Stimulus-Specific Individual Differences in Holistic Perception of Mooney Faces

Abstract

Humans perceive faces holistically rather than as a set of separate features. Previous work demonstrates that some individuals are better at this holistic type of processing than others. Here, we show that there are unique individual differences in holistic processing of specific Mooney faces. We operationalized the increased difficulty of recognizing a face when inverted compared to upright as a measure of the degree to which individual Mooney faces were processed holistically by individual observers. Our results show that Mooney faces vary considerably in the extent to which they tap into holistic processing; some Mooney faces require holistic processing more than others. Importantly, there is little between-subject agreement about which faces are processed holistically; specific faces that are processed holistically by one observer are not by other observers. Essentially, what counts as holistic for one person is unique to that particular observer. Interestingly, we found that the per-face, per-observer differences in face discrimination only occurred for harder Mooney faces that required relatively more holistic processing. These findings suggest that holistic processing of hard Mooney faces depends on a particular observer's experience whereas processing of easier, cartoon-like Mooney faces can proceed universally for everyone. Future work using Mooney faces in perception research should take these stimulus-specific individual differences into account to best isolate holistic processing.

Holistic ensemble perception

“…First, observers did (albeit to a significantly lesser degree) integrate inverted face information into their ensemble percepts. This may have occurred because the current stimulus set retained some nonholistic cues or low-level features that were available even when inverted (Canas-Bajo & Whitney, 2020). Second, we incorporated only 136 Mooney face images in our stimulus set.…”

“…For each Mooney face image, we subtracted the rating for the inverted face from the rating of the upright face to calculate the inversion effect score (indicated as blue in Fig. Whitney, 2020). Those that have strong inversion effects are operationally defined as being more holistic, following the logic of prior work (McKone, 2004).…”

“…Mooney faces are generally agreed to require holistic processing (Canas-Bajo & Whitney, 2020;Cavanagh, 1991;Kemelmacher-Shlizerman et al, 2008;McKone, 2004;Moore & Cavanagh, 1998). Despite this general agreement, specific Mooney faces require holistic processing more than others (Canas-Bajo & Whitney, 2020).…”

“…Although Mooney face stimuli are thought to require holistic processing (Latinus & Taylor, 2005;Moscovitch et al, 1997), some variations have been documented (Canas-Bajo & Whitney, 2020;McKone, Brewer, MacPherson, Rhodes, & Hayward, 2007). Our particular Mooney face stimulus set, generated by an adversarial network (Ke et al, 2017), has not been widely tested within the face literature and may retain some feature-based cues (Canas-Bajo & Whitney, 2020).…”

“…Although Mooney face stimuli are thought to require holistic processing (Latinus & Taylor, 2005;Moscovitch et al, 1997), some variations have been documented (Canas-Bajo & Whitney, 2020;McKone, Brewer, MacPherson, Rhodes, & Hayward, 2007). Our particular Mooney face stimulus set, generated by an adversarial network (Ke et al, 2017), has not been widely tested within the face literature and may retain some feature-based cues (Canas-Bajo & Whitney, 2020). To ensure that our results were not artifacts of the particular Mooney face set used, we employed another set of Mooney faces to confirm generalizability and designed Experiment 5 to ensure that holistic processing was optimally engaged.…”