Bump attractor dynamics in prefrontal cortex explains behavioral precision in spatial working memory.
Prefrontal persistent activity during the delay of spatial working memory tasks is thought to maintain spatial location in memory. A 'bump attractor' computational model can account for this physiology and its relationship to behavior. However, direct experimental evidence linking parameters of prefrontal firing to the memory report in individual trials is lacking, and, to date, no demonstration exists that bump attractor dynamics underlies spatial working memory. We analyzed monkey data and found model-derived predictive relationships between the variability of prefrontal activity in the delay and the fine details of recalled spatial location, as evident in trial-to-trial imprecise oculomotor responses. Our results support a diffusing bump representation for spatial working memory instantiated in persistent prefrontal activity. These findings reinforce persistent activity as a basis for spatial working memory, provide evidence for a continuous prefrontal representation of memorized space and offer experimental support for bump attractor dynamics mediating cognitive tasks in the cortex.
Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
Klaus
K
Wimmer
1] Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain. [2] School of Mathematics, University of Minnesota, Minneapolis, Minnesota, USA.
Duane Q
DQ
Nykamp
Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
Christos
C
Constantinidis
Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
Albert
0000000165946946
A
Compte
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D003463:Cues; D055724:Electrophysiological Phenomena / Q000502:physiology; D053483:Eye Movement Measurements; D005133:Eye Movements / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008839:Microelectrodes; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors