Asymmetries in flanker-target interference at different levels of number processing

Area of Science:

• Cognitive Psychology
• Visual Perception
• Neuroscience

Background:

• Visual crowding, the inability to recognize targets among distractors in peripheral vision, can exhibit asymmetry.
• This asymmetry is often linked to reading direction, with leftward flankers causing greater interference for letter and number recognition.
• Previous research has primarily observed this reading-related asymmetry in visual recognition tasks.

Purpose of the Study:

• To investigate whether the leftward asymmetry in visual crowding extends to more abstract, semantic levels of information processing.
• To determine if semantic feature extraction of numbers is influenced by reading-direction-based crowding effects.
• To examine the selective nature of this asymmetry across different semantic attributes of numbers.

Main Methods:

• Participants were presented with numerical triplets in either the left or right visual field.
• They were tasked with classifying the central number based on its magnitude, physical characteristics, or parity.
• The interference effects of leftward versus rightward flankers on target number classification were measured.

Main Results:

• A significant leftward asymmetry in crowding was observed, where leftward flankers interfered more with target recognition than rightward flankers.
• This leftward interference was present when participants classified the magnitude and physical characteristics of the numbers.
• The asymmetry was not observed when classifying the parity of the numbers, indicating a selective effect.

Conclusions:

• The leftward asymmetry in visual crowding extends to the semantic level of number processing.
• This extension is selective, occurring for magnitude and physical characteristics but not parity.
• Findings suggest that reading direction influences higher-level semantic feature extraction in visual perception.