Naturalistic Object Representations Depend on Distance and Size Cues.

Area of Science:

• Neuroscience
• Cognitive Science
• Visual Perception

Background:

• Traditional vision frameworks link object size to the ventral visual pathway and spatial distance to the dorsal pathway.
• These frameworks often rely on 2D stimuli with ambiguous size and distance information.
• The impact of unambiguous real-world cues on brain representations remains less understood.

Approach:

• Used functional magnetic resonance imaging (fMRI) to compare brain responses to real objects versus their 2D pictures.
• Presented stimuli at varying egocentric distances (near and far).
• Analyzed fMRI response amplitudes and patterns in relation to stimulus format and distance.

Key Points:

• Real objects, unlike pictures, elicited stronger fMRI responses in lateral occipital and posterior parietal cortices.
• Distance modulated responses to real objects in action-guidance regions, suggesting context-dependent action relevance.
• Object size was represented in both ventral and dorsal cortices for real objects, but primarily in ventral cortex for pictures.

Conclusions:

• Brain representations reflect physical object characteristics when stimuli provide unambiguous information.
• The distinction between ventral (what) and dorsal (where/how) pathway processing is less rigid when real-world cues are clear.
• Findings offer insights into naturalistic object perception and brain representations of physical attributes.