Behavioural studies have shown a significant age-related slowing in mental rotation tasks (Hertzog & Rypma, 1991). However, it is unclear whether this slower performance reflects a specific cognitive decline in spatial information processing in ageing or a more general slowing of perceptual and/or motor processes (Salthouse & Ferrer-Caja, 2003). To investigate this, event-related brain potentials (ERPs) were recorded while younger (n=10) and older participants (n=10) performed a letter rotation task involving mirror-normal letter discriminations. Behavioural results confirmed slower responses in the older compared to the younger participants. Furthermore, there was an interaction between rotation angle and group with lower mental rotation rate in older participants. The ERP analysis of the rotation-related effect, a parietal negativity which becomes more pronounced with increasing angular disparity (Heil, 2002), revealed systematic differences between old and young adults. Younger adults showed the angular disparity effect on the amplitude of the rotation-related negativity (RRN) starting from about 350 ms post-stimulus onset. This effect was reliably present for 200 ms (350-450ms and 450-550ms time windows) returning to baseline beyond 550ms post-stimulus. In contrast, reliable modulations of the RRN by angular disparity in older adults were observed between 450 and 650ms. These findings reveal that ageing selectively delays mental rotation processes, suggesting that the slower performance observed in the older participants is not simply caused by unspecific effects of aging on motor processes.
|Publication status||Unpublished - 2016|
|Event||The Eye's Mind: Visual Imagination, Neuroscience and the Humanities - University of Exeter, United Kingdom|
Duration: 21 May 2016 → 22 May 2016
|Conference||The Eye's Mind: Visual Imagination, Neuroscience and the Humanities|
|Period||21/05/16 → 22/05/16|