Disgust-Related Memory Bias in Children and Adults

The contamination effect on recognition memory: adding evidence of an adaptive mnemonic tuning

Previous research has revealed enhanced free recall for neutral items previously associated with disease-causing agents, compared to when they are associated with neutral information; this has been termed the contamination effect. However, it remains unknown whether this effect extends to recognition memory and, if so, on what processes it would rely (i.e., recollection or familiarity). This is a relevant question to establish the generality and enrich our knowledge about the effect on the various processes in which memory operates. We employed a Yes/No recognition task with Remember/Know judgments to assess the recognition experience. Online American (Experiment 1) and in-person Portuguese (Experiment 2) samples were used. Furthermore, in Experiment 2, participants responded to a Health Status questionnaire and the Fear of COVID-19 scale, allowing us to explore the relation of the effect with these individual variables. In both experiments, the results revealed that objects were significantly better recognised after having been previously associated with sick faces than with healthy faces. Moreover, participants assigned a higher proportion of Remember-judgments to contaminated (vs. non-contaminated) objects, suggesting these were retained with more contextual information. Exploratory analyses revealed that participants' illness recency correlated positively with the proportion of Remember-judgments. The robustness of this effect is supported by its replication among participants from two different countries, employing both online and on-site procedures. Notably, the to-be-recognised objects were the same across conditions, preventing possible item-selection concerns. Overall, this study expands our understanding of the impact of contamination on memory, emphasising its role in disease avoidance.

Does enhanced memory of disgust vs. fear images extend to involuntary memory?

People remember disgusting stimuli better than fearful stimuli, but do disgust's memory-enhancing effects extend to involuntary memory? This question is important because disgust reactions occur following trauma, and trauma-related involuntary memories are a hallmark of Posttraumatic Stress Disorder (PTSD) symptoms. In two experiments, we presented participants (n = 88 Experiment 1; n = 106 Experiment 2) with disgust, fear, and neutral images during an attention-monitoring task. Participants then completed an undemanding vigilance task, responding any time an image involuntarily came to mind. We measured the frequency and characteristics of these involuntary memories (e.g. emotional intensity) immediately after encoding and over a 24-hour delay (Experiment 2 only). Our main findings were mixed: participants experienced similarly frequent (Experiment 2) - or more (Experiment 1) - disgust as fear involuntary memories. Therefore, when controlling for memory-enhancing confounds (e.g. distinctiveness), in-laboratory disgust memory enhancement does not extend to involuntary memory. Disgust memories were more emotionally intense than fear memories over the 24-hour delay- but not immediately after encoding - suggesting disgust elicits additional consolidation processes to fear. Participants paid more attention towards the disgust images, but the attention did not account for the memory of disgust. In sum, disgust and fear have both similar and distinct cognitive effects.

State of the Science: Disgust and the Anxiety Disorders

Anxiety disorders have long been conceptualized as disorders of fear, while other emotions have largely been overlooked. However, an emerging literature has increasingly implicated disgust in certain anxiety-related disorders, including obsessive-compulsive disorder, specific phobias (e.g., spider phobia), health anxiety, and posttraumatic stress disorder. Roughly two decades of research has accumulated evidence identifying various mechanisms linking disgust-related phenomena to these disorders. In the present "State of the Science" review, we sought to summarize the current state of the literature with respect to disgust-related mechanisms in anxiety disorders, including trait-level vulnerabilities (e.g., disgust proneness), cognitive processes (e.g., biases of attention and memory), and associated learning mechanisms (e.g., evaluative conditioning). Research in these areas has revealed important ways in which disgust differs from fear-related phenomena, which have important treatment implications. From there, we sought to summarize research on laboratory interventions that attempt to target and attenuate disgust, as well as the early research on formal cognitive-behavioral treatments that integrate disgust-related interventions for anxiety disorders. Although the past two decades of research have revealed important insights related to the role of disgust in psychopathology, much remains to be learned in this area. We propose some future directions, emphasizing the importance of a guiding framework that highlights studying disgust-related mechanisms across different levels of analysis.

The impact of disgust learning on memory processes for neutral stimuli: a classical conditioning approach

Disgust is a basic emotion that promotes pathogen avoidance and can contaminate nearby neutral stimuli. This study investigates how neutral stimuli, which have acquired disgust value through classical conditioning, are processed in episodic memory. The Category Conditioning paradigm was utilised to assign emotional significance to neutral stimuli, followed by a recognition test conducted immediately or 24 h after conditioning (Experiment 1). The results revealed that neutral stimuli that acquired disgust value were recognised with greater accuracy and higher liberal bias compared to other neutral stimuli in the recognition test conducted after 24 h, but not immediately. Present study also indicates that the memory enhancement observed with disgust did not manifest in the context of fear (Experiment 2). Additionally, the results varied when neutral stimuli associated with disgust were presented with disgusting stimuli in recognition test (Experiment 3). Thus, the present study demonstrates that the memory advantage of disgust extends to associated stimuli when they are presented in a list without disgusting stimuli.

Cookie cravings - Examining the impact of sugar content information on Christmas treat preferences via mobile eye-tracking

BACKGROUND

Diets high in added sugar can promote the development of overweight. Especially during the Holiday season, when high-sugar food is abundant, people overeat and gain more weight than during other times of the year. The present study with mobile eye-tracking glasses (Pupil Labs Invisible) investigated how sugar content information affects food preference (liking/wanting) and visual attention (where and how long one is looking) in a buffet-like situation.

METHODS

Fifty-eight participants who were well acquainted with the local Christmas traditions and foods (38 female, 19 male, one diverse; mean age = 25 years, SD = 6.3 years; mean body mass index = 22.2 kg/m2, SD = 3.2 kg/m2) were presented with four cookies and two non-food items (wrapped presents) in a free viewing task. Two of the displayed cookies were 'Christmas cookies' (cookies that are traditionally eaten only during the Holiday season) and two cookies had no Christmas association. The cookies were either labeled as cookies made with or without sugar, resulting in a 3 (Category: cookies with sugar, cookies without sugar, non-food) by 2 (Christmas association: yes, no) repeated-measures design.

RESULTS

Analyses of variance indicated that participants reported higher wanting and liking for cookies with sugar, particularly Christmas cookies (interaction effect for wanting: p = .047, ηp2 = .059; interaction effect for liking: p = .017, ηp2 = .084). Sugar-free cookies were fixated more often (p = .028; d = 0.35) and shorter (p < .001; d = 0.64) than sugar cookies.

CONCLUSION

Assuming that cookies are sugar-free reduced the reported preference for this product, which was associated with a more detail-oriented (critical) viewing pattern. The study's findings have potential implications for public health and can aid in developing targeted interventions to promote healthier food choices during festive periods. The new strategies should not focus on the sugar content of foods.

Disgust as a basic, sexual, and moral emotion

Disgust is a basic emotion that increases the organism's survival success by preventing the transfer of pathogens. In this regard, it directs cognitive processes and motivates avoidance behaviors that prevent pathogens from entering the body. Moreover, disgust has many specific characteristics that distinguish it from other basic emotions. Firstly, unlike other basic emotions, it contaminates neutral objects around it and causes difficult-to-change learning. Another specific characteristic of disgust is that it depends on ideational processes. Objects, situations, and behaviors that do not contain pathogens can also cause disgust. In this regard, disgust appears not only as a basic emotion but also as different adaptations in different fields. In this context, two distinct adaptations of disgust stand out: sexual and moral disgust. These two adaptations of disgust benefit from disgust-related behaviors and motivations in different ways. Sexual disgust works as a gene protection mechanism, while moral disgust helps maintain social rules. The specific characteristics of disgust and its effects on cognitive processes such as attention and memory interact. In conclusion, the multifaceted structure of disgust shows that it needs to be studied more in the subfields of psychology. (Strohminger, Philos Compass 9:478-493, 2014) defines disgust as a psychological nebula that needs to be discovered. However, it is observed that disgust has not been adequately addressed. This review aims to comprehensively explore unique characteristics and diverse aspects of disgust, shedding light on its significance from various perspectives. This study underscores the broader understanding of disgust and its pivotal role in psychological research.

Is disgust more resistant to extinction than fear? A meta-analytic review of laboratory paradigms

Disgust can be acquired via evaluative conditioning; a process by which a neutral stimulus (conditioned stimulus; CS) comes to be evaluated as disgusting due to its pairing with an inherently disgusting stimulus (unconditioned stimulus; US). Research has shown that conditioned disgust responses are resistant to extinction which may have implications for disorders (i.e., contamination-based obsessive-compulsive disorder, specific phobias, and post-traumatic stress disorder) in which heightened disgust has been implicated. Importantly, extinction is the primary mechanism by which exposure therapies are thought to achieve symptom reduction for these disorders. Exposure therapies were originally modeled on fear extinction, whereas disgust extinction was largely overlooked until recently. Accordingly, differences in the degree to which learned disgust and fear can be attenuated via extinction learning remains unclear. The present investigation was a meta-analysis directly comparing the degree of extinction of conditioned disgust (n = 14) and conditioned fear (n = 14) in laboratory paradigms. Extinction was operationalized as the standardized mean difference (SMD) in evaluative ratings between the CS+ (the CS paired with the US) and CS- (the unpaired CS) after extinction training. Results of a subgroup analysis indicated that disgust (SMD = 0.52) was significantly more resistant to extinction than fear (SMD = 0.37). Additionally, a series of meta-regression analyses indicated that extinction was not influenced by important study characteristics (e.g., sex, age, number of conditioning and extinction trials). The findings suggest that extinction-based approaches may be less effective at attenuating learned disgust and research is needed to better optimize treatments for disgust-related disorders.

Child characteristic correlates of food rejection in preschool children: A narrative review

Dietary habits formed in early childhood are key for establishing a healthy diet later in life. Picky eating and food neophobia - the two main forms of food rejection in young children - form an important barricade to establishing such healthy habits. Understanding these types of food rejection is thus essential for promoting healthy eating behaviour in both children and adults. To this end, the present narrative review aims to provide an overview of food rejection research in preschool-aged children, focusing on recent advances in the cognitive literature. Specifically, we evaluate the link between children's cognitive development, chemosensory perception and affective evaluation of food, food knowledge, decision-making strategies, anxiety and disgust sensitivity, and food rejection behaviour. Longitudinal and experimental studies are necessary to establish how the relationships between food rejection and cognitive processes develop over time and to determine their causal directions.

Olfactory imagery as a retrieval method for autobiographical memories

INTRODUCTION

The retrieval of autobiographical memories is influenced by several factors, such as sensory modality and the emotional salience of memory cues. This study aimed at investigating the interaction between sensory modalities (olfaction, vision) and emotional dimensions (valence, arousal) of imagery cues, on the frequency, quality, and age distribution of the autobiographical memories (AMs) elicited.

METHOD

A total of 296 females (aged between 18 and 35 years) received one out of eight brief instructions for olfactory or visual imagery. The participants were asked to create a mental image with either high arousal/positive valence, high arousal/negative valence, low arousal/positive valence, or low arousal/negative valence (e.g., 'imagine an unpleasant and arousing odor/scene'); no specific stimulus was mentioned in the instruction.

RESULTS

The approach used elicited imagery with autobiographical content in the majority of participants (78%). In terms of frequency, odor imagery, compared to visual imagery, turned out to be more effective at retrieving either unpleasant memories associated with experiences in adulthood, or pleasant childhood memories. In terms of quality, the imagery was rated as less vivid in the olfactory compared to the visual condition (irrespective of valence and arousal of the imagery instruction). Visual imagery was associated with the experience of more diverse emotions (happiness, sadness, anxiety, anger) than odor imagery, which was related primarily with disgust and happiness.

CONCLUSION

Our findings indicate that nonspecific imagery induction is a useful approach in accessing AM.

IMPLICATION

This approach presents promising clinical applications, such as in working with autobiographical memory narratives in psychotherapy.

An Eye Tracking Study Examining the Role of Mating Strategies, Perceived Vulnerability to Disease, and Disgust in Attention to Pathogenic Cues

Disgust is an emotion that regulates disease avoidance and reduces the likelihood of pathogenic infections. Existing research suggests a bidirectional relationship between disgust and mating, where disgust inhibits sexual behavior and sexual behavior inhibits disgust. In the current study, we investigated the role of individual differences and mating motivations on visual attention to pathogenic cues. Participants (N = 103) were randomly assigned to a mating prime or control condition, and they were asked to view images of pathogenic cues (i.e., rotten food, exposed cuts, bodily fluids) paired with their non-pathogenic counterparts. The findings showed no effect of mating prime on visual attention to pathogenic stimuli; however, dispositional mating strategies (SOI-R) were associated with attention to pathogenic stimuli. Individuals with unrestricted sociosexual orientations viewed pathogenic stimuli longer. The findings demonstrate that dispositional mating orientation is associated with greater attention to disgusting images, a link between pathogens and mating orientation that warrants further exploration.

Pseudo-Contamination and Memory: Is There a Memory Advantage for Objects Touched by "Morphologically Deviant People"?

Memory plays an important role in the behavioral immune system (BIS; Schaller in Psychological Inquiry, 17(2), 96-101, 2016a), a proactive immune system whose ultimate function is to make organisms avoid sources of contamination. Indeed, it has been found that objects presented next to sick people are remembered better than objects shown next to healthy people-representing a contamination effect in memory. In the present studies, we investigated this memory effect in relation to "pseudo-contaminated" sources, that is to say, people exhibiting cues ultimately evoking the threat of contamination but objectively posing no such threat in terms of disease transmission. Common objects were shown next to photographs of people having three kinds of morphological deviations-obesity (study 1), scars and burns (study 2), strange eyes (study 3)-or no morphological deviation. Contrary to our expectations, we found that "pseudo-contaminated objects" were not remembered better than "non-contaminated objects," whereas discomfort ratings of the idea of touching the same objects were clearly higher with morphologically deviant people. Memory mechanisms do not seem to be mobilized by "pseudo-contamination" sources which are not directly related to infection risk.

Emotion schema effects on associative memory differ across emotion categories at the behavioural, physiological and neural level: Emotion schema effects on associative memory differs for disgust and fear

Previous behavioural and neuroimaging studies have consistently reported that memory is enhanced for associations congruent or incongruent with the structure of prior knowledge, termed as schemas. However, it remains unclear if similar effects arise with emotion-related associations, and whether they depend on the type of emotions. Here, we addressed this question using a novel face-word pair association paradigm combined with fMRI and eye-tracking techniques. In two independent studies, we demonstrated and replicated that both congruency with emotion schemas and emotion category interact to affect associative memory. Overall, memory retrieval was higher for faces from pairs congruent vs. incongruent with emotion schemas, paralleled by a greater recruitment of left inferior frontal gyrus (IFG) during successful encoding. However, emotion schema effects differed across two negative emotion categories. Disgust was remembered better than fear, and only disgust activated left IFG stronger during encoding of congruent vs. incongruent pairs, suggestive of deeper semantic processing for the associations. On the contrary, encoding of congruent fear vs. disgust-related pairs was accompanied with greater activity in right fusiform gyrus (FG), suggesting a stronger sensory processing of faces. In addition, successful memory formation for congruent disgust pairs was associated with a higher pupil dilation index related to sympathetic activation, longer gaze time on words compared to faces, and more gaze switches between paired words and faces. This was reversed for fear-related congruent pairs where the faces attracted longer gaze time (compared to words). Overall, our results provide converging evidence from behavioural, physiological, and neural measures to suggest that congruency with available emotion schemas influence memory associations in a similar manner to semantic schemas. However, these effects vary across distinct emotion categories, pointing to a differential role of semantic processing and visual attention processes in the modulation of memory by disgust and fear, respectively.

COVID-19 and Memory: A Novel Contamination Effect in Memory

The Behavioral Immune System (BIS, Schaller & Park, 2011) is a defense system whose function is to protect against pathogen exposure. Memory is an important component of this system (Fernandes et al., 2017). We investigated "contamination effects" in memory in relation to COVID-19. Photographs of everyday objects were shown to adults (N = 80) in the hands of either a healthy or a contagious person who had contracted SARS-CoV-2. "Contaminated objects" were recalled better than "non-contaminated objects" suggesting that a contamination effect in memory in humans is easily acquired in the absence of apparent visual cues of disease.

Sadness-associated eating styles and visual food cue reactivity: An eye-tracking investigation

BACKGROUND

Emotional eating has been associated with biases of attention and memory for visual food cues. This eye-tracking study investigated whether the tendency to overeat in response to sadness is associated with the inspection and recall of visual food cues.

METHOD

Participants (n = 115, mean age = 26 years, 70 females, 45 males) viewed images depicting food and non-food. We compared gaze duration, 'hyperscanning' parameters (fixation duration, saccadic angle, scan path length), and recall performance between different image categories (high-calorie, low-calorie food, non-food) and groups with different sadness-associated eating styles (increased, decreased, unchanged food consumption during states of sadness).

RESULTS

The group with sadness-related overeating reported a higher body mass index than the other groups, but neither displayed a visual attention bias nor memory bias for food cues. We observed a prolonged gaze duration for low-calorie food cues, which were rated as more appetizing than high-calorie cues. All participants recalled more food cues (low- and high-calorie) than non-food cues independent of gaze duration.

CONCLUSION

This study expanded previous research designs by groups that decrease vs. increase the amount eaten when feeling sad, and food/non-food images that were carefully matched for visual properties. Based on this approach, we were not able to show that self-disclosed sadness eating is associated with visual/memory biases for food images.

Effects of Self-Esteem on Self-Viewing: An Eye-Tracking Investigation on Mirror Gazing

While some people enjoy looking at their faces in the mirror, others experience emotional distress. Despite these individual differences concerning self-viewing in the mirror, systematic investigations on this topic have not been conducted so far. The present eye-tracking study examined whether personality traits (self-esteem, narcissism propensity, self-disgust) are associated with gaze behavior (gaze duration, fixation count) during free mirror viewing of one's face. Sixty-eight adults (mean age = 23.5 years; 39 females, 29 males) viewed their faces in the mirror and watched a video of an unknown person matched for gender and age (control condition) for 90 s each. The computed regression analysis showed that higher self-esteem was associated with a shorter gaze duration for both self-face and other-face. This effect may reflect a less critical evaluation of the faces.