Neural Correlates of Conscious Emotional Experience

This chapter addresses the “Hard Problem” of consciousness in the context of robot emotions. The Hard Problem, as defined by Chalmers, refers to the task of explaining the relation between conscious experience and the physical processes associated with it. For example, a robot can act afraid, but could it feel fear? Using protophenomenal analysis, which reduces conscious experience to its smallest units and investigates their physical correlates, we consider whether robots could feel their emotions, and the conditions under which they might do so. We find that the conclusion depends on unanswered but empirical questions in the neuropsychology of human consciousness. However, we do conclude that conscious emotional experience will require a robot to have a rich representation of its body and the physical state of its internal processes, which is important even in the absence of conscious experience.

Measuring emotional processes in animals: the utility of a cognitive approach

Subjective feeling, defined as the conscious experience of emotion and measured by self-report, is generally used as a manipulation check in studying emotional processes, rather than being the primary focus of research. In this paper, we report a first investigation into the processes involved in the emergence of a subjective feeling. We hypothesized that the oscillatory brain activity presumed to underlie the emergence of a subjective feeling can be measured by electroencephalographic (EEG) frequency band activity, similar to what has been shown in the literature for the conscious representation of objects. Emotional reactions were induced in participants using static visual stimuli. Episodes for which participants reported a subjective feeling were compared to those that did not lead to a conscious emotional experience, in order to identify potential differences between these two kinds of reactions at the oscillatory level. Discrete wavelet transforms of the EEG signal in gamma (31-63 Hz) and beta (15-31 Hz) bands showed significant differences between these two types of reactions. In addition, whereas beta band activities were widely distributed, differences in gamma band activity were predominantly observed in the frontal and prefrontal regions. The results are interpreted and discussed in terms of the complexity of the processes required to perform the affective monitoring task. It is suggested that future work on coherent mental representation of multimodal reaction patterns leading to the emergence of conscious emotional experience should include modifications in the time window examined and an extension of the frequency range to be considered.

Humans compute the anticipated reward value of stimuli in their environment in order to behave in an adaptive, goal-directed manner. This reward valuation ability is vital, and its disruption in a range of clinical populations has profound personal and social consequences. However, research has often failed to consider the reward-related functions of a central component of human emotion: conscious emotional experience. Alexithymia-a condition characterized by diminished conscious awareness of one's emotions-offers a unique opportunity to examine the link between emotional awareness and reward valuation. In the present study, we measured both acquired alexithymia and reward valuation ability in a large sample of patients with traumatic brain injuries (N = 112). Behavioral analyses provided evidence for a negative association between alexithymia and reward valuation ability. This association remained significant after controlling for several covariates in the model (anxiety, depression, posttraumatic stress disorder, and IQ). Voxel-based lesion-symptom mapping was carried out to identify brain regions-of-interest (ROIs) that, when damaged, lead to increased alexithymia and impaired reward valuation. Importantly, mediation models computed using the ROIs identified through the voxel-based lesion-symptom mapping revealed a specific indirect effect of left frontoinsular damage on impaired valuation that was mediated by increased levels of alexithymia. This indirect effect was not observed for any of the other candidate ROIs. The present study identifies a network of brain regions likely to be involved in the integration of subjective feelings and reward processes critical for the adaptive control of goal-directed behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Emotional states of consciousness, or what are typically called emotional feelings, are traditionally viewed as being innately programmed in subcortical areas of the brain, and are often treated as different from cognitive states of consciousness, such as those related to the perception of external stimuli. We argue that conscious experiences, regardless of their content, arise from one system in the brain. In this view, what differs in emotional and nonemotional states are the kinds of inputs that are processed by a general cortical network of cognition, a network essential for conscious experiences. Although subcortical circuits are not directly responsible for conscious feelings, they provide nonconscious inputs that coalesce with other kinds of neural signals in the cognitive assembly of conscious emotional experiences. In building the case for this proposal, we defend a modified version of what is known as the higher-order theory of consciousness.

Human emotions are characterized by a complex interaction between conscious experience, physiological arousal, and social dimension. Although the importance of considering emotion response as a nonlinear dynamical system is widely recognized, mathematical models able to describe the time-varying conscious emotional states are still lacking. In recent literature on Affective Computing, novel annotating tools have been introduced to record continuous self-assessed emotion ratings. These data represent a valuable source to describe the dynamics arising during the conscious experience of emotions. Therefore, in this study, we investigate the trajectories traced in the reconstructed phase space of continuously annotated arousal signals acquired during an experimental protocol of emotion elicitation. We use a subset of the Continuously Anno-tated Signals of Emotions (CASE) dataset, including self-assessed ratings from thirty healthy subjects while watching two video clips: one fear-inducing and one relaxing. We analyse intrinsic irregularity and complexity of arousal time-series, performing Sample Entropy and Distribution Entropy algorithms. Results show a significantly higher complexity of time-varying emotion perception during the scary video compared to the relaxing video. Our findings, although preliminary, highlight a promising field of application of chaos theory methodologies to continuous emotion ratings, which can be exploited for the prediction of pathological moods in ecological settings.

Emotional consciousness: A neural model of how cognitive appraisal and somatic perception interact to produce qualitative experience

This chapter will take into account the brain structures which play a critical role in different components and hierarchical levels of emotions. Concerning the neural substrates of different components of emotions, a distinction will be made among structures that (a) underlie the evaluation of emotional significance, (b) are involved in the generation of the conscious experience of emotion and (c) have a prominent role in the generation of the emotional response. Within this reference frame, the amygdala will be described as the structure where external stimuli are evaluated in terms of their emotional significance, the anterior insula as a structure that has a critical role in the conscious experience of emotion, the anterior cingulate cortex and the ventral striatum as involved in the generation of the expressive-motor aspects of the emotional response, and the hypothalamus and the insular cortex as having an important role in the vegetative components of emotions. On the other hand, the ventromedial prefrontal cortex (vmPFC) and the orbitofrontal areas will be considered as involved in the integration between cognition and emotion and in the control of impulsive reactions.

Models advanced to explain hemispheric asymmetries in representation of emotions will be discussed following their historical progression. First, the clinical observations that have suggested a general dominance of the right hemisphere for all kinds of emotions will be reviewed. Then the experimental investigations that have led to proposal of a different hemispheric specialization for positive versus negative emotions (valence hypothesis) or, alternatively, for approach versus avoidance tendencies (motivational hypothesis) will be surveyed. The discussion of these general models will be followed by a review of recent studies which have documented laterality effects within specific brain structures, known to play a critical role in different components of emotions, namely the amygdata in the computation of emotionally laden stimuli, the ventromedial prefrontal cortex in the integration between cognition and emotion and in the control of impulsive reactions and the anterior insula in the conscious experience of emotion. Results of these recent investigations support and provide an updated integrated version of early models assuming a general right hemisphere dominance for all kinds of emotions.

Towards solving the hard problem of consciousness: The varieties of brain resonances and the conscious experiences that they support

Many experiments have found that emotional experience affects self-focused attention. Several approaches to cognition and emotion predict that conscious emotional experience may be unnecessary for this effect. To test this hypothesis, two experiments primed emotion concepts without affecting emotional experience. In Experiment 1, subliminal exposure to sad faces (relative to happy faces and neutral faces) increased self-focused attention but not subjectively experienced affect. In Experiment 2, a scrambled-sentences task that primed happy and sad emotion concepts increased self-focused attention relative to a neutral task. Thus, simply activating knowledge about emotions was sufficient to increase self-focused attention. The discussion considers implications for research on how emotional states affect self-awareness.

Greater negative affect has been associated with an increased risk of the metabolic syndrome (METs). However, all studies to date have examined this association using explicit affect measures based on subjective ratings of emotional experiences. Prior studies suggest that implicit affect, representing the automatic, prereflective appraisal process involved in conscious emotional experiences, is associated with physiological stress responses independent of explicit affect. Furthermore, low resting heart rate variability (HRV) may increase the risk of stress-related diseases. The goals of this study were to evaluate the associations between implicit and explicit affect and METs and to assess whether these associations were amplified by lower HRV. This secondary analysis of a larger study included 217 middle-aged women who completed measures of implicit affect, explicit affect, high-frequency HRV, and the different components of METs. There was a significant interaction between implicit negative affect and HRV predicting METs (odds ratio = 0.57, 95% confidence interval = 0.35-0.92), such that the combination of higher implicit affect and lower HRV was associated with a greater likelihood of METs. Similarly, there was a main effect of implicit negative affect as well as an interaction between implicit negative affect and HRV on the lipid accumulation product (b (standard error) = -0.06 (0.02), 95% confidence interval = -0.11 to -0.02), a combination of waist circumference and triglycerides. Higher implicit negative affect in the context of lower HRV may be related to a greater risk of METs. The present findings highlight the relevance of including implicit affect measures in psychosomatic medicine research.

Emotion and reward have been proposed to be closely linked to conscious experience, but empirical data are lacking. The anterior cingulate cortex (ACC) plays a central role in the hedonic dimension of conscious experience; thus potentially a key region in interactions between emotion and consciousness. Here we tested the impact of emotion on conscious experience, and directly investigated the role of the ACC. We used a masked paradigm that measures conscious reportability in terms of subjective confidence and objective accuracy in identifying the briefly presented stimulus in a forced-choice test. By manipulating the emotional valence (positive, neutral, negative) and the presentation time (16 ms, 32 ms, 80 ms) we measured the impact of these variables on conscious and subliminal (i.e. below threshold) processing. First, we tested normal participants using face and word stimuli. Results showed that participants were more confident and accurate when consciously seeing happy versus sad/neutral faces and words. When stimuli were presented subliminally, we found no effect of emotion. To investigate the neural basis of this impact of emotion, we recorded local field potentials (LFPs) directly in the ACC in a chronic pain patient. Behavioural findings were replicated: the patient was more confident and accurate when (consciously) seeing happy versus sad faces, while no effect was seen in subliminal trials. Mirroring behavioural findings, we found significant differences in the LFPs after around 500 ms (lasting 30 ms) in conscious trials between happy and sad faces, while no effect was found in subliminal trials. We thus demonstrate a striking impact of emotion on conscious experience, with positive emotional stimuli enhancing conscious reportability. In line with previous studies, the data indicate a key role of the ACC, but goes beyond earlier work by providing the first direct evidence of interaction between emotion and conscious experience in the human ACC.

Implicit affect in organizations

The main purpose of this paper is to outline a possible reductive explanation of emotion in neurophysiological terms. But it will also be argued that such a reductive explanation is more difficult to achieve than is commonly thought, in that it has to address conscious emotional experience. It will be argued that when an emotion is conscious, what makes it the emotion it is, and an emotion at all, is its phenomenal character, and when an emotion is unconscious, what makes it the emotion it is, and an emotion at all, is the phenomenal character it would have if it were conscious. This has the consequence that the theory of emotion cannot be insulated from the theory of consciousness, and a reductive explanation of emotion must target the phenomenal character of conscious emotional experiences. A possible reductive explanation of this sort will be outlined.