Research Activities

Dynamic Pathways for Word Retrieval
Fluent word retrieval involves a dynamic neural network that includes at least five regions of primary interest (fusiform gyrus, temporal pole, middle temporal gyrus, angular gyrus, and inferior frontal gyrus), interconnected by major white matter fascicles (inferior longitudinal fascicle, the occipital frontal fascicle, and the uncinate fascicle). In addition, there is increasing but debated evidence that hippocampus is critically involved in language processes, including word retrieval. This extended network is described in theories at the cross-roads of cognitive neuroscience and psychology, and it is central in a variety of clinical contexts such pre-surgical assessment in temporal lobe epilepsy. Some theories highlight the anatomo-functional links for each of the regions involved or the temporal organization of their recruitment. Others have focused on the network of white matter connections between regions. Dr. González-Martínez’s fundamental goal is to combine these two approaches to foster understanding of word retrieval and its disruptions, by considering both the sub-second functional dynamics and the precise anatomical pathways between brain areas. This goal is achieved by expanding our previous research in patients with medically intractable epilepsy requiring SEEG (depth electrodes) implantation. The project is based on a unique and novel combination of extensive intra-cerebral stereotactic recordings of neurophysiological activity with high definition fiber tracking methods.

Human Decision Making in Complex Environments
The overall goal of the proposal is to understand the neural circuit involved in (1) representing relevant decision variables, (2) integrating these variables to form subjective values, and (3) selecting one of the options in multi-attribute decisions. 

A Biomimetic Approach Towards a Dexterous Neuroprosthesis
The loss of arm and hand function experienced by people with chronic cervical spinal cord injury limits independence and employment opportunities, increasing the extent, duration, and overall cost of care. A sensorimotor brain-computer interface can bypass the injured spinal cord to restore lost movement and sensation. Dr. González-Martínez will investigate the potential of biomimetic intracortical microstimulation for sensory restoration and motor decoding schemes that enable control over grasp kinematics and kinetics to restore dexterity for people with tetraplegia.

Hamot Health Foundation: The Role of Basal Ganglia in Language and Motor Control
The goal of this proposal is to explore the role of subcortical nodes in the basal ganglia-thalamocortical network and the cortex in coding various aspects of motor control, through electrophysiological study of networks targeted during deep brain stimulation surgery.

DIXI Neurolab: Thermocoagulation and Epilepsy
(Thermocoagulation device for diagnosis and treatment of medically refractory epilepsy)
The overall reach for this proposal is to develop and evaluate a portable and user-friendly radio-frequency generator device, compatible with the current DIXI depth electrodes. Dr. González-Martínez will develop and evaluate the efficacy and safety of the device through a series of rigorous bench testing and clinical studies with the ultimate goal of enabling its clinical use to map seizures and to allow bedside, thermocoagulation-based, treatment.