Lab Meeting

We will hear two presentations, first from Yuka Sasaki (10h) and then from Takeo Watanabe (11h), both from Brown University.

10h. Yuka Sasaki: Night watch and sleep
In human sleep studies, it has been well documented that healthy human subjects do not sleep well in the very first experimental sleep session, which is termed the first night effect. We found that the part of the brain, the default-mode network, in one hemisphere is kept more vigilant during sleep in a novel environment to act as a night watch which wakes a sleeper up at an alarming incident in a novel environment. The regional interhemispheric asymmetric sleep in human may play a similar protective role to that in marine mammals and birds.

11h. Takeo Watanabe: Roles of excitatory and inhibitory signals in perceptual learning
Perceptual learning (PL) refers to long-term performance improvement on a visual task. We have found that PL occurs as a result of interactions between excitatory reinforcement signals and bottom-up signals from an exposed feature, irrespective of whether the feature is task-relevant or task-irrelevant (Watanabe et al, Nature, 2001; Watanabe et al, 2002, Nature Neuroscience; Seitz & Watanabe, Nature, 2003; Shibata et al, 2011, Science). At the same time, PL is formed under a strong influence of inhibitory control (Tsushima et al, 2006, Science; Chang et al, 2014, Current Biology). We have also found the E(xcitatory)/I(nhibitory) balance in V1 determines post-training stages (Shibata et al, 2017, Nature Neuroscience; Bang et al,2018, Nature Human Behavior). We conclude that excitatory and inhibitory signals play critical roles in both encoding and post-encoding stages (Watanabe & Sasaki, 2016, Annual Review of Psychology).