Cognitive signals for brain-machine interfaces in posterior parietal cortex include continuous 3D trajectory commands.

Cortical neural prosthetics extract command signals from the brain with the goal to restore function in paralyzed or amputated patients. Continuous control signals can be extracted from the motor cortical areas, whereas neural activity from posterior parietal cortex (PPC) can be used to decode cognitive variables related to the goals of movement. Because typical activities of daily living comprise both continuous control tasks such as reaching, and tasks benefiting from discrete control such as typing on a keyboard, availability of both signals simultaneously would promise significant increases in performance and versatility. Here, we show that PPC can provide 3D hand trajectory information under natural conditions that would be encountered for prosthetic applications, thus allowing simultaneous extraction of continuous and discrete signals without requiring multisite surgical implants. We found that limb movements can be decoded robustly and with high accuracy from a small population of neural units under free gaze in a complex 3D point-to-point reaching task. Both animals' brain-control performance improved rapidly with practice, resulting in faster target acquisition and increasing accuracy. These findings disprove the notion that the motor cortical areas are the only candidate areas for continuous prosthetic command signals and, rather, suggests that PPC can provide equally useful trajectory signals in addition to discrete, cognitive variables. Hybrid use of continuous and discrete signals from PPC may enable a new generation of neural prostheses providing superior performance and additional flexibility in addressing individual patient needs.

The quality of life of patients with malignant gliomas and their caregivers.

The grim prognosis that accompanies a diagnosis of a malignant glioma affects quality of life (QOL) as patients attempt to adapt to overwhelming losses. Caregivers also experience negative changes in QOL as responsibilities grow. This pilot study measured the QOL of patients with malignant gliomas prior to tumor progression and the QOL of their caregivers. It examined negative and positive factors that impacted the QOL while highlighting positive factors often overlooked in brain tumor QOL research. Standardized QOL questionnaires and focus groups were utilized. Patients experienced distress in the domains of physical, psychological, and social QOL but in all four of the QOL domains there were also positive outcomes. Caregiver data demonstrated mostly positive outcomes in the four QOL domains except for loved one's declining health and fear that the loved one would die.

Spatial selectivity in human ventrolateral prefrontal cortex.

The functional organization of lateral prefrontal cortex is not well understood, and there is debate as to whether the dorsal and ventral aspects mediate distinct spatial and non-spatial functions, respectively. We show for the first time that recordings from human ventrolateral prefrontal cortex show spatial selectivity, supporting the idea that ventrolateral prefrontal cortex is involved in spatial processing. Our results also indicate that prefrontal cortex may be a source of control signals for neuroprosthetic applications.