At what level is the gap transfer illusion illusory?

The gap transfer illusion is an auditory phenomenon in which a temporal gap in a longer glide transfers perceptually to a crossing shorter glide, making the longer glide illusorily continuous. This continuity is often considered a variation of classic illusory auditory continuity attributed to auditory peripheral activity, but a new view is given here supported by a series of sound demonstrations indicating that this illusory continuity is purely caused by a higher mechanism of perceptual organization.

Auditory icons: Design and physical characteristics.

Auditory icons are short sound messages that convey information about an object, event or situation. Originally, auditory icons have been used in computer interfaces, but are nowadays found in many other fields. In this review article, an overview is given of the main theoretical ideas behind the use and design of auditory icons. We identified the most common fields in which auditory icons have been used, and analyzed their acoustic characteristics. The review shows that few studies have provided a precise description of the physical characteristics of the sounds in auditory icons, e.g., their intensity level, duration, and frequency range. To improve the validity and replicability of research on auditory icons, and their universal design, precise descriptions of acoustic characteristics should thus be provided.

Heart rate variability in drug-naïve patients with panic disorder and major depressive disorder.

Power spectral analysis of electrocardiogram (ECG) R-R intervals is useful for the detection of autonomic dysfunction in various clinical disorders. Although both panic disorder (PD) and major depressive disorder (MDD) are known to have effects on the cardiac autonomic nervous system, no previous study has tested this among drug-naïve (i.e. no history of treatment) patients with MDD and PD in the same study. The purpose of this study was to compare cardiac autonomic functions among drug-naïve patients with MDD and PD and those of healthy controls. Subjects were 17 drug-naïve PD patients, 15 drug-naïve MDD patients and 15 normal controls. ECGs were recorded under both supine resting and supine deep-breathing conditions (10-12 breaths/min; 0.17-0.20 Hz). We measured the low-frequency power (LF; 0.05-0.15 Hz), which may reflect baroreflex function, the high-frequency power (HF; 0.15-0.40 Hz), which reflects cardiac parasympathetic activity, as well as the LF/HF ratio. As expected, deep breathing induced an increase in HF power and a decrease in the LF/HF ratio in healthy controls. Compared to these controls, however, the MDD group had a lower response to regular deep breathing in LF power and in LF/HF ratio. PD patients showed intermediate results between normal controls and MDD patients. The results indicate that the reactivity to deep breathing revealed diminished cardiac autonomic reactivity in drug-naïve MDD patients.