Altersabhängigkeit impliziten sequentiellen Lernens bei gesunden Probanden Implementierung eines standardisierten Normkollektivs für den seriellen Reaktionszeittest

Implicit, procedural learning is one of the most fundamental learning mechanisms that enables humans to acquire daily motorical skills that help them to integrate into their environment. Here, we focused on a reaction time task as parameter for implicit learning capacities. In a visual serial reaction time task (SRTT), we investigated whether sequence learning differs between age-groups in healthy participants. We investigated 103 healthy participants (≥20 participant per age group: 18-30, 31-40, 41-50, 51-60 (21 p.), 61-75 (22 p.) years) without any history of neurological, psychiatric disease. Investigations included a structured interview, subjective memory opinion and standardized neuropsychological diagnostics, especially explicit memory (ExM) with the verbal learning and memory task (VLMT) and implicit memory (ImM) with serial reaction time task (SRTT). SRTT is a computer-based reaction time task (see also www.implicitHeRo.com). Participants are sitting in front of a screen and react to visually presented stimuli. While the first and sixth bloc are randomized blocs 2-5 and 7-8 display a sequence for testing implicit learning. Results Participants (female 56.3%, mean age 45.0 ± 15.6 SD, range 19-75) showed implicit learning measured by faster reaction times (RT) and lower error rates (ER) when comparing the last random bloc (bloc 6) with its adjacent sequence blocs (5&7) (MD 614.69 ms ± 115.92 vs. 568.39 ms ± 125.11; p<.001). All participants showed equal age dependent parallel shifted learning curves in SRTT (p<.001). Performance on fifth vs. seventh sequence-bloc revealed a significant interaction effect (p<.001). This was most prominent in youngest (18-30) decade vs. oldest (61-75) but all decades differed in their speed to learn (p<.001). ImM was calculated with difference between (RT bloc6) minus ((RT bloc5 + RT bloc 7)÷2). There wasn`t any prominent differentiation between the decades. There was no effect of gender or handedness on measures of ImM (p>.1). ExM, as measured by delayed recall (VLMT7, mean 12.4 ± 2.6 SD) and recognition (VLMTWK-VLMTerror, mean 13.6 ± 2.2 SD) was normal in all participants as compared to the standardized percentile for VLMT. In conclusion all age groups showed an implicit learning effect during the reaction time task and older participants showed increased RT and ER but intact procedural learning. Implicit learning is preserved over the lifespan. Performance on explicit verbal memory was normal in all groups. We provide normal data for future studies of patient cohorts.