Rumination on Memory and Emotion, Part 5: Tunnel Memory

Many studies have been conducted regarding the psychological effects of emotion on memory, but results have shown that emotion’s effects are not always consistent. “Studies have reported that emotion either enhances or impairs learning and long-term memory (LTM) retention, depending on a range of factors.” (Tyng, Amin, Saad, Malik, 1) For example, Christianson and Loftus conducted an experiment in 1991 where they compared the memory of an emotional event to the memory of a neutral, but similar event. They found that memory was improved for the central details of the emotional event, but emotion impaired peripheral information. However, in 1978 Clifford and Scott found evidence suggesting that emotion impairs memory altogether, and in 1990 Heuer and Reisberg found that emotionality improved both central and peripheral details of an event (once again compared to a similar neutral event). These major inconsistencies, though, are easy to explain: these important studies defined the categories of central and peripheral materials differently. “Christianson and Loftus (1991), for example, defined their categories largely in spatial or perceptual terms; peripheral details were those that were truly in the background. Heuer and Reisberg (1990), on the other hand, used definitions that were more conceptual and counted as central any bits of information directly relevant to the plot, or in any way important for how the story unfolded. Peripheral information, in contrast, was information that could be changed without in any material way changing the story.” (Heuer, Reisberg 8) With central and peripheral information being defined differently across studies and experiments, direct comparison should be conducted with caution.

Generally speaking, emotion appears to improve memory for central information over peripheral information. This pattern is called “tunnel memory” (Safer, Christianson, Autry, Österlund, 1998, 1). Safer, Christianson, Autry, and Österlund’s findings in their 1998 experiments support the narrowing of highly emotional memories. They showed their participants a slide of a neutral image and a slide of an emotional one. In these experiments, “subjects remembered the critical information in a traumatic slide as either more focused spatially than in its original presentation or more focused spatially than information in a matched neutral slide. Subjects comprehend a neutral scene by automatically extending its boundaries and understanding the visual information in a broader external context. However, when subjects are negatively aroused by a scene, they process more elaborately those critical details that were the source of the emotional arousal, and they maintain or restrict the scene's boundaries.” (op cit.) When it came to highly emotional events, participants were found to recall the images more cropped in than they originally were, not remembering the context they were in: the participants’ memories excluded peripheral information. Interestingly, they also found that people remembered images of neutral events with extended boundaries, or more of a scene than in the original, understanding more context: an inverse effect called “boundary extension” (Intraub, Richardson 1). 

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“Boundary Extension.” Zililab. Accessed December 5, 2021. https://zililab.psych.ucla.edu/research/boundary-extension/. 

Intraub, Helene, and Michael Richardson. “Wide-Angle Memories of Close-up Scenes.” Journal of Experimental Psychology: Learning, Memory, and Cognition 15, no. 2 (1989): 179–87. https://doi.org/10.1037/0278-7393.15.2.179. 

Reisberg, Daniel, and Friderike Heuer. “Memory for Emotional Events.” Essay. In Memory and Emotion, edited by Paula Hertel and Daniel Reisberg, 3–41. Oxford: Oxford Univ. Press, 2010.

Safer, Martin A., Sven-Åke Christianson, Marguerite W. Autry, and Karin Österlund. “Tunnel Memory for Traumatic Events.” Applied Cognitive Psychology 12, no. 2 (1998): 99–117. https://doi.org/10.1002/(SICI)1099-0720(199804)12:2<99::AID-ACP509>3.0.CO;2-7.

Tyng, Chai M., Hafeez U. Amin, Mohamad N. Saad, and Aamir S. Malik. “The Influences of Emotion on Learning and Memory.” Frontiers in Psychology 8 (2017). https://doi.org/10.3389/fpsyg.2017.01454.