OxTalks is Changing
OxTalks will soon move to the new Halo platform and will become 'Oxford Events.' There will be a need for an OxTalks freeze. This was previously planned for Friday 14th November – a new date will be shared as soon as it is available (full details will be available on the Staff Gateway).
In the meantime, the OxTalks site will remain active and events will continue to be published.
If staff have any questions about the Oxford Events launch, please contact halo@digital.ox.ac.uk
BEACON Seminar: The geometry of the representation of decision variable and stimulus difficulty in the parietal cortex
Seminars this term will be held remotely on Zoom. Links for joining will be sent out before each seminar. Please contact the host if you would like to set up a remote meeting with a speaker. If you have suggestions for future speakers, please contact Lauren (lauren.burgeno@dpag.ox.ac.uk), or Nima (nima.khalighinejad@psy.ox.ac.uk).
ABSTRACT:
Lateral intraparietal (LIP) neurons represent formation of perceptual decisions involving eye movements. In circuit models for these decisions, neural ensembles that encode actions compete to form decisions. Consequently, decision variables (DVs) are represented as partially potentiated action plans, where ensembles increase their average responses for stronger evidence supporting their preferred actions. As another consequence, DV representation and readout are implemented similarly for decisions with identical competing actions, irrespective of input and task context differences. In my talk, I will challenge those core principles using a novel face-discrimination task, where LIP firing rates decrease with supporting evidence, contrary to conventional motion-discrimination tasks. These opposite response patterns arise from similar mechanisms in which decisions form along curved, one-dimensional population-response manifolds misaligned with action representations. These manifolds rotate in state space based on task context, necessitating distinct readouts. I will show similar manifolds in lateral and medial prefrontal cortices, suggesting a ubiquitous representational geometry across decision-making circuits.
Date:
19 October 2021, 14:00
Venue:
Venue to be announced
Speaker:
Roozbeh Kiani (New York University)
Organising department:
Department of Experimental Psychology
Organiser:
Nima Khalighinejad (University of Oxford)
Organiser contact email address:
nima.khalighinejad@psy.ox.ac.uk
Host:
Nima Khalighinejad (University of Oxford)
Part of:
Behavioural and Cognitive Neuroscience (BEACON)
Booking required?:
Not required
Booking email:
nima.khalighinejad@psy.ox.ac.uk
Cost:
Free to attend
Audience:
Members of the University only
Editor:
Halley Cohen
