Deaf Individuals Show a Leftward Bias in Numerical Bisection

Area of Science:

• Cognitive Psychology
• Neuroscience
• Sensory Processing

Background:

• Hearing individuals exhibit pseudoneglect, an attentional bias to the left, in both physical and numerical space.
• Deaf individuals do not display pseudoneglect in physical space tasks.
• Attentional biases in numerical space for deaf individuals remain unexplored.

Purpose of the Study:

• To investigate attentional biases in numerical space among deaf individuals.
• To compare numerical spatial attention between deaf and hearing participants.
• To explore potential differences in mental number line representation strategies.

Main Methods:

• Participants (deaf and hearing) estimated the midpoint of numerical intervals.
• Intervals were presented in both ascending and descending order.
• Estimations were rapid, requiring intuitive judgments rather than calculation.

Main Results:

• Both deaf and hearing groups showed a bias towards lower numbers (leftward bias) on the mental number line.
• The underestimation bias was significantly smaller in deaf individuals compared to hearing individuals for descending number pairs.
• This suggests potential differences in attentional control or strategy use related to numerical magnitude.

Conclusions:

• Deaf individuals, like hearing individuals, utilize a left-to-right mental number line.
• Deaf individuals may exhibit distinct attentional patterns or strategy use within numerical space.
• Further research is needed to understand the underlying mechanisms of spatial attention lateralization in deaf populations.