Abstract
We investigate the notion that basic visual information is acting as a building block for more complex cognitive processes. Specifically, we measure individual orientation discrimination thresholds report good correlations against IQ, verbal-IQ and non-verbal IQ scores. Further we calculate correlations between the four WASI-II subtests and orientation discrimination thresholds, with Matrix Reasoning maintaining the strongest relationship, even when controlling for the effects of the other three subtests. Vocabulary raw scores which quantify the ability to describe verbally a specific word, showed the second strongest correlation, when controlling for the effects of Matrix Reasoning and Block Design, but not Similarities. Our results demonstrate that low-level visual abilities and high-level cognitive processes are more tightly interwoven together than previously thought, generating evidence to show that vision is tightly linked to human cognition.
Statement of Relevance Vision is one of the building blocks of our world experience through thoughts, emotions and actions. It is undeniably the sense upon which we rely the most, while working, driving, reading a book, dancing. So, it should come as no surprise that the intelligence quotient (IQ), widely used in the modern world to assess the cognitive abilities of a person in relation to their age group correlates well with visual abilities. Previous studies have demonstrated that pitch and colour discrimination, motion discrimination and contrast discrimination abilities are tightly linked to IQ. In this study we demonstrate for the first time, that the simplest visual ability, orientation discrimination which is computed by neurons in the primary visual cortex is tightly linked to intelligence. We believe a simple and quick orientation discrimination task could be used as an index of intelligence in clinical populations and other species, in addition to traditional measures.
Competing Interest Statement
The authors have declared no competing interest.
