In this paper, we prepare segmenting the brain portion Magnetic Resonance Image (MRI). In our method, we first find the threshold using Riddler’s method and convert gray image to binary image. The head boundaries are detected by using contour of the head. By subtracting, we detect the scalp and remove it. We perform morphological operation to disconnect the non-brain region. Finally, by applyin...

In pattern masking, the target and mask are presented at the same location and follow one another very closely in time. When the observer attends to the target, he or she must also attend to the mask, as the switching time for attention is quite slow. In a series of experiments, we present mask-target-mask sequences staggered in time and location (Cavanagh, Holcombe, & Chou, 2008) that allow pa...

Does spatial separation incur a processing time requirement before precise alignment judgements can occur? Alignment thresholds for separated lines are measured for exposure durations from 27 to 500ms, with and without post-masks. The effect of masks on visibility is controlled. Unlike without a post-mask, with an effective post-mask, alignment thresholds improve substantially with time, i.e. i...

The development of an optimized recipe for the processing of a MQW AlGaInN based oxide stripe laser diode grown on c-plane sapphire has been investigated. Two processing sequences involving Reactive Ion Etching (RIE) were compared. The first relied on the use of SiO2 as a dry etch-mask, whereas in the second, the use of nickel was utilized. The critical step of smooth and vertical mirror format...

Usually a high-contrast, co-local mask increases contrast threshold (inhibition). Interestingly, a laterally displaced mask (flanker) can facilitate contrast detection (Vision Research 33 (1993) 993; 34 (1994) 73). When spatial scaling of these flanker effects was implied, stimulus bandwidth was confounded with spatial frequency (lambda(-1)). Under conditions where at lower spatial frequencies,...

To assess the effects of spatial frequency and phase alignment of mask components in pattern masking, target threshold vs. mask contrast (TvC) functions for a sine-wave grating (S) target were measured for five types of mask: a sine-wave grating (S), a square-wave grating (Q), a missing fundamental square-wave grating (M), harmonic complexes consisting of phase-scrambled harmonics of a square w...

In this case report, we want to introduce a successful way of applying non-invasive ventilation (NIV) with a full face mask in patients with high cervical spinal cord injury through a novel alarm system for communication. A 57-year-old man was diagnosed with C3 American Spinal Injury Association impairment scale (AIS) B. We applied NIV for treatment of hypercapnia. Because of mouth opening duri...

Masked stimuli presented near the threshold of conscious awareness may act as primes, affecting responses to subsequent targets. With arrows as primes and targets, the prime-mask-target sequence has been shown to evoke triphasic lateralized readiness potentials (LRP) with two phases of imbalance between hemispheres preceding the target-related contralateral preponderance of negativity: first a ...

The threshold masking effect of one simultaneously presented grating upon another was studied as a function of mask contrast and frequency. The masking function typically obeys Weber's Law with method-of-adjustment psychophysics, and typically does not with forced-choice. This apparent discrepancy was studied in some detail. We suggest that thresholds can be set with at least two different crit...

Evidence for a divisive contrast gain control in human vision was obtained using a contrast version of the probe-on-flash technique that has been employed in the light adaptation literature. Thresholds were measured for a briefly flashed (30 ms), vertical test pattern superimposed on a cosine mask as a function of time after mask onset (SOA). Threshold elevations declined monotonically for SOAs...