Relationships among multiple task asymmetries. I. A critical review

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychometrics

Background:

• Previous studies on lateral difference measures yielded conflicting interpretations regarding global versus local relationships.
• Existing literature is debated, with some supporting global and local relationships, while others support local relationships only.

Purpose of the Study:

• To reconcile the literature on lateral difference measures by reviewing evidence from principal components, correlational, and factor analytic approaches.
• To critically evaluate the evidence for global versus local relationships among lateral difference measures.

Main Methods:

• Review of existing literature utilizing principal components analysis.
• Review of existing literature utilizing correlational analysis.
• Review of existing literature utilizing factor analytic approaches.

Main Results:

• Evidence suggests that a global relationship among all asymmetries is unlikely, as null and negative correlations exist between measures.
• All reviewed approaches consistently support the reality of local relationships among lateral difference measures.
• Factor analytic approaches provide the most detailed insights into local relationships and hemispheric processes.

Conclusions:

• The existence of null and negative correlations challenges the concept of a singular global relationship in lateral asymmetry.
• Local relationships are consistently supported across multiple analytical methods, suggesting distinct underlying processes.
• Factor analytic methods offer the most robust framework for understanding local relationships, but require methodological improvements such as larger sample sizes, reliability prescreening, and data transparency.