The placebo effect is a learning phenomenon strongly associated with cognitive mechanisms. Placebo conditioning, particularly, combines threat learning with verbal instructions and expectations....Show moreThe placebo effect is a learning phenomenon strongly associated with cognitive mechanisms. Placebo conditioning, particularly, combines threat learning with verbal instructions and expectations. These processes are central in shaping subjective pain experience and threat-related episodic memory. However, the specific influence of placebo conditioning on episodic memory accuracy and generalization is not yet known. It is hypothesized that threat associations enhance memory recognition and generalization by increasing arousal; thus, introducing a placebo manipulation in a threat conditioning paradigm might impair memory recognition by decreasing arousal. This can offer insights into the broader clinical implications of placebo, as threat-related responses and memory bias are hallmarks of anxiety disorders. This study used a within subjects experimental design with 72 healthy participants undergoing a pain calibration/placebo conditioning procedure, a Pavlovian threat conditioning paradigm with a placebo manipulation using pictures, and a memory test. Participants completed pain, mnemonic, and confidence ratings. We predicted that the placebo condition would correlate with lower subjective pain experience, and the CS+ condition with increased recognition memory and generalization compared to the CS+ placebo and CS- conditions. Although the placebo manipulation was successful, it did not significantly affect memory recognition, generalization or discrimination. There were indications that the CS+ condition correlated with higher recognition compared to the CS- condition, but these should be interpreted with caution. We conclude that the placebo manipulation’s subtle effects may not have reached the necessary threshold of arousal and motivational engagement required to alter memory processes. Limitations and suggestions for future research are discussed.Show less
Fatigue and memory are modulated by the neurotransmitter dopamine. This study aimed to explore the modulating effects of dopamine on mental fatigue and how this relationship affects memory...Show moreFatigue and memory are modulated by the neurotransmitter dopamine. This study aimed to explore the modulating effects of dopamine on mental fatigue and how this relationship affects memory performance. We hypothesised that the administration of tyrosine would lead to lower reported mental fatigue levels relative to placebo. Additionally, we hypothesised that participants who reported lower levels of mental fatigue would obtain higher memory scores in comparison to those who reported high levels of mental fatigue. 30 participants were tested on a word recall and word recognition task. Mental fatigue levels were measured using the multidimensional fatigue inventory (MFI). Our results showed no significant effect of treatment on mental fatigue. However, we found that mental fatigue did impair recognition performance in both immediate and delayed conditions, though inconsistently across sessions. The effect of time on memory was found; performance in both recognition and recall tasks deteriorated after 24 hours, regardless of treatment or mental fatigue. We discuss several study limitations, including a small, gender-imbalanced sample size, subjective mental fatigue reports and our tyrosine administration approach. We encourage further research on the topic as it is highly relevant for clinical populations who experience persistent fatigue symptoms, as well as healthy populations who regularly engage in cognitively demanding tasks.Show less
Landmarks, opvallende objecten in omgevingen, kunnen ten behoeve van het onthouden van een route worden onthouden. Een van de manieren om dit geheugenproces in te delen, is door onderscheid te...Show moreLandmarks, opvallende objecten in omgevingen, kunnen ten behoeve van het onthouden van een route worden onthouden. Een van de manieren om dit geheugenproces in te delen, is door onderscheid te maken tussen herkenning, het hebben onthouden zonder context, waarbij ook de context is onthouden. Eerder onderzoek heeft aangetoond dat stress en trait anxiety invloed hebben op herkenning en herinnering, echter is deze invloed nog niet getest bij landmarks. In de huidige studie werd dit onderzocht door 37 participanten een exploratietaak uit te laten voeren in een virtuele omgeving waarin landmarks waren geplaatst. De helft van de participanten kreeg van tevoren stress opgewekt door een zingtaak uit te voeren in de Sing-a-Song Stress Test. Na de exploratietaak werd middels de Remember / Know paradigm getest in hoeverre landmarks herkend en herinnerd waren en werd de Stait-Trait Anxiety Inventory afgenomen. De Sing-a-Song Stress Test bleek een effectieve manipulatie voor het induceren van verhoogde stressniveaus. Er werd geen verschil gevonden tussen de hoge- en lage-stressconditie in herkenning en herinnering van landmarks, als ook geen verschil in herkenning en herinnering tussen lage en hoge trait anxiety. Vervolgonderzoek wordt aanbevolen via fMRI hippocampusactiviteit te meten gedurende het Remember / Know paradigm, om meer grip te krijgen op het al dan niet onafhankelijk optreden van herkenning en herinnering onder invloed van stress en trait anxiety. Daarnaast wordt aangeraden te onderzoeken of meer opvallende landmarks, door bijvoorbeeld emotionele waarde, beter worden herkend en/of herinnerd onder stress dan wel trait anxiety.Show less
Landmarks, opvallende objecten in omgevingen, kunnen ten behoeve van het onthouden van een route worden onthouden. Een van de manieren om dit geheugenproces in te delen, is door onderscheid te...Show moreLandmarks, opvallende objecten in omgevingen, kunnen ten behoeve van het onthouden van een route worden onthouden. Een van de manieren om dit geheugenproces in te delen, is door onderscheid te maken tussen herkenning, het hebben onthouden zonder context, waarbij ook de context is onthouden. Eerder onderzoek heeft aangetoond dat stress en trait anxiety invloed hebben op herkenning en herinnering, echter is deze invloed nog niet getest bij landmarks. In de huidige studie werd dit onderzocht door 37 participanten een exploratietaak uit te laten voeren in een virtuele omgeving waarin landmarks waren geplaatst. De helft van de participanten kreeg van tevoren stress opgewekt door een zingtaak uit te voeren in de Sing-a-Song Stress Test. Na de exploratietaak werd middels de Remember / Know paradigm getest in hoeverre landmarks herkend en herinnerd waren en werd de Stait-Trait Anxiety Inventory afgenomen. De Sing-a-Song Stress Test bleek een effectieve manipulatie voor het induceren van verhoogde stressniveaus. Er werd geen verschil gevonden tussen de hoge- en lage-stressconditie in herkenning en herinnering van landmarks, als ook geen verschil in herkenning en herinnering tussen lage en hoge trait anxiety. Vervolgonderzoek wordt aanbevolen via fMRI hippocampusactiviteit te meten gedurende het Remember / Know paradigm, om meer grip te krijgen op het al dan niet onafhankelijk optreden van herkenning en herinnering onder invloed van stress en trait anxiety. Daarnaast wordt aangeraden te onderzoeken of meer opvallende landmarks, door bijvoorbeeld emotionele waarde, beter worden herkend en/of herinnerd onder stress dan wel trait anxiety.Show less
Abstract The connection between hippocampus-dependent learning and the novelty of a previously experienced environment has been investigated through animal research for a longer time. In rodents,...Show moreAbstract The connection between hippocampus-dependent learning and the novelty of a previously experienced environment has been investigated through animal research for a longer time. In rodents, it was found that they showed theta band power while encoding memories, during the initiation of explorative movements. But there has been a scarcity of research looking at these connections in humans. This study aims to investigate the associations between memory types (landmark memory, as well as recall and recognition on an unrelated word learning task) and familiarity of the environment as well as theta bands in the brain. Thirteen men and women took part in this three-day EEG study. On the first day, participant first explored one environment during the exploration phase and later explored another time an environment that was either the same as before (familiar) or a new (novel) environment. On day two, they were then exposed to a new environment (novel condition), if they have seen two times the same environment on day 1, or to an environment that they have already seen on day 1(familiar condition) if they saw two different environments on day 1. On both days they had to complete a landmark memory, recall, and recognition task. On days two and three the participants did a delayed recall and recognition task. The EEG was used during all tasks on days one and two. The results showed that landmark memory was not affected by the novelty of the environment (p = .812). Word recall was also not affected by the novelty of the environment (p = .400), and neither was recognition (p = .227). There was more theta band power during the novel environment exploration than during the familiar environment measured (p < .001). Theta bands were not correlated with recall (p = .783) or landmark memory (p = .231). This study had a small sample, no cultural diversity, and a strict theta band inclusion criterion. Because of that, the results should be interpreted with caution and further studies should include a bigger sample, with different cultures, and perhaps a wider theta frequency spectrum. This study could help closing the gap between animal and human research, as well as create tools to assist people with learning difficulties.Show less
Research master thesis | Developmental Psychopathology in Education and Child Studies (research) (MSc)
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Affective empathy and emotion recognition deficits are hypothesized to underlie impaired social interaction in children exhibiting antisocial behaviour. However, few studies have examined the...Show moreAffective empathy and emotion recognition deficits are hypothesized to underlie impaired social interaction in children exhibiting antisocial behaviour. However, few studies have examined the possible emotion recognition deficits and affective empathy. This study compared facial affect recognition, vocal emotion recognition and affective empathy of children at risk for criminal behaviour to that of normally developing children. It was expected that children at risk of criminal behaviour had impaired emotion recognition and affective empathy, and that emotion recognition deficits and affective empathy were partially related to each other. The high-risk children were recruited through and intervention project connected to several municipalities in the Netherlands, focusing on the underage siblings or children of delinquents and those exhibiting antisocial and disruptive behaviour according to teachers. Facial and vocal recognition of happy, sad, angry and fearful emotions were respectively measured with the Facial Emotion Recognition (FER) test and the Prosody test of the Amsterdam Neuropsychological Tasks (ANT). Affective empathy was assessed by recording heart rate (HR) while showing video clips with neutral and emotional content (happiness, fear, pain and sadness). It was found that the high-risk group were less able to recognize fear and sadness in still-faces, and had an overall lower percentage corrected when recognizing emotions from voices, compared to healthy controls. The high-risk group also showed reduced HR to pain and fear, but this was not related to emotion recognition deficits. These findings suggest that children that engage in antisocial behaviour have impaired emotion recognition and reduced affective empathy, but that lack of empathy cannot solely be explained by a less ability to recognize emotions.Show less
Recognition has been established as a right in political theory, with the argument that it is connected to justice since misrecognition can inflict injury to one’s identity. Meanwhile in political...Show moreRecognition has been established as a right in political theory, with the argument that it is connected to justice since misrecognition can inflict injury to one’s identity. Meanwhile in political theory there is debate about whether recognition drives out redistribution or that redistribution will eventually follow from recognition, however empirical evidence is scarce. One cross-national analysis by Banting et al. (2006) analysed the effect of multicultural recognition policies on redistribution, but concluded that there was no correlation between recognition and redistribution. Nancy Fraser (2000) made a distinction between two different kinds of recognition politics: status and identity politics. She claims that the latter drives out redistribution, while status politics does not. This thesis looks at whether the difference between identity politics and status politics can explain why recognition and redistribution are not correlated in the study by Banting et al., and if identity recognition policies indeed drive out redistribution. The performed cross-national statistical analysis does not support the hypothesis that multicultural identity policies drive out redistribution. However the data does hint in this direction.Show less
The killings of Armenians by the government of the Young Turks in the Ottoman Empire between 1915 and 1923 fit all the given definitions of genocide. However, many states from the international...Show moreThe killings of Armenians by the government of the Young Turks in the Ottoman Empire between 1915 and 1923 fit all the given definitions of genocide. However, many states from the international community have not recognized the Armenian genocide, and few have explicitly expressed recognition. This paper will analyze the revisionary processes within two countries (Argentina and Spain) that have come to different outcomes (recognition and non-recognition, respectively) and will provide preliminary evidence in response to this main puzzle: “Why has Argentina recognized the Armenian genocide, while Spain has not?” This research´s main argument revolves around the concept of realpolitik, specifically around the interests and powers that this paper will demonstrate to have a direct relation to the outcomes of the revisionary processes of the Armenian Genocide by different states.Show less
In this thesis I defend the recent ruling of the Hoge Raad that determined that free speech can be restricted when statements are contrary to democratic principles. Equal respect for dignity is one...Show moreIn this thesis I defend the recent ruling of the Hoge Raad that determined that free speech can be restricted when statements are contrary to democratic principles. Equal respect for dignity is one of those important democratic principles, therefore I focus on the principle dignity and its relation to freedom of speech. Dignity commands recognition respect which means recognizing the equal authority and accountability of people. I argue that statements without any free speech interests can be restricted. Statements that contain valuable and harmful aspects can be restricted when the harm upstages the value. This is when the statement harms the essence of dignity and negates the relational aspect of freedom of speech.Show less
