BM402: Engineering In Medicine Pop Quiz PDF

BM402: ENGINEERING IN MEDICINE 31st October 2024 M 2170 – South Campus But some good news: You have ca. half an hour to go through the course material. We will start at 1:10 pm, end 1:40 pm. Break - 15 minutes MRI Functional MRI Applications of MRI and fMRI...

BM402: ENGINEERING IN MEDICINE 31st October 2024 M 2170 – South Campus But some good news: You have ca. half an hour to go through the course material. We will start at 1:10 pm, end 1:40 pm. Break - 15 minutes MRI Functional MRI Applications of MRI and fMRI EEG Challenges of EEG-fMRI Literature EEG basics Electro-encephalo-gram Brain Electrical Picture/Record sleeping EEG is the measurement of electrical patterns at the surface of the scalp which reflect cortical activity - commonly referred as “brainwaves”. EEG - brain rhythms & frequency bands Simultaneous EEG-fMRI: how to make it compatible - the presence of static and time-varying magnetic fields and - their associated EEG artefacts; - the need to limit radiofrequency (RF) emissions to preserve image quality; - and finally the obvious requirement to avoid the introduction of ferrous materials into the scanner environment. (A) electrode cap, (B) connector box containing current-limiting resistors, (C) battery power pack and (D) 32 channel EEG amplifier/digitizer. Simultaneous EEG-fMRI: main artifacts – how bad? Correction of gradient and cardioballistic artifacts is valuable for ensuring data quality Ikemoto et al. 2022 Frequency based analysis EEG & SLEEP Frequency based analysis fMRI & EEG alpha Alpha rhythm as an index of cortical inactivity that may be generated in part by the thalamus. Event related potentials (ERPs) What is an ERP? An event-related potential (ERP) is the neural response associated with a specific sensory, e.g., cognitive, or motor event. An ERP can be recorded using scalp EEG and looks at the average change in voltage over time starting at the onset of the stimulus over multiple trials. How to record? ERPs are evoked by stimuli and measured at the scalp with EEG. They are recorded in response to an isolated, discrete event. Usually, this stimulus is presented multiple times, which allows the EEG to be averaged after discarding low-quality trials. Event related potentials (ERPs) Later ERP waves are used to index endogenous cognitive activity. The positive going ERP component at 300 ms (P300) is related to processes that involve classifying or updating memory representations of stimuli. The amplitude of the P300 increases as the demand for cognitive resources increases and as the significance of the event and its relevance to the subject increases. Event-related potential changes in psychiatric disorders – P300 Latency prolongation and amplitude reduction were seen both in schizophrenia and chronic bipolar patients (O’Donell et al., 2004). Caffeine effect on P300 EEG - brain rhythms & frequency bands High frequency EEG One more band we haven’t discussed: EEG ripples, typically defined as oscillations in the frequency range of 80–200 Hz, are fast oscillatory activities that are often associated with various brain processes. Next assignment: explain with its use in clinics, 3-4 references. Physiology, emotions and brain Emotions can have a significant impact on our physiological responses, including our heart rate and respiratory rate. Fear, anger, anxiety - release of adrenaline and other stress hormones - increase in heart rate - rapid breathing. Happiness - releases endorphins - decrease in heart rate Brain structures involved in dealing with stress and fear. - shallower breathing Happiness and fMRI - The studies found that recalling happy events activates various areas including the anterior cingulate cortex, prefrontal cortex, and insula. - These areas are also associated with other basic emotions such as sadness and anger. Suardi et al. 2016 Happiness and fMRI fMRI - Neurofeedback Real-time fMRI (rtfMRI): - fMRI data processing and display are performed at a speed that makes them consequent with image acquisition. - enabled real-time neurofeedback - allows a person to watch and regulate the fMRI signal from his or her own brain. fMRI - Neurofeedback - provides real-time feedback about brain activity to a person, with the goal of helping them learn to regulate their brain function. - a person undergoing neurofeedback training may be monitored with fMRI to identify which brain regions are involved in the process of learning to regulate brain activity. Neurofeedback - A type of biofeedback that teaches self-regulation of brain activity. - Focused on enhancing cognitive functions or managing conditions (e.g., ADHD, anxiety). - Provides real-time brain activity data to help users adjust their mental state. Brain-Computer Interface (BCI) - A system that enables direct communication between the brain and external devices. - Allows users to control devices (e.g., prosthetics, computers) using thought. - Translates brain signals into commands for devices, without a primary focus on self-regulation. Common Tools: Both use EEG and signal processing techniques. Relationship: Neurofeedback is a specialized application of BCI technology, but their intents and interactions differ. Neurofeedback - A type of biofeedback that teaches self-regulation of brain activity. - Focused on enhancing cognitive functions or managing conditions (e.g., ADHD, anxiety). - Provides real-time brain activity data to help users adjust their mental state. Brain-Computer Interface (BCI) - A system that enables direct communication between the brain and external devices. - Allows users to control devices (e.g., prosthetics, computers) using thought. - Translates brain signals into commands for devices, without a primary focus on self-regulation. Common Tools: Both use EEG and signal processing techniques. Relationship: Neurofeedback is a specialized application of BCI technology, but their intents and interactions differ. Reading – 15 minutes Neurofeedback - A type of biofeedback that teaches self-regulation of brain activity. - Focused on enhancing cognitive functions or managing conditions (e.g., ADHD, anxiety). - Provides real-time brain activity data to help users adjust their mental state. Brain-Computer Interface (BCI) - A system that enables direct communication between the brain and external devices. - Allows users to control devices (e.g., prosthetics, computers) using thought. - Translates brain signals into commands for devices, without a primary focus on self-regulation. Common Tools: Both use EEG and signal processing techniques. Relationship: Neurofeedback is a specialized application of BCI technology, but their intents and interactions differ. Neurofeedback (NFB) NFB is an operant conditioning technique for learning how to control one’s brain activity to improve cognitive performance, regulate stress levels, emotional functioning and behavior. Neurofeedback (NFB) NFB is an operant conditioning technique for learning how to control one’s brain activity to improve cognitive performance, regulate stress levels, emotional functioning and behavior. Neurofeedback (NFB) NFB is an operant conditioning technique for learning how to control one’s brain activity to improve cognitive performance, regulate stress levels, emotional functioning and behavior. Happiness and fMRI Read the abstract fMRI - Neurofeedback & Happiness Happy Memories condition: - the word ‘‘Happy’’, two color bars, and a number indicating the neurofeedback fMRI signal level were displayed on the screen. - participants were instructed to evoke happy autobiographical memories to make themselves feel happy while trying to increase the level of the red bar to a given target level (indicated by the fixed height blue bar). Happiness and fMRI Activation Network for Happy Memories and Count Conditions. The group activation analysis for Happy>Count contrast revealed significant BOLD signal changes in a fronto- temporo-limbic network, while the Count>Happy contrast revealed activations in a parietal network. Happiness and fMRI Fronto-temporo-limbic network - Important for the regulation of emotions, decision-making, and social cognition. - The fronto-temporo-limbic network is a functional network of brain regions that are involved in emotional processing, memory, and attention. - It includes the prefrontal cortex, anterior cingulate cortex, amygdala, hippocampus, insula. - Dysregulation of this network has been Activation Network for Happy Memories and Count Conditions. The implicated in various psychiatric group activation analysis for Happy>Count contrast revealed disorders, such as depression, anxiety, significant BOLD signal changes in a fronto-temporo-limbic network, and post-traumatic stress disorder. while the Count>Happy contrast revealed activations in a parietal network. EEG & Neurofeedback (NFB) Read the abstract EEG & Neurofeedback (NFB) Subjects were given a choice of visual metaphors (games) where success in the game was related to increasing the gamma power. Games included flying a plane, riding a roller-coaster, or nature scenes that morphed as the game progressed. For EEG recordings during the working memory task, EEG data were epoched from −0.25 to 1.75 s relative to the presentation of the stimuli. Average EEG power in the region of interest (ROI), gamma frequency band (30–50 Hz) and each time window at the frontal locations F3, F4, and Fz were obtained. These values were averaged to generate frontal gamma power (FGP). EEG & Neurofeedback EEG & Neurofeedback EEG & Neurofeedback – open questions Would higher treatment doses lead to greater gains? Would participants experience boredom, burnout and lack of motivation with longer protocols? How might delivering the same treatment dose over a shorter time period (e.g. 12 h of EEG-NFB delivered over 6 weeks) influence efficacy? What about long-term consequences? How long of a follow-up period is good to evaluate the effects of NFB?