Pleasant Stimuli Research Articles

Predispositions to approach and avoid are contextually sensitive and goal dependent.

The authors show that predispositions to approach and avoid do not consist simply of specific motor patterns but are more abstract functions that produce a desired environmental effect. It has been claimed that evaluating a visual stimulus as positive or negative evokes a specific motor response, extending the arm to negative stimuli, and contracting to positive stimuli. The authors showed that a large congruency effect (participants were faster to approach pleasant and avoid unpleasant stimuli, than to approach unpleasant and avoid pleasant stimuli) could be produced on a novel touchscreen paradigm (Experiment 1), and that the congruency effect could be reversed by spatial (Experiment 2) and nonspatial (Experiment 3) response effects. Thus, involuntary approach and avoid response activations are not fixed, but sensitive to context, and are specifically based on the desired goal.

Activation of the subthalamic region during emotional processing in Parkinson’s disease: insights from intracranial recordings

Event Abstract Back to Event Activation of the subthalamic region during emotional processing in Parkinson’s disease: insights from intracranial recordings Andrea A. Kuehn1* 1 Charité-University Medicine Berlin, Germany Deep brain stimulation (DBS) of the subthalamic nucleus (STN) leads to affective disturbances in about 14% of patients with Parkinson’s disease (PD; Temel et al., 2006). It is likely that some of the behavioural complications are the direct consequences of STN DBS since mood changes can be influenced by changes in stimulation parameters and deficits in facial discrimination of negative emotions have been observed after STN stimulation in PD. We directly recorded local field potential (LFP) activity from deep brain electrodes in PD patients during viewing of emotionally arousing and neutral pictures, selected from the International Affective Picture System (IAPS). A significantly larger event-related desynchronization (ERD) in the alpha frequency range occurred 1-2s after stimulus presentation of emotionally salient pictures as compared to neutral stimuli. Moreover, the alpha ERD was correlated with the individual valence rating of the pleasant stimuli, suggesting that emotional information processing at the level of the STN may be related to valence discrimination processes. The modulation of neuronal response pattern was dependent on dopamine in PD, with decreased reactivity of alpha activity after dopamine withdrawal, possibly related to abnormal processing in the limbic cortex-basal ganglia loop. Together, our findings show that the STN is active during emotional processing in PD patients as indexed by modulation of STN LFP alpha activity and that the activation pattern is modulated by valence of the stimuli and dopaminergic activation. Conference: 10th International Conference on Cognitive Neuroscience, Bodrum, Turkey, 1 Sep - 5 Sep, 2008. Presentation Type: Oral Presentation Topic: Abstracts Citation: Kuehn AA (2008). Activation of the subthalamic region during emotional processing in Parkinson’s disease: insights from intracranial recordings. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.024 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Nov 2008; Published Online: 27 Nov 2008. * Correspondence: Andrea A Kuehn, Charité-University Medicine Berlin, 82152 Planegg-Martinsried, Germany, Andrea.kuehn@charite.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Andrea A Kuehn Google Andrea A Kuehn Google Scholar Andrea A Kuehn PubMed Andrea A Kuehn Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Emotional and motivational changes after bilateral lesions of the globus pallidus.

This study investigated motivational changes in a 44 year-old man (PJ) who developed considerable reduction in spontaneous activity and speech, flat affect, social withdrawal, loss of interest, inability to "feel," and lack of concern regarding his medical condition after bilateral, focal, anoxic lesions of the globus pallidus. PJ and 30 male controls performed a task designed to parse hedonic evaluation, or liking, from incentive motivation, or wanting. Affective stimuli were presented on a computer screen and subjects controlled viewing time by pressing keys. PJ's liking and wanting of unpleasant stimuli was similar to that of controls. In response to pleasant stimuli, PJ showed normal ratings of wanting and hedonic appreciation, but significantly reduced viewing time or made no responses. Active withdrawal from liked stimuli could constitute the basic mechanism underlying poor motivation and social withdrawal associated with globus pallidus damage.

The persistence of attention to emotion: Brain potentials during and after picture presentation.

Emotional stimuli have been shown to elicit increased perceptual processing and attentional allocation. The late positive potential (LPP) is a sustained P300-like component of the event-related potential that is enhanced after the presentation of pleasant and unpleasant pictures as compared with neutral pictures. In this study, the LPP was measured using dense array electroencephalograph both before and after pleasant, neutral, and unpleasant images to examine the time course of attentional allocation toward emotional stimuli. Results from 17 participants confirmed that the LPP was larger after emotional than neutral images and that this effect persisted for 800 ms after pleasant picture offset and at least 1,000 ms after unpleasant picture offset. The persistence of increased attention after unpleasant compared to pleasant stimuli is consistent with the existence of a negativity bias. Overall, these results indicate that attentional capture of emotion continues well beyond picture presentation and that this can be measured with the LPP. Implications and directions for future research are discussed.

Effects of complexity and intensity on sensory specific satiety and food acceptance after repeated consumption

The objectives of the present work were (1) to study the effects of complexity and intensity of foods on sensory specific satiety (SSS) and their acceptance after repeated consumption, and (2) to determine the predictive value of SSS for acceptance over repeated consumption. Two studies were performed: a soup study ( N = 66) and a snack study ( N = 61). In the snack study, the intense snacks produced somewhat more SSS than the less intense snacks ( F(3, 177) = 2.2, p = 0.09). Both studies demonstrated that pleasantness of stimuli with a near to optimal arousal level, which is a combination of complexity and intensity, was more resistant to a decline over repeated exposure than of stimuli with lower arousal levels (soups: F(14, 546) = 2.0, p = 0.04; snacks: F(15, 450) = 6.1, p = 0.003). The data do not support the idea that SSS could serve as a rapid predictor of long-term acceptance (soups: r SSS-repeated consumption = −0.05, p = 0.73; snacks: r SSS-repeated consumption = 0.20, p = 0.19). These findings need to be confirmed with stimuli that are more comparable with respect to initial liking and sensory qualities other than intensity and complexity.

Nicotine effects on affective response in depression-prone smokers

Comorbidity between cigarette smoking and depression is thought to arise because depression-prone smokers self-administer nicotine to improve mood. Yet little evidence supports this view, and nicotine's effect on positive affect deficiency in depression remains largely unstudied. We hypothesized that (1) nicotine would dispel negative affect and enhance positive affect and (2) effects would be stronger for smokers vulnerable to depression, particularly during a depressed state. Regular smokers (N = 165) were recruited from the community: 63 with no history of major depressive disorder (MDD), 61 with recurrent past but no current MDD, and 41 with both current and past MDD. During four sessions, participants smoked either a nicotinized (NIC+) or denicotinized (NIC-) cigarette double blind after experiencing a negative mood induction or while undergoing a positive mood induction. Positive and negative affects were measured at baseline and at two time points after smoking. Previously depressed smokers showed a heightened positive mood response to positive mood induction when smoking a nicotinized cigarette. Nicotine also increased the degree to which positive mood induction dispelled negative mood in depression-vulnerable smokers. Finally, nicotine worsened the negative affect response to negative mood induction for all groups. Self-administering nicotine appears to improve depression-prone smokers' emotional response to a pleasant stimulus.

Hedonic-Specific Activity in Piriform Cortex During Odor Imagery Mimics That During Odor Perception

Although it is known that visual imagery is accompanied by activity in visual cortical areas, including primary visual cortex, whether olfactory imagery exists remains controversial. Here we asked whether cue-dependent olfactory imagery was similarly accompanied by activity in olfactory cortex, and in particular whether hedonic-specific patterns of activity evident in olfactory perception would also be present during olfactory imagery. We used functional magnetic resonance imaging to measure activity in subjects who alternated between smelling and imagining pleasant and unpleasant odors. Activity induced by imagining odors mimicked that induced by perceiving real odorants, not only in the particular brain regions activated, but also in its hedonic-specific pattern. For both real and imagined odors, unpleasant stimuli induced greater activity than pleasant stimuli in the left frontal portion of piriform cortex and left insula. These findings combine with findings from other modalities to suggest activation of primary sensory cortical structures during mental imagery of sensory events.

Expectation Modulates Neural Responses to Pleasant and Aversive Stimuli in Primate Amygdala

Animals and humans learn to approach and acquire pleasant stimuli and to avoid or defend against aversive ones. However, both pleasant and aversive stimuli can elicit arousal and attention, and their salience or intensity increases when they occur by surprise. Thus, adaptive behavior may require that neural circuits compute both stimulus valence--or value--and intensity. To explore how these computations may be implemented, we examined neural responses in the primate amygdala to unexpected reinforcement during learning. Many amygdala neurons responded differently to reinforcement depending upon whether or not it was expected. In some neurons, this modulation occurred only for rewards or aversive stimuli, but not both. In other neurons, expectation similarly modulated responses to both rewards and punishments. These different neuronal populations may subserve two sorts of processes mediated by the amygdala: those activated by surprising reinforcements of both valences-such as enhanced arousal and attention-and those that are valence-specific, such as fear or reward-seeking behavior.

The subthalamic region is activated during valence‐related emotional processing in patients with Parkinson's disease

Visual stimuli are judged for their emotional significance based on two fundamental dimensions, valence and arousal, and may lead to changes in neural and body functions like attention, affect, memory and heart rate. Alterations in behaviour and mood have been encountered in patients with Parkinson's disease (PD) undergoing functional neurosurgery, suggesting that electrical high-frequency stimulation of the subthalamic nucleus (STN) may interfere with emotional information processing. Here, we use the opportunity to directly record neuronal activity from the STN macroelectrodes in patients with PD during presentation of emotionally laden and neutral pictures taken from the International Affective Picture System (IAPS) to further elucidate the role of the STN in emotional processing. We found a significant event-related desynchronization of STN alpha activity with pleasant stimuli that correlated with the individual valence rating of the pictures. Our findings suggest involvement of the human STN in valence-related emotional information processing that can potentially be altered during high-frequency stimulation of the STN in PD leading to behavioural complications.

Taste Intensity and Hedonic Responses to Simple Beverages in Gastrointestinal Cancer Patients

Changes in the taste of food have been implicated as a potential cause of reduced dietary intake among cancer patients. However, data on intensity and hedonic responses to the four basic tastes in cancer are scanty and contradictory. The present study aimed at evaluating taste intensity and hedonic responses to simple beverages in 47 anorectic patients affected by gastrointestinal cancer and in 55 healthy subjects. Five suprathreshold concentrations of each of the four test substances (sucrose in black current drinks, citric acid in lemonade, NaCl in unsalted tomato juice, and urea in tonic water) were used. Patients were invited to express a judgment of intensity and pleasantness ranging from 0 to 10. Mean intensity scores directly correlated with concentrations of sour, salty, bitter, and sweet stimuli, in both normals and those with cancer. Intensity judgments were higher in cancer patients with respect to sweet (for median and high concentrations, P < 0.05), salty (for all concentrations, P < 0.05), and bitter tastes (for median concentration, P < 0.01). Hedonic function increased with the increase of the stimuli only for the sweet taste. A negative linear correlation was found between sour, bitter, and salty concentrations and hedonic score. Both in cancer patients and in healthy subjects, hedonic judgments increased with the increase of the stimulus for the sweet taste ( r = 0.978 and r = 0.985, P = 0.004 and P = 0.002, respectively), and decreased for the salty ( r = −0.827 and r = −0.884, P = 0.084 and P = 0.047, respectively) and bitter tastes ( r = −0.990 and r = −0.962, P = 0.009 and P = 0.001, respectively). For the sour taste, the hedonic scores remained stable with the increase of the stimulus in noncancer controls ( r = −0.785, P = 0.115) and decreased in cancer patients ( r = −0.996, P = 0.0001). The hedonic scores for the sweet taste and the bitter taste were similar in cancer patients and healthy subjects, and these scores were significantly higher in cancer patients than in healthy subjects for most of the concentrations of the salty taste and all the concentrations of the sour taste. The present study suggests that cancer patients, compared to healthy individuals, have a normal sensitivity, a normal liking for pleasant stimuli, and a decreased dislike for unpleasant stimuli. Moreover, when compared to controls, they show higher hedonic scores for middle and high concentrations of the salty taste and for all concentrations of the sour taste. Further studies are needed to evaluate whether these changes observed in cancer patients translate into any alteration in dietary behavior and/or food preferences.

Investigating the dynamics of affect: Psychological mechanisms of affective habituation to pleasurable stimuli

Affective habituation (i.e., reductions in stimulus-evoked affective reactions as a result of previous exposure) may serve a functional purpose. However, little is know about the psychological mechanisms underlying this process. To elucidate the characteristics of affective habituation, two experiments that examined affective reactions to repeated exposures of pleasurable stimuli were conducted. Results of these experiments indicated that habituation trajectories are characterized by linear decreases in affect. Results also demonstrated that habituation can be slowed by the introduction of novel stimuli (i.e., “novelty effects”), effects that are dimensional (rather than taxonic) in nature. Experiment 2 demonstrated that habituation is mediated by conceptual rather than perceptual processes. Depressed and anhedonic individuals were not more susceptible to habituation in either experiment. The current findings and previous theorizing suggest that habituation may be an important component of an adaptive affective processing system that promotes effective responses to salient stimuli and prevents compulsive reward-seeking behavior.

Life Satisfaction is not a Balanced Estimator of the Good Life: Evidence from Reaction Time Measures and Self-Reported Emotions

A widespread belief in happiness research is that measures of life satisfaction capture the variety of an individual’s experiences along a single favorable—unfavorable dimension. The current article points to a possible violation of this assumption. With a combination of data and theory it argues that life satisfaction is not a balanced reflection of subjective experiences because the evaluation that drives judgments of life satisfaction is tilted towards pleasure and away from engagement. We postulate that feelings of pleasure are overrated in statements of life satisfaction, whereas feelings of engagement are underrepresented. Feelings of engagement and interest are further supposed to be indicators of personal growth. Measures of personal growth and life satisfaction should thus be unrelated. Empirical evidence for our model is provided by self-report and reaction time data from a Norwegian convenience sample (N = 30). Detection latencies for pleasant stimuli correlated significantly with life satisfaction but not with measures of personal growth. Life satisfaction correlated significantly with pleasant experiences, but not with engagement. Personal growth correlated significantly with feelings of engagement. Life satisfaction and personal growth were uncorrelated.

Anhedonia in schizophrenia: Distinctions between anticipatory and consummatory pleasure

Research on anhedonia in schizophrenia has revealed mixed results, with patients reporting greater anhedonia than healthy controls on self-report measures and semi-structured interviews, but also reporting comparable experiences of positive emotions in response to pleasurable stimuli. Basic science points to the importance of distinguishing between anticipatory and consummatory (or in-the-moment) pleasure experiences, and this distinction may help to reconcile the mixed findings on anhedonia in schizophrenia. In two studies, we tested the hypothesis that anhedonia in schizophrenia reflects a deficit in anticipatory pleasure but not consummatory pleasure. In Study 1, we used experience sampling methodology to assess reported experiences of consummatory and anticipated pleasure among schizophrenia patients and controls. In Study 2, schizophrenia patients and controls completed a self-report trait measure of anticipatory and consummatory pleasure and interviews that assessed negative symptoms, including anhedonia, and community functioning. In both studies, we found evidence for an anticipatory but not a consummatory pleasure deficit in schizophrenia. In addition, anticipatory pleasure was related to clinical ratings of anhedonia and functional outcome. Clinical and research implications of these findings are discussed.

IAPS includes photographs that elicit low-arousal physiological responses in healthy volunteers

This article describes pleasant IAPS pictures that elicit low-arousal rather than the high-arousal physiological responses previously reported in the literature. Thirty-two International Affective Picture System (IAPS) photographs were grouped into 4 sets of 8 photographs: highly pleasant-arousing (sexual content and adventures), highly pleasant-relaxing pictures (landscapes, flowers or babies), neutral on both valence/arousal, and highly unpleasant-arousing ones. These stimuli were shown to 24 healthy Brazilian University students (12 males) who had their physiological responses recorded [corrugator and zygomatic facial electromyography activity, skin conductance, heart rate, and peripheral temperature]. Zygomatic EMG differentiated low-arousal pleasant photographs from high-arousal pleasant stimuli of the same valence.

Gene–gene effects on central processing of aversive stimuli

Emotional reactivity and regulation are fundamental to human behavior. As inter-individual behavioral variation is affected by a multitude of different genes, there is intense interest to investigate gene-gene effects. Functional sequence variation at two genes has been associated with response and resiliency to emotionally unpleasant stimuli. These genes are the catechol-O-methyltransferase gene (COMT Val158Met) and the regulatory region (5-HTTLPR) of the serotonin transporter gene. Recently, it has been proposed that 5-HTT expression is not only affected by the common S/L variant of 5-HTTLPR but also by an A to G substitution. Using functional magnetic resonance imaging, we assessed the effects of COMT Val(158)Met and both 5-HTT genotypes on brain activation by standardized affective visual stimuli (unpleasant, pleasant, and neutral) in 48 healthy subjects. Based on previous studies, the analysis of genotype effects was restricted to limbic brain areas. To determine allele-dose effects, the number of COMT Met158 alleles (i.e., lower activity of COMT) and the number of 5-HTT low expressing alleles (S and G) was correlated with the blood oxygen level-dependent (BOLD) response to pleasant or unpleasant stimuli compared to neutral stimuli. We observed an additive effect of COMT and both 5-HTT polymorphisms, accounting for 40% of the inter-individual variance in the averaged BOLD response of amygdala, hippocampal and limbic cortical regions elicited by unpleasant stimuli. Effects of 5-HTT and COMT genotypes did not affect brain processing of pleasant stimuli. These data indicate that functional brain imaging may be used to assess the interaction of multiple genes on the function of neuronal networks.

Common and distinct patterns of affective response in dimensions of anxiety and depression.

The authors examined the time course of affective responding associated with different affective dimensions--anxious apprehension, anxious arousal, and anhedonic depression--using an emotion-modulated startle paradigm. Participants high on 1 of these 3 dimensions and nonsymptomatic control participants viewed a series of affective pictures with acoustic startle probes presented before, during, and after the stimuli. All groups exhibited startle potentiation during unpleasant pictures and in anticipation of both pleasant and unpleasant pictures. Compared with control participants, symptomatic participants exhibited sustained potentiation following the offset of unpleasant stimuli and a lack of blink attenuation during and following pleasant stimuli. Common and unique patterns of affective responses in the 3 types of mood symptoms are discussed.

Processing of pleasant, unpleasant, and neutral words in a lateralised emotional Stroop task

According to the valence hypothesis, pleasant and unpleasant stimuli are mainly processed in the left and in the right hemisphere, respectively. To elucidate whether this reflects lateralised attentional processes, a lateralised Emotional Stroop Task was administered: Pleasant, unpleasant, and neutral words were presented to 63 male and 62 female students in four colours for 150 ms in either the left or the right visual half field. Pleasant words presented in the right (compared to the left) and unpleasant and neutral words presented in the left (compared to the right) visual field had longer latencies. Thus, attentional processes seem to be lateralised, depending on the hedonic tone of the stimuli. Predictions on personality differences in lateralised attentional processes were not confirmed.

The Neuroscience of Pleasure. Focus on “Ventral Pallidum Firing Codes Hedonic Reward: When a Bad Taste Turns Good”

For more than 2,000 years, philosophers have struggled to define, let alone explain, pleasure or hedonics. With contemporary animal models and techniques, scientists now have the ability to provide a comprehensive description of this affective state by examining its neural underpinnings. In this issue of the Journal of Neurophysiology (p. 2399 –2409), Tindell and colleagues use an elegant, reductionist approach to take a profound step in defining these neural foundations (Tindell 2006). The authors control for various elements of reward that historically have confounded researchers ambitious enough to attempt to study such an intangible topic. Specifically, Tindell and colleagues establish a role for ventral pallidum (VP) neurons in encoding hedonics. The authors infused an unpalatable concentration of saline into the oral cavities of rats while recording the extracellular electrophysiological activity of single VP neurons. Aversive orofacial reactions to the unpalatable taste were simultaneously measured. Three days later, rats were made sodium deplete and retested. In a sodium-depleted state, these rats now exhibited a behavioral switch from aversive taste reactivity to appetitive taste reactivity coincident with increased VP activity to the infusion of saline (similar to responses for a palatable sucrose solution). The clever implicit controls indicate that the altered electrophysiological activity encodes a hedonic shift rather than alterations in motivated behavior or sensory coding.

Lipopolysaccharide and interleukin-1β decrease sucrose intake but do not affect expression of place preference in rats

Immune system activation has been shown to induce decreased interest in pleasurable stimuli. Studies of this phenomenon have assessed the effect of cytokines or lipopolysaccharide (LPS) on behavior maintained by primary reinforcers, stimuli, such as palatable solutions, that effectively reinforce behavior without prior training. The studies reported in this paper replicated findings of immune system activation decreasing intake of a palatable solution and assessed the effects of immune activation on behavior maintained by a conditioned reinforcer, a stimulus paired with a the palatable solution. Using a conditioned place preference procedure, the effects of LPS and interleukin-1β (IL-1β) on sucrose intake (primary reinforcer) and preference for a sucrose-paired environment (conditioned reinforcer) were tested. LPS and IL-1β decreased sucrose intake but had no effect on the expression of a sucrose-induced place preference, indicating a differential effect of immune system activation on appetitive behaviors maintained by primary and conditioned reinforcers. Finally, it was shown that a sucrose-induced place preference is sensitive to the motivational state of the subjects at the time of testing; a sucrose-induced place preference was demonstrated if rats were tested when water deprived but not if tested after free access to water.

Neural response to sustained affective visual stimulation using an indirect task

Event-related potentials were recorded from 30 subjects using sustained stimulation and an indirect task, two strategies which facilitate affective responses that are complete and free of cognitive interference. Stimuli were of three types: pleasant, unpleasant and neutral. A three-phase pattern was found. The first phase, an amplitude increase in response to negative stimuli higher than to neutral and pleasant stimuli, was produced at 160 ms after stimulus onset, the prefrontal cortex being the origin of this phase. The second phase, characterized by maximal amplitudes in response to positive stimuli, was produced at 400 ms, originating in the visual cortex. Finally, the third phase, another amplitude increase in response to negative stimuli, was produced at 680 ms, and its source was located in the left precentral gyrus. Present data show that the cortical response to sustained emotional visual stimulation presented within indirect tasks provides information on attention-, motivation- and motor-related biases that complement information obtained under other experimental conditions.