An investigation of the neural basis of changes in tactile acuity during healthy ageing and its impact on emotional wellbeing

Description

The sense of touch refers to the perception of tactile stimuli through specialised receptors called mechanoreceptors. During tactile exploration, humans typically use their hands, which are densely innervated by these mechanoreceptors. These receptors transduce incoming tactile information, resulting in high sensory acuity. However, as humans age their tactile acuity decreases, which is linked to changes in the peripheral nervous system. Despite this, tactile perception through active exploration (when we use motor control to touch our environment) declines at a slower rate than observed with passive stimulation (when the mechanoreceptors are activated by stroking in absence of movement). Therefore suggesting that tactile acuity during active touch may be supported by additional, or compensatory, central neural mechanisms. 

Healthy aging also negatively impacts motor control, which affects how individuals interact with their environment. The inhibitory neurotransmitter gamma-aminobutyric acid (GABA) has been found to decline with age in healthy populations, which has been linked to an age-related reduction in neural oscillatory activity during movement. Together, these findings suggest that evaluating neural oscillations during active touch exploration can offer some insight into compensatory neural processing mechanisms which modulate the decline or maintenance of tactile acuity during aging. However, the impact and mechanisms of aging on tactile processing within the central nervous system are yet to be fully elucidated.  

Recently, our lab published research on brain activation during active tactile exploration and the associated hedonic properties of tactile stimuli. The link between touch and hedonic preference suggests that age-related decline in tactile acuity may negatively affect individual well-being, akin to other sensory modalities, but this is also not fully understood. Our previous work enhanced our understanding of active touch mechanisms using neural (EEG) data. The current project aims to build on this approach to investigate the central mechanisms underlying age-related decline in tactile acuity. By doing so we aim to improve our understanding of the fundamental bioscience underpinning this decline and any compensatory mechanisms, while potentially informing translational research to improve the quality of life during healthy aging. 

We will address this problem using a series of studies with the following objectives:

1. Quantify contributions of peripheral and central mechanisms to age-related tactile acuity loss during active touch, including the investigation of peripheral mechanisms in healthy aging through sensory assessment and explore age-related differences in haptic exploration patterns. 
2. Multimodal (e.g., EEG/fMRI) neuroimaging to quantify brain activity within key processing areas, highlighting differences between young and old populations to uncover age-related compensatory mechanisms in the brain.
3. Explore the impact of declining tactile acuity on emotional wellbeing and relationship to the activity of proposed neural compensatory mechanisms. 

The Department of Psychological Sciences at the University of Liverpool is a research institute encompassing more than 60 academics and +30 PhD students. The department hosts three EEG labs with a large number of stimulus control/ and data acquisition and analysis workstations.  The student will join a research group of 5 PhD students utilising similar approaches or neuroimaging methods and data analysis with similar research projects. Magnetic resonance imaging will take place in the Liverpool Magnetic Resonance Imaging Centre (LiMRIC) located on the University campus. LiMRIC has a Siemens magnetic resonance scanner (3 Tesla), with two full-time radiographers on hand to assist and support research projects. These labs offer all necessary technical facilities for a successful completion of the experimental studies.  

Candidate Essential Qualities: Good (First/Upper Second Class) degree in any relevant subject area (e.g. Psychology, Neuroscience, Computer Science, Biomedical Sciences etc.)

Desirable Qualities: Masters degree in a relevant discipline. Experience of neuroimaging data collection and/or analysis using EEG or MRI. Experience of programming in R statistics, Matlab, Python or similar. 

This project will be based in the Psychology department at the University of Liverpool.   To apply for this position, please email Dr Nick Fallon nickfal@liverpool.ac.uk attaching a covering letter, CV and details of 2 referees or via the ‘email institution’ link.