def step(self, observation, argmax_sampling=False):
        """ Select actions based on model's output """
        action_pd_params, value_output = self(observation)
        actions = self.action_head.sample(action_pd_params, argmax_sampling=argmax_sampling)

        # log likelihood of selected action
        logprobs = self.action_head.logprob(actions, action_pd_params)

        return {
            'actions': actions,
            'values': value_output,
            'action:logprobs': logprobs
        }