Sleep does not aid the generalisation of binocular disparity‐based learning to the other visual hemifield

Abstract

Recently acquired information is often susceptible to distortion and loss. A subset of novel memories must thus undergo an active process of consolidation (Squire et al., 1984). This process, often referred to as 'systems consolidation', occurs mainly during post-learning sleep (Klinzing et al., 2019). Successful consolidation reduces the probability of information to be forgotten. It also induces qualitative changes to the information, often including improved generalisation. For visual learning, this may encompass a higher invariance to specific properties of a stimulus, such as its location in the visual field.Visual learning is commonly investigated using the classical texture discrimination task (TDT). Improvements on this task tend to be confined to the trained eye or region of the visual field. This suggests that visual learning is supported by synaptic changes in the early stages of processing, where information is retinotopically organised (Karni & Sagi, 1991). This notion is supported by blood-oxygen-level-dependent responses to the TDT, which are higher in the visual cortex when stimuli are presented to the trained compared to the untrained eye (Schwartz et al., 2002). A series of studies showed benefits of sleep on TDT improvements

Sleep and testing both strengthen and distort story recollection

“…However, we note that our sample size is comparable to other sleep and memory studies (Klinzing et al, 2021;Noack et al, 2021;Scullin & McDaniel, 2010).…”

“…Although our sample size is consistent with many other sleep and memory studies (e.g. (Denis et al, 2020;Klinzing et al, 2021;Noack et al, 2021;Scullin & McDaniel, 2010), we did not perform an a priori power analysis due to the lack of a known effect size for this paradigm. Although this is a limitation of the present work, the reported data provides an important baseline for which future high-powered studies can estimate expected effect sizes from.…”

Sleep affects higher-level categorization of speech sounds, but not frequency encoding

“…[Coffey et al, 2016]). Sleep may affect only these higher processes [Klinzing et al, 2020[Klinzing et al, , 2021, meaning that a sleep effect could occur in the PI FFR even if it does not occur in the main FFR recording.…”

“…Working in the visual modality, Klinzing et al recently showed that sleep does not aid binocular disparity-based learning [Klinzing et al, 2020[Klinzing et al, , 2021, which is a low-level perceptual task involving depth assessment using small differences between images received by each eye. The authors argued against an effect of sleep on low-level perceptual neuroplasticity more generally, on the basis that the majority of evidence in its favour had relied on a single learning paradigm (the texture discrimination task; TDT; [Gais et al, 2000, Deliens et al, 2014, Karni et al, 1994, Stickgold et al, 2000, Tamaki et al, 2020).…”

“…The stimulus is briefly presented, followed by a mask, after which the subjects report the target's orientation. However, because difficulty is manipulated by changing the stimulus-to-mask onset asynchrony [Gais et al, 2000], better task performance could plausibly be driven by improvements in higher-level cognitive processes, such as learning to better allocate attentional resources, rather than plasticity of the perceptual component itself [Klinzing et al, 2020[Klinzing et al, , 2021.…”