Poster No:
2012
Submission Type:
Abstract Submission
Authors:
Kenji Ibayashi1, Naoto Kunii1, Yoshiyuki Onuki2, Kensuke Kawai2
Institutions:
1Jichi Medical University, Shimotsuke-shi, Tochigi, 2Jichi Medical University, Shimotsuke, Tochigi
First Author:
Co-Author(s):
Naoto Kunii
Jichi Medical University
Shimotsuke-shi, Tochigi
Introduction:
Odor perception related human juxta-entorhinal activity remains to be underinvestigated, despite the increased opportunities of intracranial EEG studies. One of the reasons is the in-depth location of the olfactory related areas. Recent advancement of robot-assisted-stereotactic-electroencephalography has opened the opportunity to study deep cortical structures.
Methods:
Subject:
We leveraged the opportunity of iEEG recordings from retractable epilepsy patients who underwent intracranial electrode implantation for the purpose of preoperative work up. This research has been reviewed by the JMU-IRB. The subject was a 36yo female with the history of left posterior temporal MST (multiple subpial transection), who continued to have refractory epilepsy arising from her left fusiform and inferior-temporal gyri. Electrode locations were automatically extracted by LeGUI (Davis,2021) software based on the Pre-Op T1 MRI and Post-Op head CT. Olfactory related region that was included in this study was Entorhinal Cortex (EC), as it was the only cortex among those located in the downstream of lateral olfactory tract in this subject.
Experimental design:
We conducted a odor naming task, by presenting four different odorants pseudo-randomly for 5 seconds each, with the interstimulus interval of 30 seconds. The subject was asked to name and rate the valance of the odorant they smelled naturally during nasal breathing.
Data acquisition:
Data was acquired using 256-channnel NihonKoden EEG recording system at Jichi Medical Univeristy. Signals were referenced to a subcutaneous screw electrode and sampled at 1000 Hz. Respiration belt was utilized to record subject's breathing activity.
Data analysis:
After removal of line noise, channels exceeding 5 standard deviations above or below the mean across the channels were rejected. Each channel was re-referenced to the common average per electrode array. Signals were subsequently epoched into trials, which were aligned to the trough of preceding exhalation. Time-frequency decomposition was performed via short time Fourier transform to create event related spectral perturbation. Beta band specific analysis was done by bandpass-Hilbert transformation method via FIR (odor 300) filter. Baseline was set to the cue-preceding-1seconds window. Correlation analysis was done between averaged waveforms between odor labels.
Decoding analysis and Correlation analysis:
The mean beta power was used for decoding analysis using Sparse Logistic Regression. Spearman's rho was calculated for correlation analysis between the mean beta power and the valance score reported by the subject.
Results:
Natural odor delivery entrained beta activity in the entorhinal cortex. This entrainment was significantly limited in odor-positive breathing and was not observed in odor-negative breathing. Decoding accuracy was 29%, which proved to be above chance level to classify four different odors. There was a positive correlation (Spearman rho = 0.24, p=0.04) between beta power and valence score.
Conclusions:
Beta power is entrained in human medial temporal lobe during natural inhalation of odorants, and carries information related to odor-types and odor related valence.
Emotion, Motivation and Social Neuroscience:
Emotional Perception 2
Perception, Attention and Motor Behavior:
Chemical Senses: Olfaction, Taste 1
Perception and Attention Other
Keywords:
ELECTROCORTICOGRAPHY
Electroencephaolography (EEG)
ELECTROPHYSIOLOGY
Emotions
Epilepsy
Smell
1|2Indicates the priority used for review
By submitting your proposal, you grant permission for the Organization for Human Brain Mapping (OHBM) to distribute your work in any format, including video, audio print and electronic text through OHBM OnDemand, social media channels, the OHBM website, or other electronic publications and media.
I accept
The Open Science Special Interest Group (OSSIG) is introducing a reproducibility challenge for OHBM 2025. This new initiative aims to enhance the reproducibility of scientific results and foster collaborations between labs. Teams will consist of a “source” party and a “reproducing” party, and will be evaluated on the success of their replication, the openness of the source work, and additional deliverables. Click here for more information.
Propose your OHBM abstract(s) as source work for future OHBM meetings by selecting one of the following options:
I do not want to participate in the reproducibility challenge.
Please indicate below if your study was a "resting state" or "task-activation” study.
Task-activation
Healthy subjects only or patients (note that patient studies may also involve healthy subjects):
Patients
Was this research conducted in the United States?
No
Were any human subjects research approved by the relevant Institutional Review Board or ethics panel?
NOTE: Any human subjects studies without IRB approval will be automatically rejected.
Yes
Were any animal research approved by the relevant IACUC or other animal research panel?
NOTE: Any animal studies without IACUC approval will be automatically rejected.
Not applicable
Please indicate which methods were used in your research:
EEG/ERP
Provide references using APA citation style.
Jung,J. (2006). Functional significance of olfactory-induced oscillations in the human amygdala. Cereb Cortex,16(1),1-8.
Yang,Q. (2022). Smell-induced gamma oscillations in human olfactory cortex are required for accurate perception of odor identity. PLOS Biology, 20(1), e3001509.
No