Short- and long-term forms of neural adaptation: An ERP investigation of dynamic motion aftereffects

Abstract

Adaptation is essential to interact with a dynamic and changing environment, and can be observed on different timescales. Previous studies on a motion paradigm called dynamic motion aftereffect (dMAE) showed that neural adaptation can establish even in very short timescales. However, the neural mechanisms underlying such rapid form of neural plasticity is still debated. In the present study, short-and long-term forms of neural plasticity were investigated using dynamic motion aftereffect combined with EEG (Electroencephalogram). Participants were adapted to directional drifting gratings for either short (640 msec) or long (6.4 sec) durations. Both adaptation durations led to motion aftereffects on the perceived direction of a dynamic and directionally ambiguous test pattern, but the long adaptation produced stronger dMAE. In line with behavioral results, we found robust changes in the event-related potentials elicited by the dynamic test pattern within 64 e112 msec time range. These changes were mainly clustered over occipital and parietooccipital scalp sites. Within this time range, the aftereffects induced by long adaptation were stronger than those by short adaptation. Moreover, the aftereffects by each adaptation duration were in the opposite direction. Overall, these EEG findings suggest that dMAEs reflect changes in cortical areas mediating low-and mid-level visual motion processing. They further provide evidence that short-and long-term forms of motion adaptation lead to distinct changes in neural activity, and hence support the view that adaptation is an active time-dependent process which involves different neural mechanisms.

Automatic compensation enhances the orientation perception in chronic astigmatism

“…There is much more to be revealed about the neural mechanisms of compensation. The detailed mechanisms and substrates of adaptation are known to depend on the duration of adaptation 27 , 28 . Thus, it is worth questioning whether the neural compensatory mechanisms in astigmatism also depend on the duration of experience with astigmatism, from a few seconds, to hours, to years.…”

A matter of availability: Neural representations of task-relevant stimulus features are sharper when stimuli are memorized rather than perceived

“…How can our findings be explained in the light of commonly observed reduction in visual activity over time, usually referred to as visual adaptation (Webster, 2015)? Visual adaptation has been observed on multiple time-scales in the visual system and can occur in time ranges matching the average duration of a fixation (∼400 ms) (Akyuz et al, 2020; Gutnisky & Dragoi, 2008). Although visual adaptation likely plays an important role in explaining the reduced decodability found in the present condition there still remain several open questions.…”

Electrophysiological aftereffects of high-frequency transcranial random noise stimulation (hf-tRNS): an EEG investigation

“…For example, Kubová et al ( 1990 ) found that presenting horizontally drifting gratings, the 60% of 80 observers tested showed higher N2 amplitude in the right hemisphere with respect to the left one. In addition, Akyuz et al ( 2020 ) using EEG and source localization showed that adaptation to directional motion was dominant in the left hemisphere; (ii) instead of analysing data from single electrodes, we pooled data across groups of electrodes (i.e. for Left, Central and Right regions) to measure the average modulation of cortical activity around the stimulation electrode.…”