Abstract
Objective: The present ERP study investigates the effect of ageing on automatic semantic processing and whether the process is associated with other cognitive abilities.
Methods: 15 Cantonese-speaking young adults (8F, age = 21) and 22 healthy older adults (12F, age = 68) were recruited. All older adults were cognitively normal (mean HK-MoCA = 26.32, SD = 2.28). A primed lexical decision task with a short SOA = 150 ms was used to assess automatic semantic processing (Figure 1 & Table 1).
Results: Two-way mixed ANOVA results on RT showed that both groups had significant semantic priming effect and older adults had significantly larger effect (Table 2). Three ERP components (P250/N400/LPC) were analysed (Figure 2). The young group exhibited significant SP for both P250 (t = 2.84, p = .015) and N400 (t = 3.52, p = .002). In contrast, older adults had significant SP for LPC only (t = 2.95, p = .011). Also, partial correlations controlling for age and education showed that the older adults with better short-term memory had smaller LPC at Pz (r = -.54, p = .015)
Conclusion: Although both groups showed the SP effect, the underlying neural mechanisms were different. Young adults showed significant SP in only the two earlier components, versus only significant SP in LPC for older adults. This delayed SP effect indicated that older adults may recruit more controlled processing to compensate for their declined automatic processing.
Acknowledgment: The research was partially funded by HKRGC-GRF 15601718.
Methods: 15 Cantonese-speaking young adults (8F, age = 21) and 22 healthy older adults (12F, age = 68) were recruited. All older adults were cognitively normal (mean HK-MoCA = 26.32, SD = 2.28). A primed lexical decision task with a short SOA = 150 ms was used to assess automatic semantic processing (Figure 1 & Table 1).
Results: Two-way mixed ANOVA results on RT showed that both groups had significant semantic priming effect and older adults had significantly larger effect (Table 2). Three ERP components (P250/N400/LPC) were analysed (Figure 2). The young group exhibited significant SP for both P250 (t = 2.84, p = .015) and N400 (t = 3.52, p = .002). In contrast, older adults had significant SP for LPC only (t = 2.95, p = .011). Also, partial correlations controlling for age and education showed that the older adults with better short-term memory had smaller LPC at Pz (r = -.54, p = .015)
Conclusion: Although both groups showed the SP effect, the underlying neural mechanisms were different. Young adults showed significant SP in only the two earlier components, versus only significant SP in LPC for older adults. This delayed SP effect indicated that older adults may recruit more controlled processing to compensate for their declined automatic processing.
Acknowledgment: The research was partially funded by HKRGC-GRF 15601718.
| Original language | English |
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| Publication status | Not published / presented only - 8 Aug 2022 |
| Event | BrainConnects 2022 - Nagoya, Japan Duration: 8 Aug 2022 → 8 Aug 2022 |
Conference
| Conference | BrainConnects 2022 |
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| Country/Territory | Japan |
| City | Nagoya |
| Period | 8/08/22 → 8/08/22 |