Facial expression at retrieval affects recognition of facial identity

Abstract

It is well known that memory can be modulated by emotional stimuli at the time of encoding and consolidation. For example, happy faces create better identity recognition than faces with certain other expressions. However, the influence of facial expression at the time of retrieval remains unknown in the literature. To separate the potential influence of expression at retrieval from its effects at earlier stages, we had participants learn neutral faces but manipulated facial expression at the time of memory retrieval in a standard old/new recognition task. The results showed a clear effect of facial expression, where happy test faces were identified more successfully than angry test faces. This effect is unlikely due to greater image similarity between the neural training face and the happy test face, because image analysis showed that the happy test faces are in fact less similar to the neutral training faces relative to the angry test faces. In the second experiment, we investigated whether this emotional effect is affected by the expression at the time of learning. We employed angry or happy faces as learning stimuli, and angry, happy, and neutral faces as test stimuli. The results showed that the emotional effect at retrieval is robust across different encoding conditions with happy or angry expressions. These findings indicate that emotional expressions do not only affect the stages of encoding and consolidation, but also the retrieval process in identity recognition.

The effect of variations of emotional expressions on mnemonic discrimination and traditional recognition memory

“…An impact on memory accuracy (irrespective of its direction) on both memory measures would be in line with studies using similar designs that have varied emotional expressions between learning and test, reporting differences in discrimination ability based on the expressional valence (e.g. Chen et al, 2015;Righi et al, 2012).…”

“…Inconsistencies in results have also been found in studies manipulating emotional (happy or angry) expressions of the same face at retrieval using neutral faces at learning. Either the influence of facial expression on memory did not differ (D'Argembeau & Van der Linden, 2011), or faces that returned as angry (rather than happy) improved recognition (Chen et al, 2015). Furthermore, in an attempt to create well-defined perceptual variations of facial expressions of the same face, some studies have used morphing technique to create alterations (e.g.…”

“…A lure discrimination index (LDI: Formula 1) was used to evaluate mnemonic discrimination ability between similar facial expressions. This index has been used for similar purposes (Chen et al, 2015;Stark, Yassa, Lacy, & Stark, 2013) and was also suitable for evaluating the ability to discriminate between faces that were identical or slightly changed (for an alternative measure see Yassa, Mattfeld, Stark, & Stark, 2011;Chang, Murray, & Yassa, 2015). As our design used old Targets and two types of Lures: similar and dissimilar (rather than Lures and Foils) our operationalisation of the LDI varied from the traditional calculation, (p('New'|Lure)-p('New'|Target) in the following ways: In the current design, the traditional "new" response (and Foil items) used in prior studies corresponded to "low similarity" (and dissimilar Lures), and a traditional "similar" response (Lure items) corresponded to "high similarity" (similar lures).…”

Rapid Adaptation to the Timbre of Natural Sounds

“…This said, timbre need not be equated to sound source identity: a particular sound source (e.g., a human voice, a violin) can emit multiple timbres (different vowels, bowed vs. plucked sounds). Playing an instrument in an unusual or extreme manner, thereby producing unorthodox timbres (e.g., prepared piano, muted brass, woodwind squeaks, flutter tongue) can make that instrument difficult to recognize, similar to how an extreme facial expression 25 or makeup 26 can hinder face recognition. Pitch can also contribute to the identity of a sound, but characterizations of the relationship between pitch and timbre are somewhat murky.…”

Developmental Prosopagnosia and Elastic Versus Static Face Recognition in an Incidental Learning Task

“…Second, the present design may be confounded by picture-matching instead of face-matching mechanisms as the static-static and elastic-elastic conditions showed overall better recognition compared to the other conditions. It is commonly observed in recognition research that a direct link exists between the similarity of images presented during learning and test-phase, and the recognition rate (e.g., Ritchey et al, 2013 ; Chen et al, 2015 ). Several previous studies (e.g., Lander et al, 2004 ; Pilz et al, 2006 ) have implemented changes in viewpoint or expression during recognition to ensure that they were assessing face processing instead of identical picture matching (i.e., same background lighting, same shutter settings, same focal length, et cetera), which could serve as an alternative strategy to recognition.…”