Revealing mnemonic representations of the body in the brain

• Main Author: Galvez-Pol, A.
• Published: City, University of London 2017
• Subjects: 616.8; BF Psychology
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.716125

Current accounts in the memory field suggest that perceptual mechanisms underpin both perception and memory processes. The overlap between perceptual and mnemonic mechanisms has been mainly shown when processing arbitrary stimuli (e.g., shapes and colours). Nevertheless, it still unclear how more socially meaningful stimuli such as others’ bodies are perceived and later maintained in memory. This thesis investigates the encoding and memory maintenance of visually perceived body-related information. Chapter 1 reviews current accounts in the overall memory field. Secondly, it reviews evidence for the presence of a memory system to encode and maintain body-related information in working memory. Chapter 2 describes the EEG technique and proposes a novel method to isolate brain activity arising in sensorimotor cortex from concomitant visual activity that is elicited at the sight of visually perceived body stimuli. Chapter 2.5 outlines how the stimuli for the experiments of this thesis were created. Chapter 3 reports the first study looking into the transformation of visual bodily percepts into mnemonic body representations. This was done by adapting well-known working memory paradigms and the EEG method outlined in Chapter 2. The results showed that holding in memory body-related stimuli involves visual acquisition but quick recoding of the visual input onto somatosensory cortices. Chapter 4 includes another new EEG study that allowed exploration of more anterior brain areas (i.e., motor regions) during memory maintenance of body images in memory. To this end, visual-evoked potentials were combined with motor-cortical potentials. Chapter 5 followed up the two previous EEG studies with three different behavioural versions centred on interfering with the on going processing of body stimuli. Specifically, different forms of sensorimotor suppression were applied during encoding and maintenance of body-related information in memory. Altogether, the 20 methodology and experiments of this PhD work suggest that compared to mnemonic processing of non-body-related images, holding body-related stimuli in memory (beyond the perceptual stage) recruits brain areas such as somatosensory and motor cortices. Finally, Chapter 6 reflects on the results of these studies, offering an overview of this PhD work, as well as on the limitations, technicalities, and potential future studies.