diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 15ea0d86..8bfff33a 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -2,6 +2,12 @@
 
 ## Next Release
 
+### New Levels:
+
+1.  Psychlab.
+
+    1. contributed/psychlab/harlow
+
 ### Minor Improvements:
 
 1.  Improve documentation of how to configure non-hermetic dependencies (Lua,
diff --git a/game_scripts/levels/contributed/psychlab/factories/harlow_factory.lua b/game_scripts/levels/contributed/psychlab/factories/harlow_factory.lua
new file mode 100644
index 00000000..3da371d8
--- /dev/null
+++ b/game_scripts/levels/contributed/psychlab/factories/harlow_factory.lua
@@ -0,0 +1,322 @@
+--[[ Copyright (C) 2019 Google Inc.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+]]
+
+local brady_konkle_oliva2008 = require 'datasets.brady_konkle_oliva2008'
+local game = require 'dmlab.system.game'
+local log = require 'common.log'
+local helpers = require 'common.helpers'
+local random = require 'common.random'
+local psychlab_factory = require 'factories.psychlab.factory'
+local psychlab_helpers = require 'factories.psychlab.helpers'
+local point_and_click = require 'factories.psychlab.point_and_click'
+local random = require 'common.random'
+local tensor = require 'dmlab.system.tensor'
+
+--[[ The Harlow task from:
+
+Harlow, H. F. (1949). The formation of learning sets. Psychological review,
+56(1), 51.
+
+As implemented in:
+
+Wang, J. X., Kurth-Nelson, Z., Tirumala, D., Soyer, H., Leibo, J. Z., Munos, R.,
+... & Botvinick, M. (2016). Learning to reinforcement learn. arXiv preprint
+arXiv:1611.05763.
+
+and
+
+Wang, J. X., Kurth-Nelson, Z., Kumaran, D., Tirumala, D., Soyer, H., Leibo,
+J. Z., ... & Botvinick, M. (2018). Prefrontal cortex as a meta-reinforcement
+learning system. Nature neuroscience, 21(6), 860.
+
+Two random images (selected at the beginning of the episode)
+are shown per episode for N (default 6) trials.
+One image yields positive rewards if agent saccades to it, other
+yields negative rewards. Between trials, agent saccades to a red
+fixation cross to start the trial.
+
+Images can be placed on either the left or right side of the
+screen, determined randomly at the beginning of the trial.
+
+Any images can be used, but should be placed in /data and numbered
+according to the template '%04d.png'. There should be at least
+TRAIN_BATCH + TEST_BATCH images. Set IS_TRAIN = false for
+evaluation images (held out from training).
+]]
+
+local TIME_TO_FIXATE_CROSS = 4 -- in frames
+local TIME_TO_FIXATE_TARGET = 4 -- in frames
+local FAST_INTER_TRIAL_INTERVAL = 5 -- in frames
+local SCREEN_SIZE = {width = 512, height = 512}
+local BG_COLOR = {0, 0, 0}
+local TRIALS_PER_EPISODE_CAP = 6
+
+local TARGET_SIZE = 0.4
+
+local FIXATION_REWARD = 1
+local CORRECT_REWARD = 5
+local INCORRECT_REWARD = -5
+
+local FIXATION_SIZE = 0.1
+local FIXATION_COLOR = {255, 0, 0} -- Red
+local CENTER = {0.5, 0.5}
+local LEFT = {.25, .5}
+local RIGHT = {.75, .5}
+
+local TRAIN_BATCH = 1000
+local TEST_BATCH = 1000
+local IS_TRAIN = true
+
+local factory = {}
+
+function factory.createLevelApi(kwargs)
+  kwargs.timeToFixateCross = kwargs.timeToFixateCross or TIME_TO_FIXATE_CROSS
+  kwargs.timeToFixateTarget = kwargs.timeToFixateTarget or TIME_TO_FIXATE_TARGET
+  kwargs.fastInterTrialInterval = kwargs.fastInterTrialInterval or
+    FAST_INTER_TRIAL_INTERVAL
+  kwargs.screenSize = kwargs.screenSize or SCREEN_SIZE
+  kwargs.bgColor = kwargs.bgColor or BG_COLOR
+  kwargs.trialsPerEpisodeCap = kwargs.trialsPerEpisodeCap or
+    TRIALS_PER_EPISODE_CAP
+  kwargs.targetSize = kwargs.targetSize or TARGET_SIZE
+  kwargs.fixationReward = kwargs.fixationReward or FIXATION_REWARD
+  kwargs.correctReward = kwargs.correctReward or CORRECT_REWARD
+  kwargs.incorrectReward = kwargs.incorrectReward or INCORRECT_REWARD
+  kwargs.fixationSize = kwargs.fixationSize or FIXATION_SIZE
+  kwargs.fixationColor = kwargs.fixationColor or FIXATION_COLOR
+  kwargs.center = kwargs.center or CENTER
+  kwargs.left = kwargs.left or LEFT
+  kwargs.right = kwargs.right or RIGHT
+  kwargs.trainBatch = kwargs.trainBatch or TRAIN_BATCH
+  kwargs.testBatch = kwargs.testBatch or TEST_BATCH
+  kwargs.isTrain = kwargs.isTrain or IS_TRAIN
+
+  local ARG = {
+      screenSize = kwargs.screenSize,
+  }
+
+  -- Class definition for harlow psychlab environment.
+  local env = {}
+  env.__index = env
+
+  setmetatable(env, {
+      __call = function (cls, ...)
+        local self = setmetatable({}, cls)
+        self:_init(...)
+        return self
+      end
+  })
+
+  -- 'init' gets called at the start of each episode.
+  function env:_init(pac, opts)
+    log.info('opts passed to _init:\n' .. helpers.tostring(opts))
+    log.info('ARG passed to _init:\n' .. helpers.tostring(ARG))
+
+    if self.dataset == nil then
+      self.dataset = brady_konkle_oliva2008(opts)
+    end
+
+    self.screenSize = kwargs.screenSize
+    self.numTrials = kwargs.trialsPerEpisodeCap
+
+    self.trainBatch = kwargs.trainBatch
+    self.testBatch = kwargs.testBatch
+    self.isTrain = kwargs.isTrain
+
+    self:setupImages()
+    -- Store a copy of the 'point_and_click' api.
+    self.pac = pac
+  end
+
+  --[[ Reset is called after init. It is called only once per episode.
+  Note: the episodeId passed to this function may not be correct if the job
+  has resumed from a checkpoint after preemption.
+  ]]
+  function env:reset(episodeId, seed)
+    random:seed(seed)
+
+    self.pac:setBackgroundColor(kwargs.bgColor)
+    self.pac:clearWidgets()
+    psychlab_helpers.addFixation(self, kwargs.fixationSize)
+
+    self.currentTrial = {}
+    self._previousTrialId = 0
+    self.trialNum = 0
+
+    psychlab_helpers.setTrialsPerEpisodeCap(self, kwargs.trialsPerEpisodeCap)
+
+    local targetPositions = {}
+    for i = 1, self.numTrials / 2 do
+      table.insert(targetPositions, 1)
+    end
+    for i = self.numTrials / 2 + 1, self.numTrials do
+      table.insert(targetPositions, 2)
+    end
+    local batch_offset
+    if self.isTrain then
+      self._numBatch = self.trainBatch
+      batch_offset = 0
+    else
+      self._numBatch = self.testBatch
+      batch_offset = self.trainBatch
+    end
+    self._targetPositions = random:shuffle(targetPositions)
+    -- randomly pick a correctID and an incorrectID
+    self.correctID = random:uniformInt(1, self._numBatch) + batch_offset
+    self.incorrectID = random:uniformInt(1, self._numBatch - 1) + batch_offset
+    if self.incorrectID >= self.correctID then
+      self.incorrectID = self.incorrectID + 1
+    end
+    log.info('Episode set up, corrID=' .. self.correctID ..
+             ', incorrID=' .. self.incorrectID)
+  end
+
+  function env:setupImages()
+    self.images = {}
+
+    self.images.fixation = psychlab_helpers.getFixationImage(self.screenSize,
+      kwargs.bgColor, kwargs.fixationColor, kwargs.fixationSize)
+
+    self.target = tensor.ByteTensor(256, 256, 3)
+  end
+
+  function env:finishTrial(delay)
+    self.currentTrial.reactionTime =
+      game:episodeTimeSeconds() - self._currentTrialStartTime
+
+    self.currentTrial.stepCount = self.pac:elapsedSteps()
+    psychlab_helpers.publishTrialData(self.currentTrial, kwargs.schema)
+    psychlab_helpers.finishTrialCommon(self, delay, kwargs.fixationSize)
+  end
+
+  function env:fixationCallback(name, mousePos, hoverTime, userData)
+    if hoverTime == kwargs.timeToFixateCross then
+      self.pac:addReward(kwargs.fixationReward)
+      self.pac:removeWidget('fixation')
+      self.pac:removeWidget('center_of_fixation')
+
+      self.currentTrial.trialId = self._previousTrialId + 1
+      -- Measure reaction time since the trial started.
+      self._currentTrialStartTime = game:episodeTimeSeconds()
+      self.pac:resetSteps()
+
+      self:startTrial()
+    end
+  end
+
+  function env:correctResponseCallback(name, mousePos, hoverTime, userData)
+    if hoverTime == kwargs.timeToFixateTarget then
+      self.currentTrial.response = name
+      self.currentTrial.correct = 1
+      self.pac:addReward(kwargs.correctReward)
+      self:finishTrial(kwargs.fastInterTrialInterval)
+    end
+  end
+
+  function env:incorrectResponseCallback(name, mousePos, hoverTime, userData)
+    if hoverTime == kwargs.timeToFixateTarget then
+      self.currentTrial.response = name
+      self.currentTrial.correct = 0
+      self.pac:addReward(kwargs.incorrectReward)
+      self:finishTrial(kwargs.fastInterTrialInterval)
+    end
+  end
+
+  function env:startTrial()
+    self.trialNum = self.trialNum + 1
+    -- Fixation initiates the next trial
+    self.currentTrial.trial = self.trialNum
+    self._targetPos = self._targetPositions[self.trialNum]
+    self:addObjects(self.correctID, self.incorrectID, self._targetPos)
+  end
+
+  function env:addTargetImage(targetImage, targetSize, targetPos, targetName)
+    assert(targetImage, 'targetImage must not be nil')
+    assert(targetSize, 'targetSize must not be nil')
+    assert(targetSize > 0 and targetSize <= 1, 'targetSize must in (0, 1]')
+    self.target:copy(targetImage)
+    local sizeInPixels = psychlab_helpers.getSizeInPixels(self.screenSize,
+                                                          targetSize)
+    local scaledImage = psychlab_helpers.scaleImage(self.target,
+                                                    sizeInPixels.width,
+                                                    sizeInPixels.height)
+
+    self.pac:addWidget{
+        name = targetName,
+        image = scaledImage,
+        pos = targetPos,
+        size = {targetSize, targetSize},
+    }
+  end
+
+  function env:addObjects(correctID, incorrectID, targetPos)
+    local posCorrect, posIncorrect, posCorrectButton, posIncorrectButton
+    self.currentTrial.correctResponse = targetPos
+    local upperLeft = psychlab_helpers.getUpperLeftFromCenter
+    if targetPos == 1 then
+      posCorrect = upperLeft(kwargs.left, kwargs.targetSize)
+      posIncorrect = upperLeft(kwargs.right, kwargs.targetSize)
+      posCorrectButton = upperLeft(kwargs.left, kwargs.targetSize / 2)
+      posIncorrectButton = upperLeft(kwargs.right, kwargs.targetSize / 2)
+    elseif targetPos == 2 then
+      posCorrect = upperLeft(kwargs.right, kwargs.targetSize)
+      posIncorrect = upperLeft(kwargs.left, kwargs.targetSize)
+      posCorrectButton = upperLeft(kwargs.right, kwargs.targetSize / 2)
+      posIncorrectButton = upperLeft(kwargs.left, kwargs.targetSize / 2)
+    else
+      error('targetPos not valid')
+    end
+    self:addTargetImage(self.dataset:getImage(correctID),
+                       kwargs.targetSize,
+                       posCorrect,
+                       'correct_image')
+    self:addTargetImage(self.dataset:getImage(incorrectID),
+                       kwargs.targetSize,
+                       posIncorrect,
+                       'incorrect_image')
+
+    -- Add buttons, which are invisible and colocated with the images
+    self.pac:addWidget{
+        name = 'correct_image_button',
+        image = nil,
+        pos = posCorrectButton,
+        size = {kwargs.targetSize / 2, kwargs.targetSize / 2},
+        mouseHoverCallback = self.correctResponseCallback,
+    }
+    self.pac:addWidget{
+        name = 'incorrect_image_button',
+        image = nil,
+        pos = posIncorrectButton,
+        size = {kwargs.targetSize / 2, kwargs.targetSize / 2},
+        mouseHoverCallback = self.incorrectResponseCallback,
+    }
+  end
+
+  function env:removeArray()
+    self.pac:removeWidget('correct_image')
+    self.pac:removeWidget('incorrect_image')
+    self.pac:removeWidget('correct_image_button')
+    self.pac:removeWidget('incorrect_image_button')
+  end
+
+  return psychlab_factory.createLevelApi{
+      env = point_and_click,
+      envOpts = {environment = env, screenSize = ARG.screenSize}
+  }
+end
+
+return factory
diff --git a/game_scripts/levels/contributed/psychlab/harlow.lua b/game_scripts/levels/contributed/psychlab/harlow.lua
new file mode 100644
index 00000000..62129251
--- /dev/null
+++ b/game_scripts/levels/contributed/psychlab/harlow.lua
@@ -0,0 +1,23 @@
+--[[ Copyright (C) 2019 Google Inc.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+]]
+
+local factory = require 'levels.contributed.psychlab.factories.harlow_factory'
+
+return factory.createLevelApi{
+    schema = 'harlow',
+    episodeLengthSeconds = 300,
+}