Biomedical subjects

Jeffrey P Sutton

Publications and source records attributed to Jeffrey P Sutton.

5 recordsLinked to original sources

PubMed2005

Functional brain imaging of a complex navigation task following one night of total sleep deprivation: a preliminary study.

Several neuroimaging studies have demonstrated compensatory cerebral responses consequent to sleep deprivation (SD), but all have focused on simple tasks with limited behavioral response options. We assessed the cerebral effects associated with SD during the performance of a complex, open-ended, dual-joystick, 3D navigation task (simulated orbital docking) in a cross-over protocol, with counterbalanced orders of normal sleep (NS) and a single night of total SD (approximately 27 h). Behavioral performance on multiple measures was comparable in the two sleep conditions. Functional magnetic resonance imaging revealed multiple compensatory SD > NS cerebral responses, including the posterior superior temporal sulcus [Brodmann area (BA) 39/22/37], prefrontal cortex (BA 9), lateral temporal cortex (BA 22/21), and right substantia nigra. Right posterior cingulate cortex (BA 31) exhibited NS > SD activity. Our findings extend the compensatory cerebral response hypothesis to complex, open-ended tasks.

Adult↗

PubMed2005

Learning motor sequences with and without knowledge of governing rules.

OBJECTIVE: To investigate the behavioral and neural effects of rule-based knowledge on motor sequence learning. METHODS: The authors developed a novel 2-dimensional variant of the serial reaction time (SRT) task to test the effect of prior, verbalizable rule knowledge on motor learning behavior. To examine neurophysiological effects, they also performed functional magnetic resonance imaging on a small cohort of subjects while performing the same task. RESULTS: Behavioral data demonstrated that instruction on sequence-governing rules enhanced behavioral performance in both learning magnitudes and rates. The neuroimaging data revealed substantially different, but partially overlapping, learning-related activation patterns with and without prior rule instruction. Direct comparison of these 2 conditions revealed significantly different involvement of bilateral superior and anterior prefrontal cortex (Brodmann areas 8 and 10, respectively), right superior temporal cortex (BA 38/21), and left cerebellum. CONCLUSIONS: These behavioral findings demonstrate an advantage of teaching governing rules prior to 2D-SRT task performance. While these neuroimaging findings remain to be replicated in a larger cohort of subjects, results suggest that substantially different-though partially overlapping-brain regions subserve learning in these 2 rehabilitation-relevant conditions. Thus, appropriate choice of pretraining may benefit, for example, rehabilitation populations, at least in motor skill acquisition that requires sequencing.

Adolescent↗

PubMed2002

Non-invasive neuroimaging using near-infrared light.

This article reviews diffuse optical brain imaging, a technique that employs near-infrared light to non-invasively probe the brain for changes in parameters relating to brain function. We describe the general methodology, including types of measurements and instrumentation (including the tradeoffs inherent in the various instrument components), and the basic theory required to interpret the recorded data. A brief review of diffuse optical applications is included, with an emphasis on research that has been done with psychiatric populations. Finally, we discuss some practical issues and limitations that are relevant when conducting diffuse optical experiments. We find that, while diffuse optics can provide substantial advantages to the psychiatric researcher relative to the alternative brain imaging methods, the method remains substantially underutilized in this field.

Brain↗

PubMed2002

Reconfigurable networking for coordinated multi-agent sensing and communications.

An implementation of a neurally-inspired system comprised of multiple mobile sensor-effector agents is described. Each agent has features of a complex neural network that is able to communicate and adjust its behavior depending upon a variety of parameters, including changes in the environment and the behavior of other agents. The system as a whole spatiotemporally reconfigures itself to perform coordinated behaviors not obtainable with single agents. Transient clustering of agents into functional subsystems to perform specific tasks generates a "system of systems" architecture. The interesting findings of this dynamic platform show that (a) the formation and dissolution of functional subsystems is a local phenomenon without the need for global control and (b) minimal intermittent communication among the agents can yield large-scale, coordinated, goal-driven behavior under a wide range of conditions.

Aerospace Medicine↗

PubMed2002

Smart medical systems with application to nutrition and fitness in space.

Smart medical systems are being developed to allow medical treatments to address alterations in chemical and physiologic status in real time. In a smart medical system, sensor arrays assess subject status, which is interpreted by computer processors that analyze multiple inputs and recommend treatment interventions. The response of the subject to the treatment is again assessed by the sensor arrays, thus closing the loop. An early form of "smart medicine" has been practiced in space to assess nutrition. Nutrient levels are assessed with food frequency questionnaires, which are interpreted by flight surgeons to recommend inflight alterations in diet. In the future, sensor arrays will directly probe body chemistry. Near-infrared spectroscopy can be used to non-invasively measure several blood and tissue parameters that are important in the assessment of nutrition and fitness. In particular, this technology can be used to measure blood hematocrit and interstitial fluid pH. The non-invasive measurement of interstitial pH is discussed as a surrogate for blood lactate measurement for the development and real-time assessment of exercise protocols in space. Earth-based application of these sensors is also described.

Aerospace Medicine↗