In dit onderzoek is gekeken naar de rol van kenmerken van ADHD bij de werking van stabiliteit en flexibiliteit bij jongvolwassenen (N = 121). Om dit verschil in kaart te brengen is er gebruik...Show moreIn dit onderzoek is gekeken naar de rol van kenmerken van ADHD bij de werking van stabiliteit en flexibiliteit bij jongvolwassenen (N = 121). Om dit verschil in kaart te brengen is er gebruik gemaakt van de Parity-magnitude task-switching test. Met behulp van deze taak wordt flexibiliteit gemeten in termen van switch costs en stabiliteit in termen van incongruence costs. Doordat in huidig onderzoek een neurotypische populatie bekeken is, zijn de participanten opgedeeld in twee groepen: een groep die hoog scoort op kenmerken van ADHD en een groep die laag scoort op kenmerken van ADHD. Hierbij zijn de kenmerken van ADHD gemeten aan de hand van een aantal vragen die gebaseerd zijn op de Nederlandstalige ADHD ratingscale. Vervolgens zijn deze twee groepen vergeleken door middel van een independent-samples t-test. Uit de resultaten is gebleken dat er geen significant verschil is in de scores op switch costs en incongruence costs tussen participanten met veel en weinig kenmerken van ADHD. Op basis van de totaalscore op de vragen met betrekking tot ADHD blijkt er dus geen effect over alle domeinen heen. Maar ook wanneer er wordt gekeken naar twee specifieke domeinen van ADHD, onoplettendheid en impulsiviteit, wordt er geen significant effect gevonden. Hoewel jongvolwassenen die hoog scoren op kenmerken van ADHD zowel minder flexibel als minder stabiel lijken dan jongvolwassenen die lager scoren op kenmerken van ADHD, blijkt dit verschil niet significant. Deze trend in de richting van de in dit onderzoek opgestelde hypotheses is nader onderzoek waard.Show less
ADHD is a well-known neurodevelopmental disorder that extends from childhood into adulthood for many individuals. Symptoms of ADHD can be categorized into three subtypes: hyperactivity, inattention...Show moreADHD is a well-known neurodevelopmental disorder that extends from childhood into adulthood for many individuals. Symptoms of ADHD can be categorized into three subtypes: hyperactivity, inattention, and impulsivity. Males typically exhibit more external symptoms, while females tend to display more internal symptoms, such as inattention. However, both genders are diagnosed using the same criteria, resulting in a higher rate of ADHD diagnosis among males. Our understanding of gender differences in the presentation of symptoms, particularly inattention, remains limited. However, exploring the concept of cognitive flexibility becomes relevant when examining inattention, as it encompasses the ability to adapt and shift one's thinking and behavior in response to changing circumstances or tasks. By considering cognitive flexibility, we can gain valuable insights into how inattention may impact individuals with ADHD and potentially contribute to gender differences in symptomatology. A total of 100 participants completed a computer-based task that assessed task-switching performance which measured reaction time and accuracy for switch cost and incongruent cost. A Multiple Regression Analysis was conducted to examine the relationships between gender, inattention, and task-switching performance. The results of the study did not yield statistically significant findings, indicating no substantial gender differences in task-switching performance and its association with inattention in individuals with ADHD. A few limitations of the study include a relatively small sample size and the possibility that females filled in the self- report questionnaire based on their presumption that they are less likely to have characteristics of ADHD. Future studies should focus on larger and more diverse samples to enhance the generalizability of the findings.Show less
Attention can be divided into stability versus flexibility. Switching between these two is needed for adaptive behavior. It requires blocking distractions from our current goals (stability), and...Show moreAttention can be divided into stability versus flexibility. Switching between these two is needed for adaptive behavior. It requires blocking distractions from our current goals (stability), and simultaneously switching between alternating demands of our environment (flexibility). People with autism are generally less flexible and therefore more stable in attention. (Cognitive) flexibility is an important predictor of the quality of life for people with autism. To add, most people with autism have trouble with social skills, though some research in non-clinical populations show a relationship between social skills and quality of life. Interventions for improving cognitive flexibility in people with autism mainly focus on improving social skills. Yet, there is little evidence for this relationship, especially in people with autism. Therefore, the hypothesis in this study was: “There is a positive relationship between social skills and cognitive flexibility. This relationship may be different across levels of autism traits”. The outcome will help to find out if social skills are indeed predictors of flexibility and stability in attention and thus, if interventions for improving cognitive flexibility in people with autism should focus on social problems. The participants in this study (N=101) responded to an autism questionnaire (which measures social problems and autism traits) and participated in a task switch experiment (to calculate the switch-cost). Results of the ANOVA show a non-significant relationship between social problems and switch-cost (F (1,90) = 3.569, p=0.062) (in reaction time). When looking at switch-cost on error rates however, there is a significant relationship between social problems and switch-cost (F (1,90) = 5.018, p = 0.028). People with lower social skills have a lower error rate than people with high social problems. The relationship between social problems and cognitive flexibility does not differ between levels of autism. The hypothesis is rejected. The results show a speed-accuracy tradeoff (longer reaction time means higher accuracy). This study shows that there is limited evidence on the relationship between social problems and cognitive flexibility in people who score high versus low on traits of autism. More research is needed into this topic to find out if this relationship is found in a larger population and in a clinical population. For now, interventions targeted at social problems alone do not seem to be sufficient for people with autism to improve their cognitive flexibility. This may ultimately help to establish more appropriate interventions.Show less
This study aimed to expand on previous research regarding the stability-flexibility dilemma and the adjustment of neural gain. Specifically, it was investigated if people lower their neural gain in...Show moreThis study aimed to expand on previous research regarding the stability-flexibility dilemma and the adjustment of neural gain. Specifically, it was investigated if people lower their neural gain in response to a short CSI. Previous research showed that people can adjust their neural gain based on the demand for flexibility. Specifically, lower neural gain would facilitate flexibility, but at the cost of stability. In addition, the relation between ADHD and neural gain was studied. Participants were asked to take part in a task-switching experiment in which they had to classify digits either based on parity or magnitude. Herein, the CSI duration was manipulated. Afterwards, a computational model estimated the neural gain values per condition. Participants were also asked to fill out an ADHD questionnaire. The final number of participants was 60 aged between 18 and 30. The results showed that the participants had higher switch costs and higher incongruency costs when the time to prepare was short. In addition, it was found that the participants lowered their neural gain in response to a short preparation time. Contradictory to our expectations, no relation was found between ADHD and neural gain adjustment. Together, the behavioral results and the neural gain analysis show that while lowering gain facilitates switching and thus flexibility, it also reduces focus and thus stability. For future research, it is suggested to replicate the study in a controlled environment and specifically regarding ADHD to either use a clinical sample or additional assessment tools, such as eye-tracking.Show less
Neural gain is the mechanism underlying the stability/flexibility trade-off, which is fundamental for goal-directed yet adaptive behavior. Inspired by the development of a computational model that...Show moreNeural gain is the mechanism underlying the stability/flexibility trade-off, which is fundamental for goal-directed yet adaptive behavior. Inspired by the development of a computational model that estimates gain, we assessed whether people rationally modulate gain to demands for stability and flexibility. We designed two task-switch digit-classification experiments with 60 participants each, in which we manipulated the proportion incongruency (PI) in experiment one and cue-to-stimulus interval (CSI) in experiment two. Our results indicated that PI manipulation did not significantly affect gain, yet incongruency costs and switch costs demonstrated an increase in stability in response to high PI. CSI manipulation significantly affected both gain and incongruency costs, demonstrating increased flexibility in response to a short preparation time. Furthermore, we used questionnaires to assess participants' ASD and ADHD trait scores and tested whether these predicted biases in gain and/or impairments in gain modulation. Despite the lack of conclusive findings, this study offers insight in the relation between ASD and ADHD and neural gain. More studies that overcome our limitations may discover the impairments in neurocognitive mechanisms underlying psychological disorders and inform treatment. Altogether, our results indicate that people rationally adapt to demands for stability and flexibility following an antagonistic trade-off. Therefore, this study contributes to the research on neuromodulation and adds to the general understanding of attention. Our findings may also help to inform applied research on the benefits and drawbacks of stability and flexibility in the workplace. Thereby, managers could be made aware of the number of tasks assigned to their employees and whether the demand to switch between them is proportional to their difficulty.Show less
Cognitive stability and flexibility are a continuous trade-off. To exert stable task focus, humans need deeper attractor states and higher neural gain to shield distractors. For cognitive...Show moreCognitive stability and flexibility are a continuous trade-off. To exert stable task focus, humans need deeper attractor states and higher neural gain to shield distractors. For cognitive flexibility, shallower attractor states and lower gain are beneficial to switch tasks quicker. Individuals with attention deficit hyperactivity disorder (ADHD) seem to have problems adjusting stability and flexibility. This study examined the influence of two contextual demands on a computational estimate of neural gain. First, we expected people to increase neural gain with a higher proportion of incongruent stimuli to facilitate focus on the task relevant stimulus dimension. Second, we hypothesised that participants decrease neural gain when presented a short versus long cue to stimulus interval (CSI) to allow faster switching. Generally, we expected individuals with higher levels of ADHD to have lower gain and more difficulties adjusting it. These hypotheses were tested separately with a cued task-switch paradigm online. First, the proportion of incongruent stimuli was manipulated (75% versus 25%). With a high proportion incongruency, participants lowered their incongruency cost and increased switch cost. However, they did not change gain. Second, the CSI length was varied (300ms versus 1000ms). With a short CSI, people lowered gain and made more errors on incongruent switch trials. We found partial support that individuals with self-reported ADHD have less optimal gain. We recommend that individuals work in environments matching their demands. If a task demands focus, one should not work in a flexibility demanding space. When focus and accuracy are required, sufficient time must be given.Show less
