Interstimulus intervals

Removing Physiological Noise. One method of removing the low frequency artifact is to convolve the response signal with a model of stimulus signal. Such methods have been used to increase the SNR in fMRI [54], The stimulus signal is usually modeled as a pulse train with evenly spaced interstimulus interval as in Equation (11)... 

Here, M is the total number of stimulis and tisi is the interstimulus interval. The convolved signal is used to fit a generalized regression model of the form... 

The interstimulus interval should be sufficient to avoid adaptation of the panelist to the odour and sufficient to allow the olfacto meter to provide the new stimulus. This can be attained with a cycle time of 1 minute (cycle time=exposition time plus interval). 

List of Abbreviations ISI, interstimulus interval LGN, lateral geniculate nucleus M, magnocellular MST, medial superior temporal area MT, medial temporal area NMDA, N-methyl-D-aspartate P, parvocellular ssVEP, steady-state visual evoked potential TE, temporal lobe TEO, temporal occipital area tVEP, transient visual evoked potential YEP, visual evoked potential VI, primary visual cortex... 

List of Abbreviations ABRs, acoustic brainstem responses cAMP, cyclic AMP DHBE, dihydro-P-ery-throidine ERPs, event-related potentials GBO, gamma band oscillation ISI, interstimulus interval MLA, methyllycaconitine MMN, mismatch negativity nAChR, nicotinic acetylcholinergic receptor NMDA,... 

Ceponiene R, Cheour M, Naatanen R. 1998. Interstimulus interval and auditory event-related potentials in children evidence for multiple generators. Electroencephalogr Clin Neurophysiol 108 345-354. 

Onitsuka T, Ninomiya H, Sato E, Yamamoto T, Tashiro N. 2000. The effect of interstimulus intervals and between-block rests on the auditory evoked potential and magnetic field is the auditory P50 in humans an overlapping potential Clin Neurophysiol 111 237-245. 

Vollenweider FX, Csomor PA, Knappe B, Geyer MA, Quednow BB. The effects of the preferential 5-HT2a agonist psilocybin on prepulse inhibition of startle in healthy human volunteers depend on interstimulus interval. Neuropsychopharmacology 2007 32(9) 1876-87. 

The most pronounced effect of paired-pulse depression occurs at an interstimulus interval of 200 ms [64]. The impact of paired-pulse depression is significantly larger for the GABAb receptor mediated inhibitory postsynaptic currents. The IPSCb evoked by the second stimulus was depressed by 62 8%, whereas the IPSCa evoked by the second stimulus was depressed by 37 4% as shown in Fig. 10 [64]. 

The parameters recommended for ESCM are as follows 2 h of daily stimulation sessions. Stimulus consists of 1-min trains of Lilly pulses with an interstimulus interval of 4 min, alternating right and left CM. Such trains consist in a 130-Hz frequency, with individual pulses of 450 fxs in duration and amplitude of 400 to 600 fxA. 

The odors were applied to both nostrils within a constantly flowing airstream, non-synchronously to breathing. Stimulus temperature was 38 C and the relative humidity was above 80% (method according to Kobal Hummel, 1991). A total of 200 trials was carried out per session. The stimulus duration was 600 ms and the interstimulus interval varied between 18 and 22 s. After every 50 trials a break was included and the subjects had to subjectively evaluate the valence of the body odors. The functional significance of stimuli d2 and d3 (target or distracter) was changed after every 50 trials and the order was varied between the subjects. 

Aster prenanthoides, Aster praealtus, and Solidago rugosa. Volatiles from 10 g of each plant were allowed to accumulate in 125 ml flasks for 15 min at 23°C. Fifty cc of headspace from each flask was then withdrawn by syringe, and injected into the left naris of each bird at a rate of 10 cc/sec. Five min interstimulus intervals were used, and as many series of the eight stimuli as possible were presented to each bird at 20 min intervals. 

The area on the display used by the stimuli was 10 cm x 5 cm. The subject was instructed to press one key as rapidly as possible as soon as the stimulus appeared on the display. The attachment of a stimulus to a key was told to him by a brief instruction on the display before the beginning of each task. By pressing any key the task started. The sequence of visual stimuli was randomized, all stimuli had about the same probability to be shown, the mean interstimulus interval was 2.5 sec. Each task consisted of a training sequence of 10 trials and then a sequence of 100 trials. Only the latter were used as results. The subject performed 100 trials with the possibility to pause 10-60 seconds after every 10 trials. 

Methods Data were obtained from 10 normal hearing subjects. The auditory stimuli were pure tones of 1 kHz with a duration of 40 ms and a constant interstimulus interval (ISI) of 1 s and presented at 50 desibel (dB) sound pressure level (SPL) and 100 dB SPL consecutively. Subject were in relaxing condition and awake over the experiment. 

This test measures the child s ability to sustain attention. The child is seated in front of a screen with a response box. The test starts with a practice session to make sure that the child understands the task. The stimulus for this test is 12 letters. One letter at a time appears on the screen, with a stimulus duration of 0.2 s and a interstimulus interval of 1.5 s. The stimulus to which the child is instructed to respond is the letter H when it is immediately following the letter S. The 12 letters are randomized over a series of 100 stimuli, with 15 significant stimuli (S followed by H). The total run of 100 stimuli is repeated six times. A session of the task lasts about 15 min. The test is controlled by a computer which also collects data. 

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