Using pupillometry to quantify mental effort and the intrusion of unwanted memories during retrieval suppression

• Grant number: 16/22257-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: February 01, 2017
• End date: September 30, 2017
• Field of knowledge: Humanities - Psychology - Cognitive Psychology
• Principal Investigator: Orlando Francisco Amodeo Bueno
• Grantee: Marcus Vinicius Costa Alves
• Supervisor: Jonathan Fawcett
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Institution abroad: Memorial University of Newfoundland (MUN), Canada
• Associated to the scholarship: 13/24847-2 - Cognitive effort on the susceptibility to interference in memory consolidation, BP.DR

Abstract

We all have experiences that we would rather forget and require a means of keeping these experiences out of mind to ensure that they do not monopolize our thoughts. One effective method of controlling unwanted memories is to prevent those experiences from coming to mind when faced with a reminder; suppressing retrieval in this manner reduces the probability of the suppressed memories coming to mind again in the future. However, control is not always effective - and sometimes the unwanted memories intrude into conscious awareness despite our best efforts. We propose two experiments to quantify the mechanisms involved in controlling unwanted retrieval and to identify a psychophysiological correlate of memory intrusions during retrieval suppression. Our first experiment will use pupil diameter to quantify the mental effort exerted during retrieval suppression in a Think/No-Think paradigm. Our second experiment will then incorporate a measure of whether the memory intruded into awareness during suppression in this task. These ratings will be used to isolate a pupillometric signature unique to trials in which unwanted memories intruded into conscious awareness despite efforts to control them. These experiments will expand our knowledge of the mechanisms involved in controlling unwanted memories, demonstrating whether retrieval suppression invokes an effortful control process that is predictive of the successful control of intrusions as well as a reduction in the subsequent accessibility of the suppressed memory. (AU)