Representation Of Valence Research Articles

Conflict during learning reconfigures the neural representation of positive valence and approach behavior.

Punishing and rewarding experiences can change the valence of sensory stimuli and guide animal behavior in opposite directions, resulting in avoidance or approach. Often, however, a stimulus is encountered with both positive and negative experiences. How is such conflicting information represented in the brain and resolved into a behavioral decision? We address this question by dissecting a circuit for sexual conditioning in C.elegans. In this learning paradigm, an odor is conditioned with both a punishment (starvation) and a reward (mates), resulting in odor approach. We find that negative and positive experiences are both encoded by the neuropeptide pigment dispersing factor 1 (PDF-1) being released from, and acting on, different neurons. Each experience creates a distinct memory in the circuit for odor processing. This results in the sensorimotor representation of the odor being different in naive and sexually conditioned animals, despite both displaying approach. Our results reveal that the positive valence of a stimulus is not represented in the activity of any single neuron class but flexibly represented within the circuit according to the experiences and predictions associated with the stimulus.

The hippocampal CA2 region discriminates social threat from social safety.

The dorsal cornu ammonis 2 (dCA2) region of the hippocampus enables the discrimination of novel from familiar conspecifics. However, the neural bases for more complex social-spatial episodic memories are unknown. Here we report that the spatial and social contents of an aversive social experience require distinct hippocampal regions. While dorsal CA1 (dCA1) pyramidal neurons mediate the memory of an aversive location, dCA2 pyramidal neurons enable the discrimination of threat-associated (CS+) from safety-associated (CS-) conspecifics in both female and male mice. Silencing dCA2 during encoding or recall trials disrupted social fear discrimination memory, resulting in fear responses toward both the CS+ and CS- mice. Calcium imaging revealed that the aversive experience strengthened and stabilized dCA2 representations of both the CS+ and CS- mice, with the incorporation of an abstract representation of social valence into representations of social identity. Thus, dCA2 contributes to both social novelty detection and the adaptive discrimination of threat-associated from safety-associated individuals during an aversive social episodic experience.

Brain representations of affective valence and intensity in sustained pleasure and pain

Pleasure and pain are two fundamental, intertwined aspects of human emotions. Pleasurable sensations can reduce subjective feelings of pain and vice versa, and we often perceive the termination of pain as pleasant and the absence of pleasure as unpleasant. This implies the existence of brain systems that integrate them into modality-general representations of affective experiences. Here, we examined representations of affective valence and intensity in an functional MRI (fMRI) study (n = 58) of sustained pleasure and pain. We found that the distinct subpopulations of voxels within the ventromedial and lateral prefrontal cortices, the orbitofrontal cortex, the anterior insula, and the amygdala were involved in decoding affective valence versus intensity. Affective valence and intensity predictive models showed significant decoding performance in an independent test dataset (n = 62). These models were differentially connected to distinct large-scale brain networks-the intensity model to the ventral attention network and the valence model to the limbic and default mode networks. Overall, this study identified the brain representations of affective valence and intensity across pleasure and pain, promoting a systems-level understanding of human affective experiences.

The preoptic area and dorsal habenula jointly support homeostatic navigation in larval zebrafish

Animals must maintain physiological processes within an optimal temperature range despite changes in their environment. Through behavioral assays, whole-brain functional imaging, and neural ablations, we show that larval zebrafish, an ectothermic vertebrate, achieves thermoregulation through homeostatic navigation-non-directional and directional movements toward the temperature closest to its physiological setpoint. A brain-wide circuit encompassing several brain regions enables this behavior. We identified the preoptic area of the hypothalamus (PoA) as a key brain structure in triggering non-directional reorientation when thermal conditions are worsening. This result shows an evolutionary conserved role of the PoA as principal thermoregulator of the brain also in ectotherms. We further show that the habenula (Hb)-interpeduncular nucleus (IPN) circuit retains a short-term memory of the sensory history to support the generation of coherent directed movements even in the absence of continuous sensory cues. We finally provide evidence that this circuit may not be exclusive for temperature but may convey a more abstract representation of relative valence of physiologically meaningful stimuli regardless of their specific identity to enable homeostatic navigation.

The spread of affective and semantic valence representations across states

In many decision problems, outcomes are not reached after a single action but rather after a series of events or states. To optimize decisions over multiple states, representations of how good or bad the outcomes are, that is, the outcomes’ valence, should spread across states. One mechanism for valence spreading is a temporal, state-independent process in which a single valence representation is updated when an outcome is experienced and fades away afterwards. Each state’s valence is based on its temporal proximity to the experienced outcome. An alternative, state-dependent mechanism relies on the structure of transitions between states, updating a separate valence representation for each state according to its spatial distance from the outcomes. We examined how these mechanistic accounts shape the spread of two formats of valence representation, feelings (affective valence) and knowledge (semantic valence), between states.In two pre-registered experiments (N = 585), we used a novel task in which participants move in a four-state maze, one of which contains an outcome. The participants provide self-reports of affective and semantic valence throughout the maze and after finishing it. Results show that the affective representation of negative valence is more localized in state-space than the semantic representation. We also found evidence for the relative reliance of the affective valence on a temporal, state-independent mechanism and of the semantic valence on a structured, state-dependent mechanism.Our findings provide mechanistic accounts for the differences between affective and semantic valence representations and indicate how such representations may play a role in associative learning and decision-making.

The Representation of Valence by Visual Category in the Orbitofrontal Cortex and Amygdala

Emotion is critical for survival in all animals. Even in modern humans, processing emotion holds significant adaptive value. In neuroscientific investigations of emotion, both the amygdala, part of the evolutionarily primitive limbic system, and the orbitofrontal cortex, part of the evolutionarily newer cortical system, have been highly implicated in the representation of valence, a major emotional component. Although the strict divide between the limbic system and the cortical system in brain function has been rejected, the underlying notions of theories of brain evolution lead to the hypothesis that the amygdala is advantageous in processing evolutionarily older adaptive value whereas the orbitofrontal cortex is advantageous in processing evolutionarily newer adaptive value. In this study, this hypothesis is tested using a functional magnetic resonance imaging dataset in which human participants made valence judgments on natural items and scenes (i.e., evolutionarily old with greater immediate adaptive value) and man-made items and scenes (i.e., evolutionarily new with lesser immediate adaptive value). The results show that the amygdala represents valence of natural but not man-made scenes, consistent with the hypothesis. The orbitofrontal cortex, in contrast, represents valence of both natural and man-made scenes, partially consistent with the hypothesis. The findings illustrate how visual categories defined by adaptive value shape the neural representation of valence in the contrasting limbic and cortical systems.

Dimensional emotions are represented by distinct topographical brain networks

The ability to recognize others’ facial emotions has become increasingly important after the COVID-19 pandemic, which causes stressful situations in emotion regulation. Considering the importance of emotion in maintaining a social life, emotion knowledge to perceive and label emotions of oneself and others requires an understanding of affective dimensions, such as emotional valence and emotional arousal. However, limited information is available about whether the behavioral representation of affective dimensions is similar to their neural representation. To explore the relationship between the brain and behavior in the representational geometries of affective dimensions, we constructed a behavioral paradigm in which emotional faces were categorized into geometric spaces along the valence, arousal, and valence and arousal dimensions. Moreover, we compared such representations to neural representations of the faces acquired by functional magnetic resonance imaging. We found that affective dimensions were similarly represented in the behavior and brain. Specifically, behavioral and neural representations of valence were less similar to those of arousal. We also found that valence was represented in the dorsolateral prefrontal cortex, frontal eye fields, precuneus, and early visual cortex, whereas arousal was represented in the cingulate gyrus, middle frontal gyrus, orbitofrontal cortex, fusiform gyrus, and early visual cortex. In conclusion, the current study suggests that dimensional emotions are similarly represented in the behavior and brain and are presented with differential topographical organizations in the brain.

A divergent effect of stimulus perceptual details on affective and semantic representations of valence.

The current work investigated the potential dissociation between two modes of valence: affective valence (valence of the emotional response) and semantic valence (stored knowledge about the valence of an object/event). A series of six experiments systematically examined the divergent effect of manipulating the amount of perceptual details on affective valence and semantic knowledge about valence. We predicted that affective valence, more than semantic valence, will be affected by manipulating the amount of stimulus perceptual details. Experiment 1a manipulated the amount of perceptual details by presenting the same stimulus content with different quantity of perceptual details. We compared three conditions: a very short movie clip, a still picture that was taken from the movie clip, and a blurred version of the picture from the movie clip. Experiment 1b replicated Experiment 1a using a stronger filter for blurring the picture. Experiment 2 used different manipulation of filtering out visual perceptual details by comparing still pictures to outlined images. Experiment 3 generalized the results of Experiments 1 and 2 by comparing pictures and written words. Experiments 4a and 4b examined the hypothesis regarding the divergent effect of the amount of perceptual details on semantic and affective valence, using physiological signals and a reaction time task, measures that do not rely on self-reports. Results suggest that affective valence is more sensitive to the change in the amount of perceptual details of the stimulus than semantic valence. The psychological mechanism that might underlie this effect and the theoretical implications of the findings are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Temporal dynamics of the semantic versus affective representations of valence during reversal learning

Valence, the representation of a stimulus in terms of good or bad, plays a central role in models of affect, value-based learning theories, and value-based decision-making models. Previous work used Unconditioned Stimulus (US) to support a theoretical division between two different types of valence representations for a stimulus: the semantic representation of valence, i.e., stored accumulated knowledge about the value of the stimulus, and the affective representation of valence, i.e., the valence of the affective response to this stimulus. The current work extended past research by using a neutral Conditioned Stimulus (CS) in the context of reversal learning, a type of associative learning. The impact of expected uncertainty (the variability of rewards) and unexpected uncertainty (reversal) on the evolving temporal dynamics of the two types of valence representations of the CS was tested in two experiments. Results show that in an environment presenting the two types of uncertainty, the adaptation process (learning rate) of the choices and of the semantic valence representation is slower than the adaptation of the affective valence representation. In contrast, in environments with only unexpected uncertainty (i.e., fixed rewards), there is no difference in the temporal dynamics of the two types of valence representations. Implications for models of affect, value-based learning theories, and value-based decision-making models are discussed.

Intrinsic Excitability in Layer IV-VI Anterior Insula to Basolateral Amygdala Projection Neurons Correlates with the Confidence of Taste Valence Encoding.

Avoiding potentially harmful, and consuming safe food is crucial for the survival of living organisms. However, the perceived valence of sensory information can change following conflicting experiences. Pleasurability and aversiveness are two crucial parameters defining the perceived valence of a taste and can be impacted by novelty. Importantly, the ability of a given taste to serve as the conditioned stimulus (CS) in conditioned taste aversion (CTA) is dependent on its valence. Activity in anterior insula (aIC) Layer IV-VI pyramidal neurons projecting to the basolateral amygdala (BLA) is correlated with and necessary for CTA learning and retrieval, as well as the expression of neophobia toward novel tastants, but not learning taste familiarity. Yet, the cellular mechanisms underlying the updating of taste valence representation in this specific pathway are poorly understood. Here, using retrograde viral tracing and whole-cell patch-clamp electrophysiology in trained mice, we demonstrate that the intrinsic properties of deep-lying Layer IV-VI, but not superficial Layer I-III aIC-BLA neurons, are differentially modulated by both novelty and valence, reflecting the subjective predictability of taste valence arising from prior experience. These correlative changes in the profile of intrinsic properties of LIV-VI aIC-BLA neurons were detectable following both simple taste experiences, as well as following memory retrieval, extinction learning, and reinstatement.

Supplemental Material for A Divergent Effect of Stimulus Perceptual Details on Affective and Semantic Representations of Valence

Supplemental Material for A Divergent Effect of Stimulus Perceptual Details on Affective and Semantic Representations of Valence

When self comes to a wandering mind: Brain representations and dynamics of self-generated concepts in spontaneous thought.

Self-relevant concepts are major building blocks of spontaneous thought, and their dynamics in a natural stream of thought are likely to reveal one’s internal states that are important for mental health. Here, we conducted a functional magnetic resonance imaging experiment (n = 62) to examine brain representations and dynamics of self-generated concepts in the context of spontaneous thought using a newly developed free association–based thought sampling task. The dynamics of conceptual associations were predictive of individual differences in general negative affectivity, replicating across multiple datasets (n = 196). Reflecting on self-generated concepts strongly engaged brain regions linked to autobiographical memory, conceptual processes, emotion, and autonomic regulation, including the medial prefrontal and medial temporal subcortical structures. Multivariate pattern–based predictive modeling revealed that the neural representations of valence became more person-specific as the level of perceived self-relevance increased. Overall, this study sheds light on how self-generated concepts in spontaneous thought construct inner affective states and idiosyncrasies.

Distinct representation of cue-outcome association by D1 and D2 neurons in the ventral striatum's olfactory tubercle.

Positive and negative associations acquired through olfactory experience are thought to be especially strong and long-lasting. The conserved direct olfactory sensory input to the ventral striatal olfactory tubercle (OT) and its convergence with dense dopaminergic input to the OT could underlie this privileged form of associative memory, but how this process occurs is not well understood. We imaged the activity of the two canonical types of striatal neurons, expressing D1- or D2-type dopamine receptors, in the OT at cellular resolution while mice learned odor-outcome associations ranging from aversive to rewarding. D1 and D2 neurons both responded to rewarding and aversive odors. D1 neurons in the OT robustly and bidirectionally represented odor valence, responding similarly to odors predicting similar outcomes regardless of odor identity. This valence representation persisted even in the absence of a licking response to the odors and in the absence of the outcomes, indicating a true transformation of odor sensory information by D1 OT neurons. In contrast, D2 neuronal representation of the odor-outcome associations was weaker, contingent on a licking response by the mouse, and D2 neurons were more selective for odor identity than valence. Stimulus valence coding in the OT was modality-sensitive, with separate sets of D1 neurons responding to odors and sounds predicting the same outcomes, suggesting that integration of multimodal valence information happens downstream of the OT. Our results point to distinct representation of identity and valence of odor stimuli by D1 and D2 neurons in the OT.

TRPV1-Lineage Somatosensory Fibers Communicate with Taste Neurons in the Mouse Parabrachial Nucleus.

Trigeminal neurons convey somatosensory information from craniofacial tissues. In mouse brain, ascending projections from medullary trigeminal neurons arrive at taste neurons in the parabrachial (PB) nucleus, suggesting that taste neurons participate in somatosensory processing. However, the cell types that support this convergence were undefined. Using Cre-directed optogenetics and in vivo neurophysiology in anesthetized mice of both sexes, here we studied whether transient receptor potential vanilloid 1 (TRPV1)-lineage nociceptive and thermosensory fibers are primary neurons that drive trigeminal circuits reaching PB taste cells. We monitored spiking activity in individual PB neurons during photoexcitation of the terminals of TRPV1-lineage fibers arriving at the dorsal trigeminal nucleus caudalis, which relays orofacial somatosensory messages to the PB area. We also recorded PB neural responses to oral delivery of taste, chemesthetic, and thermal stimuli. We found that optical excitation of TRPV1-lineage fibers elicited responses in traditionally defined taste neurons in lateral PB nuclei. The tuning of neurons across diverse tastes associated with their sensitivity to TRPV1-lineage fiber stimulation, which only sparingly engaged neurons oriented to preferred tastes like sucrose. Moreover, neurons responsive to photostimulation of TRPV1-lineage afferents showed strong responses to temperature including noxious heat, which predominantly excited PB bitter taste cells. Multivariate and machine learning analyses revealed the PB confluence of TRPV1-lineage signals with taste captured sensory valence information shared across aversive gustatory, nociceptive, and thermal stimuli. Our results reveal that TRPV1-lineage fibers, which have defined roles in thermosensation and pain, communicate with PB taste neurons. This multisensory convergence supports dependencies between gustatory and somatosensory hedonic representations in the brain.SIGNIFICANCE STATEMENT The parabrachial (PB) nucleus participates in autonomic and integrative neural processing for diverse sensory modalities. We recently found in mice that trigeminal neurons supplying craniofacial somatosensation project to PB neurons sensitive to tastes. Here, we show that trigeminal projections to PB gustatory cells are driven by a genetic class of thermosensory and nociceptive fiber. Input from these fibers was associated with PB neural sensitivity to aversive oral temperatures and tastes and supported a multimodal neural representation of sensory valence across gustatory, nociceptive, and thermal stimuli. These results reveal gustation and somatosensation to be only components of a larger PB code that captures sensory value. Defining this circuit has implications for understanding the neural representation of taste, temperature, and also pain-related phenomena.

Normalization by valence and motivational intensity in the sensorimotor cortices (PMd, M1, and S1)

Our brain’s ability to represent vast amounts of information, such as continuous ranges of reward spanning orders of magnitude, with limited dynamic range neurons, may be possible due to normalization. Recently our group and others have shown that the sensorimotor cortices are sensitive to reward value. Here we ask if psychological affect causes normalization of the sensorimotor cortices by modulating valence and motivational intensity. We had two non-human primates (NHP) subjects (one male bonnet macaque and one female rhesus macaque) make visually cued grip-force movements while simultaneously cueing the level of possible reward if successful, or timeout punishment, if unsuccessful. We recorded simultaneously from 96 electrodes in each the following: caudal somatosensory, rostral motor, and dorsal premotor cortices (cS1, rM1, PMd). We utilized several normalization models for valence and motivational intensity in all three regions. We found three types of divisive normalized relationships between neural activity and the representation of valence and motivation, linear, sigmodal, and hyperbolic. The hyperbolic relationships resemble receptive fields in psychological affect space, where a unit is susceptible to a small range of the valence/motivational space. We found that these cortical regions have both strong valence and motivational intensity representations.

Do You Approach Positive Events or Do They Approach You? Linking Event Valence and Time Representations in a Dutch Sample

Abstract In order to think and talk about time, people often use the ego- or time-moving representation. In the ego-moving representation, the self travels through a temporal landscape, leaving past events behind and approaching future events; in the time-moving representation, the self is stationary and temporal events pass by. Several studies contest to the psychological ramifications of these two representations by, inter alia, demonstrating a link between them and event valence. These studies have, however, been limited to English speakers, even though language has been found to affect time representation. The present study therefore replicated Margolies and Crawford’s (2008) experiment on event valence and time representation amongst speakers of Dutch. Unlike Margolies and Crawford (2008), we do not find that positive valence leads to the endorsement of an ego-moving statement. Future studies will need to determine the ways through which language might moderate the relation between event valence and time representation.

Modality-general and modality-specific audiovisual valence processing

A fundamental question in affective neuroscience is whether there is a common hedonic system for valence processing independent of modality, or there are distinct neural systems for different modalities. To address this question, we used both region of interest and whole-brain representational similarity analyses on functional magnetic resonance imaging data to identify modality-general and modality-specific brain areas involved in valence processing across visual and auditory modalities. First, region of interest analyses showed that the superior temporal cortex was associated with both modality-general and auditory-specific models, while the primary visual cortex was associated with the visual-specific model. Second, the whole-brain searchlight analyses also identified both modality-general and modality-specific representations. The modality-general regions included the superior temporal, medial superior frontal, inferior frontal, precuneus, precentral, postcentral, supramarginal, paracentral lobule and middle cingulate cortices. The modality-specific regions included both perceptual cortices and higher-order brain areas. The valence representations derived from individualized behavioral valence ratings were consistent with these results. Together, these findings suggest both modality-general and modality-specific representations of valence.

Deeply Felt Affect: The Emergence of Valence in Deep Active Inference.

The positive-negative axis of emotional valence has long been recognized as fundamental to adaptive behavior, but its origin and underlying function have largely eluded formal theorizing and computational modeling. Using deep active inference, a hierarchical inference scheme that rests on inverting a model of how sensory data are generated, we develop a principled Bayesian model of emotional valence. This formulation asserts that agents infer their valence state based on the expected precision of their action model—an internal estimate of overall model fitness (“subjective fitness”). This index of subjective fitness can be estimated within any environment and exploits the domain generality of second-order beliefs (beliefs about beliefs). We show how maintaining internal valence representations allows the ensuing affective agent to optimize confidence in action selection preemptively. Valence representations can in turn be optimized by leveraging the (Bayes-optimal) updating term for subjective fitness, which we label affective charge (AC). AC tracks changes in fitness estimates and lends a sign to otherwise unsigned divergences between predictions and outcomes. We simulate the resulting affective inference by subjecting an in silico affective agent to a T-maze paradigm requiring context learning, followed by context reversal. This formulation of affective inference offers a principled account of the link between affect, (mental) action, and implicit metacognition. It characterizes how a deep biological system can infer its affective state and reduce uncertainty about such inferences through internal action (i.e., top-down modulation of priors that underwrite confidence). Thus, we demonstrate the potential of active inference to provide a formal and computationally tractable account of affect. Our demonstration of the face validity and potential utility of this formulation represents the first step within a larger research program. Next, this model can be leveraged to test the hypothesized role of valence by fitting the model to behavioral and neuronal responses.

Audiovisual Representations of Valence: a Cross-study Perspective.

Hedonic valence describes the pleasantness or unpleasantness of psychological states elicited by stimuli and is conceived as a fundamental building block of emotional experience. Multivariate pattern analysis approaches contribute to the study of valence representation by allowing identification of valence from distributed patterns of activity. However, the issue of construct validity arises in that there is always a possibility that classification results from a single study are driven by factors other than valence, such as the idiosyncrasies of the stimuli. In this work, we identify valence across participants from six different fMRI studies that used auditory, visual, or audiovisual stimuli, thus increasing the likelihood that classification is driven by valence and not by the specifics of the experimental paradigm of a particular study. The studies included a total of 93 participants and differed on stimuli, task, trial duration, number of participants, and scanner parameters. In a leave-one-study-out cross-validation procedure, we trained the classifiers on fMRI data from five studies and predicted valence, positive or negative, for each of the participants in the left-out study. Whole-brain classification demonstrated a reliable distinction between positive and negative valence states (72% accuracy). In a searchlight analysis, the representation of valence was localized to the right postcentral and supramarginal gyri, left superior frontal and middle frontal cortices, and right pregenual anterior cingulate and superior medial frontal cortices. The demonstrated cross-study classification of valence enhances the construct validity and generalizability of the findings from the combined studies.

A study in affect: Predicting valence from fMRI data

Previous studies have shown that affective valence states induced by brief stimulus presentations are identifiable from whole brain activation patterns observed with functional magnetic resonance imaging (fMRI). However, it is unclear whether those results will generalize to identification of continuous changes in affective valence states under naturalistic settings, such as watching a movie. We examined neural representations of signed (positive versus negative) and unsigned (valenced versus non-valenced) valence on previously collected fMRI data from 17 participants who watched a TV show episode in a passive viewing task in the scanner (Chen et al., 2017). These data were correlated with behavioral valence ratings from a separate group of 125 participants. We spatially localized both signed and unsigned valence representations and were able to predict valence ratings for most participants based on the signed valence model in a cross-participant cross-validation procedure. These findings extend previous results from controlled experimental studies to naturalistic settings, demonstrating the ecological validity of prior findings.