Sabine Leske

Solbakk, Anne-Kristin; Lubell, James; Leske, Sabine; Funderud, Ingrid; Anais, Llorens; Blenkmann, Alejandro Omar; Foldal, Maja Dyhre; Meling, Torstein R.; Knight, Robert T. & Endestad, Tor (2021). Monitoring of self-paced action timing and sensory outcomes after lesions to the orbitofrontal cortex. Journal of Cognitive Neuroscience. 

Llorens, Anaïs; Funderud, Ingrid; Blenkmann, Alejandro Omar; Lubell, James; Foldal, Maja Dyhre; Leske, Sabine Liliana; Huster, Rene; Meling, Torstein Ragnar; Knight, Robert T; Solbakk, Anne-Kristin & Endestad, Tor (2020). Preservation of Interference Effects in Working Memory After Orbitofrontal Damage. Frontiers in Human Neuroscience.

Leske, S., Dalal, S.S. (2019). Reducing power line noise in EEG and MEG data via spectrum interpolation. NeuroImage. 

Frey, J.N., Ruhnau, P., Leske, S., Siegel, M., Braun, C. and Weisz, N. (2016). The Tactile Window to Consciousness is Characterized by Frequency-Specific Integration and Segregation of the Primary Somatosensory Cortex. Scientific Reports.

Leske, S., Ruhnau, P., Frey, J., Lithari, C., Müller, N., Hartmann, T. and Weisz, N. (2015). Prestimulus Network Intergration of Auditory Cortex Predisposes Near-Threshold Perception Independently of Local Excitability. Cerebral Cortex. 

Hauswald, A., Übelacker, T., Leske, S., Weisz, N. (2015). What it means to be Zen: Marked modulations of local and interareal synchronization during open monitoring meditation. NeuroImage. 

Leske, S., Tse, A., Oosterhof, N., Hartmann, T., Müller, N., Keil, J. and Weisz, N. (2014). The strength of alpha and beta oscillations parametrically scale with the strength of an illusory auditory percept. NeuroImage. 

Müller, N., Leske, S., Hartmann, T., Szebeny, S. and Weisz, N. (2014). Listen to yourself: The medial prefrontal cortex modulates auditory alpha power during speech preparation. Cerebral Cortex. 

Weisz, N., Müller, N., Jatzev, S., & Bertrand, O. (2014). Oscillatory alpha modulations in right auditory regions reflect validity of acoustic cues in an auditory spatial attention task. Cerebral Cortex. 

Zander, T.O., Lehne, M. Ihme, K., Jatzev, S., Correia, J., Kothe, C., Picht, B., Nijboer, F. (2012). A dry EEG-system for scientific research and brain-computer interfaces. Frontiers in Neuroprosthetics.

Zander, T. O., Jatzev, S. (2012). Context-aware brain-computer interfaces: Exploring the information space of user, technical system and environment. Journal of Neural Engineering. 

Book chapters
Zander, T.O., Kothe, C., Jatzev, S., Gaertner, M. (2010). Enhancing Human-Computer Interaction with input from active and passive Brain-Computer Interfaces. In Tan, Nijholt (Eds.): (B+H)CI: The Human in Brain-Computer Interfaces and the Brain in Human-Computer Interactions.

• Olgerta Asko, Vegard Akselsson Volehaugen, Anaïs Llorens, Ingrid Funderud, Sabine Liliana Leske & Jugoslav Ivanovic [Vis alle 13 forfattere av denne artikkelen] (2025). Predictive encoding of auditory sequences in the human prefrontal cortex. bioRxiv - the preprint server for biology. doi: 10.1101/2025.08.22.671264. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Humans extract regularities from the environment to form expectations that guide perception and optimize behavior. Although the prefrontal cortex (PFC) is central to this process, the relative contributions of orbitofrontal (OFC) and lateral PFC (LPFC) remain unclear. Here, we show that the brain tracks sound regularities in an auditory deviance detection task to predict when a target deviant will occur. Intracranial EEG in epilepsy patients reveals prefrontal engagement, with earlier expectancy-related modulation in OFC and later modulation in LPFC. Connectivity analyses indicate bidirectional and asymmetrical expectancy-related information exchange between the two areas, with a first lead by OFC, consistent with its role in initiating predictive encoding. Converging causal evidence shows that OFC lesions abolish sensitivity to expectancy, whereas LPFC lesions yield only modest effects not significantly different from controls. Together, these results provide electrophysiological and causal evidence for distinct, temporally organized contributions of prefrontal subregions to predictive processing. Significance Statement The human brain builds probabilistic associations capturing the dynamic environmental structure in a predictive manner. The ability to encode and deploy predictive information to anticipate future events relies on the prefrontal cortex (PFC). However, the specific roles of PFC subregions in this process remain unclear. Here, we provide converging electrophysiological and causal lesion evidence on the distinct involvement of the orbital and lateral PFC in generating anticipatory neural signals based on probabilistic auditory structure.

• Ya-Ping Chen, Patrick Neff, Sabine Liliana Leske, Daniel D. E. Wong, Nicole Peter & Jonas Obleser [Vis alle 10 forfattere av denne artikkelen] (2025). Cochlear implantation in adults with acquired single-sided deafness improves cortical processing and comprehension of speech presented to the non-implanted ears: a longitudinal EEG study. Brain Communications. 7(1). doi: 10.1093/braincomms/fcaf001. Fulltekst i vitenarkiv
• Sabine Liliana Leske, Tor Endestad, Vegard Akselsson Volehaugen, Maja Dyhre Foldal, Alejandro Omar Blenkmann & Anne-Kristin Solbakk [Vis alle 7 forfattere av denne artikkelen] (2025). Beta oscillations predict the envelope sharpness in a rhythmic beat sequence. Scientific Reports. 15(1). doi: 10.1038/s41598-025-86895-y. Fulltekst i vitenarkiv Vis sammendrag

  Periodic sensory inputs entrain oscillatory brain activity, reflecting a neural mechanism that might be fundamental to temporal prediction and perception. Most environmental rhythms and patterns in human behavior, such as walking, dancing, and speech do not, however, display strict isochrony but are instead quasi-periodic. Research has shown that neural tracking of speech is driven by modulations of the amplitude envelope, especially via sharp acoustic edges, which serve as prominent temporal landmarks. In the same vein, research on rhythm processing in music supports the notion that perceptual timing precision varies systematically with the sharpness of acoustic onset edges, conceptualized in the beat bin hypothesis. Increased envelope sharpness induces increased precision in localizing a sound in time. Despite this tight relationship between envelope shape and temporal processing, it is currently unknown how the brain uses predictive information about envelope features to optimize temporal perception. With the current EEG study, we show that the predicted sharpness of the amplitude envelope is encoded by pre-target neural activity in the beta band (15–25 Hz), and has an impact on the temporal perception of target sounds. We used probabilistic sound cues in a timing judgment task to inform participants about the sharpness of the amplitude envelope of an upcoming target sound embedded in a beat sequence. The predictive information about the envelope shape modulated task performance and pre-target beta power. Interestingly, these conditional beta-power modulations correlated positively with behavioral performance in the timing judgment task and with perceptual temporal precision in a click-alignment task. This study provides new insight into the neural processes underlying prediction of the sharpness of the amplitude envelope during beat perception, which modulate the temporal perception of sounds. This finding could reflect a process that is involved in temporal prediction, exerting top-down control on neural entrainment via the prediction of acoustic edges in the auditory stream.

• Jan Weber, Anne-Kristin Solbakk, Alejandro Omar Blenkmann, Llorens Anais, Ingrid Funderud & Sabine Liliana Leske [Vis alle 11 forfattere av denne artikkelen] (2024). Ramping dynamics and theta oscillations reflect dissociable signatures during rule-guided human behavior. Nature Communications. 15(1). doi: 10.1038/s41467-023-44571-7. Fulltekst i vitenarkiv
• Alejandro Omar Blenkmann, Sabine Liliana Leske, Llorens Anais, Jack J. Lin, Edward F. Chang & Peter Brunner [Vis alle 12 forfattere av denne artikkelen] (2024). Anatomical registration of intracranial electrodes. Robust model-based localization and deformable smooth brain-shift compensation methods. Journal of Neuroscience Methods. ISSN 0165-0270. 404. doi: 10.1016/j.jneumeth.2024.110056. Fulltekst i vitenarkiv
• Sandra Solli, Anne Danielsen, Sabine Liliana Leske, Alejandro Omar Blenkmann, Keith Doelling & Anne-Kristin Solbakk [Vis alle 7 forfattere av denne artikkelen] (2024). Rhythm-based Temporal Expectations: Unique Contributions of Predictability and Periodicity. Journal of Cognitive Neuroscience. ISSN 0898-929X. doi: 10.1162/jocn_a_02261. Fulltekst i vitenarkiv Vis sammendrag

  Anticipating events and focusing attention accordingly are crucial for navigating our dynamic environment. Rhythmic patterns of sensory input offer valuable cues for temporal expectations and facilitate perceptual processing. Rhythm-based temporal expectations may rely on oscillatory entrainment, where neural activity and perceptual sensitivity synchronize with periodic stimuli. However, whether entrainment models can account for aperiodic predictable rhythms remains unclear. Our study aimed to delineate the distinct roles of predictability and periodicity in rhythm-based expectations. Participants performed a pitch-identification task preceded by periodic predictable, aperiodic predictable, or aperiodic unpredictable temporal sequences. By manipulating the temporal position of the target sound, we observed how auditory perceptual performance was modulated by the target position's relative phase relationship to the preceding sequences. Results revealed a significant performance advantage for predictable sequences, both periodic and aperiodic, compared with unpredictable ones. However, only the periodic sequence induced an entrained modulation pattern, with performance peaking in synchrony with the inherent sequence continuation. Event-related brain potentials corroborated these findings. The target-evoked P3b, possibly a neural marker of attention allocation, mirrored the behavioral performance patterns. This supports our hypothesis that temporal attention guided by rhythm-based expectations modulates perceptual performance. Furthermore, the predictive sequences were associated with enhanced target-preceding negativity (akin to the contingent negative variation), indicating enhanced target preparation. The periodic-specific modulation likely reflects more precise temporal expectations, potentially involving neural entrainment and/or more focused attention. Our findings suggest that predictability and periodicity influence perception through distinct mechanisms.

• Olgerta Asko, Alejandro Omar Blenkmann, Sabine Liliana Leske, Maja Dyhre Foldal, Llorens Anais & Ingrid Funderud [Vis alle 10 forfattere av denne artikkelen] (2024). Altered hierarchical auditory predictive processing after lesions to the orbitofrontal cortex. eLIFE. 13. doi: 10.7554/eLife.86386. Fulltekst i vitenarkiv
• Henning Leske, Ulrike Camenisch Gross, Silvia Hofer, Marian Christoph Neidert, Sabine Liliana Leske & Michael Weller [Vis alle 8 forfattere av denne artikkelen] (2023). MGMT methylation pattern of long-term and short-term survivors of glioblastoma reveals CpGs of the enhancer region to be of high prognostic value. Acta neuropathologica communications. 11:139(1), s. 1–12. doi: 10.1186/s40478-023-01622-w. Fulltekst i vitenarkiv Vis sammendrag

  Treatment with the alkylating agent temozolomide is known to be prognostically beneficial in a subset of glioblastoma patients. Response to such chemotherapeutic treatment and the prognostic benefit have been linked to the methylation status of O6-methylguanine-DNA methyltransferase (MGMT). To date, it has not been entirely resolved which methylation pattern of MGMT is most relevant to predict response to temozolomide treatment and outcome. In this retrospective study, we compared the methylation patterns, analyzed by Sanger sequencing, of 27 isocitrate dehydrogenase (IDH)-wildtype glioblastoma patients that survived more than 3 years (long-term survivors) with those of 24 patients who survived less than a year after initial surgery (short-term survivors). Random Forest-, Correlation-, and ROC-curve analyses were performed. The data showed that MGMT is typically methylated in long-term survivors, whereas no prominent methylation is observed in short-term survivors. The methylation status of CpGs, especially in the promoter and exon1/enhancer region correlated highly with outcome. In addition, age and temozolomide treatment were strongly associated with overall survival. Some CpGs in the enhancer region, in particular CpG 86 (bp + 154), demonstrated high values associated with overall survival in the Random Forest analysis. Our data confirm previously published prognostic factors in IDH-wildtype glioblastoma patients, including age and temozolomide treatment as well as the global MGMT methylation status. The area frequently used for decision making to administer temozolomide at the end of exon1 of MGMT, was associated with outcome. However, our data also suggest that the enhancer region, especially CpG 86 (bp + 154) is of strong prognostic value. Therefore, we propose further investigation of the enhancer region in a large prospective study in order to confirm our findings, which might result in an optimized prediction of survival in glioblastoma patients, likely linked to response to temozolomide treatment.

• Maja Dyhre Foldal, Sabine Liliana Leske, Alejandro Omar Blenkmann, Tor Endestad & Anne-Kristin Solbakk (2022). Attentional modulation of beta-power aligns with the timing of behaviorally relevant rhythmic sounds. Cerebral Cortex. ISSN 1047-3211. 33(5), s. 1876–1894. doi: 10.1093/cercor/bhac179. Fulltekst i vitenarkiv
• Anne-Kristin Solbakk, James Lubell, Sabine Leske, Ingrid Funderud, Llorens Anais & Alejandro Omar Blenkmann [Vis alle 10 forfattere av denne artikkelen] (2021). Monitoring of self-paced action timing and sensory outcomes after lesions to the orbitofrontal cortex. Journal of Cognitive Neuroscience. ISSN 0898-929X. 33(9), s. 1956–1975. doi: 10.1162/jocn_a_01733. Fulltekst i vitenarkiv
• Anaïs Llorens, Ingrid Funderud, Alejandro Omar Blenkmann, James Lubell, Maja Dyhre Foldal & Sabine Liliana Leske [Vis alle 11 forfattere av denne artikkelen] (2020). Preservation of Interference Effects in Working Memory After Orbitofrontal Damage. Frontiers in Human Neuroscience. 13, s. 1–15. doi: 10.3389/fnhum.2019.00445. Fulltekst i vitenarkiv Vis sammendrag

  Orbitofrontal cortex (OFC) is implicated in multiple cognitive processes, including inhibitory control, context memory, recency judgment, and choice behavior. Despite an emerging understanding of the role of OFC in memory and executive control, its necessity for core working memory (WM) operations remains undefined. Here, we assessed the impact of OFC damage on interference effects in WM using a Recent Probes task based on the Sternberg item-recognition task (1966). Subjects were asked to memorize a set of letters and then indicate whether a probe letter was presented in a particular set. Four conditions were created according to the forthcoming response ("yes"/"no") and the recency of the probe (presented in the previous trial set or not). We compared behavioral and electroencephalography (EEG) responses between healthy subjects (n = 14) and patients with bilateral OFC damage (n = 14). Both groups had the same recency pattern of slower reaction time (RT) when the probe was presented in the previous trial but not in the current one, reflecting the proactive interference (PI). The within-group electrophysiological results showed no condition difference during letter encoding and maintenance. In contrast, event-related potentials (ERPs) to probes showed distinct within-group condition effects, and condition by group effects. The response and recency effects for controls occurred within the same time window (300-500 ms after probe onset) and were observed in two distinct spatial groups including right centro-posterior and left frontal electrodes. Both clusters showed ERP differences elicited by the response effect, and one cluster was also sensitive to the recency manipulation. Condition differences for the OFC group involved two different clusters, encompassing only left hemisphere electrodes and occurring during two consecutive time windows (345-463 ms and 565-710 ms). Both clusters were sensitive to the response effect, but no recency effect was found despite the behavioral recency effect. Although the groups had different electrophysiological responses, the maintenance of letters in WM, the evaluation of the context of the probe, and the decision to accept or reject a probed letter were preserved in OFC patients. The results suggest that neural reorganization may contribute to intact recency judgment and response after OFC damage.

• Sabine Leske & Sarang S. Dalal (2019). Reducing power line noise in EEG and MEG data via spectrum interpolation. NeuroImage. ISSN 1053-8119. 189, s. 763–776. doi: 10.1016/j.neuroimage.2019.01.026. Fulltekst i vitenarkiv Vis sammendrag

  Electroencephalographic (EEG) and magnetoencephalographic (MEG) signals can often be exposed to strong power line interference at 50 or 60 Hz. A widely used method to remove line noise is the notch filter, but it comes with the risk of potentially severe signal distortions. Among other approaches, the Discrete Fourier Transform (DFT) filter and CleanLine have been developed as alternatives, but they may fail to remove power line noise of highly fluctuating amplitude. Here we introduce spectrum interpolation as a new method to remove line noise in the EEG and MEG signal. This approach had been developed for electromyographic (EMG) signals, and combines the advantages of a notch filter, while synthetic test signals indicate that it introduces less distortion in the time domain. The effectiveness of this method is compared to CleanLine, the notch (Butterworth) and DFT filter. In order to quantify the performance of these three methods, we used synthetic test signals and simulated power line noise with fluctuating amplitude and abrupt on- and offsets that were added to an MEG dataset free of line noise. In addition, all methods were applied to EEG data with massive power line noise due to acquisition in unshielded settings. We show that spectrum interpolation outperforms the DFT filter and CleanLine, when power line noise is nonstationary. At the same time, spectrum interpolation performs equally well as the notch filter in removing line noise artifacts, but shows less distortions in the time domain in many common situations.

Se alle arbeider i NVA

• Pål Strande Gamlemoen, Anne-Kristin Solbakk, Ole Petter Hjelle, Maja Dyhre Foldal & Sabine Liliana Leske (2025). Blir du også rasende når sidemannen prater i mobilen? Det er det gode grunner til. [Internet]. Aftenposten.no. Fulltekst i vitenarkiv Vis sammendrag

  Høy mobilprating ute i det offentlige kan være skikkelig plagsomt. Og det er faktisk gode grunner til at hjernen vår ikke liker det.

• Isak Elling August Støver, Sabine Liliana Leske, Anne-Kristin Solbakk, Maria Cecilie Forsmo & Venke Arntsberg Grane (2025). Nevropsykologi i det kliniske forskningsfeltet: Tankevandring hos voksne med ADHD. Fulltekst i vitenarkiv
• Alejandro Omar Blenkmann, Sabine Liliana Leske, Vegard Akselsson Volehaugen, Vinicius Rezende Carvalho, Silvia Kochen & Tor Endestad [Vis alle 10 forfattere av denne artikkelen] (2025). Intracranial high-frequency activity and oscillatory cortical dynamics of auditory prediction error propagation in humans. doi: https:/www.maastrichtuniversity.nl/file/icac2025abstracts-2025-09-11pdf. Fulltekst i vitenarkiv
• Alejandro Omar Blenkmann, Sabine Liliana Leske, Vegard Akselsson Volehaugen, Vinicius Rezende Carvalho, Silvia Kochen & Tor Endestad [Vis alle 8 forfattere av denne artikkelen] (2025). Spatiotemporal dynamics of auditory prediction error propagation via intracranial EEG in humans. doi: https:/www.frm2025oslo.no/s/FRM2025_AbstractBook.pdf. Fulltekst i vitenarkiv
• Sabine Liliana Leske, Isak Elling August Støver, Anne-Kristin Solbakk, Tor Endestad, Julia Kam & Venke Arntsberg Grane (2025). Behavioral, electromyographic and electrophysiological indicators of altered deviance detection and mind wandering in adult ADHD. Fulltekst i vitenarkiv
• Sabine Liliana Leske, Alejandro Omar Blenkmann, Jamie Lubell, Anaïs Llorens, Pål Gunnar Larsson & Ingrid Funderud [Vis alle 12 forfattere av denne artikkelen] (2025). INTRACRANIAL CORRELATES OF ACTION-BASED AUDITORY PREDICTION ERRORS IN HUMANS. Fulltekst i vitenarkiv
• Sandra Solli, Anne Danielsen, Sabine Liliana Leske, Alejandro Omar Blenkmann, Keith Doelling & Anne-Kristin Solbakk [Vis alle 7 forfattere av denne artikkelen] (2024). Rhythm-based temporal expectations: Unique contributions of predictability and periodicity. Fulltekst i vitenarkiv Vis sammendrag

  Flexibly adapting to our dynamic surroundings requires anticipating upcoming events and focusing our attention accordingly. Rhythmic patterns of sensory input offer valuable cues for these temporal expectations and facilitate perceptual processing. However, a gap in understanding persists regarding how rhythms outside of periodic structures influence perception. Our study aimed to delineate the distinct roles of predictability and periodicity in rhythm-based expectations. Participants completed a pitch-identification task preceded by different rhythm types: periodic predictable, aperiodic predictable, and aperiodic unpredictable. By manipulating the timing of the target sound, we observed how auditory sensitivity was modulated by the target position in the different rhythm conditions. The results revealed a clear behavioral benefit of predictable rhythms, regardless of their periodicity. Interestingly, we also observed an additional effect of periodicity. While both periodic and aperiodic predictable rhythms improved overall sensitivity, only the periodic rhythm seemed to induce an entrained sensitivity pattern, wherein sensitivity peaked in synchrony with the expected continuation of the rhythm. The recorded event-related brain potentials further supported these findings. The target-evoked P3b, possibly a neural marker of attention allocation, mirrored the sensitivity patterns. This supports our hypothesis that perceptual sensitivity is modulated by temporal attention guided by rhythm-based expectations. Furthermore, the effect of rhythm predictability seems to operate through climbing neural activity (similar to the CNV), reflecting preparation for the target. The effect of periodicity is likely related to more precise temporal expectations and could possibly involve neural entrainment. Our findings suggest that predictability and periodicity influence perception via distinct mechanisms.

• Alejandro Omar Blenkmann, Vegard Akselsson Volehaugen, Vinicius Rezende Carvalho, Sabine Liliana Leske, Anais Llorens & Ingrid Funderud [Vis alle 14 forfattere av denne artikkelen] (2024). An intracranial EEG study on auditory deviance detection. Fulltekst i vitenarkiv
• Sandra Solli, Anne Danielsen, Sabine Liliana Leske, Alejandro Omar Blenkmann, Keith Doelling & Anne-Kristin Solbakk [Vis alle 7 forfattere av denne artikkelen] (2024). Rhythm-based temporal expectations: Unique contributions of predictability and periodicity. Fulltekst i vitenarkiv
• Olgerta Asko, Vegard Akselsson Volehaugen, Sabine Liliana Leske, Ingrid Funderud, Anaïs Llorens & Jugoslav Ivanovic [Vis alle 12 forfattere av denne artikkelen] (2024). Predictive encoding of deviant tone sequences in the human prefrontal cortex. Fulltekst i vitenarkiv
• Olgerta Asko, Vegard Akselsson Volehaugen, Sabine Liliana Leske, Ingrid Funderud, Llorens Anais & Jugoslav Ivanovic [Vis alle 12 forfattere av denne artikkelen] (2024). Predictive encoding of deviant tone sequences in the human prefrontal cortex. Fulltekst i vitenarkiv Vis sammendrag

  The ability to use predictive information to guide perception and action relies heavily on the prefrontal cortex (PFC), yet the involvement of its subregions in predictive processes remains unclear. Recent perspectives propose that the orbitofrontal cortex (OFC) generates predictions about perceptual events, actions, and their outcomes while the lateral prefrontal cortex (LPFC) is involved in prospective functions, which support predictive processes, such as selective attention, working memory, response preparation or inhibition. To further delineate the roles of these PFC areas in predictive processing, we investigated whether lesions would impair the ability to build predictions of future events and detect deviations from expected regularities. We used an auditory deviance detection task, in which the structural regularities of played tones were controlled at two hierarchical levels by rules defined at a local (i.e., between tones within sequences) and global (i.e., between sequences) level. We have recently shown that OFC lesions affect detecting prediction violations at two hierarchical levels of rule abstraction, i.e., altered MMN and P3a to local and simultaneous local + global prediction violations (https://doi.org/10.7554/eLife.86386). Now, we focus on the task's predictive aspect and present the latest results showing the involvement of PFC subregions in anticipation of deviances informed by implicit predictive information. Behavioral data shows that deviance expectancy induced faster deviance detection in healthy adults (n=22), suggesting that participants track a state space representation of the task and anticipate upcoming deviant sequences. The analysis of EEG data from patients with focal lesions to the OFC (n = 12) or LPFC (n = 10), and SEEG from the same areas in patients with epilepsy (n = 7), revealed interesting differences. Healthy adults (n = 15) showed modulations of the Contingent Negative Variation (CNV) – a marker of anticipatory activity - tracking the expectancy of deviant tone sequences. However, patients with OFC lesions lacked CNV sensitivity to the predictive context, while patients with LPFC lesions showed moderate sensitivity compared to healthy adults. These results were further supported by intracranial recordings, which revealed expectancy modulation of the high-frequency broadband signal from electrodes in OFC and LPFC, with an earlier latency of activity modulation for the OFC and a later one for the LPFC. Altogether, the complementary approach from behavioral, intracerebral EEG, scalp EEG, and causal lesion data provides compelling evidence for the distinct engagement of the two prefrontal areas in predicting future events and signaling deviations.

• Alejandro Omar Blenkmann, Sabine Liliana Leske, Anaïs Llorens, Jack J. Lin, Edward Chang & Peter Brunner [Vis alle 12 forfattere av denne artikkelen] (2024). Novel tools for the anatomical registration of intracranial electrodes. Fulltekst i vitenarkiv
• Anne-Kristin Solbakk, Mikael Hope, Sandra Solli, Sabine Liliana Leske, Maja Dyhre Foldal & Alejandro Omar Blenkmann (2024). Research seminar. Fulltekst i vitenarkiv
• Venke Arntsberg Grane, Tor Endestad, Isak Elling August Støver, Sabine Liliana Leske & Anne-Kristin Solbakk (2024). Executive Function in a Treatment-Naive ADHD Cohort Diagnosed in Adulthood. Fulltekst i vitenarkiv Vis sammendrag

  Background: Attention Deficit Hyperactivity Disorder (ADHD) is an early onset neurodevelopmental condition presenting with diverse cognitive/behavioral impairments that persist into adulthood for half of those affected. Objective: To examine whether unmedicated adults show general- or specific reductions in core executive functions (EFs). Method: Performance on EF-tasks was assessed in adult patients with ADHD, Combined type (n=36) and in healthy controls (n=34), matched on gender, age, and education level. The tasks tapped memory span/working memory (Digit Span), interference control/response inhibition (Color Word Interference Test; CWIT-Inhibition), set-shifting/switching (CWIT-Switching; Trail Making Test [TMT]), and abstract reasoning (Wisconsin Card Sorting Test; [WCST]). Results: There was no group difference in immediate memory span, but the patients performed significantly worse than controls when there was an additional demand on working memory. Statistically controlling for individual differences in information processing speed (using an independent reaction time measure) did not alter the result. Patients performed inferiorly on basic psychomotor speed conditions of the TMT, but the most pronounced group difference appeared on the set-shifting condition. The CWIT-Inhibition condition did not distinguish the groups, but patients had a near-significant tendency to perform more poorly when a concurrent demand on rapid set-switching was introduced. They completed fewer card-sorting categories on the WCST than controls, with more errors overall. There was no significant difference in perseverative errors, but patients committed more non- perseverative errors and failures to maintain set, indicating more random choices and/or losing track of the current sorting principle. Conclusion: ADHD-related reductions of attention maintenance, switching, and working memory, but not inhibitory control, support the literature indicating that ADHD in adulthood is neither associated with specific deficits in inhibitory control, and nor with a general executive impairment. Accordingly, clinical assessment should span a range of EF tests, including the core control functions studied here.

• Vegard Akselsson Volehaugen, Sabine Liliana Leske, Ingerid Funderud, Vinicius Rezende Carvalho, Tor Endestad & Anne-Kristin Solbakk [Vis alle 7 forfattere av denne artikkelen] (2024). Unheard Surprises: Attention-Dependent Neocortical Dynamics Following Unexpected Omissions Revealed by Intracranial EEG. Fulltekst i vitenarkiv
• Sabine Liliana Leske, Tor Endestad, Vegard Akselsson Volehaugen, Maja Dyhre Foldal, Alejandro Omar Blenkmann & Anne-Kristin Solbakk [Vis alle 7 forfattere av denne artikkelen] (2024). Predicting the Beat Bin: Beta Oscillations Predict the Envelope Sharpness in a Rhythmic Sequence. Fulltekst i vitenarkiv
• Sabine Liliana Leske, Isak Elling August Støver, Anne-Kristin Solbakk, Tor Endestad, Julia Kam & Venke Arntsberg Grane (2024). Behavioral and Electrophysiological Markers of Altered Mind Wandering and Sustained Attention in Adult ADHD. Fulltekst i vitenarkiv Vis sammendrag

  Background: Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that often persists into adulthood. Difficulties with executive control and sustained attention are key characteristics of the disorder that often lead to thoughts that are unrelated to the current task, i.e., mind wandering. Objective: Investigate behavioral and neurophysiological correlates of sustained attention and mind wandering in adults with ADHD not on medication when examined. Method: Sustained attention and propensity to mind-wander was investigated in ADHD patients (n=17) and in healthy controls (n=17), matched on gender, age, and IQ. Participants performed an auditory oddball task (participant feedback: On or Off Task), which required continuous manual responses to standard and target tones, while Electroencephalography (EEG) was measured. Sustained attentional control was additionally examined with the Test of Variables of Attention (T.O.V.A.). General IQ was estimated with a reduced version of the Wechsler Adult Intelligence Scale, 4th edition (WAIS-IV). Results: ADHD patients reported significantly more episodes of mind wandering (Off Task), exhibited reduced target detection accuracy and more Off Task impulsive responses compared to controls. Patients showed a significantly reduced P300 for the target-standard difference components, for both On and Off Task conditions. This target-standard P300 difference was less modulated between On versus Off Task conditions in patients compared to controls. In the T.O.V.A. test, patients committed significantly more Commission Errors, but did not differ from controls on other variables (Attention Comparison score, Reaction Time variability and latency, Omission Errors). Conclusion: In comparison to controls, patients showed deteriorated behavioral performance, more episodes of mind wandering, and reduced P300 in a sustained attention task. The P300 decrease likely reflects impaired control of attentional resources allocated to the task, which has an impact on high-level cognitive processing abilities, while early sensory-related stimulus processing is intact.

• Alejandro Omar Blenkmann, Sabine Liliana Leske, Anais Llorens, Jack J. Lin, Edward Chang & Peter Brunner [Vis alle 12 forfattere av denne artikkelen] (2024). Anatomical registration of intracranial electrodes. Fulltekst i vitenarkiv
• Olgerta Asko, Anne-Kristin Solbakk, Sabine Liliana Leske, Torstein Ragnar Meling, Robert T. Knight & Tor Endestad [Vis alle 7 forfattere av denne artikkelen] (2023). The orbitofrontal cortex (OFC) has a critical role in the generation of high-level expectations. Fulltekst i vitenarkiv
• Sabine Liliana Leske, Tor Endestad, Vegard Volehaugen, Maja Dyhre Foldal, Alejandro Omar Blenkmann & Anne-Kristin Solbakk [Vis alle 7 forfattere av denne artikkelen] (2023). Predicting the Beat Bin – Beta Oscillations Support Top-Down Prediction of The Temporal Precision of a Beat. Fulltekst i vitenarkiv
• Sandra Solli, Anne Danielsen, Sabine Liliana Leske, Alejandro Omar Blenkmann, Anne-Kristin Solbakk & Tor Endestad (2023). Periodic vs Aperiodic Temporal Predictions: Shared or Separate Mechanisms? Fulltekst i vitenarkiv
• Sandra Solli, Anne Danielsen, Sabine Liliana Leske, Anne-Kristin Solbakk & Tor Endestad (2023). Periodic vs Aperiodic Temporal Predictions: Shared or Separate Mechanisms? Fulltekst i vitenarkiv
• Sandra Solli, Keith Doelling, Sabine Liliana Leske, Anne Danielsen & Tor Endestad (2023). The role of the motor system in predicting accelerating and decelerating auditory rhythms. Fulltekst i vitenarkiv
• Sandra Solli, Anne Danielsen, Sabine Liliana Leske, Alejandro Omar Blenkmann, Anne-Kristin Solbakk & Tor Endestad (2023). Both periodic and aperiodic rhythms facilitate perceptual processing. Fulltekst i vitenarkiv
• Alejandro Omar Blenkmann, Olgerta Asko, Vegard Volehaugen, Maja Dyhre Foldal, Sandra Solli & Sabine Liliana Leske [Vis alle 9 forfattere av denne artikkelen] (2023). Auditory perception, memory, and predictions. Fulltekst i vitenarkiv
• Anne-Kristin Solbakk, Alejandro Omar Blenkmann, Sabine Liliana Leske & Tor Endestad (2023). Orbitofrontal lesion impacts formation of auditory expectations. Fulltekst i vitenarkiv
• Alejandro Omar Blenkmann, Anne-Kristin Solbakk, Sabine Liliana Leske, Anaïs Llorens, Ingrid Funderud & Pål Gunnar Larsson [Vis alle 10 forfattere av denne artikkelen] (2023). Temporal and precentral brain activity in automatic auditory deviance detection. Evidence from human intracranial EEG recordings. Fulltekst i vitenarkiv
• Vegard Volehaugen, Sabine Liliana Leske, Ingrid Funderud, Anaïs Llorens, Vinicius Rezende Carvalho & Tor Endestad [Vis alle 8 forfattere av denne artikkelen] (2023). Echoes of the unheard: An intracranial electrophysiology study of expectation and attention in auditory omission processing. Fulltekst i vitenarkiv
• Olgerta Asko, Anne-Kristin Solbakk, Sabine Liliana Leske, Torstein Ragnar Meling, Robert T. Knight & Tor Endestad [Vis alle 7 forfattere av denne artikkelen] (2023). Orbitofrontal lesion impacts formation of auditory expectations. Fulltekst i vitenarkiv Vis sammendrag

  Current findings of orbitofrontal cortex (OFC) function suggest that this region might have a role in the generation of prediction error signals associated with top-down expectation of upcoming stimuli. We investigated the impact of lesions to the OFC on the Contingent Negative Variation (CNV), an electrophysiological marker of cognitive expectation and time perception. Twelve OFC patients and fifteen healthy controls performed an auditory local-global paradigm while brain electrical activity was recorded. The structural regularities of the tones were controlled at two hierarchical levels by rules defined at a local (i.e., between tones within sequences) level with a short timescale and at a global (i.e., between sequences) level with a longer timescale. At the global level, deviant tone sequences were interspersed among standard tone sequences in a pseudorandom order, rendering some deviant sequences more anticipated than others. We found that healthy controls exhibited CNV build-up before the occurrence of deviant sequences. The CNV drift rate was modulated by the expectancy of deviant sequences (i.e., the higher the expectancy, the higher the CNV drift rate), reflecting their ability to anticipate when a deviant tone sequence would occur. However, patients with OFC lesions did not show CNV drift modulations by the expectancy of the deviant tone sequences, indicating impaired anticipation of these upcoming events. These findings suggest involvement of the OFC in generating auditory expectations based on the contextual and temporal structure of the task.

• Leonardo Bonetti, Maja Dyhre Foldal, Sabine Liliana Leske, Olgerta Asko, Vegard Akselsson Volehaugen & Sandra Solli [Vis alle 7 forfattere av denne artikkelen] (2023). Auditory perception, memory, and predictions. Fulltekst i vitenarkiv
• Vegard Volehaugen, Sabine Liliana Leske, Tor Endestad, Anne-Kristin Solbakk & Alejandro Omar Blenkmann (2022). Violation of rule-based auditory patterns is detected independently of attention. Fulltekst i vitenarkiv
• Sabine Liliana Leske (2022). Phase Amplitude Coupling (PAC). Fulltekst i vitenarkiv Vis sammendrag

  An introduction to the Phase Amplitude Coupling (PAC) measure and how it is applied to EEG data (example code in MATLAB). The caveats of the measure are covered and which sanity checks might be necessary.

• Sabine Liliana Leske (2022). Inter-Trial Coherence (ITC). Fulltekst i vitenarkiv Vis sammendrag

  An introduction to the inter-trial coherence measure (ITC) and how it is applied to EEG data (with example code/scripts in MATLAB). Furthermore caveats of the measure are discussed along with it's relation to phase opposition measures.

• Sabine Liliana Leske (2022). Fourier Transform. Fulltekst i vitenarkiv Vis sammendrag

  An introduction to the Fourier transform and how it is applied to EEG data. The short time fourier transform (STFT) and different measures (phase and amplitude) derived from it are explained.

• Olgerta Asko, Alejandro Omar Blenkmann, Sabine Liliana Leske, Maja Dyhre Foldal, Anaïs Llorens & Ingrid Funderud [Vis alle 10 forfattere av denne artikkelen] (2022). Altered hierarchical auditory predictive processing after lesions to the orbitofrontal cortex. Fulltekst i vitenarkiv Vis sammendrag

  In this study, we tested the causal involvement of the OFC in noticing breaches of predictions (i.e., PEs) at different hierarchical levels of task structural complexity. With this aim, we examined the event-related potentials (ERPs) of patients with focal OFC lesions and healthy adults while performing an auditory local-global oddball paradigm. Altogether, we found that after OFC damage, low-level PEs (i.e., processing of stimuli that are unpredicted at the local level) and combined low- and high-level PEs (i.e., processing of stimuli that are unpredicted at both the local and global level) were impacted. However, the processing of standard tones was not affected. We conclude that the OFC may contribute to a top-down process that modulates the deviance detection system in the primary auditory cortices, and may be involved in connecting PEs at lower hierarchical areas with predictions at higher areas. The study sheds new light on the poorly explored deficits of hierarchical auditory prediction in patients with damaged OFC.

• Alejandro Omar Blenkmann, Anne-Kristin Solbakk, Sabine Liliana Leske, Anaïs Llorens, Ingrid Funderud & Santiago Collavini [Vis alle 13 forfattere av denne artikkelen] (2022). Human brain network involved in auditory deviance detection. An intracranial EEG study. Fulltekst i vitenarkiv
• Anne Danielsen, Guilherme Schmidt Câmara, Olivier Lartillot, Sabine Liliana Leske & Connor Spiech (2022). Musical rhythm. Behavioural, computational and neurophysiological perspectives. Fulltekst i vitenarkiv
• Anne Danielsen & Sabine Liliana Leske (2022). How the brain tracks the precision of a beat bin - musical, behavioral and neurophysiological perspectives. Fulltekst i vitenarkiv Vis sammendrag

  The internal beat or pulse in the listener is not a single point in time, but has a shape and a width and can be described via a probability distribution. This phenomenon has been conceptualized in the beat bin thoery (Danielsen 2010). The internal beat bin of the listener varies systematically with the precision needed in the given musical or sonic context. Anne and Sabine will present behavioral evidence for this phenomenon and a first attempt to reveal the underlying neural mechanism behind the flexible adaptation to the precision of the current beat bin context. They will present effects of acoustic factors on the perceptual center and the beat bin, as well as preliminary results on how neural oscillatory activity might represent a neural mechanism behind this phenomenon.

• Ingrid Funderud, Anne Danielsen, Tor Endestad, Alexander Refsum Jensenius, Sabine Liliana Leske & Anne-Kristin Solbakk (2021). Improving working memory in patents with epilepsy by rhythmic sounds. Fulltekst i vitenarkiv
• Maja Dyhre Foldal, Sabine Liliana Leske, Alejandro Omar Blenkmann, Tor Endestad & Anne-Kristin Solbakk (2021). Attentional modulation of alpha- and beta oscillations during perception of auditory rhythms. Fulltekst i vitenarkiv
• Anne-Kristin Solbakk, Sabine Liliana Leske, James Isaac Lubell, Alejandro Omar Blenkmann, Anais Llorens & Ingrid Funderud [Vis alle 13 forfattere av denne artikkelen] (2021). Auditory prediction and prediction error in self-generated tones. Fulltekst i vitenarkiv
• Sabine Liliana Leske, James Lubell, Alejandro Omar Blenkmann, Anaïs Llorens, Ingrid Funderud & Maja Dyhre Foldal [Vis alle 13 forfattere av denne artikkelen] (2019). Action-based auditory predictions. Fulltekst i vitenarkiv Vis sammendrag

  Sensory consequences of actions are predicted by the brain via an internal forward model to prepare sensory cortical areas, referred to as motor prediction. In a similar vein, the predictive coding framework suggests that perception is based on internal models making predictions about sensory events, based on statistical probabilities of the stimuli. In the current study we investigated action-based sensory predictions. We used a self-paced, two-choice random generation task, infrequently inducing deviant outcomes of voluntary action. Participants repeatedly pressed a right and a left button normatively associated with a 70 ms long 1 kHz and 2 kHz tone, respectively. Occasional deviants occurred, inverting the learned button-tone association. Participants were instructed that their button presses should be random, at a regular but self-paced tempo of one press per 1-2 s, and that they should press both buttons with equal probability. They were informed that the tones are task-irrelevant. We used intracranial EEG (iEEG) data recorded from 10 adult patients with electrodes localized in frontal and temporal lobes. The patients had drug resistant epilepsy and were undergoing presurgical monitoring via implanted stereotactic electrodes. Electrode coordinates and anatomical labels were obtained from coregistered MRI and CT images using iElectrodes toolbox. Initial results indicate that violations of action intentions modulated high frequency band activity (HFA, 75-145 Hz) in distributed brain regions including temporal and prefrontal cortices.

• Sabine Liliana Leske, James Isaac Lubell, Alejandro Omar Blenkmann, Anaïs Llorens, Ingrid Funderud & Maja Dyhre Foldal [Vis alle 13 forfattere av denne artikkelen] (2019). Auditory prediction and prediction error in self-generated tones. Fulltekst i vitenarkiv
• Britta Westner, Lau Møller Andersen, Alejandro Omar Blenkmann & Sabine Liliana Leske (2019). RITMO International EEG FieldTrip workshop, Lectures and Hands-on sessions. Fulltekst i vitenarkiv
• Sabine Liliana Leske (2019). Oscillations and their functional relevance and Experimental design issues in EEG studies investigating oscillations. Fulltekst i vitenarkiv
• Alejandro Omar Blenkmann, Anne-Kristin Solbakk, James Lubell, Sabine Liliana Leske, Anaïs Llorens & Ingrid Funderud [Vis alle 14 forfattere av denne artikkelen] (2019). Human brain network involved in auditory deviance detection: Evidence from intracranial EEG recordings. Fulltekst i vitenarkiv Vis sammendrag

  The neural network underlying human auditory deviance detection is not fully understood. To address this, we recorded intracranial EEG from 22 adult patients with drug resistant epilepsy undergoing presurgical monitoring who had depth electrodes implanted in all brain lobes (1193 channels in total). Patients passively heard a stream of bilaterally presented tones while reading. We used the Optimum-1 paradigm, that consisted of 300 standard tones interleaved with 300 randomly presented deviant tones per block. Patients completed between 3 to 10 blocks. Deviant tones differed from standards in: 1) intensity (louder or softer), 2) frequency (higher or lower), 3) sound source location (right or left), 4) a shorter duration, or 5) a silent gap in the middle of the tone (Näätänen et al., 2004). Electrode coordinates were obtained from coregistered MRI and CT images using iElectrodes toolbox (Blenkmann et al., 2017). Channels were bipolar referenced and high frequency band activity (HFA) analytic amplitude signal was obtained using the Hilbert transform (75-145 Hz). Compared to the baseline period, significant HFA responses to tones in general were observed in 31% of the channels. We used an ANOVA to quantify the HFA response variance across trials that could be explained by the different factors of the stimuli: Intensity, Laterality, Frequency, Duration and Gap. We estimated the amount of explained variance by using ?2 (Siegel et al., 2015). Eighteen % of the channels showed a significant increase of the condition-specific explained variance. Some channels showed condition-specific activations to one particular deviant, while others showed activations to a combination of two or more deviants. The channels showing responses to tones in general and condition-specific effects were mostly observed bilaterally in temporal cortex. Frontal, anterior cingulate, and parietal cortices were also involved to a lesser extent. Our results, in line with the predictive coding framework, reveal that a distributed brain network is involved in auditory processing and deviance detection.

• Alejandro Omar Blenkmann, Anne-Kristin Solbakk, James Lubell, Sabine Liliana Leske, Anaïs Llorens & Ingrid Funderud [Vis alle 14 forfattere av denne artikkelen] (2019). Human brain network involved in auditory deviance detection: Evidence from intracranial EEG recordings. Fulltekst i vitenarkiv

Se alle arbeider i NVA