Title: Decoding the neural signals and circuits for perceptual decisions
Speaker: Prof. Kristine Krug
Time：June 13, 2023, 1:00-2:30 pm
Venue：Wang Ke Zhen Bldg, 1113
Host：Prof. Cong Yu
Our visual experience is far more than what meets the eye. Bistable figures like structure-from-motion objects or the art works by M.C. Escher highlight the cortical decision processes that shape our rich perceptual experience of the world. In the brains of non-human primates, we can decode the perceptual decision processes about 3D signals and motion at the level of brain cells and circuits. Strikingly, we are also able to control and shape these processes by direct cortical interventions in extra-striate visual cortex. This demonstrates that these signals and circuits make a causal contribution to perceptual decisions.
I will present recent evidence that we can successfully predict monkeys' cognitive strategy across consecutive perceptual choices (win-stay vs. win-switch) using a linear decoder on single neuron activity in visual area V5/MT. At a step further in the cortical network for perceptual decisions in parietal area LIP, neurophysiological and anatomical studies converge to reveal distinct intrinsic networks within the dorsal subdivision LIPd and ventral LIPv. The networks bring together a sensory receptive field and a spatially distinct motor response field in single neurons, providing the necessary circuitry to convert the information about the visual stimulus to be judged to the decision signal conveyed as an eye movement response.
Thus, these circuits and signals delineate the neuronal mechanisms for perceptual decision-making and longer-term cognitive influences on these processes, like decision strategy. Decision strategy affects perceptual decisions by shaping visual perceptual signals rather than just bias motor responses. The connectivity within LIP provides a circuit for flexible sensori-motor transformation for generating decisions from visual information.