Foreknowledge of a repeated sequence provided substantially greater benefit for Hebb repetition learning in younger adults compared to older adults, while learning without foreknowledge was comparable between age groups across verbal, visual, and spatial domains.
Key Findings
Results
Hebb repetition learning rates were comparable between younger and older adults in the no foreknowledge condition across all three experiments.
This pattern held across verbal (letters), visual (Chinese characters), and spatial (dot locations) serial recall tasks.
Each experiment used a serial recall task in which a repeated sequence was presented on every third trial.
Participants in the no foreknowledge condition were not explicitly made aware of the repeated sequence.
The comparable learning rates suggest age-related differences in Hebb learning are not universal but depend on encoding conditions.
Results
Foreknowledge of the repeated sequence provided substantially greater benefit for learning in younger adults than in older adults.
Half of participants received foreknowledge — they were informed a repeated sequence would occur and were signalled its presence prior to presentation.
The foreknowledge advantage for younger adults was observed consistently across verbal, visual, and spatial Hebb repetition learning paradigms.
Older adults did not benefit from the foreknowledge cue to the same degree as younger adults.
This age-related difference in foreknowledge benefit was found across all three experiments.
Discussion
The authors attribute the reduced foreknowledge benefit in older adults to difficulties in forming associations between the foreknowledge cue and the repeated sequence.
The interpretation is that older adults' associative binding deficits limit their ability to use an explicit cue to enhance learning.
This account distinguishes between the ability to learn repeated sequences implicitly (preserved in older adults) and the ability to leverage explicit foreknowledge cues (impaired in older adults).
The finding is consistent with prior research suggesting older adults may not benefit from foreknowledge in the same way as younger adults.
The authors frame this as a difficulty in forming cue-sequence associations rather than a general Hebb learning deficit.
Methods
The study systematically investigated Hebb repetition learning across three stimulus domains: verbal (letters), visual (Chinese characters), and spatial (dot locations).
Three separate experiments were conducted, one per stimulus domain.
Each experiment used a serial recall paradigm with a repeated sequence embedded every third trial.
Both younger and older adults participated, with half in each age group assigned to foreknowledge and half to no foreknowledge conditions.
The multi-domain approach allowed assessment of whether age-related foreknowledge effects were domain-general.
Background
Awareness of the repeated sequence enhances Hebb repetition learning, consistent with recent research showing foreknowledge effects.
The study builds on prior demonstrations that explicit awareness of the repeated sequence improves recall performance for that sequence.
Hebb repetition learning is defined as improved recall for repeated sequences compared to non-repeated sequences.
The foreknowledge manipulation involved both informing participants about the repeated sequence and providing a signal before its presentation.
The foreknowledge benefit was evident in younger adults across all three stimulus domains.
What This Means
This research investigated how being told in advance about a repeating memory sequence affects learning in younger versus older adults. The researchers used a task called Hebb repetition learning, where participants had to recall sequences of letters, Chinese characters, or dot locations, and one sequence was secretly repeated every few trials. Some participants were explicitly told that a sequence would repeat and were given a signal when it appeared, while others received no such information. The key question was whether this advance notice ('foreknowledge') would help both age groups equally.
The results showed two distinct patterns. When participants were not told about the repeated sequence, both younger and older adults learned it at similar rates — meaning older adults are just as capable as younger adults of picking up on repeating patterns without explicit instruction. However, when participants were given foreknowledge, younger adults benefited substantially more than older adults. This difference appeared consistently across all three types of memory tasks (verbal, visual, and spatial), suggesting it reflects a broad and reliable age-related difference rather than something specific to one type of material.
The researchers suggest that older adults may have difficulty linking an external cue (the foreknowledge signal) to the repeated sequence in memory, a process known as associative binding. This research suggests that simply telling older adults to pay attention to repeated information may not be as effective a strategy for them as it is for younger adults. The findings have implications for understanding memory aging and for designing memory training or support strategies that take into account how different age groups process explicit learning instructions.
Leach H, Guitard D. (2026). Age-related differences in the role of explicit encoding instructions on verbal, visual and spatial Hebb learning.. Cognition. https://doi.org/10.1016/j.cognition.2026.106691