Subjectivity: Who cares?Symposium Session 5: Monday, April 15, 2024, 10:00 am – 12:00 pm EDT, Ballroom East
Chairs: Brian Levine1,2, Brad Buchsbaum1,2; 1Rotman Research Institute, Baycrest Academy for Research and Education, 2Department of Psychology, University of Toronto
Presenters: Peggy L. St. Jacques, Brad Buchsbaum, Brian Levine, Wilma Bainbridge
Science demands operationalization. In the study of memory, recall or recognition responses are interpreted according to that test’s scoring criteria, enabling agreement on what is right and wrong. Yet the same answer can arise from vastly different subjective experiences. Two rats may select the same option upon presentation with a forced-choice, yet one is – in Guthrie’s words – “buried in thought” while the other selects without a care. Plumbing a rat’s consciousness is ill-advised, and by some accounts the attempted measurement of subjectivity in humans is only slightly better, and yet we still do it because it currently provides the only way we know how to access the inner life of other people. This symposium will address the scientific study of subjectivity within and beyond memory through experimentation, analysis of cortical reinstatement, and analysis of individual differences. These presentations will address whether subjectivity matters, how it relates to objective neural activity measures, and how to leverage networked brain connectivity and cognitive science to improve both the understanding of conscious experience and outcome prediction. The symposium will conclude with a discussion led by Dr. Andy Yonelinas
Visual Perspective Biases Autobiographical Remembering
Peggy L. St. Jacques1; 1University of Alberta, Edmonton, Canada
Autobiographical memories are not veridical records of the personal past but instead can be retrieved in novel ways from how the past occurred, such as when people adopt alternative visual perspectives. People report that they can retrieve events from one of two perspectives: 1) an own eyes perspective, from the same viewpoint where the event was initially experienced, and 2) an observer-like perspective, where one might “see” themselves in the remembered event. In this talk, I will discuss how the flexible ability to shift perspective in autobiographical memories biases how people remember. First, I will describe evidence about how that visual perspective alters subjective and objective characteristics of autobiographical memories and contributes to inconsistencies in narratives of the personal past. Then, I will present fMRI evidence demonstrating how visual perspective cues bias autobiographical memory recall in a goal-directed way by recruiting angular gyrus and precuneus. Finally, I will end with a discussion of whether all individuals are able to adopt multiple viewpoints, and the potential implications on how shifts in visual perspective influence memory. Together these findings reveal how our subjective point-of-view biases the way that we remember the personal past.
Grounding introspective episodic memory judgements with neural readouts
Brad Buchsbaum1,2; 1Rotman Research Institute, Baycrest Academy for Research and Education, 2Department of Psychology, University of Toronto
At the turn of the 20th century the budding field of experimental psychology was dominated by “introspectionism”, a methodology in which the “observer” and the “subject” are one and the same person. Introspectionism was, for good reason, a dead end; however, human episodic memory is inescapably subjective, and although introspectionism may not be a grounds for a science of memory, phenomenological experience remains an important and valid object of study. I will present a line of evidence that uses functional magnetic resonance imaging (fMRI), behavioural measures, and eye-movement data, as a way to objectively link subjective experience associated with detailed memory retrieval, and co-occurring physiological signals measured in the brain. In a series of studies we have shown that 1) judgements of memory vividness correspond to the decodability of multivoxel patterns of neural activity, 2) that memories that are reported to be vivid are also more accurate, 3) that eye-movement patterns are more faithfully “reinstated” during vivid memories, and 4) that individual differences in average vividness ratings are linked to neural reinstatement in distributed areas of the neocortex. Finally, we outline a new method for classifying the vividness of a memory or imagination based only on a “readout” of fMRI patterns of activity. Such a method holds the promise of offering a scientifically neutral way of assessing subjective memory experiences with physiological measurement tools.
Individual differences in subjective memory: brain imaging, cognition, and psychopathology
Brian Levine1; 1Rotman Research Institute, Baycrest Academy for Research and Education, 2Department of Psychology, University of Toronto
It has long been understood that responses on memory tests -- whether free recall or recognition -- are associated with heterogenous subjective experiences, including confidence, familiarity, or recollection. While there is a rich tradition of assessing such responses across items or in response to manipulations, comparatively little research has been conducted on individual differences in recollection or stable mnemonic traits, yet the existence of such differences ("How good (or bad) is my memory?") is generally accepted. The identification of extreme individual difference profiles in memory and imagery (e.g., Highly Superior Autobiographical Memory, HSAM; Severely Deficient Autobiographical Memory, SDAM; hyperphantasia, aphantasia) provides leverage on such traits in group studies, leading in turn to full-spectrum assessment individual differences in large samples. Structural and functional neuroanatomical findings in SDAM provide objective measures of subjectively-reported low recollection and imagery, including marked asymmetries (L>R) in medial temporal lobe structures, reduced integrity of the fornix, and reduced cortical re-instatement of low-level visual features in visual memory. People with SDAM are biased towards processing of semantic or implicational features that cut across epodes, as opposed to unique details. This processing mode confers advantages on tasks requiring conceptual analysis, including STEM occupations that are more prevalent in SDAM. Moreover, when exposed to trauma, people with SDAM are less likely to develop post-traumatic psychopathology, possibly due to their reduced visual re-experiencing. This and other research underscores the importance of considering subjectivity in mnemonic assessments, as well as an individual differences framework in cognitive and clinical neuroscience.
Is a lack of visual imagery subjective or objective (or both)?
Wilma Bainbridge1; 1Department of Psychology, University of Chicago
Congenital aphantasia has emerged as a fascinating condition in which individuals report no experience of visual imagery or recall, despite intact perception and semantic memory. As a result, this group serves as a natural “knock-out” case of visual memory that allows us to examine dissociations between visual perception and recall. However, one major question is whether the lack of visual imagery could be explained by a lack of conscious access to successfully reinstated information. To answer this question, we studied the imagery experience of a pair of identical twins: one with aphantasia and one with typical imagery. First, we confirmed their divergent imagery experiences through behavioral and drawing measures. Second, we conducted an fMRI study in which they performed visual perception and recall tasks using both novel and highly familiar stimuli. We were successfully able to decode the stimulus category (i.e., face or scene) being perceived and recalled by both individuals, suggesting the aphantasic twin still experiences retrieval of visual memory. However, importantly, while we could cross-decode patterns between perception and recall across multiple cortical regions in the typical imagery twin, we could not in the twin with aphantasia. This suggests that their reinstated representation is fundamentally different from their perceptual representation. Additionally, we could cross-decode perceptual representations for the same items between twins but not memory representations. In sum, these results suggest that the experience of aphantasia can be objectively measured in the brain, and may reflect an interesting difference in how their memories are represented and retrieved.
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April 13–16 | 2024