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Multisensory integration through auditory and somatosensory mismatch negativity
In everyday life, we rely on our sensory organs to gather information from the environment to take evolutionarily necessary actions. The most crucial of these information comes from the novelty in the stimulus we face. While a pattern of the same sensory cue repeats, it usually does not pose a danger to the self. However, a change in this pattern could mean a novelty in the environment that is needed to be processed to gain enough information about this new situation. In this aspect, mammal brains have a unique mechanism of mismatch responses which are elicited after a certain deviancy appears in the pattern of the stimuli. These responses have been observed with electroencephalography (EEG) in auditory, somatosensory and visual modalities as mismatch negativity (MMN). However, the effect of multisensory integration has not been studied in audiotactile mismatch responses. In this study, I examined the audiotactile novelty detection mechanisms using EEG. I found that, in the presence of auditory deviance, mismatch negativity (MMN) usually is within the auditory MMN range. Also, in presence of auditory standard stimuli, somatosensory mismatch negativity tends to be at the more negative side resembling its auditory counterpart.
The effect of parametric physical attributes of 2d shapes on shape recall and on classifiying shapes as natural or unnatural
Previous research in the visual perception domain has shown the interaction between some attributes of shapes and how humans perceive them differently when those attributes are changing. However we felt there are not enough resources in the literature regarding the geometrical parameters of 2D shapes. Also about the naturalness classification in visual perception, there are studies focusing on the natural scenes but again, the knowledge of the naturalness perception according to the 2D geometrical shape parameters is pretty limited. In this study we aimed at combining these two subdomains and providing quantitative findings about how the geometrical parameters like edge count, concavity, naturalness and uniformity are affecting the memory performance and naturalness classification for a shape. We designed a behavioural experiment to test different shapes with different values of those parameters and presented these shapes to participants in a recall task and a naturalness survey. Then we ran some correlation analysis between those values and memory performance and naturalness rating. We found out that edge count and concavity significantly affects the memory performance for a shape. Another finding was that our judgement of a shape being natural or artificial is affected by the edge count, concavity level and roundness level of a shape. Lastly, we observed that the memory performance is worse for the shapes that are rated as natural.
Behavioral correlates of perceptual confidence in a motion tracking paradigm
Perceiving motion of objects around the environment requires understanding of several features of motion such as direction, speed, and density. In this process, we rely both on the sensory input and our confidence level regarding our decision about the features of motion. However, the signal reaching our senses is not always entirely intact hence it includes noise. In this context, signal-to-noise ratio affects both motion detection and perceptual confidence. In this study, I examined the effect of signal-to-noise ratio on motion detection accuracy and perceptual confidence with the Continuous Perceptual Task Paradigm (CPR). Participants were asked to hit a target with a joystick that randomly appeared on the outer diameter of a circular random dot cinematogram (RDC). In addition, individuals were prepared for the main experiment by applying the Reaction Time (RT) task and 4 Alternative Forced Choice (4AFC) tasks before the main experiment. I found out that radial joystick accuracy increased with increasing signal-to-noise ratio. Also, joystick strain increased with increasing signal-to-noise ratio. These results indicate that perceptual confidence and motion detection accuracy rely on the availability of the information about the direction of motion.
Meditasyonun, bir duygu düzenleme stratejisi olan kopma (detachment) üzerindeki etkisi
Meditation is a highly practiced technique to create emotional balance, cognitive enhancement, and general well-being. The aim of this study is to investigate the benefits of meditation on attentional stability and emotion regulation. We created a psychophysics task consist of number counting Stroop task and played emotionally triggering sounds on the headphones during the experiment. We intended to create cognitive load by asking the participants to respond to the tasks by congruent or incongruent according to the condition of the visuals in 1 second, while the affective sounds would distract their attention. The study consisted of 8 conditions as the combination of 2 visual conditions (congruent and incongruent) and 4 auditory conditions (arousal high- arousal low- pleasure high- pleasure low). We expected the group consisted of meditation practitioners to respond with higher accuracy rate (percentage) in lower reaction time (ms) compared to the meditation naïve control group. During the experiment, we recorded the electrophysiological activations of the participants and expected lower beta and gamma oscillations in the meditation group's frontal and temporal regions. The behavioral results fulfilled our expectations since the meditation group performed with higher accuracy rate and lower reaction time. Although the analysis of behavioral results showed that congruency had significant effect, there were no effect of affective sounds on participants' accuracy rate and reaction time. On the other hand, electrophysiological results revealed that both the congruency and sound type affected the participants', and in group comparison, the meditation group generated lower gamma oscillations both in frontal region which is associated with cognitive control and temporal region where the emotion processing occur. Our results indicated that meditation provides higher attentional stability and increase emotion regulation skills especially in neural level.
The effect of harmonic and inharmonic sound on roughness perception in the tongue and fingertip
Multisensory integration refers to the integration of multiple senses by the nervous system. Auditory and tactile features are closely related senses as can be understood from the fact that adjectives such as soft, rough, and warm are used commonly for auditory and tactile features. Previous studies show that different characteristics of auditory cues may cause perceiving tactile cues as smoother or rougher. In this thesis, the effect of harmonic and inharmonic sounds on tactile roughness perception was studied by tongue and fingertip while they are presented simultaneously. We expected the participants to perceive surfaces rougher while they listen to inharmonic sounds due to auditory roughness. We presented simultaneous and sequential harmonic and inharmonic sounds with three sandpapers with different roughness levels (P100, P120, P150 grit numbers) to the participants. Results suggest that participants perceive sandpaper with the P120 grit number rougher while they listen to simultaneous inharmonic sounds than simultaneous harmonic sounds by their fingertip in two different experiments. However, any effect of harmonicity on the sandpapers with P100 and P150 grit numbers was not observed for fingertip. In addition to this, there is no effect of harmonic and inharmonic sounds on roughness perception for tongue. We suggest that auditory roughness may enhance tactile roughness perception for surfaces with particular roughness levels for fingertip, possibly when there is an ambiguity in roughness estimation.
Investigating the role of position and orientation in shape perception using visual crowding and contour integration
The deterioration or reduction of the perception of the target due to the nearby objects is called the visual crowding effect. Crowding can occur as a result of similarity and proximity. These two conditions also result in contour perception with high congruency between the elements. Contour perception is the unitary perception of congruent individual items. Although many physical aspects can result in crowding and contour perception, congruencies of orientation and position are the two primary indicators. In this experiment, four positional configurations, namely left-circle, right-circle, left-diagonal and right-diagonal, of the target and flankers were used. According to these positional configurations, congruent and incongruent orientations were created. We hypothesized that crowding and contour should have an exhibitory effect on each other. In the previous studies, target and contour objects were separated from each other. In this study, the target was also a part of the contour pattern. This allowed us to observe the interaction of crowding and contour in the same arrangement. The task was a simple orientation discrimination task between two targets. Another hypothesis was that low-level shapes' contour perception should occur even with three objects in the scene. The accuracy rates (percentage) and reaction times (ms) were compared as outcome variables. The results indicated that contour and crowding are two concepts that cannot co-exist based on the accuracy results. Also, the analysis of the accuracy rates confirmed that the three objects were enough to create simple linear shapes but not circular shapes.
Preferences, timing, and limitations during reasoning: A dual process approach
How are reasoning processes shaped by the heuristic system and analytic system? In the present study, we were focused on how heuristics and analytical thinking affect reasoning. According to dual-process theories, reasoning consists of two distinct modes of processing: System 1 and System 2. System 1 generates responses that are automatic, fast, and intuitive. This system does not need working memory resources. The other system is reflective. Characteristics of this system are deliberative, slow, and conscious. System 2 depends on working memory capacity. Therefore, system 2 needs working memory resources. In the present study, the experimental design was as follows: All participants performed randomly distributed modified version of the bat and ball problems and the syllogistic reasoning problems while they kept memory load in mind and had a time limit in the initial response stage. Then the questions were asked again without memory load and deadline. Both tasks consist of conflict (experiment questions) and no-conflict (control questions) questions. Whereas participants chose among four options in a modified version of the bat and ball problems, they chose between yes and no, considering two premises and a conclusion in the syllogistic reasoning problems. A two-response paradigm was applied. The problems were asked twice. In the first presentation of the problems, we occupied the participant's working memory with a dual task procedure and time pressure. We replicated the common implication of system 1 with fast response and system 2 with slow thinking.
Examining the role of eye movements in facial expression and emotional intensity recognition via machine learning
Recognition and classification of emotional face expressions is one of the most advanced abilities of humans. Many studies have investigated recognition processes and scanning strategies for different facial expressions but there is still no consensus on a particular scanning pattern for emotion types. Most of the previous studies also did not include the level of emotional intensity of facial expressions. The aim of this study is to investigate which eye movement parameters are important for emotional expression recognition and emotional intensity recognition processes. Eye movements provide important clues about face scanning strategies. Therefore, we examined the eye movements of 60 participants and fed machine learning models with eye tracking data. Neutral, surprised, sad, happy, and fearful facial expressions were presented to the participants with 0%, 25%, %50, %75, and %100 emotional intensity. Half of the participants were asked to classify the emotion type and half of them were asked to rate the intensity level of the emotion. Total number of fixations, pupil size and number of fixations on areas of interest (AOIs: eyes, nose and mouth) were collected for eye tracking analysis. Results showed that the fixation number on facial expressions decreased as the intensity of the expression increased. It was also found that participants fixated most to the eyes and least to the mouth regardless of the task. There was no difference between fixation numbers to eyes and nose during intensity recognition tasks for all emotion types. However, the fixation number towards the eye, nose and mouth differed between emotion types during the emotion recognition task. Higher emotional intensity resulted in less fixations in the mouth area. Analysis of pupillary response showed that fearful faces resulted in larger pupil size compared to all other expressions during the emotion recognition task but this difference was not evident during the intensity recognition task. Data collected from the eye tracking device has also been implemented in Random Forest (RF), Decision Tree and k-Nearest Neighbors (k-NN) models. All models achieved an accuracy rate at above chance level for both emotion classification and intensity classification. The highest accuracy rate was achieved with the RF method. The model was able to classify emotion types with an average accuracy of 85.8% for emotion recognition task and with an average accuracy of 89.2% for intensity recognition task when implemented with fixation point of gaze, fixation duration and pupil size. Emotion and intensity classification remained similar for the intensity recognition task with the same parameters. Effect of task, emotion type and intensity level were observed for pupil size and fixation numbers in the eye tracking analysis. However, the task did not affect the classification performance of the model. Also, intensity level of expressions or emotion type of an intensity level did not affect machine's performance as well. We interpreted these results as scanning strategies implemented by viewers while reading emotional expressions with different intensities. Results of the current study further discussed possible application areas.
Image to music: Cross-modal melody generation through image captioning
Advances in machine learning in recent years have also been seen in computationally creative systems. Interest in machine-generated artifacts paved a way for creative models to evolve as such. But the earlier methods mostly explored a one-domain approach and cross-modal learning has stayed relatively unexplored. Thus, the direct mapping between modalities for cross-modal creative models is not fully explored. This work proposes a novel methodology for generating symbolic music through images by directly mapping their features. A CNN encoder and deep-stacked LSTM decoder are the base models as the proposed method uses the image captioning approach to map the two domains' features. The generated music is evaluated quantitatively by using a custom genre classification model and BLEU scores calculations. The qualitative evaluation involves a melody listening test with human evaluators. The results show that the proposed method works well for music generation.
Cognitive biases and social cognition among people with psychotic-like experiences: Do jumping to conclusions bias and bias against disconfirmatory evidence play a role in social judgements?
Cognitive biases such as Jumping to Conclusions (JTC) and Bias Against Disconfirmatory Evidence (BADE) have been implicated in the delusion formation and maintenance. In line with the continuum approaches to psychosis, such biases have been observed not just in clinical populations but also in otherwise healthy individuals with psychotic-like experiences. Current study aimed to assess JTC and BADE biases in a community sample with a novel paradigm. The results of the current study showed that a tendency to arrive hasty decisions and belief inflexibility in the face of new information might be present in people with psychosis proneness in their daily interactions.
The influence of community size on constituent order: A comparison between emerging and conventionalized sign languages
The current study examines the effect of community size on constituent order by comparing conventionalized sign languages (TID and LIBRAS) and emerging sing languages (CTSL and CENA) from two different countries. When the relevant literature is examined, it is observed that languages that emerge in communities with larger populations tend to have a more uniform structure, while languages that emerge in smaller and closed-knit communities exhibit greater diversity regarding their constituent order. Data was collected through an elicitation task comprised of 30 video short video clips containing sentences with intransitive, transitive (reversible vs. irreversible events), and ditransitive structures. Significant relationships were found between community size and constituent order, revealing that conventionalized sign languages presented more uniform word orders in intransitive and ditransitive structures and transitive structures with irreversible events, whereas no significant relationship was detected for reversible events. The study contributes to the existing literature by demonstrating that languages from larger communities rely on commonly used constituent orders to describe events; in contrast, languages from smaller communities produce more uncommon constituent orders. The current study has practical implications for the relationship between sign languages in different stages of development and constituent order preferences, highlighting the developmental phases of language emergence and evolution.
On the universality of cognitive biases in natural language:The case of noun phrase internal ordering
The present study experimentally investigates the order of NP-internal modifiers in gesture modality as practiced by Turkish speaking participants in an attempt to understand the natural order within NPs crosslinguistically, whether the participants' preferences reflect a homomorphism bias, and whether their preferences are influenced by their native language. For these purposes, Turkish-speaking participants (N=44) randomly assigned to two conditions where access to their native language was suppressed in the first block (suppression-first condition) or where access to their native language was suppressed in the second block (no-suppression-first condition). Under both conditions, the participants were asked to improvise gestures to describe visauls showing geometric shape clusters varying in distance, number and features. Results of the experiment indicate that the majority of gesture strings produced by Turkish speaking participants is homomorphic and the mostly preferred NP internal order is Dem
Examining the effects of interoceptive awareness and self-focus on emotion perception from point-light dance movements: An eye-tracking study
Emotional expressions are vital in human social interactions and effective communication. This study explored the influence of interoceptive awareness and self-focused attention on emotion perception from dynamic point-light dance movements along with the underlying eye behaviour. Eighty adult participants underwent random assignment into either the self-focus or control group, while considering age, gender, and interoceptive awareness. To assess interoceptive awareness, data were collected through both a heartbeat counting task and the implementation of the MAIA-2 Questionnaire. Self-focus group was supraminally primed with their self-face photograph with a neutral expression, prior to emotion recognition task. Consistent with prior research, the results revealed that participants with higher interoceptive awareness exhibited greater emotion recognition accuracy, alongside longer fixation durations, indicating increased attention to emotional stimuli. On the other hand, participants in the self-focus group demonstrated improved recognition of neutral stimuli. We interpret this finding that self-focus can enhance attention to the emotional expressions related to the self. Additionally, results revealed that females outperformed males in recognizing anger. Interestingly, females also displayed shorter fixation durations and higher fixation counts compared to males. While we found a similar fixation duration pattern in participants with low interoceptive awareness, females' shorter looking times at sad and neutral stimuli might suggest a potential higher experience or sensitivity to emotional cues. These findings were further discussed pointing to the roles of interoceptive awareness and self-focus in inferring the emotions of others as well as the underlying eye behaviour.
The influence of visual movement priming on novel and conventional metaphor comprehension: An eye-tracking study
Understanding metaphors is key to language processing. This research examined the influence of visual priming on action metaphor comprehension, addressing a critical gap in understanding cognitive mechanisms behind language comprehension. Based on the principles of embodied cognition, the research investigated how visual priming impacts comprehension of action metaphors, both novel and conventional, and literal action verbs. An experimental design was adopted, with eye-tracking technology used to capture eye movements as participants read metaphor-rich sentences. We executed a repeated measures ANOVA to analyze various eye movement metrics such as initial reading durations, the length of forward fixations, and the times spent on initial rereading. This was done to assess the influence of priming across varying categories of text. Results highlighted a significant effect of visual priming on first-pass reading times, especially for novel action metaphors, and forward-fixation and first-pass rereading times for all text types. The priming effects were confined to the target sentence. The study emphasized the facilitating role of visual priming in metaphor comprehension, hinting at the involvement of perceptual and sensorimotor systems in language comprehension. It also sets the stage for further research into the neural underpinnings of metaphor comprehension and broader priming modalities.
Muzikal metaforlar: Doğuştan ve nesnel
As in the recent approach cognition is embodied and metaphor theory of meaning metaphoricity of music is a topic that is mostly studied in cognitive musicology and cognitive linguistics and should be studied from the perspective of cognitive scientists. Musicologists use metaphors to describe the musical system itself in the music theory, music psychologists also use metaphors to describe perceptual facts like a tone is higher as in it resonates somewhere higher in the body or conceptual as in the tone's place in the musical spectrum. This conceptual part tells us that this kind of metaphor derives from a more complex activity of the cognitive system, a complex interaction of the environment with human posture and bodily movement during cognition of music. Metaphors are always in account when describing music. In my research I will try to determine if the musical metaphors are innate and objective by analysing how human posture and movement interacts in describing music by researching on bodily metaphors called image schemas using methods similar to Mihailo Antovic(2014) where he presents 5 different sound stimuli to children subjects and asks them to describe their experience and then analysing the subject answers using the image schemas and conceptual metaphor theory. The results showed musical comprehension is metaphorical and image schemas employed in subjects metaphors. In this research I examined a broader age range and compared musical instrument players and non players to see if their comprehension of music is also metaphorical and which image schemas they employ in metaphors. I used 9 different sound stimuli and 7 different image schemas to analyse with. According to results of this study, body-environment interactions which are related to force image schemas utilized in the metaphors the most.
Attribution bias in the context of intergroup relations: The case of natives and immigrants
Ultimate attribution error (UAE) is the tendency to attribute negative outgroup behavior to disposition factor and negative ingroup behavior to external circumstances. This study investigates the UAE committed by Turkish individuals in the context of intergroup relations between Syrian immigrants and Turkish citizens in. The purpose of this study is to investigate the impact of the other's out-group status and perceptual salience on the UAE. We intended to investigate these effects using a Virtual Reality configuration with virtual agents of a Turkish national and a Syrian immigrant. We hypothesized that Turkish citizens will make more dispositional attributions toward the Syrian immigrant agent in a negative scenario. Plus, the perceptually salient agent is expected to be attributed with more causality about the conversation and more dispositional. Results on the UAE yielded a significant interaction effect of Salience and Ethnicity. For the Syrian agent in a negative scenario, being visually salient resulted in higher ratings for the attribution of the negative behavior to personal decision. For the condition that Turkish agent is talking about a negative behavior, when Syrian agent is salient, the ratings for the same question were higher than the condition that Syrian agent is talking about a negative behavior, when Turkish agent is salient. Emotional and physiological (heart rate) reactions were also assessed, but yielded no significant results. This study contributes to the social and political psychology and cognitive science research by investigating both the perceptual salience and negative behavior effects in the context of ethnicity in VR environment.
Zaman algısının duyusal motor mekanizmaları: Öngörü mekanizmaları üzerinden bir zamansal kısalma incelemesi
Temporal binding refers to the perception that two events, which are related in terms of their cause and effect, occur closer together in time than they actually do. This effect not only creates a perceived cause-and-effect relationship but also compresses the time interval between events. Since the influential article on the intentional binding effect was published by Haggard, Clarke, and Kalogeras in 2002, researchers put forth several necessary conditions for the explanation of the effect. While proximity in time and predictability play a crucial role, it is primarily causality that determines the outcome rather than intentional action. According to Buehner (2012), causality is the fundamental factor behind the effect. Despite the productive work done in this area, there is still much to be discovered about the mechanisms that underlie temporal binding. In this thesis, we aim to investigate two main aspects of temporal binding. Firstly, we aim to determine whether the act of performing an action alone is sufficient to induce temporal binding or if outcome prediction plays a critical role. To achieve this, we conduct a series of experiments to compare congruent and incongruent outcomes, with the aim of uncovering the underlying mechanisms that cause this intriguing time distortion. Secondly, we examine the various factors that contribute to temporal binding. In addition to outcome prediction, we investigate the role of temporal control, which is the ability to dictate timing, in shaping our perception of time. We aim to understand how different factors affect temporal binding by analyzing each component.
Ön-eğitimli dil modelleri ile Türk işaret dili için işaret dili çevirisi
Sign Language Translation (SLT) is a machine learning task that aims to provide accessibility systems for the deaf and hard-of-hearing community. With the recent advances within the area, SLT technologies have shifted towards large-scale training with pretrained large language models (LLMs). However, most technologies and datasets are provided for American Sign Language (ASL) and British Sign Language (ASL). To achieve similar advances for Turkish Sign Language (TID) translation, we are proposing the first large-scale open-source translation dataset for TID, comprising over 500 hours of video footage and aligned Turkish translations by utilizing publicly available YouTube content. In this work, our dataset provides a scalable and reproducible framework for SLT research. We propose a comprehensive translation system with various inter-changeable components designed for SLT on an agglutinative language to compensate for the learning alignment between both low-resource languages, namely TID and Turkish. This body of work compares feature extraction strategies (Linear layers, Multi-layer Perceptrons, and Convolutional encoders), model sizes, and their pretraining approaches (multilingual versus Turkish-specific) to the effect on sign translation performance. Innovative training and evaluation techniques, including paraphrasing-based reference generation and sign language-specific augmentations, are also introduced for developing an SLT benchmark for TID.
Radikali radikalleştirmek: Radikal dışsalcı bir biliş biyolojisine doğru
In this thesis, I outline a radically externalist approach to cognitive science, explain why such an approach is needed, and discuss the potential benefits it offers. I examine the dominant divisions in the field, i.e. internalism vs. externalism and representationalism vs. anti-representationalism, and track the argumentative steps that yield these positions. Along the way, I identify key background assumptions, particularly realism, multiple realizability, and the autonomy of the special sciences. I argue that these assumptions underlie most theoretical frameworks in cognitive science and that they ultimately lead to the problem of mental causation and the hard problem of content. I claim that these problems disappear once we abandon those assumptions. In their place, I defend an anti-realist stance, draw on the new mechanistic philosophy of science, and propose a new tool: the Naturalistic Coherence Criterion. I argue that this framework points us toward a radically externalist cognitive science, one that remains agnostic about the metaphysics of mind and avoids unnecessary theoretical burdens.
Investigating the category effect in freely associated word responses and predicting free word associations using language models
The process of free association is key to human meaning-making, influencing both shared and individual understanding. Useful in many aspects, free association word resources are costly to make and attempts in computational modelling of free associations has yielded limited results only. Designed in two separate steps, current study first investigates whether sensory categories in the brain play a predictive role in the process of freely associating words. For this purpose, the data previously collected by De Deyne et al. (2018), namely Small World of Words (SWOW), was categorized by the aid of the pretrained Word2Vec model and analyzed. Secondly, the study tests whether a computational language model is able to capture the general regularities of freely associated human responses after being fine-tuned with relevant data. For this purpose, two language models, namely Tiny Llama and Google Gemma 3 were fine-tuned with SWOW data and the models were tested. Results show that there is a significant relation between the sensory areas in the brain and free word association responses and it is possible to say that fine-tuning significantly improves semantic understanding in free association responses in both models. However, values also highlight the limitations of both the base and fine-tuned models for handling such an open-ended task.
Consciousness and implicit memory trace for the unexpected stimulus in inattentional blindness
Inattentional blindness (IB) demonstrates that an unexpected stimulus (US) may be undetected when attention is engaged in a task. Previous studies using direct memory measurements relying on verbal report failed to find a memory trace for the US. Block (2011) suggested that contrary to Access Consciousness, Phenomenal Consciousness can exist without verbal report and attention. Mack and Rock (1998) found perceptual and semantic priming effects for the undetected US by using indirect memory tests. However, there are no items to be ignored in their paradigm. The present study aimed to show that the undetected US in an IB paradigm involving items to be ignored is processed and produces priming effects at the perceptual and semantic level. In Experiment 1, participants who were blind to the unexpected word were more likely to complete a single-solution word fragment with the US than the participants who were not exposed to the word. In Experiment 2, inattentionally blind participants were more likely to choose the picture for the unexpected word than the ones who were not exposed to the word. These two studies replicated previous findings in a paradigm with ignored items. The results showed that the undetected US is presumably processed at a phenomenally conscious level and produces perceptual and semantic priming effects on a subsequent task. The findings are also consistent with studies showing neural activations in the brain for the undetected US. The findings have implications for possible memory correlates of undetected visual information and for theoretical propositions regarding consciousness. Keywords: Inattentional blindness, priming, consciousness, word fragment completion, picture choice
The role of expectation in change blindness
Human may believe that they notice every important change in their environment. However, the phenomenon of change blindness – a failure to notice salient changes to our visual world – tells a different story. The present research investigated the role of expectation in change blindness by using a modified version of the flicker paradigm. The sample consisted of 120 university students (60 females and 60 males) aged between 18-26. The study used two stimuli, ball and clock, which had an original and a changed version. The changes in the images were either in the expected direction with the minute hand of the clock moving clockwise and the ball sliding down or in the unexpected direction. Response times for the detection of change were collected. It was hypothesized that response time (RT) for expected changes would be lower than RT for unexpected changes. The overall results of the experiment with the two stimuli combined showed that participants were able to detect expected changes faster than unexpected ones, supporting our hypothesis. When the two stimuli were investigated separately, participants were able to detect expected changes faster than unexpected changes for the ball, while the difference between the two conditions was non-significant for the clock. The findings are discussed within the framework of expectation-based theories.
An erp study of the processing of subject and objectrelative clauses in Turkish
The first aim of this study is to determine which type of relative clauses – subject relative clauses or object relative clauses – are easier to process. The second aim, assuming that there will be a difference between subject relative clauses (SRC) and object relative clauses (ORC) in terms of the processing difficulty, is to reveal on which words or word groups in the sentence the difficulty presents itself. In an Event-Related Brain Potentials (ERP) experiment, participants were given a total of 240 sentences, where 120 had SRCs in them (60 of which were in the grammatical function-subject, "[The senator who applauded the PM] scolded the minister"), and the other 60 were in the grammatical function-object,"The minister scolded [the senator who applauded the PM"]); the remaining 120 sentences had ORCs (again, 60 of which were in the grammatical function-subject, "[The senator that the PM applauded] scolded the minister," and the other 60 were in the grammatical function-object, "The minister scolded [the senator that the PM applauded])." The following factors were used in the statistical analysis: Grammatical Function (GF) (subject, object) x Clause Type (SRC, ORC) x A(nterior)-P(osterior) distribution (frontal, parietal) x LAT(eralization) (left, right). Behavioral findings revealed that participants perform better when SRCs are in the subject function and ORCs are in the object function. In ERP findings, the results of the experiment revealed that subject relative clauses are easier to process than object relative clauses in the subject function. Therefore, object relative clauses revealed Left Anterior Negativity. The second result is the cognitive difficulty observed on the head noun of the relative clauses. In this study, relative clauses were investigated for the first time by using the ERP technique. Key words: Language Processing, Event-Related Brain Potentials, Relative Clauses, LAN
An investigation of false memory in Turkish-English bilinguals-
False recognition across languages is investigated using the Deese-Roediger-McDermott (DRM) paradigm. English-Turkish balanced bilinguals studied word lists which are associates of a critical lure. Some lists were received by the participants in English while others in Turkish. After the study phase, participants performed a recognition test that included studied words, nonstudied critical lures, and nonstudied new items whose language were either the same with or different from those used in the study phase. Half of the participants were instructed to recognize only if the test word was in the same language as the studied word while the remaining received no such instruction. The results demonstrated a strong false memory effect for both within-language and across-language conditions. False recognition decreased when the study and test languages differed compared to when they were the same, and this effect was similar for both groups which had an instruction and no instruction. These results were interpreted in such a way that even though false memories can occur across different languages, they are not completely independent from the language assuming that the participants encode not only the meaning of the words but also the language of the words (i.e., the phonological form of a word in that particular language) that they were presented during the study phase, so that they were encoded as distinct and presented less false alarms. In terms of bilingual language representation, the results are consistent with models that assume a separate lexical representation for each language and yet a common single conceptual representation for both languages.
Repetition in dementia: A study on Turkish
Objective: This study investigates the repetition performance of individuals with dementia on a repetition task. Method: The research examines the performance of 30 young adults, 32 senior adults (65+), and 32 individuals diagnosed with dementia on word and pseudoword repetition task. In addition to word repetition, this study also examines sentence repetition task constructed on a length-based scale with manipulations of complexity and reversibility in individuals with dementia. The task used in this study is divided into four main parts: the Mini-Mental State Examination to assess cognitive integrity; forward and backward digit span tests to assess working memory; the Turkish clinical adaptation of the Western Aphasia Battery's word repetition test; a pseudoword test, designed on the basis of the Turkish word repetition task list. Finally, a sentence repetition test constructed on a length-based scale, manipulating subject and object relative clauses and reversible/irreversible parameters. The research was conducted with young (18–64), senior (65+), and dementia-diagnosed participants. Results: Linear mixed modeling showed that semantic meaningfulness was important for correct word repetition in individuals with dementia (dementia group, meaningful word repetition coefficient = −8.119, p < .001, CI = [−11.602, −4.636]; nonword repetition coefficient = −0.300, p < .001, CI = [−0.413, −0.187]). In sentence repetition with relative clauses, object-relative clauses were observed to be more difficult than subject-relative and simple sentence repetition (subject-relative coefficient = −0.123, p = .005, CI = [−0.208, −0.038]; object-relative coefficient = −0.151, p = .001, [−0.236, −0.066]). For reversibility-based sentences, reversible sentences were more difficult (dementia group coefficient = −0.667, p < .001, CI = [−0.863, −0.471]). In addition, sentence- and word-length effects increased in direct proportion to the intactness of working memory. Conclusion: Participants diagnosed with dementia perform worse at pseudoword repetition task than word repetition. It is also demonstrated that participants perform worse at repetition of complex sentence structures than simple structures. While an intact working-memory helped with the repetition of longer words and sentences, and positively affected the repetition of subject and object-relative clauses, the impact was modest rather than significant. Similarly, for reversible sentences, a positive effect was noted, though it was not significant. Keywords: dementia, repetition task, semantics, syntax
The effect of transcranial direct current stimulation on syntactic processing in aphasia
There are studies that investigated the effects of tDCS on linguistic abilities both in healthy and aphasic individuals. tDCS studies in aphasic individuals revealed positive effects on linguistic abilities based on the cerebral area of stimulation and conditions. The aim of the current study was to evaluate the effect of tDCS on syntactic processing by activating or supressing Wernicke's area in anodal and cathodal conditions. 10 individuals with aphasia participated in the study. All aphasic indiviuals were administered the Test of Language Assessment in Aphasia. In the beginning of each session we applied our linguistic task via a computer program that consisted of 20 target sentences, which were formed of four different syntactic structures with varying complexities. This task measured the true/false scores, reaction times, and the distractor use by aphasic individuals. After the linguistic task, each participant was subjected to 2mA tDCS for 20 minutes. In the anodal condition we applied tDCS on the left Wernicke's area (CP5), while in the cathodal stimulation we applied tDCS on right the homologue area for Wernicke (CP6). Immediately after the tDCS session, participants were subjected to the linguistic task once again. Five consecutive sessions were conducted in a period of one week. The results of the study revealed that Anodal-tDCS may improve language skills by decreasing bilateral activation whereas Cathodal-tDCS was ineffective on syntactic processing and had a negative effect on certain syntactic structures. Key words: Syntactic processing, aphasia, tDCS, neurolinguistics, language disorder
Effects of Amygdala lesions on social behavior in rats
Despite its importance mechanisms of prosociality are still not well known. In the literature, helping behaviour of rats to a restrained rat is becoming a tool for assesing this topic. Helping behavior is closely associated with sensitivity to another one's distress, and amygdala plays an important role in this sensitivity. The present study investigated whether bilateral amygdala lesion would affect rats' decision making to help when their cage-mate was restrained. Adult Wistar rats were subjected to a role reversal acquisition where they acquired the behavior of opening the door of the restrainer in which one of their cagemates was captive. Then, they were divided in three groups; naive, sham operated (Sham) and basolateral amygdala lessioned (Lesion). The rats were tested in an open field with three restrainers (empty, with a Sham or Lesion, with a Naive). The door opening and side preferences of rats were measured. In the control test there was a naive in the formerly empty restrainer, and the other two restrainers were empty which they formerly were not. No significant differences were found among the groups with respect to door opening and side preferences in both the main and the control tests. Door opening and to be close to the empty restrainer preferences were lowest in the main test and highest in the control test. The lower interest in the restrainer with a cagemate during the control test indicates that, the dominant door opening behaviour drive was not helping but was probably habit formation.
Syntactic processing differences and the effects of memory-load interference for object relative and subject relative clauses in Turkish
The purpose of the study, which focuses on the relative clauses in Turkish, is twofold: In Experiment 1, it was aimed to fill the gap in Turkish literature with regard to syntactic complexity difference between subject relative clauses and object relative clauses. As a self-paced reading experiment, participants read either subject relative clause of object relative clause to measure the processing cost as a slowing down in reading. The result of Experiment 1 revealed that object relative clauses are harder to process than subject relative clauses suggesting that there is a subject preference in Turkish. Secondly, as a separate but related follow-up study, it was tested whether such complexity interacts with memory load in any way. For this purpose, participants memorized a set of words while reading syntactically complex sentences and syntactically simpler sentences (object and subject relative clauses, respectively). The study also manipulated whether the memory load items and the words in the sentence were similar or not (matched or unmatched conditions). Performance in recall was significantly higher for the unmatched condition than the matched condition. Recall was also higher in simpler sentences than complex sentences. Results of Experiment 2 indicated that syntactic processing is not modular meaning that both linguistic and non-linguistic verbal processings share the same verbal working memory resource. Moreover, online and offline measurements of both studies are compared to show why offline studies are different in nature and why online studies are more reliable as long as sentence processing is concerned.
Duration of stability differences for words and pseudowords in the verbal transformation effect
Verbal transformation effect (VTE) refers to the phenomenon in which listening to the same word presented repeatedly leads to multiple interpretations (e.g. 'life life life...' becomes 'fly fly fly...'). Although there are several psychological models trying to account for VTE, the underlying neural mechanisms are largely unknown. Short-term synaptic depression (STD) is a related biophysical mechanism in that constant stimulation of a pre-synaptic neuron reduces the probability of a post-synaptic neuron firing due to neurotransmitter depletion. In addition, the rate of depression depends on whether the action potential activity between pre- and post-synaptic neurons is paired (paired activity results in a faster depression rate). We used 18 Turkish stem words and pseudowords as examples of paired and unpaired AP activity, respectively, in a standard VTE experiment paradigm and found that words remained stable approximately 400 ms shorter on average compared to pseudowords. This difference in stability durations may be due to faster depression of synapses in networks processing words, which suggests that STD could be considered as a suitable neural mechanism for VTE.
Motion perception in multiclustered environments
The ability to recognise objects in the environment is a fundamental process for all living beings. The features of the objects (size, color, location, etc) in addition to their integration with the environment play a significant role in identifying the object. Despite the extensive evidence in psychology and neuropsychology, the exact contribution for various features to recognition is still inconclusive. Although it is an easy task for the brain to identify an object, it remains difficult to identify an object in a crowded scene – a perceptual phenomenon where having similar flankers around a target object decreases the visual acuity of the target. The more the objects are similar to each other, the more difficult it is to identify the target object. In this thesis, we focused on studying the effect of global and local features in a crowded scene of multiple clusters on detecting the target object. To achieve this, similar stimulus metrics (e.g. density, distance, size) are calculated globally for the entire scene and locally for the target object and/or cluster. We found a global effect of the density metrics (e.g. the number of clusters) on performance. We also found a significant effect on global and local aspects of eccentricity and size metrics. Keywords: Motion Perception , Ensemble Perception, Attention
Recognition of sequential harmonic and inharmonic sound sequences investigated by behavioral and electrophysiological studies
Consonance rating when listening to the two consecutive or simultaneously presented sounds is associated with the ratio of their fundamental frequencies. The simpler ratio is perceived as more consonant. In this thesis, two melodies that consist of the same 10 tones were generated. Melodies had the same contour but differed with the order of tones so formed different harmonic relations between consecutive tones. Non musician participants were asked to choose which melody (harmonic or inharmonic tone sequences) was more consonant and the rating for each melody was not significantly different than each other. However, it was easier for them to notice the same amount of frequency change that occurs in one note of the harmonic sound sequence. Results suggest that better performance of the recognition task for harmonic sequence is related to better encoding and building a higher level expectation due to harmonic relations of sounds. An EEG experiment was conducted to test memory load hypothesis. The sustained anterior negativity (SAN) and power of alpha/beta oscillations were compared as a measure of working memory load. Amplitude of SAN did not reveal a difference in working memory load. However, beta and low gamma power was lower for harmonic sequences in the frontal cortex at the end of the stimulus presentation which suggests a more stable memory trace for harmonic sequences. Nonmatch stimulus elicited a P3b signal with higher amplitude for harmonic condition. This result suggests that a higher level expectation occurs for harmonic condition as all the other parameters that affect P3 signal were well controlled in the experiment.
The underlying cause of the framing effect: A dual process approach
A switch of preference is often observed in identical questions, depending on how the choices are framed. This phenomenon is called the framing effect and it displays a violation of the rational choice theory and provides support for dual process theory accounts. Many dual process accounts indicate that; an emotional System 1 is the underlying cause of the framing effect however there are counter arguments that support the idea that; an analytic and working memory dependent System 2 is the underlying cause. Working memory dependence of System 2 is regarded as the main differentiator between the two systems. Thus in this research, a concurrent digit span backwards (DSB) task was given to suppress System 2, with risky choice framing type questions. It was hypothesised that, framing effect can be the result of an irrational emotional reaction to the positive and negative words that describe the choices thus the underlying cause might have been attributed to System 1. As a result, under a suppressed System 2 the amount of framing effects would increase. However findings showed that there was no significant effect of the memory load and counter to the expectation, in the memory load condition the number of framing effects were reduced. This result supports the argument that the underlying cause of the framing effect is System 2 , which means that context effects increase with analytical thinking. Thus this research signifies the importance of emotions and System 1 processes in leading to rational choices.
An investigation of differences between visual and auditory memory
The main aim of this study was to examine the differences between auditory and visual memory and to investigate the encoding strategies during the recall of the unfamiliar Chinese words that was presented briefly, both visually (written word) and aurally (spoken word). Furthermore, primacy and recency effect were investigated and each stimuli was analyzed in accordance with the visual and auditory scores. The experiment took place in the psychology laboratory and 88 university students between the ages of 19-25 were selected for the experiment. The trial consisted of three parts. The first part was the learning phase. Learning phase of the trial process required participants to attend combination of visual and auditory modalities by visually monitoring the Chinese words' representations in picture format, together with textually displayed related Chinese word, and aurally, by hearing the same Chinese words in audio format. Participants were then tested with regard to their recall ability of the Chinese words in both modalities. During the auditory and visual tests in the second and third parts of the trial, the Chinese words that were presented in the first part were given one by one as a cue in mixed order without images, and the participants were instructed to write down the Turkish meaning of the words they recalled in the answer form. In the auditory test section, the auditory cue words were repeated five times over a period of time (13400 ms) as it was in the first section and participants only heard the Chinese words. Also, in the visual section, the words remained on the screen for the same period of time (13400 ms) as shown in the first part and participants only saw the Chinese cue words on the screen without any accompanying spoken word. In both test parts, all the words were identical to what they exposed in the learning phase. In order to randomize and eliminate possible differences, half of the participants were given the auditory test first and then the visual test; the other half first started with the visual test and then the auditory test. Immediately after being tested, participants were asked to describe the recall strategy they used to remember the words through a short questionnaire and all the results were analyzed. Individual differences in visual and auditory encoding strategies and their effect on recall performance were also investigated. In conclusion, the findings of this research were as follows: although it was observed that the number of correct recall in the auditory test was higher than those in the visual test, there was no statistically significant difference in between auditory and visual memory performances, the recall rates of visual and auditory information did not differ significantly by gender, in comparison of individual differences in visual and auditory recall scores, individuals whose auditory memory performance is superior to visual were predominant, primacy effect was superior in the recall rate of visual items and recency effect were superior in the recall rate of auditory items. Nonetheless, primacy effect was found as effective as recency effect in the recall of the auditory information. Furthermore, participants who used the "associated them with some other words" strategy achieved the highest level of auditory recall performance. On the other hand, "matched the Chinese characters with fruit images" strategy provided the highest level of visual recall performance to the participants. All of the results supported our hypotheses except the first and the last finding. Keywords: auditory memory, visual memory, modality effect, recall, primacy effect, recency effect, encoding strategies
Machine learning and EEG in epilepsy
Purpose: This study investigates the ability of deep learning to improve epilepsy diagnosis. Without pathology diagnosis involves long and costly EEG monitoring. To achieve faster diagnosis, researchers used graph theoretical metrics from brain connectivity networks. However, diagnosis by deep learning, directly on connectivity data, was not yet studied. Methods: A convolutional neural network (CNN) algorithm was applied on directed Granger causality (GC) connectivity measures, which were derived from 50 seconds of interictal resting-state surface EEG recordings from a group of 30 subjects with epilepsy and a 30 subject control group. The same EEG data was also used to train a long-short-term-memory (LSTM). Performance was determined with a k-fold cross validation approach. Results: Largest connectivity reductions occurred in frontal regions in the delta band, and largest increase occurred in the gamma band for left lateralized connectivity from frontal to posterior regions. The CNN achieved highest accuracy (82%) with directed GC matrices that included delta and gamma frequency bands, using the FP1, F3 and P3 electrodes. Notably, the LSTM achieved highest accuracy (70%) on the same electrodes. Other electrode combinations only showed significant accuracies with differently normalized GC data. A high accuracy of 90% (F1-score 90%) was achieved by fusing the CNN predictions that resulted from the three best performing data preparation methods. Conclusions: A generic CNN algorithm is able to detect epileptic features from GC matrices, provided that the data is prepared appropriately. To exploit multiple epileptic features, different predictions can be fused into a hybrid classifier. Recommendations: The high accuracy achieved in this study shows that this approach could prove a valuable aid for clinicians.
The role of awe on self-referential processing: AN EEG oscillation study
This study aimed to investigate the effects of awe on self-referential processing (SRP) at the electrophysiological level. Participants were exposed to awe-inducing or neutral video clips, followed by semantic, somatic, attention, and meditation tasks. EEG was recorded throughout the experiment to analyze peak frequency and peak magnitude in the alpha (8-13 Hz) and theta (4-7 Hz) bands. Additionally, heart rate (ECG) was measured to validate the successful induction of awe. Thirty-one healthy adults viewed three awe-inducing and three neutral videos, each followed by the corresponding tasks. Participants also completed the Self-Size Scale before and after each block to report perceived changes in self-representation. Results showed no significant differences in perceived self-size, heart rate, or subjective ratings of attention and pleasantness between awe and control conditions. EEG analyses revealed robust regional and hemispheric patterns in alpha and theta activity; however, these reflected general task engagement rather than awe-specific modulation. Likewise, grouping participants into "Smaller Self," "No Change," and "Bigger Self" categories did not yield significant differences in neural measures. These findings highlight the methodological challenges of reliably eliciting awe in laboratory settings using video-based induction. Factors such as stimulus duration, repetition, and reduced ecological validity may have limited the strength of the awe experience. Nevertheless, the study provides a comprehensive paradigm integrating EEG with validation via ECG, underscoring the complexities of awe research. Its contribution lies in offering an interdisciplinary perspective on self-referential processing and establishing a methodological foundation for future research.
Müzikle uyarilan duygularda kendini referanslama süreçlerinin hemodinamik tepkileri ve interosepsiyon arasindaki korelasyonu
Interoception, an embodied emotion and cognition theory, refers to the tracking of bodily and mental states. Higher interoceptive awareness enhances emotion perception and affective intensity by relying on bodily signals. Closely related, self-referential processing integrates new perceptual input with prior knowledge through top-down and bottom-up mechanisms that align sensory information with internal models. Music, given its emotional and social nature, provides a highly embodied experience and can act as a proxy for a social agent, enabling listeners to infer intentions. When paired with interoception, music-evoked emotions offer a valuable framework for exploring individual differences in evaluative processes such as emotion processing. This study examined how interoception influences behavioral and neural responses during music-evoked emotions. Participants completed implicit and explicit interoception assessments, followed by music listening and emotion processing tasks. Behaviorally, emotion perception accuracy differed marginally across categories, without any effect of interoceptive awareness. In contrast, functional near-infrared spectroscopy (fNIRS) revealed trend-level and group-specific hemodynamic differences in prefrontal subregions, with several channels modulated by interoception. Overall, the findings suggest that interoceptive awareness slightly modulated neural engagement during emotional evaluation. Despite modest effects, the results point to a potential link with embodiment, emphasizing the roles of interoception and self-referential processing in music-evoked emotions.
Examining the complexities of decision-making:The connection of risk-taking, working memory, and second-language usage
This study aims to research whether individuals in a foreign language context make safer choices than when operating in their native language. In particular, we intended to analyze the impact of the framing effect, foreign language proficiency, and working memory on the behavior of decision-making. Prospect Theory was employed to measure the level of risk-taking during ambiguous decision-making situations (Asian Disease Problem) depending on the setting of reference points. Eighty-one participants took the English language proficiency test, working memory test, and decision-making tasks. The individual differences in language proficiency were related to reduced risk-taking when operating in the foreign language. A significant main effect of framing and a strong Language-Framing interaction were found; the framing effect was enhanced in Turkish and reduced in English. No main effect of language was found overall. The use of foreign language may alter the cognitive mechanism, although there is no general tendency for risk-aversive decisions. Research with larger and more balanced samples and neurocognitive methods is necessary to uncover the dynamics of decision-making context and its interaction with neural processing.
The influence of context structurization on attention dynamics and representational spaces in bert for question answering
Understanding how Large Language Models (LLMs) like BERT process and represent information is important for improving their abilities in tasks such as question answering. This thesis investigates how context structurization, a technique informed by cognitive principles of information organization, influences attention dynamics and representational spaces within bert-base-cased models. To support this investigation, a new dataset, 'SQuAD with Structurized Contexts' (SQSC), was created by applying a structurization method to original SQuAD contexts. The research compares three BERT model states: a pre-trained vanilla model (BERT-V), a model fine-tuned on unstructured SQSC contexts (BERT-UN), and one fine-tuned on structurized SQSC contexts (BERT-ST). Using an out-of-distribution (OOD) data sample generated for this study, experiments analyze these models' internal mechanisms when processing both unstructured and structurized versions of this OOD input. The study utilizes a range of quantitative analyses to compare attention distributions and hidden state representations across the different models and input conditions, employing measures of distributional divergence, vector similarity, and comparative representational geometry. This research aims to provide detailed insights into how structural modifications to input context affect BERT's internal processing. The findings are expected to contribute a better understanding of the relationship between input data structure and model mechanisms, offer the SQSC dataset as a new public resource, and inform future work in developing more understandable and effective language models.