Thread by @alexeijoel

I'm very pleased to share that my recent work with the wonderful @Becca_Keogh_PhD, Sarah Robuck, and @ProfJoelPearson on episodic autobiographical #memory and #imagination in #aphantasia is out now in Cognition (authors.elsevier.com/a/1fHsW2Hx2pisH).
Thread below!

1/ What do you see in your mind’s eye when you remember the places you’ve been and the things you've experienced in your life? That first time at the beach, that summer picnic in the park- can you conjure those memories back again? What happens when you try to imagine the future?

2/ Episodic memory and future prospection are functionally similar: both are everyday cognitive processes involving the reconstructive simulation of events and scenes, typically accompanied by anecdotally vivid online sensory replay (or 'preplay') in the form of visual imagery.

3/ But although this imagery feels qualitatively rich for most people (often dominating the subjective content of our memories), there is in fact little robust behavioural evidence to suggest that visual imagery plays any useful, non-epiphenomenal role in remembering the past.

4/ We investigated imagery's role in mental simulation by assessing the experiences of people with #aphantasia (who show reduced or absent visual imagery capacity). This allowed us to explore the adaptive benefit of imagery during naturalistic episodic memory and prospection.

5/ We compared a group of aphantasic subjects with a control group of imagers on an adapted form of the Autobiographical Interview, a robust behavioural task assessing the retrieval of episodic and non-episodic event details during episodic memory and future prospection.

6/ We added in some subjective event ratings, some fine-grained extraction of detail sub-categories on the task (such as the proportion of perceptual memory details compared to other memory details), and some supplementary linguistic analysis of subjects' event descriptions.

7/ Here's what we found: significantly reduced episodic detail retrieval amongst aphantasic subjects compared to controls for both past and future event conditions. This demonstrates greatly diminished richness and specificity of episodic simulation capacity in aphantasia.

8/ Moreover, this outcome appeared to be partially driven by reduced visual detail retrieval, especially when imagining future events- corroborating aphantasic self-reports and suggesting an increased dependency on visual imagery by future prospection relative to episodic memory.

9/ This pattern of results was mirrored by our automated linguistic analysis, which revealed decreased visual language use (but equivalent language use in non-sensory domains) by aphantasic subjects both when remembering the past and imagining the future.

10/ Feature scores from automated linguistic analysis were also surprisingly good at predicting outcomes on the human-scored Autobiographical Interview (for both groups), motivating the use of such measures as analysis tools in naturalistic memory research.

11/ An important caveat: our results show a stark reduction in the capacity to internally construct sensory representations of episodic events in aphantasia, but this is dissociable from the capacity to accurately retrieve the semantic and temporal features of an episodic memory.

12/ Individuals with aphantasia are clearly still able to recall the past and describe the future. However, our collective data shows that visual imagery is an important pre-cursor to the capacity to internally reconstruct, represent and re-live episodic events in sensory detail.

13/ We'd like to express our gratitude to other @FMLabUNSW members for their support, reviewers who helped to shape and improve this work, and most of all to the subjects themselves (with or without aphantasia) who generously gave their time and energy to our body of research 🙏