Spatial Reference Frames
spatial reference frames
Space and its computational challenges
How our senses work both separately and together involves rich computational problems. I will discuss the spatial and representational problems faced by the visual and auditory system, focusing on two issues. 1. How does the brain correct for discrepancies in the visual and auditory spatial reference frames? I will describe our recent discovery of a novel type of otoacoustic emission, the eye movement related eardrum oscillation, or EMREO (Gruters et al, PNAS 2018). 2. How does the brain encode more than one stimulus at a time? I will discuss evidence for neural time-division multiplexing, in which neural activity fluctuates across time to allow representations to encode more than one simultaneous stimulus (Caruso et al, Nat Comm 2018). These findings all emerged from experimentally testing computational models regarding spatial representations and their transformations within and across sensory pathways. Further, they speak to several general problems confronting modern neuroscience such as the hierarchical organization of brain pathways and limits on perceptual/cognitive processing.
Space for Thinking - Spatial Reference Frames and Abstract Concepts
People from cultures around the world tend to borrow from the domain of space to represent abstract concepts. For example, in the domain on time, we use spatial metaphors (e.g., describing the future as being in front and the past behind), accompany our speech with spatial gestures (e.g., gesturing to the left to refer to a past event), and use external tools that project time onto a spatial reference frame (e.g., calendars). Importantly, these associations are also present in the way we think and reason about time, suggesting that space and time are also linked in the mind. In this talk, I will explore the developmental origins and functional implications of these types of cross-dimensional associations. To start, I will discuss the roles that language and culture play in shaping how children in the US and India represent time. Next, I will use word learning and memory as test cases for exploring why cross-dimensional associations may be cognitively advantageous. Finally, I will talk about future directions and the practical implications for this line of work, with a focus on how encouraging spatial representations of abstract concepts could improve learning outcomes.