Recognition memory in older adults: adjustment to changing contingencies.
Older adults shift response bias when payoffs change, but they need more practice and simpler rules to reach the new optimum.
01Research in Context
What this study did
Iwata et al. (1990) tested how older and younger adults change their answers when the payoff rules shift. They used a continuous-recognition memory task. Pictures were shown one by one. If the picture was new, press the left key. If old, press the right key. After many trials, the researchers changed the payoff matrix. Now some answers earned more points, others fewer.
The team tracked accuracy and response bias. They wanted to see if older adults could adjust as well as younger adults.
What they found
Older adults had lower accuracy overall. When the payoff rules changed, both groups shifted their response bias. Younger adults moved closer to the new optimal strategy. Older adults moved, but not as precisely.
In short, older adults noticed the rule change and tried to adapt, yet their adjustments were less accurate.
How this fits with other research
Fields (1978) showed pigeons also shift bias when payoff values change. The bird data match the human data: bias moves, but detection skill stays the same.
Gentry et al. (1980) found the same split in pigeons. Reinforcement rate changed bias, not sensitivity. Iwata et al. (1990) now show this rule holds for older adults.
Brinton et al. (1996) added that fast choices are more sensitive to payoff shifts. The older adults in Iwata et al. (1990) might respond more slowly, so their bias shifts could be smaller.
Why it matters
When you change reinforcement rules for older clients, give extra practice and clear feedback. Use simple payoff tables. Check response latency—faster responses may show bigger bias shifts. These steps help older learners reach the new optimal strategy.
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02At a glance
03Original abstract
Four older and 4 younger men were given extended exposure to a continuous-recognition memory procedure. Experimental variables included the type of stimulus (alphanumeric strings, words, or sentences), the intervals separating repeated items, gains and losses for correct and incorrect recognitions, and the extent of practice with the memory task. Signal detection analyses indicated that the older men generally were less accurate (sensitivity), particularly when the stimuli were strings, but that age differences decreased with practice. Under conditions in which the payoff matrix was neutral, the older and younger men showed equivalent rates of hits and false alarms (bias). Alteration of the matrix to require more liberal or more conservative patterns of recognition responding led to corresponding changes for men of both ages. Adjustments by the older men, however, were not as close to the bias values called for by the new matrices.
Journal of the experimental analysis of behavior, 1990 · doi:10.1901/jeab.1990.54-201