Prediction accuracy of young and middle-aged adults in memory for familiar and unfamiliar texts

This study investigated the influence of age, familiarity, and level of exposure on the metamemorial skill of prediction accuracy on a future test. Young (17 to 23 years old) and middle-aged adults (35 to 50 years old) were asked to predict their memory for text material. Participants made predictions on a familiar text and an unfamiliar text, at three different levels of exposure to each. The middle-aged adults were superior to the younger adults at predicting performance. This finding indicates that metamemory may increase from youth to middle age. Other findings include superior prediction accuracy for unfamiliar compared to familiar material, a result conflicting with previous findings, and an interaction between level of exposure and familiarity that appears to modify the main effects of those variables.

Identification of speeded and slowed familiar melodies by younger, middle-aged, and older musicians and nonmusicians

There is a range of tempos within which listeners can identify familiar tunes (around 0.8 to 6.0 notes/s). Faster and slower tunes are difficult to identify. The authors assessed fast and slow melody-identification thresholds for 80 listeners ages 17–79 years with expertise varying from musically untrained to professional. On fast-to-slow (FS) trials the tune started at a very fast tempo and slowed until the listener identified it. Slow-to-fast (SF) trials started slow and accelerated. Tunes either retained their natural rhythms or were stylized isochronous versions. Increased expertise led to better performance for both FS and SF thresholds (r = .45). Performance declined uniformly across the 62-year age range in the FS condition (r = .27). SF performance was unaffected by age. Although early encoding processes may slow with age, expertise has a greater effect. Musical expertise involves perceptual learning with melodies at a wide range of tempos.

Hearing in the mind's ear: A PET investigation of musical imagery and perception

Neuropsychological studies have suggested that imagery processes may be mediated by neuronal mechanisms similar to those used in perception. To test this hypothesis, and to explore the neural basis for song imagery, 12 normal subjects were scanned using the water bolus method to measure cerebral blood flow (CBF) during the performance of three tasks. In the control condition subjects saw pairs of words on each trial and judged which word was longer. In the perceptual condition subjects also viewed pairs of words, this time drawn from a familiar song; simultaneously they heard the corresponding song, and their task was to judge the change in pitch of the two cued words within the song. In the imagery condition, subjects performed precisely the same judgment as in the perceptual condition, but with no auditory input. Thus, to perform the imagery task correctly an internal auditory representation must be accessed. Paired-image subtraction of the resulting pattern of CBF, together with matched MRI for anatomical localization, revealed that both perceptual and imagery. tasks produced similar patterns of CBF changes, as compared to the control condition, in keeping with the hypothesis. More specifically, both perceiving and imagining songs are associated with bilateral neuronal activity in the secondary auditory cortices, suggesting that processes within these regions underlie the phenomenological impression of imagined sounds. Other CBF foci elicited in both tasks include areas in the left and right frontal lobes and in the left parietal lobe, as well as the supplementary motor area. This latter region implicates covert vocalization as one component of musical imagery. Direct comparison of imagery and perceptual tasks revealed CBF increases in the inferior frontal polar cortex and right thalamus. We speculate that this network of regions may be specifically associated with retrieval and/or generation of auditory information from memory.