Browsing by Author "Gokce, Ahu"

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The effects of knowledge evoking style and icon arrays on perceived risk and willingnes
(Kadir Has Üniversitesi, 2022) ÖZDEMİR, Deniz; Gökçe, Ahu; Gokce, Ahu
One of the most denoted cognitive errors in terms of judgments of risk probabilities was denominator neglect, and it happens when people pay more attention to numerators (subsets) and neglect the denominators (superordinate sets) during risk judgments, and it arises from the "gist-pop-out" of the numerator according to Fuzzy Trace Theory (FTT) and is defined as a class inclusion error. Previous studies which focus on visual demonstration of risk probabilities suggest that visuals help improve risk comprehension (reduce denominator neglect) and gist/verbatim knowledge extraction. Icon arrays are known to be proper visual communicators for displaying part-to-whole relationships via showing numerator and the denominator visually and utilized in reducing denominator neglect. The main objective of the thesis is to investigate risk evaluations under different risk scenarios (Experiment 1A: non-medical; Experiment 1B: medical) and to investigate the effects of visual aids, knowledge instruction types, and numeracy, health literacy on complex risk judgments, confidence levels and willingness to choose better outcomes within the overarching scope of FTT. The main hypotheses are as follows: Visual aids and instruction types will help mitigate denominator neglect and then in turn, improve risk evaluations, and higher numeracy will yield better risk evaluation accuracies. The findings demonstrated contrary results in terms of visual aids, which have been known for mitigating the effects of denominator neglect, the effects of visual aids were not replicated. Instruction types did not have the main effect on risk evaluations to help to reduce denominator neglect. Numeracy was the most prominent factor in risk accuracy, confidence in answers, and willingness. Health literacy did not show the main effect on willingness. Denominator neglect was found only in Experiment 1B.
Citation Count: 3
Exploring the Space-Calorie Association: Preliminary Evidence from Reaction Time Performance
(Univ Economics & Human Sciences Warsaw, 2021) Gökçe, Ahu; Gokce, Ahu
The present study was designed to investigate the representation of calorie levels in space. Previously an association between numerical magnitude and space has been established, namely, the Spatial Numerical Association of Response Codes (SNARC) effect. The spatial-numerical association reveals representation of smaller and larger numbers by the left and right sides, respectively. In addition, previous studies showed that spatial arrangement of foods in space affects the food selection behavior. In three experiments, the presence of an association between calorie magnitude and space was tested to understand how it could potentially affect food selection behavior. Reaction times were recorded to investigate the speed of information processing. In Experiment 1, locations of low and high calorie food stimuli were (in)congruent in terms of the space-calorie association. In Experiment 2, endogenous spatial cues were used to bias attention to investigate if this bias would lead to formation of the space-calorie association. Finally, Experiment 3 investigated whether green and red colors evoke approach or avoidance behavior and prevent formation of the space-calorie association. In all experiments, results revealed lack of an association between space and calorie, that is, presenting low/high calorie items on the left/right hemispace, respectively, did not modulate the processing speed.
Citation Count: 0
Exploring the spatial mental associations of distinct food types
(Academic Press Ltd- Elsevier Science Ltd, 2024) Gökçe, Ahu; Gokce, Ahu
Previous research explored the spatial representations of healthy low -calorie and unhealthy high -calorie food items, revealing an association of healthy low -calorie food with left and top sides, and unhealthy/high-calorie food with right and top sides. This association, namely side bias, was limited to these specific categories leaving the representations of healthy high -calorie and unhealthy low -calorie food categories yet to be explored. Present study was designed to examine the spatial representation of four food categories (unhealthy low -calorie, unhealthy high -calorie, healthy low -calorie, healthy high -calorie) using a computerized food placement task. In Experiment 1, participants placed four food items from different categories into eight locations. In Experiment 2, identical task was used with the addition of centrally presented anchor food item to investigate the mental representation of food items in relation to each other. The frequency of placing food items in specific spatial locations were measured. The results of Experiment 1 provided partial support for side bias. However, the use of anchor items in Experiment 2 provided compelling evidence for vertical side bias, demonstrating consistent pattern of placing healthy foods on the upper sides and unhealthy foods on the lower sides. In both experiments, real -life food choices were examined to investigate whether the high -calorie bias would be observed in actual food choice behavior. The results from both experiments indicated strong preference to select high -calorie foods, supporting high -calorie bias. Overall, this study extends the evidence on the spatial representations of distinct food categories.
Citation Count: 5
Inter-trial effects in priming of pop-out: Comparison of computational updating models
(Public Library Science, 2021) Gökçe, Ahu; Gokce, Ahu; Geyer, Thomas; Zinchenko, Artyom; Mueller, Hermann J.; Shi, Zhuanghua
In visual search tasks, repeating features or the position of the target results in faster response times. Such inter-trial 'priming' effects occur not just for repetitions from the immediately preceding trial but also from trials further back. A paradigm known to produce particularly long-lasting inter-trial effects-of the target-defining feature, target position, and response (feature)-is the 'priming of pop-out' (PoP) paradigm, which typically uses sparse search displays and random swapping across trials of target- and distractor-defining features. However, the mechanisms underlying these inter-trial effects are still not well understood. To address this, we applied a modeling framework combining an evidence accumulation (EA) model with different computational updating rules of the model parameters (i.e., the drift rate and starting point of EA) for different aspects of stimulus history, to data from a (previously published) PoP study that had revealed significant inter-trial effects from several trials back for repetitions of the target color, the target position, and (response-critical) target feature. By performing a systematic model comparison, we aimed to determine which EA model parameter and which updating rule for that parameter best accounts for each inter-trial effect and the associated n-back temporal profile. We found that, in general, our modeling framework could accurately predict the n-back temporal profiles. Further, target color- and position-based inter-trial effects were best understood as arising from redistribution of a limited-capacity weight resource which determines the EA rate. In contrast, response-based inter-trial effects were best explained by a bias of the starting point towards the response associated with a previous target; this bias appeared largely tied to the position of the target. These findings elucidate how our cognitive system continually tracks, and updates an internal predictive model of, a number of separable stimulus and response parameters in order to optimize task performance. Author summary In many perceptual tasks, performance is faster and more accurate when critical stimulus attributes are repeated from trial to trial compared to when they change. Priming of pop-out (PoP), visual search with sparse search displays and random swapping of the target feature between trials, is a paradigm in which such inter-trial effects can be traced back over several recent trial episodes. While many studies have explored PoP paradigms, the mechanisms underlying priming of the search-critical target feature, the target position, and the response-critical information are not yet fully understood. Here, we addressed this question by applying evidence accumulation (EA) decision models to the data from a previously published PoP study. The modeling framework combines evidence accumulation with Bayesian updating of the model parameters. Comparison of (> 1000) different combinations of decision models and updating rules revealed that the featural and positional priming effects were best explained by assuming that attentional weight resources are dynamically redistributed based on the recent history of target color and position, whereas response decisions are biased based on the recent history of the response-critical property of targets occuring at a particular (and nearby) position(s). These findings confirm that our cognitive system continually tracks, and updates an internal predictive model of, a number of separable stimulus and response parameters in order to optimize task performance.
Citation Count: 0
Visual processing of food stimuli: The impact of working memory load and color
(Springer, 2023) Gökçe, Ahu; Gokce, Ahu
Our environment is surrounded by appetizing food stimuli that contribute to an increase in health problems such as obesity and overweight. Understanding the cognitive factors underlying the processing of food stimuli can play an important role in health interventions. Recent studies showed that high-calorie food stimuli impair working memory (WM) task performance, and some individuals, such as restrained eaters, are more susceptible to this WM performance decrement. The present study investigated the effect of low and high WM load on the processing of food stimuli in restrained and unrestrained eaters. Using an n-back task, identical food (low and high calorie) and non-food (object) stimuli were presented in colored (Experiment 1A) or in grayscale (Experiment 1B) versions. Performance was assessed by reaction time (RT), d-prime, and response bias C variables. Results revealed differences in the different WM load conditions. While no effects were observed in the low load, higher WM load impaired task performance. Processing the food stimuli, compared to objects, led to longer RTs and decreased task performance, indicated by d prime and response bias, only when the stimuli were presented in color but not in grayscale. Though no difference was observed in restrained and unrestrained eaters, the role of WM load on the visual processing of the food stimuli remains to be further examined.