Effects of Brain Stimulation on Learning and Reasoning
Effects of Brain Stimulation on Learning and Reasoning
Imaging studies of the brain have revealed the different areas involved in the processes of
 learning and reasoning. However, the specific role these regions play in these processes, or
 if stimulating these areas can improve these processes is unknown.

 Researchers would like to use repetitive transcranial stimulation (rTMS) to better understand
 the roles of individual brain regions on the processes of learning and reasoning. Repetitive
 transcranial magnetic stimulation (rTMS) involves the placement of a cooled electromagnet
 with a figure-eight coil on the patient's scalp, and rapidly turning on and off the magnetic
 flux. This permits non-invasive, relatively localized stimulation of the surface of the brain
 (cerebral cortex). The effect of magnetic stimulation varies, depending upon the location,
 intensity and frequency of the magnetic pulses.

 The purpose of this study is to use rTMS to help determine the roles of different brain
 regions in the development of implicit learning of motor sequences and analogic reasoning. In
 addition, researchers hope to evaluate if stimulation of these regions speeds up the process
 of learning or analogic reasoning.
The human frontal cortex subserves a number of psychological processes including those
 necessary for adequate implicit learning of visuomotor sequences and analogical reasoning.

 1. Implicit learning is a form of procedural learning indicated by behavioral improvement
 without awareness of a repeated stimulus structure that leads to improved performance.
 This type of learning has been associated with activation of the primary motor cortex
 (M1) in neuroimaging studies. While neuroimaging studies contributed to identify this
 region, they do not provide information about its relative role in the process of
 implicit learning. Is activity in this region necessary for implicit learning to occur?
 Is it possible that "energizing" this region using subthreshold transcranial magnetic
 stimulation can accelerate the implicit phase of learning? The purpose of this protocol
 is to transiently stimulate focally M1 and dorsolateral prefrontal cortex during
 acquisition of implicit learning and evaluate the effects on reaction times and accuracy
 of performance. We plan to study a group of normal volunteers, and three groups of
 patients who demonstrate impaired visuomotor procedural learning tasks: those with
 Parkinson's disease, cerebellar disease, and focal frontal lesions. The result expected
 from this study is an advanced understanding of the role that the motor cortex and
 dorsolateral prefrontal cortex plays in implicit learning in health and disease.
 Additionally, we expect to be able to shorten the implicit phase of learning by rTMS
 particularly in the patient groups that exhibit abnormal procedural learning.

 2. Analogical reasoning requires that subjects adequately process different forms of
 information and then perform a mapping process that allows them to recognize the
 similarity between two or more forms of information. Evidence has been provided that
 indicates this process of analogical mapping is subserved by the frontal cortex. We plan
 to study a group of normal volunteers, and three groups of patients who demonstrate
 impaired performance on tests of analogical reasoning and problem-solving: those with
 Parkinson's disease, frontal lobe dementia, and focal frontal lesions. We predict that
 subthreshold rTMS will facilitate analogical reasoning by promoting the activation of
 established or novel neural activation patterns that represents the actual mapping and
 decision processes required for analogical reasoning. Additionally, we expect to
 facilitate response times and accuracy in analogical mapping in those patients that
 exhibit abnormal analogical reasoning performance.
INCLUSION CRITERIA

 Right handed normal volunteers (18-65 years old).

 Patients with Parkinson's disease off medication.

 Patients with cerebellar deficits.

 Patients with frontal lobe lesions.

 Patients with frontal lobe dementia.

 EXCLUSION CRITERIA

 Subjects with personal or family history of seizures or other neurological disorders.

 Pregnant women.

 Volunteers or patients with severe coronary artery disease.

 Metal in the cranium except mouth.

 Intracardiac lines.

 Increased intracranial pressure as evaluated by clinical means.

 Cardiac pacemakers.

 Intake of neuroleptics.