Publications
Takayuki Tsurumi, Ayaka Kato,
Arvind Kumar, & Kenji Morita
Online reinforcement learning of state
representation in recurrent network supported by the power of random feedback
and biological constraints.
eLife 14: RP104101 (2025) [Link]
(Version of Record)
Ayaka Kato & Kenji Morita
Striatal gradient in value-decay explains regional
differences in dopamine patterns and reinforcement learning computations.
The
Journal of Neuroscience 45(35):
e0170252025 (2025) [Link]
Kanji Shimomura & Kenji Morita
State optimism as a state-dependent prior about
rewarding outcomes.
Computational
Brain & Behavior https://doi.org/10.1007/s42113-025-00256-6 (2025) [Link]
Kanji Shimomura & Kenji Morita
The effect of reward magnitude on different types of
exploration in human reinforcement learning.
Computational
Brain & Behavior 8: 147-161 (2025) [Link]
Kanji Shimomura, Kenji Morita, Yuki
Nishiguchi, Jeff C. Huffman, & Rachel A. Millstein
Intraindividual fluctuation in optimism under daily
life circumstances: a longitudinal study.
Affective
Science 5: 1-12 (2024) [Link]
Reo Sato#, Kanji Shimomura#, & Kenji Morita (#: equal contribution)
Opponent learning with different representations in
the cortico-basal ganglia pathways can develop obsession-compulsion cycle.
PLoS Computational Biology 19(6):
e1011206. (2023) [Link]
Kenji Morita, Kanji Shimomura, &
Yasuo Kawaguchi
Opponent learning with different representations in
the cortico-basal ganglia circuits.
eNeuro 10(1) ENEURO.0422-22.2023 (2023) [Link]
Ayaka Kato, Kanji Shimomura, Dimitri Ognibene, Muhammad A. Parvaz, Laura A.
Berner, Kenji Morita, & Vincenzo
G. Fiore
Computational models of behavioral addictions: State
of the art and future directions.
Addictive
Behaviors 140:107595 (2023) [Link]
Sanghun Im, Yoshifumi Ueta,
Takeshi Otsuka, Mieko Morishima, Mohammed Youssef, Yasuharu
Hirai, Kenta Kobayashi, Ryosuke Kaneko, Kenji
Morita, & Yasuo Kawaguchi
Corticocortical innervation subtypes of layer 5 intratelencephalic cells in the murine secondary motor
cortex.
Cerebral
Cortex 33(1):50–67 (2023). [Link]
Kenji Morita & Ayaka Kato
Dopamine ramps for accurate value learning under
uncertainty.
Trends
in Neurosciences 45(4):254-256 (2022). [Link] (Spotlight)
Zheyu Feng, Asako Mitsuto
Nagase, & Kenji Morita
A reinforcement learning approach to understanding
procrastination: does inaccurate value approximation cause irrational
postponing of a task?
Frontiers
in Neuroscience 15:660595 (2021). [Link]
Kanji Shimomura#, Ayaka Kato#, & Kenji Morita (#: equal contribution)
Rigid reduced successor representation as a
potential mechanism for addiction.
European
Journal of Neuroscience 53(11):3768-3790 (2021). [Link]
Sai Tanimoto#, Masashi Kondo#, Kenji Morita, Eriko Yoshida, & Masanori Matsuzaki (#:
equal contribution)
Non-action learning: saving action-associated cost
serves as a covert reward.
Frontiers
in Behavioral Neuroscience 14:141 (2020). [Link]
Kenji Morita & Asako Mitsuto Nagase
Caution in exploring the effects of distant past
outcomes on sequential choices.
Neuroscience
Research 156:159-164 (2020). [Link]
Kenji Morita#, Sanghun Im#, &
Yasuo Kawaguchi (#: equal contribution)
Differential striatal axonal arborizations of the intratelencephalic and pyramidal-tract neurons: analysis of
the data in the MouseLight database.
Frontiers
in Neural Circuits 13:71 (2019). [Link]
Jerome Clifford Foo, Valentina Vengeliene, Hamid Reza
Noori, Ikuhiro Yamaguchi, Kenji Morita, Toru Nakamura, Yoshiharu Yamamoto, & Rainer Spanagel
Drinking levels and profiles of alcohol addicted
rats predict response to nalmefene.
Frontiers
in Pharmacology 10:471 (2019). [Link]
Kenji Morita & Yasuo Kawaguchi
A dual role hypothesis of the cortico-basal-ganglia
pathways: opponency and temporal difference through dopamine and adenosine.
Frontiers
in Neural Circuits 12:111 (2019). [Link]
Ryota Nomura, Ying-Zong Liang, Kenji
Morita, Kantaro Fujiwara, & Tohru Ikeguchi
Threshold-varying integrate-and-fire model
reproduces distributions of spontaneous blink intervals.
PLoS One 13(10):e0206528 (2018). [Link]
Asako Mitsuto Nagase, Keiichi Onoda, Jerome Clifford Foo, Tomoki Haji, Rei
Akaishi, Shuhei Yamaguchi, Katsuyuki Sakai, & Kenji Morita
Neural mechanisms for adaptive learned avoidance of
mental effort.
The
Journal of Neuroscience
38(10):2631-2651 (2018). [Link]
Kenji Morita & Ayaka Kato
A neural circuit mechanism for the involvements of
dopamine in effort-related choices: decay of learned values, secondary effects
of depletion, and calculation of temporal difference error.
eNeuro 5(1) pii:
ENEURO.0021-18.2018 (2018). [Link]
Jerome Clifford Foo, Hamid Reza Noori, Ikuhiro
Yamaguchi, Valentina Vengeliene, Alejandro Cosa-Linan, Toru Nakamura, Kenji Morita, Rainer Spanagel, &
Yoshiharu Yamamoto
Dynamical state transitions into addictive behaviour and their early-warning signals.
Proceedings
of the Royal Society B: Biological Sciences 284(1860) pii: 20170882 (2017). [Link]
Jerome C. Foo, Kohei Nagase, Sawako Naramura-Ohno, Kazuhiro Yoshiuchi,
Yoshiharu Yamamoto, & Kenji Morita
Rank among peers during game competition affects the
tendency to make risky choices in adolescent males.
Frontiers
in Psychology 8:16 (2017). [Link]
Ayaka Kato & Kenji Morita
Forgetting in reinforcement learning links sustained
dopamine signals to motivation.
PLoS Computational Biology
12(10):e1005145 (2016). [Link]
Kenji Morita, Jenia Jitsev, &
Abigail Morrison
Corticostriatal circuit mechanisms of value-based action selection:
Implementation of reinforcement learning algorithms and beyond.
Behavioural Brain Research 311:110-21 (2016). [Link]
Kenji Morita & Yasuo Kawaguchi
Computing reward-prediction error: an integrated
account of cortical timing and basal-ganglia pathways for appetitive and
aversive learning.
European
Journal of Neuroscience 42(4):2003-21 (2015). [Link]
Kenji Morita & Ayaka Kato
Striatal dopamine ramping may indicate flexible
reinforcement learning with forgetting in the cortico-basal ganglia circuits.
Frontiers
in Neural Circuits 8:36. doi:
10.3389/fncir.2014.00036 (2014). [Link]
<Corrigendum>
Kenji Morita
Differential cortical activation of the striatal
direct and indirect pathway cells: reconciling the anatomical and optogenetic
results by using a computational method.
Journal of Neurophysiology
112(1):120-46 (2014). [Link]
Kenji Morita, Mieko Morishima,
Katsuyuki Sakai, & Yasuo Kawaguchi
Dopaminergic control of motivation and reinforcement
learning: a closed-circuit account for reward-oriented behavior.
The
Journal of Neuroscience
33(20):8866-8890 (2013). [Link]
Xiumin Li, Kenji
Morita, Hugh P. C. Robinson, & Michael Small
Control of layer 5 pyramidal cell spiking by
oscillatory inhibition in the distal apical dendrites: a computational
modelling study.
Journal of Neurophysiology
109(11):2739-2756 (2013). [Link]
Tae Twomey, Keith J. Kawabata Duncan, John S. Hogan, Kenji Morita, Kazumasa Umeda, Katsuyuki Sakai, & Joseph T.
Devlin
Dissociating visual form from lexical frequency
using Japanese.
Brain
& Language 125(2):184-93 (2013). [Link]
Kenji Morita, Mieko Morishima,
Katsuyuki Sakai, & Yasuo Kawaguchi
Reinforcement learning: computing the temporal
difference of values via distinct corticostriatal
pathways.
Trends
in Neurosciences 35(8):457-467 (2012). [Link] <Correction>
Xiumin Li, Kenji
Morita, Hugh P. C. Robinson, & Michael Small
Impact of gamma-oscillatory inhibition on the signal
transmission of a cortical pyramidal neuron.
Cognitive
Neurodynamics 5:241–251 (2011). [Abstract]
Mieko Morishima, Kenji Morita,
Yoshiyuki Kubota, & Yasuo Kawaguchi
Highly differentiated projection-specific cortical
subnetworks.
The
Journal of Neuroscience
31(28):10380-10391 (2011). [Abstract]
Kenji Morita
Possible dendritic contribution to unimodal
numerosity tuning and Weber-Fechner law-dependent numerical cognition.
Frontiers in Computational
Neuroscience 3:12 (2009). [Abstract]
[Full-text]
Kenji Morita
Dynamical foundations of the neural circuit for
Bayesian decision making.
Journal of Neurophysiology
102(1):1-6 (2009). [Abstract]
[Full-text]
(Neuro Forum)
Kenji Morita
Computational implications of cooperative plasticity
induction at nearby dendritic sites.
Science Signaling 2(52):pe2
(2009). [Abstract]
[Full-text:
Please visit my old website] (Perspectives)
Kenji Morita
Possible role of dendritic compartmentalization in
the spatial working memory circuit.
The
Journal of Neuroscience
28(30):7699-7724 (2008). [Abstract]
[Full-text]
Kenji Morita, Rita Kalra, Kazuyuki
Aihara, & Hugh P. C. Robinson
Recurrent synaptic input and the timing of
gamma-frequency-modulated firing of pyramidal cells during neocortical “UP”
states.
The
Journal of Neuroscience
28(8):1871-1881 (2008). [Abstract]
[Full-text]
Kenji Morita, Masato Okada, &
Kazuyuki Aihara
Selectivity and stability via dendritic
nonlinearity.
Neural Computation
19(7):1798-1853 (2007). [Abstract]
Hiroyuki Nakahara, Kenji Morita,
Robert H. Wurtz, & Lance M. Optican
Saccade-related spread of activity across superior
colliculus may arise from asymmetry of internal connections.
Journal of Neurophysiology
96(2):765-774 (2006). [Abstract] [Full-text]
Kenji Morita, Kunichika Tsumoto,
& Kazuyuki Aihara
Bidirectional modulation of neuronal responses by
depolarizing GABAergic inputs.
Biophysical Journal
90(6):1925-1938 (2006). [Abstract] [Full-text]
Kenji Morita, Kunichika Tsumoto,
& Kazuyuki Aihara
Possible effects of depolarizing GABAA conductance
on the neuronal input-output relationship: a modeling study.
Journal of Neurophysiology
93(6):3504-3523 (2005). [Abstract]
[Full-text]
Kenji Morita & Kazuyuki Aihara
A network model with pyramidal cells and GABAergic
non-FS cells in the cerebral cortex.
Neurocomputing 65-66:697-707
(2005).
Ko Kobayakawa, Reiko Hayashi, Kenji
Morita, Kazunari Miyamichi, Yuichiro Oka, Akio Tsuboi, & Hitoshi Sakano
Stomatin-related olfactory protein, SRO,
specifically expressed in the murine olfactory sensory neurons.
The
Journal of Neuroscience
22(14):5931-5937 (2002). [Abstract]
[Full-text]