Accurate heading perception relies on visual information integrated across a wide field, that is, optic flow. Numerous computational studies have speculated how local visual information might be pooled by the brain to compute heading, but these hypotheses lack direct neurophysiological support. In the current study, we instructed human and monkey subjects to judge heading directions based on global optic flow. We showed that a local perturbation cue applied within only a small part of the visual field could bias the subjects' heading judgments, and shift the neuronal tuning in the macaque middle temporal (MT) area at the same time. Electrical microstimulation in MT significantly biased the animals' heading judgments predictable from the tuning of the stimulated neurons. Masking the visual stimuli within these neurons' receptive fields could not remove the stimulation effect, indicating a sufficient role of the MT signals pooled by downstream neurons for global heading estimation. Interestingly, this pooling is not homogeneous because stimulating neurons with excitatory surrounds produced relatively larger effects than stimulating neurons with inhibitory surrounds. Thus our data not only provide direct causal evidence, but also new insights into the neural mechanisms of pooling local motion information for global heading estimation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/cercor/bhw402 | DOI Listing |
Psychon Bull Rev
January 2025
NYU-ECNU Institute of Brain and Cognitive Science, New York University Shanghai, Shanghai, China.
We examined the intricate mechanisms underlying visual processing of complex motion stimuli by measuring the detection sensitivity to contraction and expansion patterns and the discrimination sensitivity to the location of the center of motion (CoM) in various real and unreal optic flow stimuli. We conducted two experiments (N = 20 each) and compared responses to both "real" optic flow stimuli containing information about self-movement in a three-dimensional scene and "unreal" optic flow stimuli lacking such information. We found that detection sensitivity to contraction surpassed that to expansion patterns for unreal optic flow stimuli, whereas this trend was reversed for real optic flow stimuli.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Environmental Sciences Department, Wageningen University & Research, Wageningen 6708 PB, The Netherlands.
The boreal forest biome is warming four times faster than the global average. Changes so far are moderate, but time lags in responses may transiently maintain forest states which are no longer supported by current environmental conditions. Here, we explore whether tree cover dynamics hint at the state to which the biome may be shifting.
View Article and Find Full Text PDFInt J Biometeorol
January 2025
Department of Climate Change Impacts on Agroecosystems, Institute of Global Change Research of the Academy of Sciences of the Czech Republic, Bělidla 986/4b, Brno, 60300, Czech Republic.
Phenological shifts in wild-growing plants and wild animal phenophases are well documented at many European sites. Less is known about phenological shifts in agricultural plants and how wild ecosystem phenology interacts with crop phenology. Here, we present long-term phenological observations (1961-2021) from the Czech Republic for wild plants and agricultural crops and how the timing of phenophases differs from each other.
View Article and Find Full Text PDFFront Plant Sci
December 2024
School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, India.
Women Birth
January 2025
Faculty of Health, University of Technology Sydney (UTS), Sydney, NSW 2007, Australia; School of Clinical Medicine, Faculty of Medicine & Health, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; The George Institute for Global Health, Faculty of Medicine and Health, UNSW Sydney, NSW 2052, Australia.
Problem: Despite the significance of the perinatal period, postnatal care remains insufficient for optimising long-term health.
Background: The perinatal period is a vulnerable time in a woman's life-course health trajectory. Supporting transitions from hospital to primary care is essential to promote health and guide evidence-based follow-up care.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!