Intuitively detecting what is hidden within a visual mask: Familiar–novel discrimination and threat detection for unidentified stimuli

Abstract

Recognition without identification is the finding that, among recognition test items that go unidentified (as when a word is unidentified from a fragment), participants can discriminate those that were studied from those that were unstudied. In the present study, we extended this phenomenon to the more life-like situation of discriminating known from novel stimuli. Pictures of famous and nonfamous faces (Exp. 1), famous and nonfamous scenes (Exp. 2), and threatening and nonthreatening images (Exp. 3) were filtered in order to impede identification. As in list-learning recognition-without-identification paradigms, participants attempted to identify each image (e.g., whose face it was, what scene it was, or what was in the picture) and rated how familiar the image seemed on a scale of 0 (very unfamiliar) to 10 (very familiar). Among the unidentified stimuli, higher familiarity ratings were given to famous than to nonfamous faces (Exp. 1) and scenes (Exp. 2), and to threatening than to nonthreatening living/animate (but not to nonliving/nonanimate) images (Exp. 3). These findings suggest that even when a stimulus is too occluded to allow for conscious identification, enough information can be processed to allow a sense of familiarity or novelty with it, which appears also to be related to the sense of whether or not a living creature is a threat. That the sense of familiarity for unidentified stimuli may be related to threat detection for living or animate things suggests that it may be an adaptive aspect of human memory.

The biasing nature of the tip-of-the-tongue experience: When decisions bask in the glow of the tip-of-the-tongue state.

“…bias, as reviewed by Cleary et al (2014). Third, participants have been shown to give higher ratings to threatening than to nonthreatening unidentified targets in some circumstances, and similarly so to their tendency to give higher ratings to old than to new unidentified targets (Cleary, Ryals, & Nomi, 2013). To the extent that threatening stimuli are also negative, those findings resemble the present old-new discrimination findings somewhat.…”

Detecting valence from unidentified images: A link between familiarity and positivity in recognition without identification

“…The finding that threatening stimuli were rated as more familiar (Cleary et al, 2013 , Experiment 3) is the focus of the present study. The results are intriguing, in part because they seem to represent a departure from prior literature that has shown a strong link between positivity and a sense of familiarity.…”

“…However, much less is known about valence recognition for stimuli that are not consciously identifiable due to a visual mask, and the underlying mechanisms are not well understood. However, given that familiarity is typically associated with safety and positive affect (Reber et al, 1998 ; Westerman et al, 2015 ; Whittlesea, 1993 ; Winkielman et al, 2003 ), and that this link is bidirectional (Claypool et al, 2008 ; Corneille et al, 2005 ) one might expect the positive images would be rated as more familiar than the negative images—the opposite of what was found by Cleary et al ( 2013 ). In addition, the images that were used in their study were obtained from the International Affective Picture System (IAPS; Lang et al, 2005 ).…”

“…For example, Bolte and Goschke ( 2008 ) found that participants could discriminate between coherent and scrambled versions of unidentified fragmented line drawings, and this discrimination seems to be based on general knowledge rather than presentation on a study list. In a similar non-list-learning RWI paradigm investigating the influence of preexperimental familiarity, Cleary et al ( 2013 ) applied a visual noise filter to images of famous actors (Experiment 1) and famous locations (Experiment 2). The filter obscured the images, making them difficult to identify.…”

“…The finding of an RWI effect relying on preexperimental familiarity as opposed to a defined study phase led Cleary et al ( 2013 , Experiment 3) to investigate the possible evolutionary benefits of this phenomenon, focusing on threat detection and the ability to make snap judgments in the face of minimal information. The stimuli were images that varied in threat level (threatening or nonthreatening) and animacy (animate or inanimate) that were filtered to obscure identification.…”