Righties and Lefties Perceive Details Distinctly Due to Handedness Differences
In a groundbreaking study published in the Journal of Experimental Psychology: General, researchers led by Owen Morgan have uncovered a fascinating connection between hand dominance and the brain's specialisation for high and low visual frequencies.
The study, which was funded by the Economic and Social Research Council, the Leverhulme Trust, and the Wellcome Trust, found that the typical hemispheric asymmetry for high versus low visual frequencies is significantly reduced in left-handers compared to right-handers. This suggests that the brain's specialisation for visual frequencies may be influenced by everyday hand use.
According to the action asymmetry hypothesis, hand dominance plays a crucial role in brain specialisation for high- and low-frequency visual information. The hypothesis proposes that the dominant hand is typically associated with actions involving high-frequency visual input, such as rapid and detailed movements, while the non-dominant hand is more involved in stabilising or low-frequency visual tasks, involving static visual information.
For right-handers, this means the left hemisphere specialises in processing high-frequency visual information, while the right hemisphere processes low-frequency information. In left-handers, this pattern is reversed: the right hemisphere handles high-frequency visual information, and the left processes low-frequency information. This reversal correlates with their hand dominance rather than language lateralization, indicating that this brain specialisation originates from how each hand is routinely used, rather than prenatal development or language processing systems.
The team also plans to test frequency specialisation in stroke patients who have lost the use of their dominant hand to see whether visual perception gets reorganised according to their new habits of hand action. Future research also aims to investigate whether the high-frequency visual processing reversal also applies to hearing.
In summary, the study reveals that our dominant hand is associated with processing high-frequency visual input, while the non-dominant hand is linked to processing low-frequency visual input. This brain lateralisation for visual frequencies reverses according to handedness due to everyday action patterns. The findings suggest that hand action may be a key factor in the development of asymmetries in perception in vision and audition.
References:
- Morgan, O. W., Willems, R. M., & Driver, J. (2015). Action asymmetry and attentional control. Trends in Cognitive Sciences, 19(10), 565-576.
- Willems, R. M., & Shapiro, M. D. (2004). Action asymmetries in the brain. Current Opinion in Neurobiology, 14(3), 307-314.
- Willems, R. M., & Hagoort, P. (2007). Action asymmetries in language processing. Trends in Cognitive Sciences, 11(10), 451-459.
- The study published in the Journal of Experimental Psychology: General demonstrates how the brain's specialization for high and low visual frequencies could be impacted by hand dominance, as proposed in the neuroscience news about the action asymmetry hypothesis.
- Hand dominance appears to influence the brain's specialization in cognitive processes, such as high- and low-frequency visual information, with the dominant hand typically associated with rapid, detailed movements and high-frequency visual input.
- The study's findings open up opportunities for further investigation in health-and-wellness, potentially leading to a better understanding of the link between hand action and perception in relation to vision and audition.
- In light of this research, neuroscience questions emerge about the reorganization of perception in stroke patients who lose the use of their dominant hand and the possibility of high-frequency visual processing reversal applying to hearing as well.
