An enduring topic of research interest relates to the heritability of mental traits, such as intelligence. Some of the work on this topic has focussed on genetic contributions to the speed of cognitive processing, by examination of response times in psychometric tests. An important limitation of previous work is the underlying assumption that variability in response times solely reflects variability in the speed of cognitive processing. This assumption has been problematic in other domains, due to the confounding effects of caution and motor execution speed on observed response times. We extend a cognitive model of decision-making to account for the relatedness structure in a twin study paradigm. This approach has the potential to separately quantify different contributions to the heritability of response time: contributions from cognitive processing speed, caution, and motor execution speed. In some ways, this is a typical usage of an evidence accumulation model, and it throws up all the typical problems that we struggle with in data visualisation. Those problems will become evident during the talk, as we discuss data from the Human Connectome Project. We find that caution is both highly heritable and highly influenced by the environment, while cognitive processing speed is moderately heritable with little environmental influence, and motor execution speed appears to have no strong influence from either. Our study suggests that the assumption made in previous studies of the heritability being within mental processing speed is incorrect, with response caution actually being the most heritable part of the decision process.
How to participate in this seminar:
To participate remotely, connect to the ViewMe meeting called “carmaspecial” (you can enter that name, or the meeting number 8882491714). This will be persistant for future talks in this series. The ViewMe client is free and you do not need an account. You can install ViewMe on a computer or phone to take part, or use the web interface (Firefox or Chrome) at https://viewme.ezuce.com/webrtc/?meetingID=8882491714. It’s quite easy to use, but for assistance please contact Andrew.Danson@newcastle.edu.au. Some guides are available at https://viewme.ezuce.com/support/guides-tutorials/.
This talk is part of the CARMA Special Semester in Computation and Visualisation.