25.04.2026, Saturday, 10:00-11:30
Chair: Renate Rutiku
Institute of Psychology, Jagiellonian University, Cracow, Poland
10:00 Julia Papiernik-Kłodzińska
C-lab, Institute of Psychology, Jagiellonian University, Cracow, Poland;
Centre for Brain Research, Jagiellonian University, Cracow, Poland;
Doctoral School in the Social Sciences, Jagiellonian University, Cracow, Poland
"Visual Field Asymmetries in Temporal Object Perception – Behavioral and Neurophysiological Correlates"
It is established that visual perception varies across the visual field. Performance is better along the horizontal than the vertical meridian of the visual field (horizontal-vertical asymmetry, HVA), and along the lower than the upper half of the vertical meridian of the visual field (vertical meridian anisotropy, VMA). These phenomena have been demonstrated in various tasks. However, it is not apparent to what extent they influence temporal object perception.
The study aimed to determine whether temporal object perception is modulated by visual field location, and to test whether HVA and VMA extend to subjective temporal perception.
25 healthy participants took part in the study. We used a custom experimental paradigm combining figure-ground modulation with steady-state visual potential (SSVEP) stimulation to assess the disparities between subjective perception and objective neural markers of stimulus processing. Pop-out figures emerged from a background of rotating line segments flickering randomly at 6 and 15 Hz. The figures appeared in one of eight locations across the visual field and flickered at 6 Hz. The objective stimulus duration consisted of either 5, 6, or 7 cycles. Participants counted the perceived number of flickers. Neurophysiological responses were recorded using a 64-channel BioSemi EEG system.
Participants systematically underestimated stimulus duration, reporting on average 4.56 figure flickers per trial. Location significantly affected behavioral responses, revealing HVA but no VMA. Overall accuracy was low (0.16). ERP analysis differentiated objective stimulus duration, with no modulation by visual field location. SSVEP analysis revealed increased 6 Hz activity during the figure relative to the baseline, again without location effects. Ongoing analyses will additionally examine the time-frequency dynamics across stimulus durations and locations.
Behavioral asymmetries in subjective temporal perception were not mirrored by ERP or SSVEP measures.
FINANCIAL SUPPORT: This work was supported by the National Science Centre, Poland (grant number 2021/42/E/HS6/00425).
10:15 Sofiia Honcharova
Doctoral School in the Social Sciences, Jagiellonian University, Cracow, Poland;
Institute of Psychology, Jagiellonian University, Cracow, Poland
"It's Complicated: Optimal Visual Features for Maximizing SSVEP Responses are Frequency-Dependent"
Steady-state visual evoked potentials (SSVEPs) are an increasingly popular methodology in vision research and beyond. Yet, a comprehensive understanding of what drives the response magnitude remains limited. To date, systematic comparisons have been largely restricted to square versus sine waves, leaving a gap in practical guidelines for optimising SSVEP paradigms.
This study aimed to (I) systematically map the effects of multiple stimulus parameters on SSVEP strength across frequencies; (II) better understand the neural basis of SSVEP generation.
Twenty-nine participants completed a within-subject experiment crossing three frequencies (6, 15 & 40 Hz), three flicker types (on/off square, sine and 2-frame “tick” waves), two contrast levels (high contrast vs. isoluminant) and two visual complexity levels (low: uniform squares vs. high: dynamic stochastic “sprinkles” pattern). EEG was recorded alongside trial-by-trial subjective flicker visibility ratings.
Apart from frequency, contrast had the largest influence on SSVEP power (high contrast > isoluminant), while complexity emerged as the second most impactful factor. Flicker type had the smallest, mostly negligible effect. This pattern was also mirrored in the subjective flicker strength ratings. Critically, the effects of complexity reversed across frequencies: while low-complexity stimuli elicited stronger SSVEPs at 15 & 40 Hz, high-complexity stimuli yielded stronger SSVEPs at 6 Hz. Topographical analysis further supported the dissimilarity of SSVEP responses across frequencies.
SSVEP generation appears to operate differently across frequency ranges. Stimulus complexity emerged as a previously overlooked yet significant determinant of SSVEP magnitude. These results challenge assumptions about SSVEP uniformity and carry direct practical implications for paradigm design. Additionally, this work raises broader questions about the distinct neural processes engaged at different stimulation frequencies.
FINANCIAL SUPPORT: This work was supported by research grant nr 2021/42/E/HS6/00425, awarded by the National Science Center of Poland.
10:30 Rob van der Lubbe
Faculty of Physics, Adam Mickiewicz University, Poznan, Poland;
Faculty of Behavior, Management, and Social Sciences, University of Twente, Enschede, Netherlands
"Posterior Theta Reflects Suppression of Competitive S-R Links"
Recent studies employing the electroencephalogram (EEG) revealed that posterior theta after the presentation of arrays in the Eriksen task is sensitive to cognitive conflict. This posterior effect precedes effects on theta power over midfrontal areas, suggesting that it is an earlier sign of conflict detection. A few studies observed that this effect is largest when the flankers signal the alternative response.
Two experiments were performed to further examine these effects on posterior theta.
In the first experiment, we aimed at a conceptual replication with another version of an Eriksen task. The central target (C or S) required a left, or a right (H or K) response, and arrays were either congruent (e.g., CCC or KKK), incongruent but response compatible, (e.g., CSC or KHK), or incongruent and response incompatible (e.g., KCK or SKS). In a second experiment, we examined sequential effects in a standard Eriksen task with response compatible (e.g., SSS) and response incompatible arrays (e.g., HSH).
Experiment 1 replicated the largest increase in posterior theta for incongruent and incompatible arrays. Experiment 2 revealed largest posterior theta in the case of a repetition of incompatible arrays with response repetition (I-I-R), the smallest posterior theta in the case of a repetition of identical compatible arrays (C-C-R), but also relatively low theta when a compatible array was followed by an incompatible array with a response repetition (C-I-R). However, responses for the latter sequence were slowest and the least accurate.
These results may indicate that multiple mechanisms are involved resolving conflicts in the Eriksen task. One mechanism, reflected in posterior theta, may reflect suppression of competitive S-R links at an early sensory level, preventing the propagation of interfering information along the dorsal pathway, while a second more central mechanism intervenes in the case of a low level of early suppression.
FINANCIAL SUPPORT: This work was supported by one grant from the National Science Center (Narodowe Centrum Nauki) of Poland awarded to R.L. (2019/33/B/HS6/00096), and one awarded to D.A. (2022/45/B/HS6/01107).
10:45 Paweł Basoń
Doctoral School in the Social Sciences, Jagiellonian University, Cracow, Poland;
Centre for Cognitive Science, Jagiellonian University, Cracow, Poland
"Beyond Valence: Visual Feedback Type Modulates Neural Correlates of Feedback Processing"
Performance monitoring, particularly feedback processing, plays an important role in multiple areas, such as learning or decision-making. Depending on specific objectives, researchers use various types of feedback stimuli, which can make the interpretation and comparison of results across studies more challenging. To date, relatively few studies have systematically examined how qualitative differences in feedback format influence the neural correlates of feedback processing. Consequently, discrepancies observed between studies may not solely reflect theoretical manipulations (e.g., reward vs. punishment) but may instead result from low-level perceptual features (e.g., visual complexity, salience) or higher-level representational properties (e.g., symbolic vs. social content).
The aim of the study was to examine how the type of visual feedback influences neural correlates of performance monitoring.
103 participants (73 female) performed a Time Estimation Task while EEG data were recorded. Participants received performance feedback presented in one of six different visual formats: color, text, points, face, emoticon, or a pictogram. The analysis focused primarily on Feedback-Related Negativity (FRN) as a key neural marker of feedback processing, while not being limited exclusively to this component.
The analysis revealed a significant main effect of feedback type, F(5, 115.98) = 324.62, p < .001. Additionally, there was a significant valence × type interaction, F(10, 115.98) = 7.20, p < .001, demonstrating that the effect of valence on FRN amplitude depended on feedback type. Additionally, a series of post hoc analyses was conducted to identify which stimulus pairs within each valence condition exhibited the most pronounced differences.
These results support the view that early feedback processing reflects an integration of evaluative and representational stimulus features rather than a purely valence-driven response.
FINANCIAL SUPPORT: This study was funded by the Excellence Initiative program for PhD students Research Support Module 2025 granted to P.B. & by a grant from the Faculty of Philosophy under the Strategic Programme Excellence Initiative at Jagiellonian University granted to M.S. This study was also supported by Sonata Bis grant 2020/38/E/HS6/00490 from the National Science Centre of Poland.
11:00 Julia Klimecka
Doctoral School in the Social Sciences, Jagiellonian University, Cracow, Poland
Centre for Cognitive Science, Jagiellonian University, Cracow, Poland
"Performance Monitoring and Decision Formation Under Uncertainty: ERP Evidence from a Speeded Raven’s Task"
Performance monitoring has primarily been studied in simple speeded paradigms with unambiguous outcomes, where the error-related negativity (ERN) reliably differentiates erroneous from correct responses. It remains unclear whether this marker generalizes to complex reasoning tasks in which decisions unfold over extended intervals and remain ambiguous at response execution.
The primary aim of this study was to test whether classical response-locked components, such as ERN/correct-related negativity (CRN) and error/correct positivity (Pe/Pc), differentiate correct and incorrect responses in a speeded reasoning task. The secondary aim was to characterize neural indices of decision formation by examining the centroparietal positivity (CPP) as a marker of evidence accumulation and stimulus-locked components related to matrix processing (N1, P3, LPP).
EEG and behavioral data were collected from 97 participants (49F; 48M) aged 18 to 35 years (M = 23.76, SD = 4.03) while they completed a modified, speeded version of Raven’s Standard Progressive Matrices. ERN/CRN and Pe/Pc were first examined using a standard pre-response baseline and, exploratorily, with an earlier baseline to account for possible pre-response error-related activity.
Using the conventional baseline, the ERN and Pe amplitudes did not significantly differentiate errors from correct responses. Baseline adjustment yielded only a marginal correctness effect. In contrast, the CPP was significantly larger for correct than error trials (p = .009), whereas the LPP (p = .017) and N1 (p = .011) were enhanced for errors. The P3 did not mirror CPP effects, supporting a dissociation between these components, which are often interpreted as reflecting the same underlying decision process.
These findings suggest that classical response-locked error signals may be attenuated in complex reasoning under uncertainty, whereas centroparietal decision dynamics remain sensitive to decisional outcomes.
FINANCIAL SUPPORT: This work was supported by a Sonata Bis grant 2020/38/E/HS6/00490 from the National Science Centre of Poland to MS. Data collection was funded by a Sonata Bis grant 2017/26/E/HS6/00595 from the National Science Centre of Poland to AC.
