• Trained rats in a working-memory task, in which the animals listened to two tones separated by a delay of a few seconds, and had to indicate, through a nose poke, which was the louder. 
  • From the Brody Lab: How perception and working memory are affected by prior sensory information

    Professor Carlos Brody and his research team identify an area of the rat brain that holds recent sensory history, and show that temporarily silencing this area removes history-related biases in memory-guided decision-making.

    "There's truckloads of theories of cognitive function that talk about how sensory history biases our perceptions, but the neurophysiological basis of that phenomenon has remained almost entirely obscure. By identifying the PPC as a central node in the phenomenon, this work now opens the door towards unraveling its neural circuit basis and mechanisms. We will be able to understand the phenomenon at a much deeper level than was previously possible," said Brody.

    Athena Akrami, a PNI postdoctoral research fellow, was the lead author on their paper entitled Posterior parietal cortex represents sensory history and mediates its effects on behavior in the journal Nature.

    In this paper, Athena combined formal algorithmic behavioral analysis, optogenetic inactivations, and electrophysiological recordings in rats to show that Posterior Parietal Cortex (PPC) is specifically involved in the representation and use of prior sensory experience in Parametric Working Memory (PWM) tasks, where rats compare two sequential auditory stimuli, separated by a delay.

    Read more:
    Nature News and Views: Working memory freed from the past