Transcranial magnetic stimulation (TMS) is a non-invasive neurostimulatory and neuromodulatory technique that can transiently or lastingly modulate cortical excitability (either increasing or decreasing it) via the application of localized magnetic field pulses. Within the field of TMS, the term state dependency refers to the initial, baseline condition of the particular neural region targeted ...

Truth maintenance systems provide caches of beliefs and inferences that support explanations and search. Traditionally, the cost of using a TMS is monotonic growth in the size of this cache. In some applications this cost is too high; for example, intelligent learning environments may require students to explore many alternatives, which leads to unacceptable performance. This paper describes an...

Activation of the left posterior parietal cortex (PPC) has been associated with the encoding of letters independent of visual form. Here we used transcranial magnetic stimulation (TMS)-adaptation to investigate whether this abstract letter selectivity plays a causal role in letter processing. Visual adaptation was used to manipulate the initial activation state of neurons tuned to different let...

The precise role of frontal eye fields (FEF) in vision independent of their role in eye movements remains a matter of debate. One proposal is that the FEF exert top-down influences on the extrastriate visual cortex prior to eye movement preparation. Here we establish, by use of transcranial magnetic stimulation (TMS), that activity in the human FEFs has a direct effect on the sensitivity of ext...

Transcranial magnetic stimulation (TMS) is a noninvasive and painless tool for the electrical stimulation of the human cortex (Barker et al. 1985). TMS depolarizes cortical neurons and can evoke measurable electrophysiological and behavioral effects. TMS is usually applied to one cortical area, but can also be given to two or more areas (i.e., multi-site TMS). Single or paired stimuli and short...

We address the importance of understanding initial states of neuronal populations and of state-dependent responses in cognitive neuroscience experiments with special emphasis on brain stimulation studies of perception and cognition. The approach we present is based on evidence that behavioural and perceptual effects of transcranial magnetic stimulation (TMS) are determined by initial neural act...

Several methods can be used to treat patients with epilepsy: antiepileptic drugs(AED), surgery and neuromodulation. AED is the most common method and also the first choice in the treatment of epilepsy. However, some patients are drug-resistant, or encounter severe adverse effects. In this case, surgery is an alternative to drug therapy for part of these patients. But surgery has several drawbac...

This study examines the effects of TMS of the right PPC on the latency of saccades and vergence alone or combined and the role of experimental design. Two designs were used: pure blocks with exclusively no-TMS or TMS trials; mixed blocks in which no-TMS and TMS trials were interleaved; a control study with TMS of the primary motor cortex (pure blocks) was also conducted and showed no effects on...

OBJECTIVE To further evaluate the potential of slew-rate limiting amplifiers to record electrophysiological signals in spite of concurrent transcranial magnetic stimulation (TMS), and to explore the effects of single-pulse TMS on electroencephalographic (EEG) correlates of functional brain activity. METHODS Visual-evoked potentials (VEPs) to checkerboards were recorded in 7 right-handed subje...