Alejandro Omar Blenkmann

Researcher - RITMO Centre for Interdisciplinary Studies in Rhythm, Time and Motion (PSI)

Norwegian version of this page

Email a.o.blenkmann@psykologi.uio.no

Available hours By agreement

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Visiting address 澳门葡京手机版app下载sv. 3A Harald Schjelderups hus 0373 Oslo

Postal address Postboks 1133 Blindern 0318 Oslo

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Academic interests

My major interest is how our brains make predictions of future events. Is our brain a prediction machine to some extent?

I'm the project leader of AudioPred, a project where we study predictive processes in the auditory domain, and part of FrontNeurolab and RITMO. We use different experiments to characterize the neuronal networks that are active when we make predictions and when unexpected events violate these predictions. I��m interested in understanding the neurophysiological basis and the brain network supporting this complex task. I work with intracranial recordings (ECoG or SEEG) obtained from epilepsy patients implanted for medical reasons. These recordings allow us to observe brain activity with a unique spatiotemporal resolution. I also study patients with frontal lobe lesions to understand the frontal lobe's role in the prediction network.

I��m also interested in methods for localizing intracranial electrodes. In this vein, I developed iElectrodes, an open-source toolbox running on MATLAB ? to perform intracranial electrode localization. The toolbox uses MRI and CT images to localize, number, and anatomically label intracranial grids (ECoG) and depth (SEEG) electrodes. For more information, please visit the iElectrodes project page.

Background

Education

2012 PhD. in Engineering, National University of La Plata, Argentina. Topic: Localization of Brain Activity Sources

2007 Biomedical Engineer (with honors), Favaloro University, Buenos Aires, Argentina

2004 Bachelor in Engineering (with honors), Favaloro University, Buenos Aires, Argentina

Employment history

2020 - present Researcher, RITMO, University of Oslo, Norway

2018 - (6m) Visiting Scientist at Knight's lab, University of California, Berkeley, USA

2015 �C 2019 Postdoctoral Fellow, Department of Psychology, University of Oslo, Norway

2014 �C 2015 Researcher, IBCN, UBA-CONICET, Argentina

2014 �C 2015 Associate Professor, National Technological University, Argentina

2013 - (5m) Visiting Scientist at Bekinschtein's lab, MRC Cognition and Brain Sciences Unit, Cambridge, UK

2012 �C 2015 Associate Professor, Favaloro University, Argentina

2013 �C 2014 Senior Lecturer, National Technological University, Argentina

2012 �C 2014 Postdoctoral Fellow, IBCN, UBA-CONICET, Argentina

2012 �C 2013 Assistant Lecturer, National Technological University, Argentina

2009 �C 2012 Lecturer, Favaloro University, Argentina

2007 �C 2012 Ph.D. Fellow, IBCN, UBA-CONICET, Argentina

2007 - (3m) Research Assistant, UPM, Spain

Graduate students (co-)supervision

Julian Fuhrer, University of Oslo, 2023. A Small Step Closer to Separating Prediction from Repetition Suppression in the Auditory Mismatch Negativity Response.
Vegard Volehaugen, University of Oslo. Ongoing.
Olgerta Asko, University of Oslo. Ongoing.
Saira Jameela H��benette, University of Oslo. Ongoing.

Master students (co-)supervision

Eng. Soledad Reyes - Favaloro Univ., Arg., 2012. HL7 Medical record for epilepsy.
Eng. Santiago Collavini - Favaloro Univ., Arg., 2015. Effective connectivity in epileptogenic networks in the Occipital Lobe.
MPsych. Rebecca Millichamp, University of Oslo, 2018. A Small Step Closer to Separating Prediction from Repetition Suppression in the Auditory Mismatch Negativity Response.
MPsych. Vegard Volehaugen, University of Oslo, 2021. Attention in the Hierarchy of Predictions and Prediction Errors.
MPsych Sara Kruge Nossen, University of Oslo, 2023. Automatic Deviance Detection in the Human Auditory Cortex and Temporoparietal Junction.

Partners

Main collaborations (head of lab):

Dr. Silvia Kochen, UNAJ �C El Cruce Hospital - CONICET, Argentina.
Dr. Carlos Muravchik. LEICI, National University of La Plata, Argentina.
Dr. Tristan Bekinschtein. Department of Psychology, University of Cambridge, United Kingdom.
Dr. Robert Knight - Dept. of Psychology/Helen Wills Neuroscience Institute, University of Berkeley, USA.
Dr. P?l G. Larsson, Department of Neurosurgery, University of Oslo.
Dr. Andres Canales-Johnson. Department of Psychology, University of Cambridge, United Kingdom.
Dr. J?rgen Sugar, Institute of Medical Sciences, University of Oslo
Dr. Krzysztof Basi��ski, Department of Psychology, Medical University of Gda��sk, Poland.
Dr. Leonardo Bonetti, Department of Clinical Medicine - Center for Music In the Brain, Aarhus University, Denmark.
Dr. David Quiroga-Martinez, University of Copenhagen, Denmark

Media and general public content

Interview for the Argentinean TV show "Salud en Movimiento", Radio Television Neuqu��n, Argentina [in Spanish]. 29.03.23 YouTube link
Interview at radio La Divina Providencia FM 97.3, Neuqu��n, Argentina [in Spanish]. 30.03.23 [download mp3 file]
Presentation at RITMO Centre for Interdisciplinary Studies in Rhythm, Time and Motion, University of Oslo, Norway. 12.03.21 YouTube link
Kids presentation for the Organization for Human Brain Mapping 30.05.22. [in Spanish with English subtitles] YouTube link

Tags: Cognitive neuroscience, predictive coding, methods, intracranial EEG, frontal lobe, lesion

Asko, Olgerta; Volehaugen, Vegard Akselsson; Llorens, Ana?s; Funderud, Ingrid; Leske, Sabine Liliana & Ivanovic, Jugoslav [Show all 13 contributors for this article] (2025). Predictive encoding of auditory sequences in the human prefrontal cortex. bioRxiv - the preprint server for biology. doi: 10.1101/2025.08.22.671264. Show summary
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.
Leske, Sabine Liliana; Endestad, Tor; Volehaugen, Vegard Akselsson; Foldal, Maja Dyhre; Blenkmann, Alejandro Omar & Solbakk, Anne-Kristin [Show all 7 contributors for this article] (2025). Beta oscillations predict the envelope sharpness in a rhythmic beat sequence. Scientific Reports. 15(1). doi: 10.1038/s41598-025-86895-y. Full text in Research Archive Show summary
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�C25 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.
Fuhrer, Julian; Glette, Kyrre; Ivanovic, Jugoslav; Larsson, P?l Gunnar; Bekinschtein, Tristan & Kochen, Silvia [Show all 11 contributors for this article] (2025). Direct brain recordings reveal implicit encoding of structure in random auditory streams. Scientific Reports. 15(1). doi: 10.1038/s41598-025-98865-5. Show summary
The brain excels at processing sensory input, even in rich or chaotic environments. Mounting evidence attributes this to sophisticated internal models of the environment that draw on statistical structures in the unfolding sensory input. Understanding how and where such modeling proceeds is a core question in statistical learning and predictive processing. In this context, we address the role of transitional probabilities as an implicit structure supporting the encoding of the temporal structure of a random auditory stream. Leveraging information-theoretical principles and the high spatiotemporal resolution of intracranial electroencephalography, we analyzed the trial-by-trial high-frequency activity representation of transitional probabilities. This unique approach enabled us to demonstrate how the brain automatically and continuously encodes structure in random stimuli and revealed the involvement of a network outside of the auditory system, including hippocampal, frontal, and temporal regions. Our work provides a comprehensive picture of the neural correlates of automatic encoding of implicit structure that can be the crucial substrate for the swift detection of patterns and unexpected events in the environment.
Weber, Jan; Solbakk, Anne-Kristin; Blenkmann, Alejandro Omar; Anais, Llorens; Funderud, Ingrid & Leske, Sabine Liliana [Show all 11 contributors for this article] (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.
Blenkmann, Alejandro Omar; Leske, Sabine Liliana; Anais, Llorens; Lin, Jack J.; Chang, Edward F. & Brunner, Peter [Show all 12 contributors for this article] (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.
Solli, Sandra; Danielsen, Anne; Leske, Sabine Liliana; Blenkmann, Alejandro Omar; Doelling, Keith & Solbakk, Anne-Kristin [Show all 7 contributors for this article] (2024). Rhythm-based Temporal Expectations: Unique Contributions of Predictability and Periodicity. Journal of Cognitive Neuroscience. ISSN 0898-929X. doi: 10.1162/jocn_a_02261.
Asko, Olgerta; Blenkmann, Alejandro Omar; Leske, Sabine Liliana; Foldal, Maja Dyhre; Anais, Llorens & Funderud, Ingrid [Show all 10 contributors for this article] (2024). Altered hierarchical auditory predictive processing after lesions to the orbitofrontal cortex. eLIFE. 13. doi: 10.7554/eLife.86386.
Weber, Jan; Iwama, Gabriela; Solbakk, Anne-Kristin; Blenkmann, Alejandro Omar; Larsson, P?l Gunnar & Ivanovic, Jugoslav [Show all 9 contributors for this article] (2023). Subspace partitioning in the human prefrontal cortex resolves cognitive interference. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 120(28). doi: 10.1073/pnas.2220523120. Full text in Research Archive
Anais, Llorens; Bellier, Ludovic; Blenkmann, Alejandro Omar; Ivanovic, Jugoslav; Larsson, P?l Gunnar & Lin, Jack J. [Show all 9 contributors for this article] (2023). Decision and response monitoring during working memory are sequentially represented in the human insula. iScience. 26(10). doi: 10.1016/j.isci.2023.107653. Full text in Research Archive
Fuhrer, Julian; Glette, Kyrre; Anais, Llorens; Endestad, Tor; Solbakk, Anne-Kristin & Blenkmann, Alejandro Omar (2023). Quantifying evoked responses through information-theoretical measures. Frontiers in Neuroinformatics. 17. doi: 10.3389/fninf.2023.1128866. Full text in Research Archive
Foldal, Maja Dyhre; Leske, Sabine Liliana; Blenkmann, Alejandro Omar; Endestad, Tor & Solbakk, Anne-Kristin (2022). Attentional modulation of beta-power aligns with the timing of behaviorally relevant rhythmic sounds. Cerebral Cortex. ISSN 1047-3211. 33(5), p. 1876�C1894. doi: 10.1093/cercor/bhac179.
Blenkmann, Alejandro Omar; Solbakk, Anne-Kristin; Ivanovic, Jugoslav; Larsson, P?l Gunnar; Knight, Robert Thomas & Endestad, Tor (2022). Modeling intracranial electrodes. A simulation platform for the evaluation of localization algorithms. Frontiers in Neuroinformatics. 16, p. 1�C20. doi: 10.3389/fninf.2022.788685. Full text in Research Archive
Fuhrer, Julian; Blenkmann, Alejandro Omar; Endestad, Tor; Solbakk, Anne-Kristin & Glette, Kyrre (2022). Complexity-based Encoded Information Quantification in Neurophysiological Recordings. Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). p. 2319�C2323. doi: 10.1109/EMBC48229.2022.9871501. Show summary
Brain activity differs vastly between sleep, cognitive tasks, and action. Information theory is an appropriate concept to analytically quantify these brain states. Based on neurophysiological recordings, this concept can handle complex data sets, is free of any requirements about the data structure, and can infer the present underlying brain mechanisms. Specifically, by utilizing algorithmic information theory, it is possible to estimate the absolute information contained in brain responses. While current approaches that apply this theory to neurophysiological recordings can discriminate between different brain states, they are limited in directly quantifying the degree of similarity or encoded information between brain responses. Here, we propose a method grounded in algorithmic information theory that affords direct statements about responses' similarity by estimating the encoded information through a compression-based scheme. We validated this method by applying it to both synthetic and real neurophysiological data and compared its efficiency to the mutual information measure. This proposed procedure is especially suited for task paradigms contrasting different event types because it can precisely quantify the similarity of neuronal responses.
Solbakk, Anne-Kristin; Lubell, James; Leske, Sabine; Funderud, Ingrid; Anais, Llorens & Blenkmann, Alejandro Omar [Show all 10 contributors for this article] (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), p. 1956�C1975. doi: 10.1162/jocn_a_01733.
Foldal, Maja Dyhre; Blenkmann, Alejandro Omar; Llorens, Ana?s; Knight, Robert T.; Solbakk, Anne-Kristin & Endestad, Tor (2020). The brain tracks auditory rhythm predictability independent of selective attention. Scientific Reports. 10, p. 1�C13. doi: 10.1038/s41598-020-64758-y. Full text in Research Archive Show summary
The brain responds to violations of expected rhythms, due to extraction- and prediction of the temporal structure in auditory input. Yet, it is unknown how probability of rhythm violations affects the overall rhythm predictability. Another unresolved question is whether predictive processes are independent of attention processes. In this study, EEG was recorded while subjects listened to rhythmic sequences. Predictability was manipulated by changing the stimulus-onset-asynchrony (SOA deviants) for given tones in the rhythm. When SOA deviants were inserted rarely, predictability remained high, whereas predictability was lower with more frequent SOA deviants. Dichotic tone-presentation allowed for independent manipulation of attention, as specific tones of the rhythm were presented to separate ears. Attention was manipulated by instructing subjects to attend to tones in one ear only, while keeping the rhythmic structure of tones constant. The analyses of event-related potentials revealed an attenuated N1 for tones when rhythm predictability was high, while the N1 was enhanced by attention to tones. Bayesian statistics revealed no interaction between predictability and attention. A right-lateralization of attention effects, but not predictability effects, suggested potentially different cortical processes. This is the first study to show that probability of rhythm violation influences rhythm predictability, independent of attention.
Llorens, Ana?s; Funderud, Ingrid; Blenkmann, Alejandro Omar; Lubell, James; Foldal, Maja Dyhre & Leske, Sabine Liliana [Show all 11 contributors for this article] (2020). Preservation of Interference Effects in Working Memory After Orbitofrontal Damage. Frontiers in Human Neuroscience. 13, p. 1�C15. doi: 10.3389/fnhum.2019.00445. Full text in Research Archive Show summary
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.
Rey, Hernan; Gori, Belen; Chaure, Fernando; Collavini, Santiago; Blenkmann, Alejandro Omar & Seoane, Pablo [Show all 9 contributors for this article] (2020). Single Neuron Coding of Identity in the Human Hippocampal Formation. Current Biology. ISSN 0960-9822. 30. doi: 10.1016/j.cub.2020.01.035. Full text in Research Archive
Blenkmann, Alejandro Omar; Collavini, Santiago; Lubell, James; Anais, Llorens; Funderud, Ingrid & Ivanovic, Jugoslav [Show all 13 contributors for this article] (2019). Auditory deviance detection in the human insula: An intracranial EEG study. Cortex. ISSN 0010-9452. 121, p. 189�C200. doi: 10.1016/j.cortex.2019.09.002. Full text in Research Archive
Blenkmann, Alejandro Omar; Phillips, Holly N.; Princich, Juan Pablo; Rowe, James B.; Bekinschtein, Tristan & Muravchik, Carlos [Show all 7 contributors for this article] (2017). iElectrodes: a comprehensive open-source toolbox for depth and subdural grid electrode localization. Frontiers in Neuroinformatics. 11:14, p. 1�C16. doi: 10.3389/fninf.2017.00014. Full text in Research Archive
Phillips, Holly; Blenkmann, Alejandro Omar; Hughes, Laura E; Kochen, Silvia; Bekinschtein, Tristan & Rowe, James (2016). Convergent evidence for hierarchical prediction networks from human electrocorticography and magnetoencephalography. Cortex. ISSN 0010-9452. doi: 10.1016/j.cortex.2016.05.001.
Phillips, Holly; Blenkmann, Alejandro Omar; Hughes, Laura E; Bekinschtein, Tristan & Rowe, James (2015). Hierarchical Organization of Frontotemporal Networks for the Prediction of Stimuli across Multiple Dimensions. Journal of Neuroscience. ISSN 0270-6474. doi: 10.1523/JNEUROSCI.5095-14.2015.
Blenkmann, Alejandro Omar; Phillips, Holly; Princich, Juan Pablo; Muravchik, Carlos & Kochen, Silvia (2014). Grid and depth intracranial electrodes localization in a normalized space using MRI and CT images. International Federation for Medical and Biological Engineering Proceedings. ISSN 1680-0737. doi: 10.1007/978-3-319-13117-7_106.
Collavini, Santiago; Blenkmann, Alejandro Omar & Kochen, Silvia (2014). Effective Connectivity in Epileptogenic Networks. International Federation for Medical and Biological Engineering Proceedings. ISSN 1680-0737. doi: 10.1007/978-3-319-13117-7_174.
Princich, Juan Pablo; Wassermann, Demian; Latini, Facundo; Oddo, Silvia; Blenkmann, Alejandro Omar & Seifer, Gustavo [Show all 7 contributors for this article] (2013). Rapid and efficient localization of depth electrodes and cortical labeling using free and open source medical software in epilepsy surgery candidates. Frontiers in Neuroscience. ISSN 1662-4548. doi: 10.3389/fnins.2013.00260.
Jacobacci, Florencia; Sapir, Martin; Collavini, Santiago; Kochen, Silvia & Blenkmann, Alejandro Omar (2013). Assessing effective connectivity in epileptogenic networks. A model-based simulation approach. Journal of Physics: Conference Series (JPCS). ISSN 1742-6588. doi: 10.1088/1742-6596/477/1/012037.
Ibanez, Agustin; Cardona, Juan; Santos, Yamil Vidal Dos; Blenkmann, Alejandro Omar; Aravena, Pia & Roca, Mar��a [Show all 17 contributors for this article] (2013). Motor-language coupling: Direct evidence from early Parkinson��s disease and intracranial cortical recordings. Cortex. ISSN 0010-9452. 49(4). doi: 10.1016/j.cortex.2012.02.014.
Chennu, Srivas; Noreika, Valdas; David, Gueorguiev; Blenkmann, Alejandro Omar; Kochen, Silvia & Ibanez, Agustin [Show all 8 contributors for this article] (2013). Expectation and Attention in Hierarchical Auditory Prediction. Journal of Neuroscience. ISSN 0270-6474. doi: 10.1523/JNEUROSCI.0114-13.2013.
Blenkmann, Alejandro Omar; Seifer, Gustavo; Princich, Juan Pablo; Consalvo, Damian; Kochen, Silvia & Muravchik, Carlos (2012). Association between equivalent current dipole source localization and focal cortical dysplasia in epilepsy patients. Epilepsy Research. ISSN 0920-1211. 98, p. 223�C231. doi: 10.1016/j.eplepsyres.2011.09.018.
Ibanez, Agustin; Urquina, Hugo; Petroni, Agustin; Baez, Sandra; Nascimiento, Micaela Do & Herrera, Eduar [Show all 17 contributors for this article] (2012). Neural Processing of Emotional Facial and Semantic Expressions in Euthymic Bipolar Disorder (BD) and Its Association with Theory of Mind (ToM). PLOS ONE. doi: 10.1371/journal.pone.0046877.
Princich, Juan Pablo; Consalvo, Damian; Kaufman, Marcelo; Seifer, Gustavo; Blenkmann, Alejandro Omar & Kochen, Silvia (2012). Contribuci��n de las im��genes de resonancia magn��tica por tensor de difusi��n al diagn��stico de displasias corticales focales. Revista de neurolog��a (Ed. impresa). ISSN 0210-0010. 54(8). doi: 10.33588/rn.5408.2011659.
Seifer, Gustavo; Blenkmann, Alejandro Omar; Princich, Juan Pablo; Consalvo, Damian; Papayannis, Cristina & Muravchik, Carlos [Show all 7 contributors for this article] (2012). Noninvasive Approach to Focal CorticalDysplasias: Clinical, EEG, and Neuroimaging Features. Epilepsy Research and Treatment. ISSN 2090-1348. doi: 10.1155/2012/736784.
Beltrachini, Leandro; Blenkmann, Alejandro Omar; Ellenrieder, Nicolas von; Petroni, Agustin; Urquina, Hugo & Manes, Facundo [Show all 8 contributors for this article] (2011). Impact of head models in N170 component source imaging: results in control subjects and ADHD patients. Journal of Physics: Conference Series (JPCS). ISSN 1742-6588. doi: 10.1088/1742-6596/332/1/012019.

View all works in NVA

Blenkmann, Alejandro Omar (2025). iElectrodes Toolbox: Fast, Robust, and Open-Source Localization of Intracranial Electrodes. doi: https:/cuttingeeg.org/practicalmeeg2025/bouquet/. Show summary
Precise anatomical localization of intracranial electrodes is crucial for interpreting invasive recordings in clinical and cognitive neuroscience research. The open-source iElectrodes toolbox offers a fast, semi-automated, and robust solution for localizing subdural grids, depth electrodes, and strips from MRI and CT images, supporting automatic anatomical labeling. iElectrodes was initially introduced in Blenkmann et al. (2017), and has been updated with major methodological innovations in Blenkmann et al. (2024). To date, it has >2000 downloads. In this 90-minute session, I will first provide an introductory lecture on the core functionalities of iElectrodes, including image pre-processing steps, semi-automatic electrode localization, brain shift compensation, and standardized anatomical registration. We will cover the recent major upgrades to the toolbox: the GridFit algorithm for robust localization of SEEG and ECoG electrodes under challenging conditions (e.g., noise, overlaps, and high-density implants), and CEPA (Combined Electrode Projection Algorithm) for smooth compensation methods for grids, addressing brain deformations based on mechanical modeling principles. These developments significantly enhanced the robustness and precision of intracranial electrode localization. In the second part of the session, we will move into a hands-on tutorial, where participants will learn how to use the toolbox through practical exercises. Using real patient datasets (anonymized), we will cover: ? Preprocessing MRI and CT images. ? Semi-automatic detection and localization of electrode coordinates using clustering and GridFit algorithms. ? Brain shift correction using CEPA. ? Automatic anatomical labeling of electrodes. ? Generation of an iElectrodes localization project file. ? Exporting electrode coordinates into formats compatible with Fieldtrip, EEGLAB, and text reports. ? Integration with further analysis workflows. This session is intended for both clinical and cognitive neuroscience research users working with SEEG or ECoG. Attendees will leave with practical skills for reliable and reproducible electrode localization, ready to apply to their own datasets.
Blenkmann, Alejandro Omar (2025). Auditory Prediction and Its Neural Correlates. doi: https:/csan2025.saneurociencias.org.ar/symposia/neurophysiological-bases-of-memory-consciousness-and-interoception-in-humans-from-the-neuron-to-neural-networks/. Show summary
This panel presents research on the neural mechanisms underlying auditory prediction��a fundamental process for the perception of sound, language, and music. Evidence is presented on how the brain anticipates and processes auditory stimuli through neural networks that integrate prior sensory information, thereby facilitating the interpretation of speech and complex musical structures. Using neurophysiological and neuroimaging studies, researchers have identified the neural correlates of auditory prediction in regions such as the auditory cortex and areas involved in memory and attention. Additionally, computational models are analyzed to explain how the brain dynamically adjusts its expectations in response to variations in auditory stimuli.
H��benette, Saira Jameela; Solbakk, Anne-Kristin; Danielsen, Anne; Endestad, Tor & Blenkmann, Alejandro Omar (2025). Hearing in motion: Spatial and temporal processing of auditory stimuli. doi: https:/www.dropbox.com/scl/fi/ijya3kj1w1dl2e7vyjo5y/ICAC25-poster.pdf?rlkey=2516eohjz9vyx3g7qj7rjsedc&st=wm335i35&dl=0. Show summary
Tracking a moving sound in space requires continuous prediction of its next location. This implies that we must combine information about the time and location of the sound, to accurately predict its trajectory. Using EEG, auditory motion processing has previously been found in frontal, central, and parietal areas of the brain. Prior studies have suggested that space and time for auditory stimuli are processed separately in the brain. Despite the seemingly distinct processing pathways of spatial and temporal sound information, they must integrate at some stage to enable the prediction of movement. It remains unknown if these processes are initially working in parallel and then converging at some point, or if there are several instances of convergence throughout. The goal of this study was to delineate the neural correlates of spatial and temporal processing of moving sounds, and to assess how and when they converge to aid in the tracking of the sound movement.
Carvalho, Vin��cius Rezende; Collavini, Santiago; Nasimbera, Alejandro; Kochen, Silvia; Solbakk, Anne-Kristin & Blenkmann, Alejandro Omar (2025). Single-Neuron Evidence for Attention and Prediction Error to Nested Auditory Regularities in the Human Auditory Cortex. doi: https:/2025.ccneuro.org/abstract_pdf/Carvalho_2025_Single-Neuron_Evidence_Attention_Prediction_Error_.pdf.
Blenkmann, Alejandro Omar (2025). The role of the Orbitoforontal cortex in building predictions and detecting violations.
Blenkmann, Alejandro Omar; Leske, Sabine Liliana; Volehaugen, Vegard Akselsson; Carvalho, Vinicius Rezende; Kochen, Silvia & Endestad, Tor [Show all 10 contributors for this article] (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.
Blenkmann, Alejandro Omar; Leske, Sabine Liliana; Volehaugen, Vegard Akselsson; Carvalho, Vinicius Rezende; Kochen, Silvia & Endestad, Tor [Show all 8 contributors for this article] (2025). Spatiotemporal dynamics of auditory prediction error propagation via intracranial EEG in humans. doi: https:/www.frm2025oslo.no/s/FRM2025_AbstractBook.pdf.
Carvalho, Vinicius Rezende; Collavini, Santiago; Kochen, Silvia; Solbakk, Anne-Kristin & Blenkmann, Alejandro Omar (2025). Amygdala Responses to Auditory Prediction Violations: Evidence from Human Single-Neuron Recordings. doi: https:/static1.squarespace.com/static/66795375ff6aa75dff1c9eac/t/685e37792a21147062408469/1751005079975/FRM2025_AbstractBook.pdf.
Leske, Sabine Liliana; Blenkmann, Alejandro Omar; Lubell, Jamie; Llorens, Ana?s; Larsson, P?l Gunnar & Funderud, Ingrid [Show all 12 contributors for this article] (2025). INTRACRANIAL CORRELATES OF ACTION-BASED AUDITORY PREDICTION ERRORS IN HUMANS.
Solli, Sandra; Danielsen, Anne; Leske, Sabine Liliana; Blenkmann, Alejandro Omar; Doelling, Keith & Solbakk, Anne-Kristin [Show all 7 contributors for this article] (2024). Rhythm-based temporal expectations: Unique contributions of predictability and periodicity. Show summary
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.
Blenkmann, Alejandro Omar; Volehaugen, Vegard Akselsson; Carvalho, Vinicius Rezende; Leske, Sabine Liliana; Llorens, Anais & Funderud, Ingrid [Show all 14 contributors for this article] (2024). An intracranial EEG study on auditory deviance detection.
Solli, Sandra; Danielsen, Anne; Leske, Sabine Liliana; Blenkmann, Alejandro Omar; Doelling, Keith & Solbakk, Anne-Kristin [Show all 7 contributors for this article] (2024). Rhythm-based temporal expectations: Unique contributions of predictability and periodicity.
Basi��ski, Krzysztof; Dom?alski, Tomasz & Blenkmann, Alejandro Omar (2024). The effect of harmonicity on mismatch negativity responses to different auditory features.
Carvalho, Vinicius Rezende; Collavini, Santiago; Kochen, Silvia; Solbakk, Anne-Kristin & Blenkmann, Alejandro Omar (2024). Human single-neuron responses to a local-global oddball paradigm.
Asko, Olgerta; Volehaugen, Vegard Akselsson; Leske, Sabine Liliana; Funderud, Ingrid; Llorens, Ana?s & Ivanovic, Jugoslav [Show all 12 contributors for this article] (2024). Predictive encoding of deviant tone sequences in the human prefrontal cortex.
Asko, Olgerta; Volehaugen, Vegard Akselsson; Leske, Sabine Liliana; Funderud, Ingrid; Anais, Llorens & Ivanovic, Jugoslav [Show all 12 contributors for this article] (2024). Predictive encoding of deviant tone sequences in the human prefrontal cortex. Show summary
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) �C 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.
Blenkmann, Alejandro Omar (2024). Current challenges in human EEG/iEEG/SUA.
Blenkmann, Alejandro Omar; Leske, Sabine Liliana; Llorens, Ana?s; Lin, Jack J.; Chang, Edward & Brunner, Peter [Show all 12 contributors for this article] (2024). Novel tools for the anatomical registration of intracranial electrodes.
Carvalho, Vinicius Rezende; Collavini, Santiago; Kochen, Silvia; Solbakk, Anne-Kristin & Blenkmann, Alejandro Omar (2024). Single-neuron responses to a multifeature oddball paradigm.
Solbakk, Anne-Kristin; Hope, Mikael; Solli, Sandra; Leske, Sabine Liliana; Foldal, Maja Dyhre & Blenkmann, Alejandro Omar (2024). Research seminar.
Blenkmann, Alejandro Omar (2024). The role of the Orbitofrontal Cortex in building predictions and detecting violations.
Volehaugen, Vegard Akselsson; Leske, Sabine Liliana; Funderud, Ingerid; Carvalho, Vinicius Rezende; Endestad, Tor & Solbakk, Anne-Kristin [Show all 7 contributors for this article] (2024). Unheard Surprises: Attention-Dependent Neocortical Dynamics Following Unexpected Omissions Revealed by Intracranial EEG.
Leske, Sabine Liliana; Endestad, Tor; Volehaugen, Vegard Akselsson; Foldal, Maja Dyhre; Blenkmann, Alejandro Omar & Solbakk, Anne-Kristin [Show all 7 contributors for this article] (2024). Predicting the Beat Bin: Beta Oscillations Predict the Envelope Sharpness in a Rhythmic Sequence.
Blenkmann, Alejandro Omar (2024). Electrophysiological correlates of auditory regularity expectations and violations at short and long temporal scales: Studies in intracranial EEG and prefrontal cortex lesion patients.
Blenkmann, Alejandro Omar; Leske, Sabine Liliana; Llorens, Anais; Lin, Jack J.; Chang, Edward & Brunner, Peter [Show all 12 contributors for this article] (2024). Anatomical registration of intracranial electrodes.
Blenkmann, Alejandro Omar (2024). Audiopred Project: Neurophysiological mechanisms of auditory predictions.
Asko, Olgerta; Solbakk, Anne-Kristin; Leske, Sabine Liliana; Meling, Torstein Ragnar; Knight, Robert T. & Endestad, Tor [Show all 7 contributors for this article] (2023). The orbitofrontal cortex (OFC) has a critical role in the generation of high-level expectations.
Blenkmann, Alejandro Omar & Agrawal, Rahul Omprakash (2023). Intracranial Electrode Localization workshop.
Leske, Sabine Liliana; Endestad, Tor; Volehaugen, Vegard; Foldal, Maja Dyhre; Blenkmann, Alejandro Omar & Solbakk, Anne-Kristin [Show all 7 contributors for this article] (2023). Predicting the Beat Bin �C Beta Oscillations Support Top-Down Prediction of The Temporal Precision of a Beat.
Solli, Sandra; Danielsen, Anne; Leske, Sabine Liliana; Blenkmann, Alejandro Omar; Solbakk, Anne-Kristin & Endestad, Tor (2023). Periodic vs Aperiodic Temporal Predictions: Shared or Separate Mechanisms?
Blenkmann, Alejandro Omar; Ianni, Pablo & Verdugo, Rodrigo (2023). Interview for TV show "Salud en Movimiento", Radio Television Neuqu��n. [TV]. Neuquen, Argentina.
Blenkmann, Alejandro Omar & Puppio, Daniel (2023). Interview at "La Ma?ana de la Radio" FM 97.3. [Radio]. Neuquen, Argentina.
Blenkmann, Alejandro Omar (2023). Altered hierarchical auditory predictive processing after lesions to the orbitofrontal cortex - Quantifying Evoked Responses through Encoded Information.
Solli, Sandra; Danielsen, Anne; Leske, Sabine Liliana; Blenkmann, Alejandro Omar; Solbakk, Anne-Kristin & Endestad, Tor (2023). Both periodic and aperiodic rhythms facilitate perceptual processing.
Carvalho, Vinicius Rezende; Collavini, Santiago; Kochen, Silvia; Solbakk, Anne-Kristin & Blenkmann, Alejandro Omar (2023). Single-neuron responses to a multifeature oddball paradigm.
Blenkmann, Alejandro Omar (2023). Neurophysiological Mechanisms of Human Auditory Predictions: From population- to single neuron recordings.
Blenkmann, Alejandro Omar; Asko, Olgerta; Volehaugen, Vegard; Foldal, Maja Dyhre; Solli, Sandra & Leske, Sabine Liliana [Show all 9 contributors for this article] (2023). Auditory perception, memory, and predictions.
Solbakk, Anne-Kristin; Blenkmann, Alejandro Omar; Leske, Sabine Liliana & Endestad, Tor (2023). Orbitofrontal lesion impacts formation of auditory expectations.
Blenkmann, Alejandro Omar (2023). Expectation and attention in auditory prediction.
Blenkmann, Alejandro Omar (2023). Neural correlates of auditory predictions using intracranial EEG. Show summary
Website https://gumed.edu.pl/76777.html
Blenkmann, Alejandro Omar; Solbakk, Anne-Kristin; Leske, Sabine Liliana; Llorens, Ana?s; Funderud, Ingrid & Larsson, P?l Gunnar [Show all 10 contributors for this article] (2023). Temporal and precentral brain activity in automatic auditory deviance detection. Evidence from human intracranial EEG recordings.
Volehaugen, Vegard; Leske, Sabine Liliana; Funderud, Ingrid; Llorens, Ana?s; Carvalho, Vinicius Rezende & Endestad, Tor [Show all 8 contributors for this article] (2023). Echoes of the unheard: An intracranial electrophysiology study of expectation and attention in auditory omission processing.
Asko, Olgerta; Solbakk, Anne-Kristin; Leske, Sabine Liliana; Meling, Torstein Ragnar; Knight, Robert T. & Endestad, Tor [Show all 7 contributors for this article] (2023). Orbitofrontal lesion impacts formation of auditory expectations. Show summary
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.
Bonetti, Leonardo; Foldal, Maja Dyhre; Leske, Sabine Liliana; Asko, Olgerta; Volehaugen, Vegard Akselsson & Solli, Sandra [Show all 7 contributors for this article] (2023). Auditory perception, memory, and predictions.
Volehaugen, Vegard; Leske, Sabine Liliana; Endestad, Tor; Solbakk, Anne-Kristin & Blenkmann, Alejandro Omar (2022). Violation of rule-based auditory patterns is detected independently of attention.
Blenkmann, Alejandro Omar (2022). How does the brain process unexpected sounds?
Fuhrer, Julian; Glette, Kyrre; Ivanovic, Jugoslav; Larsson, P?l Gunnar; Bekinschtein, Tristan & Kochen, Silvia [Show all 11 contributors for this article] (2022). Direct brain recordings reveal continuous encoding of structure in random stimuli.
Fuhrer, Julian; Blenkmann, Alejandro Omar; Endestad, Tor; Solbakk, Anne-Kristin & Glette, Kyrre (2022). Complexity-Based Encoded Information Quantification in Neurophysiological Recordings.
Asko, Olgerta; Blenkmann, Alejandro Omar; Leske, Sabine Liliana; Foldal, Maja Dyhre; Llorens, Ana?s & Funderud, Ingrid [Show all 10 contributors for this article] (2022). Altered hierarchical auditory predictive processing after lesions to the orbitofrontal cortex. Show summary
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.
Blenkmann, Alejandro Omar; Fuhrer, Julian; Glette, Kyrre; Ivanovic, Jugoslav; Larsson, P?l Gunnar & Bekinschtein, Tristan [Show all 11 contributors for this article] (2022). Direct brain recordings reveal continuous encoding of structure in random stimuli.
Blenkmann, Alejandro Omar; Solbakk, Anne-Kristin; Leske, Sabine Liliana; Llorens, Ana?s; Funderud, Ingrid & Collavini, Santiago [Show all 13 contributors for this article] (2022). Human brain network involved in auditory deviance detection. An intracranial EEG study.
Blenkmann, Alejandro Omar (2022). Auditory deviance detection in the human insula. Evidence from intracranial EEG recordings.
Foldal, Maja Dyhre; Leske, Sabine Liliana; Blenkmann, Alejandro Omar; Endestad, Tor & Solbakk, Anne-Kristin (2021). Attentional modulation of alpha- and beta oscillations during perception of auditory rhythms.
Solbakk, Anne-Kristin; Leske, Sabine Liliana; Lubell, James Isaac; Blenkmann, Alejandro Omar; Llorens, Anais & Funderud, Ingrid [Show all 13 contributors for this article] (2021). Auditory prediction and prediction error in self-generated tones.
Blenkmann, Alejandro Omar (2021). Electrode localization in intracranial EEG. From simulations to novel electrode localization and brain-shift correction algorithms.
Blenkmann, Alejandro Omar (2021). Some advances in neuroscience using intracranial EEG recordings.
Leske, Sabine Liliana; Lubell, James; Blenkmann, Alejandro Omar; Llorens, Ana?s; Funderud, Ingrid & Foldal, Maja Dyhre [Show all 13 contributors for this article] (2019). Action-based auditory predictions. Show summary
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.
Leske, Sabine Liliana; Lubell, James Isaac; Blenkmann, Alejandro Omar; Llorens, Ana?s; Funderud, Ingrid & Foldal, Maja Dyhre [Show all 13 contributors for this article] (2019). Auditory prediction and prediction error in self-generated tones.
Fuhrer, Julian; Blenkmann, Alejandro Omar; T?rresen, Jim; Endestad, Tor & Glette, Kyrre (2019). Making Sense of Randomness?
Westner, Britta; Andersen, Lau M?ller; Blenkmann, Alejandro Omar & Leske, Sabine Liliana (2019). RITMO International EEG FieldTrip workshop, Lectures and Hands-on sessions.
Blenkmann, Alejandro Omar (2019). Origins of the EEG signal and Technical setup of EEG.
Foldal, Maja Dyhre; Blenkmann, Alejandro Omar; Llorens, Ana?s; Knight, Robert Thomas; Solbakk, Anne-Kristin & Endestad, Tor (2019). The brain tracks global temporal regularity in auditory patterns.
Blenkmann, Alejandro Omar; Solbakk, Anne-Kristin; Lubell, James; Leske, Sabine Liliana; Llorens, Ana?s & Funderud, Ingrid [Show all 14 contributors for this article] (2019). Human brain network involved in auditory deviance detection: Evidence from intracranial EEG recordings. Show summary
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 (N??t?nen 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.
Blenkmann, Alejandro Omar (2019). Auditory deviance detection network in the human brain.
Endestad, Tor; Solbakk, Anne-Kristin; Ivanovic, Jugoslav; Larsson, P?l Gunnar; Knight, Robert T. & Blenkmann, Alejandro Omar (2019). A robust intracranial electrode localization algorithm. Show summary
The accurate localization of electrodes in relationship to the brain��s anatomy is the foundation of the spatial resolution of intracranial EEG recordings. However, in ��difficult cases�� the localization needs to be done manually since automatic methods fails, e.g high density arrays up to 3 mm inter-electrode distance, overlapping electrodes, low resolution CT images, or connection cables ovelaying grids. Here, we present a new automatic method that models a flexible array of electrodes and fits it to the artifacts observed in post implantation CT images. We evaluated data from 18 adult patients with drug resistant epilepsy implanted with depth electrodes and/or subdural grids (18 patients, 3261 electrodes). The automatic method was contrasted against manual localization. The main processing steps (Fig. 1 A) were: Thresholding and selection of a cloud of CT voxels containing the electrode artifacts Assembling a model of the grid (depth) array of electrodes Fitting the model to a smooth surface (line) approximation of CT artifacts Fitting the model to the cloud of voxels by minimizing the energy function E = -Ec + Et + Ed Ec was the gaussian weighted spatial correlation between the electrodes and the cloud of voxels. Et penalized the translation of electrodes, and Ed the deformation of a spring grid connecting the electrodes. Automatic localization resulted to be more precise than manual selection, observed as a significant reduction of the inter-electrode distance variance (Fig. 1 B). We provide a robust method for intracranial electrode localization that is applicable to ��difficult cases�� were previous automatic methods fail (Fig. 1 C). The method was implemented in the open-source iElectrodes toolbox and is available to the research community (Blenkmann et al., 2017).
Blenkmann, Alejandro Omar; Solbakk, Anne-Kristin; Lubell, James; Leske, Sabine Liliana; Llorens, Ana?s & Funderud, Ingrid [Show all 14 contributors for this article] (2019). Human brain network involved in auditory deviance detection: Evidence from intracranial EEG recordings.
Blenkmann, Alejandro Omar; Lubell, James; Llorens, Anais; Funderud, Ingrid; Collavini, Santiago & Larsson, PG [Show all 13 contributors for this article] (2018). Human insula response to auditory deviants: Evidence from intracranial EEG recordings.
Ibanez, Agustin; Petroni, Agustin; Urquina, Hugo; Torralva, Teresa; Blenkmann, Alejandro Omar & Beltrachini, Leandro [Show all 15 contributors for this article] (2012). Cortical deficits in emotion processing for faces in adults with ADHD: Its relation to social cognition and executive functioning. In Manes, Facundo & Mendez, Mario (Ed.), Social Neuroscience of Psychiatric Disorders. Psychology Press. ISSN 9781848727571.