A5053955951- Neural dynamics and brain function
- Neural and Behavioral Psychology Studies
- EEG and Brain-Computer Interfaces
- Functional Brain Connectivity Studies
- Motor Control and Adaptation
- Hemispheric Asymmetry in Neuroscience
- Memory and Neural Mechanisms
- Spatial Neglect and Hemispheric Dysfunction
- Visual perception and processing mechanisms
- Neuroscience and Neuropharmacology Research
- Spacecraft Design and Technology
- Adolescent and Pediatric Healthcare
- Atomic and Subatomic Physics Research
- Advanced Memory and Neural Computing
- Face Recognition and Perception
- Neuroscience and Neural Engineering
- Neural Networks and Reservoir Computing
- Meningioma and schwannoma management
- Neurobiology of Language and Bilingualism
- Cellular transport and secretion
- Neural Networks and Applications
- Memory Processes and Influences
- Neuroscience and Music Perception
- Head and Neck Surgical Oncology
- Tactile and Sensory Interactions
California Pacific Medical Center
2015-2025
University of California, Irvine
1995-2025
University of Washington
1995-2003
Neurological Surgery
1995
Patients with temporal lobe epilepsy (TLE) often have a shrunken hippocampus that is known to be the location in which seizures originate. The role of sclerotic causation and maintenance has remained incompletely understood despite extensive neuropathological investigations this substrate. To gain new insights develop testable hypotheses on sclerosis pathophysiology TLE, differential gene expression profile was studied. end, DNA microarray analysis used compare profiles non-sclerotic...
Word retrieval is core to language production and relies on complementary processes: the rapid activation of lexical conceptual representations word selection, which chooses correct among semantically related competitors. Lexical measured by semantic priming. In contrast, selection indexed interference hampered in homogeneous (HOM) contexts. We examined spatiotemporal dynamics these processes a picture naming task with blocks heterogeneous (HET) or HOM stimuli. used electrocorticography data...
Neurophysiological studies in humans and nonhuman primates have revealed movement representations both the contralateral ipsilateral hemispheres. Inspired by clinical observations, we ask if this bilateral representation differs for left right Electrocorticography was recorded human participants during an instructed-delay reaching task, with movements produced either or arm. Using a cross-validated kinematic encoding model, found stronger hemisphere, effect that present preparation amplified...
How does the human brain rapidly process incoming information in working memory? In growing divergence from a single-region focus on prefrontal cortex (PFC), recent work argues for emphasis how distributed neural networks are coordinated support of this central neurocognitive function. Previously, we showed that memory everyday "what," "where," and "when" associations depends multiplexed oscillatory systems, which signals different frequencies simultaneously link PFC to parieto-occipital...
Summary Declarative memory depends on the coordination of local processing, indexed by high-frequency broadband (HFB) activity, with global network organization, theta oscillations. However, and HFB exhibit asynchronous timing, raising question how results processing are communicated throughout network. Using intracranial EEG in patients performing a recognition task, we examined this across medial temporal lobe (MTL) prefrontal cortex (PFC). peak activity was earlier MTL than PFC. Anchoring...
Goal-directed behavior requires adjusting cognitive control to both react and prepare for conflict. Previous work indicates theta oscillations population activity in dorsomedial prefrontal cortex (dmPFC) dorsolateral (dlPFC) are critical reactive control. However, the neural mechanisms supporting proactive less clear. Here, we investigated basis of behavioral adaptations when is prepared anticipation conflict using intracranial EEG (iEEG) dmPFC dlPFC during a Stroop task where frequency was...
Episodic memory relies on the formation and retrieval of content-specific traces. In addition to their veridical reactivation, previous studies have indicated that traces may undergo substantial transformations. However, exact time course regional distribution reinstatement transformation during recognition remained unclear. We applied representational similarity analysis human intracranial electroencephalography track spatiotemporal dynamics underlying Specifically, we examined how...
Abstract The signed value and unsigned salience of reward prediction errors (RPEs) are critical to understanding reinforcement learning (RL) cognitive control. Dorsomedial prefrontal cortex (dMPFC) insula (INS) key regions for integrating surprise information, but conflicting evidence both activity has led multiple proposals the nature RPE representations in these brain areas. Recently developed RL models allow neurons respond differently positive negative RPEs. Here, we use intracranially...
Abstract Flexible behavior requires gating mechanisms that encode only task-relevant information in working memory. Extant literature supports a theoretical division of labor whereby lateral frontoparietal interactions underlie maintenance and the striatum enacts gate. Here, we reveal neocortical intracranial EEG patients by identifying rapid, within-trial changes regional inter-regional activities predict subsequent behavioral outputs. Results first demonstrate accumulation extend prior...
The auditory cortex is well-known to be critical for music perception, including the perception of consonance and dissonance. Studies on neural correlates dissonance have largely employed non-invasive electrophysiological functional imaging techniques in humans as well neurophysiological recordings animals, but fine-grained spatiotemporal dynamics within human remain unknown. We recorded electrocorticographic (ECoG) signals directly from lateral surface either left or right temporal lobe...
The temporal lobe has a role in memory and learning. objective of this study was to assess the activity neurons cortex humans during Single neuron recorded with extracellular microelectrodes adults undergoing awake craniotomies for resections medically intractable epilepsy. Participants were administered control tasks overt reading, silent nonword visual controls recent verbal task distracters followed by paired associates (PA) paradigm. Forty-nine identified characterized their relationship...
Abstract Visual search is a fundamental human behavior, providing gateway to understanding other sensory domains as well the role of in higher-order cognition. Search has been proposed include two component processes: inefficient (search) and efficient (pop-out). According extant research, these processes map onto separable neural systems located frontal parietal association cortices. In this study, we use intracranial recordings from 23 participants delineate correlates pop-out with an...
Abstract Visual search is a fundamental human behavior, which has been proposed to include two component processes: inefficient (Search) and efficient (Pop-out). According extant research, these processes map onto separable neural systems located in the frontal parietal association cortices. In present study, we use intracranial recordings from 23 participants delineate correlates of Search Pop-out with an unprecedented combination spatiotemporal resolution coverage across cortical...
ABSTRACT The signed value and unsigned salience of reward prediction errors (RPEs) are critical to understanding reinforcement learning (RL) cognitive control. Dorsomedial prefrontal cortex (dMPFC) insula (INS) key regions for integrating surprise information, but conflicting evidence both activity has led competing proposals the nature RPE representations in these brain areas. Recently, distributional RL theory (dRL) been used explain coding diversity rodent midbrain by proposing that...
ABSTRACT Neurophysiological studies in humans and non-human primates have revealed movement representations both the contralateral ipsilateral hemisphere. Inspired by clinical observations, we ask if this bilateral representation differs for left right hemispheres. Electrocorticography (ECoG) was recorded human participants during an instructed-delay reaching task, with movements produced either or arm. Using a cross-validated kinematic encoding model, found stronger hemisphere, effect that...