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The effects of age, education, and gender on visual confrontation naming using the 60-item Boston Naming Test (BNT) were studied in 1111 "normal" elderly (ages 50-101) and 61 younger adults (ages 20-49). Significantly poorer mean BNT scores and increasing variability (measured in standard deviations) were found with successively older age groups and with lower educational levels even after stratification on the demographic variables. There was a non-significant trend for males to score slightly higher than females. Age declines on the BNT were considerably greater for this cross-sectional data than for the longitudinal data we previously reported.

Gap-induced prepulse inhibition of acoustic startle (GPIAS) has been used in rats and mice to study the problem of tinnitus. The current study demonstrates that similar methods can be used to study the temporal development of tinnitus over time in middle-aged mice. Six-month-old mice on a mixed C57Bl6×129 background were anesthetized with isoflurane and exposed to unilateral noise (n=15), or sham exposure for controls (n=8), for one hour (16 kHz octave band signal, 116 dB SPL). Tinnitus was tested in eight different sound frequency bands before and at post-exposure time points of 1, 3–4, 7, 14, 21, and 30 days, and monthly thereafter until 7 months post exposure. Noise-exposed mice displayed a number of changes in GPIAS consistent with the presence of hyperacusis and tinnitus. Noise exposure was associated with acute tinnitus measured one day later at several frequencies at and above the exposure frequency center. Consistent, chronic tinnitus then emerged in the 24 kHz range. Several time points following noise exposure suggested evidence of hyperacusis, often followed temporally by the development of deficits in GPIAS (reflecting tinnitus). Temporal development of these changes following noise exposure are discussed in the context of the interactions between aging, noise exposure and the associated neurochemical changes that occur at early stages of auditory processing.

The longitudinal effects of age on confrontation naming using the 60-item Boston Naming Test (BNT) were studied in 541 "normal" elderly (ages 50-99). For participants with at least 4 annual assessments (n = 238), 150 were followed for > or =6 years, 81 for > or =8 years, and 43 for > or =10 years. A small practice effect (0.21 words, p = 0.06) and moderately high test-retest reliability were found when comparing the first 2 assessments, which were 9-15 months apart (r = 0.76, n = 353). Reliable change index scores indicated that an annual decline of > or =4 points on the BNT is needed for a statistically reliable decline in an individual. A gradient in the mean annual rate of change on the BNT was found with improvement in the 50s age group, no change in the 60s age group, and decline in the 70s and 80s age groups. When projected over 10 years, the magnitudes of the mean changes were relatively small, that is, a 1-word improvement for participants in their 50s and a 1.3-word decline for participants in their 70s. These findings demonstrate that lexical retrieval as measured by a visual object confrontation naming task is generally well preserved in aging with only subtle decline in the 7th and 8th decades of age.

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