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Ivo Stuldreher

3 records found

Authored

A Review on the Role of Affective Stimuli in Event-Related Frontal Alpha Asymmetry

Review (2022) - Priya Sabu, Priya Sabu, Ivo Stuldreher, Daisuke Kaneko, Anne-Marie Brouwer

Frontal alpha asymmetry refers to the difference between the right and left alpha activity over the frontal brain region. Increased activity in the left hemisphere has been linked to approach motivation and increased activity in the right hemisphere has been linked to avoidance or withdrawal. However, research on alpha asymmetry is diverse and has shown mixed results, which may partly be explained by the potency of the used stimuli to emotionally and motivationally engage participants. This review gives an overview of the types of affective stimuli utilized with the aim to identify which stimuli elicit a strong approach-avoidance effect in an affective context. We hope this contributes to better understanding of what is reflected by alpha asymmetry, and in what circumstances it may be an informative marker of emotional state. We systematically searched the literature for studies exploring event-related frontal alpha asymmetry in affective contexts. The search resulted in 61 papers, which were categorized in five stimulus categories that were expected to differ in their potency to engage participants: images & sounds, videos, real cues, games and other tasks. Studies were viewed with respect to the potency of the stimuli to evoke significant approach-avoidance effects on their own and in interaction with participant characteristics or condition. As expected, passively perceived stimuli that are multimodal or realistic, seem more potent to elicit alpha asymmetry than unimodal stimuli. Games, and other stimuli with a strong task-based component were expected to be relatively engaging but approach-avoidance effects did not seem to be much clearer than the studies using perception of videos and real cues. While multiple factors besides stimulus characteristics determine alpha asymmetry, and we did not identify a type of affective stimulus that induces alpha asymmetry highly consistently, our results indicate that strongly engaging, salient and/or personally relevant stimuli are important to induce an approach-avoidance effect.

@en

Analytic approaches for the combination of autonomic and neural activity in the assessment of physiological synchrony

Conference paper (2019) - Ivo Stuldreher, J.C.F. de Winter, Nattapong Thammasan, Anne-Marie Brouwer

Physiological synchrony (PS) refers to the similarity in physiological responses of two or more individuals and may be an informative source of information in the field of affective computing. Up to now, PS has been assessed using either autonomic measures or neural measures. Whi ...

Contributed

Assessing the effects of social pressure on implicit and explicit measures of food experience

Master thesis (2022) - P. Sabu, D. Dodou, J.C.F. de Winter, Ivo Stuldreher, Anne-Marie Brouwer, Daisuke Kaneko

Food-evoked emotions are essential for consumers’ food choice prediction and market success. These food-evoked emotions are predominantly measured by explicit self-reports. Yet in certain situations such as social desirability, explicit measures might not reflect one’s true emotional experience. The additional use of implicit measures can be beneficial.
The present study investigated whether social pressure truly changes food experience by means of explicit and implicit measures of food liking. Explicit ratings were EmojiGrid valence and arousal ratings in response to familiar and unfamiliar food images and soups. Implicit measures consisted of frontal alpha asymmetry during pre-selected scenes of a movie about Japanese soy sauce as well as sip size of the soup. Explicit and implicit measures were compared to assess the effect of social pressure on Japanese and Dutch food liking.
No differences between the social pressure (n = 19) and control group (n = 23) emerged in any of the measures. Explicit ratings and the implicit measure sip size, but not frontal alpha asymmetry during watching the movie, showed differences between participants with high and low food neophobia. The insensitivity of frontal alpha asymmetry to food neophobia groups could be explained by the movie scenes showing rather familiar foods. BMI grouping similarly showed no effect on frontal alpha asymmetry during watching the movie, but also explicit measures were unaffected.
It was concluded that the social pressure intervention itself was not effective in inducing increased liking of Japanese food, since there was no increase in neither reported liking nor ‘true’ liking. Additional ways to induce social pressure, e.g., observation during rating, are advisable if the study was repeated. Furthermore, the use of stronger stimuli to induce approach or avoidance motivation as measured by frontal alpha asymmetry, is recommended. It cannot be concluded whether social pressure truly affects food experience.