Furthermore, orientation selectivity is subject to plastic changes as demonstrated in adaptation paradigms 12. A growing body of work suggests that orientation-tuning functions are not hard-set properties 9 but are dynamically shaped over time by suppressive mechanisms, such as lateral inhibition 10 or divisive normalization 11. Orientation selectivity is a crucial property of neurons in retinotopic cortex, which has been studied extensively using animal electrophysiology and psychophysics 7, 8. In the visual system, orientation of a contrast stimulus is an obvious choice to study tuning behaviour of neural populations. Here we use single-trial estimates of sustained visual cortical activity evoked by orientation gratings to characterize the time course of neural changes as humans learn to bias perception in favour of a visual feature predicting a noxious, loud noise. However, the absence of methods for non-invasively quantifying the extent and temporal dynamics of visual cortical changes on a trial-by-trial basis in the human brain has prevented empirical testing of this hypothesis. Paralleling work in the rodent auditory system 5, these findings have led researchers to hypothesize that the tuning of visual cortical neurons may be altered so that they respond more readily to features that are predictive of behaviourally relevant outcomes 6. This research has suggested that neural populations lower in the visual hierarchy respond more strongly to features signalling threat and danger than to features associated with safety 4. In the laboratory, fear-conditioning paradigms have been used to study the neural mechanisms underlying such prioritization in both animals 2 and human participants 3.
![andreas keil uf andreas keil uf](https://lab-smile.github.io/img/lab/smile.jpeg)
Visual information associated with motivational or affective value typically elicits heightened response amplitudes in visual neurons and is more readily detected and remembered 1. These findings suggest that short-term behaviourally driven retuning of human visual cortical neurons involves distal top–down projections as well as local inhibitory interactions. Changes in cortical connectivity between occipital and fronto-temporal regions mirror the changes in visuo-cortical response amplitudes. Furthermore, as learning progresses, responses to the orientations with greatest similarity to the sound-paired grating are increasingly suppressed, suggesting inhibitory interactions between orientation-selective neuronal populations. After as few as two grating-sound pairings, visual cortical responses to the sound-paired grating show selective amplification.
#Andreas keil uf series#
We use classical aversive conditioning to associate one out of a series of oriented gratings with a noxious sound stimulus. Here we examine the involvement of human visual cortex in the formation of learned perceptual biases. As a result perceptual biases evolve, selectively facilitating the detection and identification of sensory events that are relevant for adaptive behaviour.
![andreas keil uf andreas keil uf](https://lab-smile.github.io/img/lab/matthewnguyen.png)
![andreas keil uf andreas keil uf](https://www.researchgate.net/profile/Wendy-Yoder-2/publication/264432469/figure/fig4/AS:392364490280963@1470558392957/Time-course-of-adaptation-plotted-as-changes-in-threshold-at-different-AO_Q640.jpg)
We value collaboration and we would welcome an opportunity to discuss potential projects with you.The responses of sensory cortical neurons are shaped by experience. Our research has been funded by the National Science Foundation (Science of Learning, Cyberlearning and Future Technologies, GoLife, and Improving Undergraduate STEM Education programs), the National Aeronautics and Space Administration, and the University of Florida (College of Education Research Incentive Fund and UF Research Opportunity Fund). Our focus is on the learners who exhibit a wide range of attentional and cognitive differences (e.g., inhibitory control, spatial ability, working memory capacity, reading ability etc.) Studies are designed using (or replicating) the authentic learning contexts of the 21st century and produce implications for improving the design and practice of learning and teaching. Neuroscience Applications for Learning (NeurAL) Laboratory is a team of faculty and students who use cognitive and social neuroscience methodologies and technologies to explore how people learn individually and in groups.