–1,000 ms), patients displayed diminished electrophysiological discrimination between pleasant versus neutral stimuli. This pattern suggests that patients demonstrated normal self-reported emotional experience and intact initial sensory processing of and resource allocation to emotional stimuli. However, they showed a disruption in a later component associated with sustained attentional processing of emotional stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)