Gast ::
| Hauptseite > Publikationsdatenbank > Sensory and behavioural tuning along the dorsal pathway |
| Hauptseite > Publikationsdatenbank > Sensory and behavioural tuning along the dorsal pathway |
| Conference Presentation (After Call) | FZJ-2024-05897 |
; ; ; ;
2024
Abstract: Directional tuning of motor cortex neurons is typically characterized by a sinusoidal tuning curve with a preferred direction (PD) represented by its peak. While PDs across neurons were assumed to be uniformly distributed over all directions, recent experiments reported a bimodal distribution of hand movement PDs when the movements are constrained to a horizontal work area. Several modelling studies attribute this to the limb biomechanics, which indicates more kinetic (muscle force based) rather than kinematic (movement parameter based) representation in the motor cortex. We conducted neuronal recordings in behaving macaques to elucidate to what extent this kinetic tuning extends down along the dorsal pathway. The monkeys were trained for a visually guided reaching task in the horizontal plane. Spiking activity was recorded in visual (V1/V2), parietal (DP, 7A) and motor (M1/PMd) areas. To estimate the tuning curve of each neuron to sensory and behavioural modalities, we regressed the spiking activity of each neuron on all available behavioural and sensory covariates (visual input, eye/hand position, saccade, hand movement direction and speed) at once by using generalized linear models. The model fitting results reveal a gradual shift in visual and motor tuning along the dorsal pathway: increasing of motor and decreasing of visual tuning towards the motor cortex. We confirm the bimodal hand movement PD distribution in M1/PMd, and also find, after eliminating the confounding effect of the visual tuning, similar bimodal PD distributions in V1/V2, DP and 7A, suggesting an influence of limb biomechanics even in the lower hierarchy levels of the dorsal visual stream.
|
The record appears in these collections: |