Melody recognition at fast and slow tempos: Effects of age, experience, and familiarity

Eighty-one listeners defined by three age ranges (18–30, 31–59, and over 60 years) and three levels of musical experience performed an immediate recognition task requiring the detection of alterations in melodies. On each trial, a brief melody was presented, followed 5 sec later by a test stimulus that either was identical to the target or had two pitches changed, for a same–different judgment. Each melody pair was presented at 0.6 note/sec, 3.0 notes/sec, or 6.0 notes/sec. Performance was better with familiar melodies than with unfamiliar melodies. Overall performance declined slightly with age and improved substantially with increasing experience, in agreement with earlier results in an identification task. Tempo affected performance on familiar tunes (moderate was best), but not on unfamiliar tunes. We discuss these results in terms of theories of dynamic attending, cognitive slowing, and working memory in aging.

Slow Strain Rate Testing and Stress Corrosion Cracking of Ultra-Fine Grained and Conventional Al-Mg Alloy

Stress corrosion cracking susceptibility was investigated for an ultra-fine grained (UFG) AI-7.5Mg alloy and a conventional 5083 H111 alloy in natural seawater using slow strain rate testing (SSRT) at very slow strain rates between 1E(-5) s(-1), 1E(-6) s(-1) and 1E(-7) s(-1). The UFG Al-7.5Mg alloy was produced by cryomilling, while the 5083 H111 alloy is considered as a wrought manufactured product. The response of tensile properties to strain rate was analyzed and compared. Negative strain rate sensitivity was observed for both materials in terms of the elongation to failure. However, the UFG alloy displayed strain rate sensitivity in relation to strength while the conventional alloy was relatively strain rate insensitive. The mechanical behavior of the conventional 5083 alloy was attributed to dynamic strain aging (DSA) and delayed pit propagation while the performance of the UFG alloy was related to a diffusion-mediated stress relaxation mechanism that successfully delayed crack initiation events, counteracted by exfoliation and pitting which enhanced crack initiation. (C) 2014 Elsevier B.V. All rights reserved.