Aging: Sensitivity vs Criterion in Taste Perception

The study employed the signal-detection paradigm as a model for investigating age related biological vs cognitive (decision) effects on perceptual behavior. Old and young subjects reported the presence or absence of sugar in threshold level solutions and tap water. It was found that the aged subjects displayed a higher detection threshold. They also obtained a higher (stricter) criterion of decision, fewer false-positives and a greater false-negatives-to-total-errors ratio. These findings were interpreted as strategic behavior motivated by the elderly subjects’ greater need to perform well through reducing the error rate. A post-hoc interview found that most subjects equated the term ’error’ with false-positives only. Therefore, the negative response bias found among the elderly subjects may represent a strategic attempt to reduce the rate of false-positive errors. It is also speculated that it may reflect a need to save energy, since negative responses imply an unwillingness to commit oneself to exert effort.