Longer resistance of associative versus item memory to interference-based forgetting, even in older adults.

Abstract

Few studies have compared interference-based forgetting between item versus associative memory. The memory-system dependent forgetting hypothesis (Hardt, Nader, & Nadel, 2013) predicts that effects of interference on associative memory should be minimal because its hippocampal representation allows pattern separation even of highly similar information. In contrast, there should be strong interference effects on extra-hippocampally represented item memory. We tested this prediction in behavioral data from 3 experiments using continuous recognition paradigms. Given older adults’ greater deficits in associative than item memory, we also compared younger and older adults to test whether this associative deficit extends to greater interference susceptibility in older adults’ associative memory. Experiment 1 examined item-item associative memory with participants studying unrelated word pairs continuously intermixed with item (single words) and associative (intact vs. recombined pairs) recognition tests across interference-filled lags. Experiments 2 and 3 examined item-context (i.e., source) associative memory with participants studying words in different spatial positions continuously intermixed with source-monitoring tests (presented on top vs. on bottom vs. new?) across interference-filled lags (Experiment 3 controlling for delay/decay-based effects). In all experiments, item memory declined from the first lag on. In contrast, associative memory initially remained stable, with strong evidence for null effects of interference even in older adults, but showed some declines at later lags. The data supports Hardt et al.’s proposal of differential interference-based forgetting in item versus associative memory. The results further show that the age-related associative memory deficit does not extend to greater interference-based forgetting in older adults’ associative memory.

Does unitization really function like items? The role of time and interference on item and associative memory processes.

“…While earlier work suggests that delay and interference have similar effects on associative memory and item memory across the lifespan with respects to shorter term memory (e.g., lags up to 10 seconds) (Chen & Naveh-Benjamin, 2012), results from recent work suggest that item and associative memory may be differentially affected by interval length (Kuhlmann et al, 2021). Specifically, Kuhlmann and colleagues found that while both item and associative memory declined across lags of varying lengths, item memory declined linearly across all lags, while associative memory remained relatively stable at shorter lags (1 and 11 trials), declining only in later lags (24 and 44 trials).…”

“…A power analysis, based upon the sample size of Kuhlmann et al (2021), showed that in order to reach a medium effect size of f = .25, 55 participants in each age group would be needed.…”

“…The unitized word pairs were presented separately with a dot and spacing between the two components of the pair as seen above. Associative word pairs were taken from Kuhlmann and colleagues recent work (Kuhlmann et al, 2021), and random unrelated words 1 Note: older adults were tested online and were rejected for high numbers of no responses and failure to complete the task; these numbers are not reflected in the total number of 'removed' participants.…”

“…In addition to these age deficits in associative memory, retention intervals and interference can also affect both item and associative memory. Historically, research has found that increased time between study and test, results in a decrease in memory, one paramount study being that of Ebbinghaus' forgetting curve (Ebbinghaus, 1880) and more recent work using a continuous recognition paradigm (Ashford et al, 2011;Berman et al, 1991;Jones & Atchley, 2002;Kuhlmann et al, 2021;Poon & Fozard, 1980). The continuous recognition paradigm features a constant encoding and simultaneous retrieval of information, such that there is no break between the two tasks, with new and repeating information being intermixed in a continuous stream (Hockley, 1982).…”

“…While age did not interact with lag, there was a significant interaction between age and type of memory, such that older adults performed worse on the associative memory trials than younger adults, demonstrating the typical associative deficit in aging. The authors interpreted the difference between item and associative declines across lags as associative memory having greater resistance to interference than item memory (Kuhlmann et al, 2021).…”