Experience-dependent modulation of the visual evoked potential: Testing effect sizes, retention over time, and associations with age in 415 healthy individuals

Sensory-Induced Human LTP-Like Synaptic Plasticity – Using Visual Evoked Potentials to Explore the Relation Between LTP-Like Synaptic Plasticity and Visual Perceptual Learning

“…These findings add to previous studies demonstrating that high-frequency (Teyler et al, 2005;Spriggs et al, 2017;Rygvold et al, 2020) and prolonged (Normann et al, 2007;Valstad et al, 2020) sensory stimulation modulate several VEP component amplitudes. This modulation effect has been repeatedly demonstrated for components C1, P1, N1b, and N1, of which modulation of the N1/N1b complex is the most consistent finding (Teyler et al, 2005;Normann et al, 2007;Elvsåshagen et al, 2012;Spriggs et al, 2017;Zak et al, 2018;Valstad et al, 2020). However, in contrast to some previous results, as well as the current hypothesis, we failed to replicate a corresponding modulation of the P1 peak amplitude.…”

“…In humans, differences in SRM magnitude are evident between age groups, drawing parallels to the age-related decline in LTP observed in animal studies (Spriggs et al, 2017;Abuleil et al, 2019). However, recently, it has been proposed that age-dependency is limited to a subset of the VEP components (Valstad et al, 2020). This latter study also reported significant modulation of several VEP components after prolonged visual stimulation and showed that the retention patterns of the N1b and N1 closely resemble LTP-like mechanisms.…”

“…However, this effect of age has not been reported in other studies (e.g., Teyler et al, 2005;Normann et al, 2007;Elvsåshagen et al, 2012), suggesting that the SRM effect is not necessarily a phenomenon that can be generalized across individuals (Abuleil et al, 2019). This notion is further supported by the observation of sex differences in amplitude modulation magnitude (Valstad et al, 2020), a finding which may be related to systematic sex differences in the shape of cortical convolutions in the brain (Luders et al, 2004). Importantly, anatomical differences can potentially affect ERP amplitude measures (Valstad et al, 2020), making generalization challenging.…”

“…However, in contrast to some previous results, as well as the current hypothesis, we failed to replicate a corresponding modulation of the P1 peak amplitude. In a similar vein, Abuleil et al (2019) found depotentiation in younger participants, whereas Valstad et al (2020) report an association between P1 modulation and increasing age. The current sample was young (mean age 23.7), possibly explaining the absence of a P1 amplitude modulation.…”

“…Due to methodological limitations, the transition to human models explaining LTP have proven difficult. However, initiated by Teyler et al (2005), non-invasive EEG-derived methods have been developed to study LTP-like phenomena in humans, targeting changes in sensory evoked potential amplitudes following high-frequency sensory stimulation (e.g., Teyler et al, 2005;Spriggs et al, 2017;Rygvold et al, 2020) or prolonged sensory stimulation (e.g., Normann et al, 2007;Valstad et al, 2020). The experimental procedure involving the modulation of sensory evoked potentials which is regarded as a valid assay of LTP-like plasticity phenomena, is commonly referred to as the stimulus-selective response modulation (SRM) paradigm (Rygvold et al, 2020).…”