Megan H. Papesh

Deficits in Cross-Race Face Learning: Insights From Eye Movements and Pupillometry

The own-race bias (ORB) is a well-known finding wherein people are better able to recognize and discriminate own-race faces, relative to cross-race faces. In 2 experiments, participants viewed Asian and Caucasian faces, in preparation for recognition memory tests, while their eye movements and pupil diameters were continuously monitored. In Experiment 1 (with Caucasian participants), systematic differences emerged in both measures as a function of depicted race: While encoding cross-race faces, participants made fewer (and longer) fixations, they preferentially attended to different sets of features, and their pupils were more dilated, all relative to own-race faces. Also, in both measures, a pattern emerged wherein some participants reduced their apparent encoding effort to cross-race faces over trials. In Experiment 2 (with Asian participants), the authors observed the same patterns, although the ORB favored the opposite set of faces. Taken together, the results suggest that the ORB appears during initial perceptual encoding. Relative to own-race face encoding, cross-race encoding requires greater effort, which may reduce vigilance in some participants.

Pupil Dilation Reflects the Creation and Retrieval of Memories

It has long been known that pupils—the apertures that allow light into the eyes—dilate and constrict not only in response to changes in ambient light but also in response to emotional changes and arousing stimuli (e.g., Fontana, 1765). Charles Darwin (1872) related changes in pupil diameter to fear and other “emotions” in animals. For decades, pupillometry has been used to study cognitive processing across many domains, including perception, language, visual search, and short-term memory. Historically, such studies have examined the pupillary reflex as a correlate of attentional demands imposed by different tasks or stimuli—pupils typically dilate as cognitive demand increases. Because the neural mechanisms responsible for such task-evoked pupillary reflexes (TEPRs) implicate a role for memory processes, recent studies have examined pupillometry as a tool for investigating the cognitive processes underlying the creation of new episodic memories and their later retrieval. Here, we review the historical antecedents of current pupillometric research and discuss several recent studies linking pupillary dilation to the on-line consumption of cognitive resources in long-term-memory tasks. We conclude by discussing the future role of pupillometry in memory research and several methodological considerations that are important when designing pupillometric studies.

Memory strength and specificity revealed by pupillometry

Voice-specificity effects in recognition memory were investigated using both behavioral data and pupillometry. Volunteers initially heard spoken words and nonwords in two voices; they later provided confidence-based old/new classifications to items presented in their original voices, changed (but familiar) voices, or entirely new voices. Recognition was more accurate for old-voice items, replicating prior research. Pupillometry was used to gauge cognitive demand during both encoding and testing: enlarged pupils revealed that participants devoted greater effort to encoding items that were subsequently recognized. Further, pupil responses were sensitive to the cue match between encoding and retrieval voices, as well as memory strength. Strong memories, and those with the closest encoding-retrieval voice matches, resulted in the highest peak pupil diameters. The results are discussed with respect to episodic memory models and Whittleseas (1997) SCAPE framework for recognition memory.

Sparse and distributed coding of episodic memory in neurons of the human hippocampus

Significance The ability to form episodic memories in rapid succession depends on the hippocampus, but how do hippocampal neurons represent such memories? Most neurocomputational models envision a sparse distributed coding scheme in which individual neurons each participate in the coding of a few memories, and each memory is coded by a small fraction of hippocampal neurons. We investigated this issue with epilepsy patients undergoing intracranial monitoring and found evidence consistent with sparse distributed coding in the hippocampus. These findings shed new light on the basic neural mechanisms that underlie the ability to remember events. A detailed characterization of those mechanisms is an essential part of the larger effort to understand memory loss associated with normal aging and dementia. Neurocomputational models hold that sparse distributed coding is the most efficient way for hippocampal neurons to encode episodic memories rapidly. We investigated the representation of episodic memory in hippocampal neurons of nine epilepsy patients undergoing intracranial monitoring as they discriminated between recently studied words (targets) and new words (foils) on a recognition test. On average, single units and multiunits exhibited higher spike counts in response to targets relative to foils, and the size of this effect correlated with behavioral performance. Further analyses of the spike-count distributions revealed that (i) a small percentage of recorded neurons responded to any one target and (ii) a small percentage of targets elicited a strong response in any one neuron. These findings are consistent with the idea that in the human hippocampus episodic memory is supported by a sparse distributed neural code.

The poverty of embodied cognition

In recent years, there has been rapidly growing interest in embodied cognition, a multifaceted theoretical proposition that (1) cognitive processes are influenced by the body, (2) cognition exists in the service of action, (3) cognition is situated in the environment, and (4) cognition may occur without internal representations. Many proponents view embodied cognition as the next great paradigm shift for cognitive science. In this article, we critically examine the core ideas from embodied cognition, taking a “thought exercise” approach. We first note that the basic principles from embodiment theory are either unacceptably vague (e.g., the premise that perception is influenced by the body) or they offer nothing new (e.g., cognition evolved to optimize survival, emotions affect cognition, perception–action couplings are important). We next suggest that, for the vast majority of classic findings in cognitive science, embodied cognition offers no scientifically valuable insight. In most cases, the theory has no logical connections to the phenomena, other than some trivially true ideas. Beyond classic laboratory findings, embodiment theory is also unable to adequately address the basic experiences of cognitive life.

Pupil-BLAH-metry: Cognitive effort in speech planning reflected by pupil dilation

In reading research, a longstanding question is whether any stages of lexical processing require central attention, and whether such potential demands are frequency-sensitive. In the present study, we examined the allocation of cognitive effort in lexical processing by examining pupil dilations and naming latencies in a modified delayed naming procedure. In this dual-task/change procedure, participants read words and waited for various delays before being signaled to issue a response. On most trials (80%), participants issued a standard naming response. On the remaining trials, they were cued to abandon the original speech plan, saying “blah” instead, thereby equating production across different words. Using feature-matched low- and high-frequency words, we observed the differences in pupil dilations as a function of word frequency. Indeed, frequency-sensitive cognitive demands were seen in word processing, even after naming responses were issued. The results suggest that word perception and/or speech planning requires the frequency-sensitive allocation of cognitive resources.

Your Effort Is Showing! Pupil Dilation Reveals Memory Heuristics

It is an honour to contribute to a collection of essays celebrating Bruce Whittlesea’s career. The research and ideas from Whittlesea and his colleagues have heavily influenced much of the research in our laboratory, particularly our studies of face perception and memory. Although face processing is often considered ‘modular’ (i.e., highly specialized in neural and computational terms; Haxby et al., 2000), we have consistently observed that judgements of face memory are affected by the evaluative and heuristic processes that Whittlesea has hypothesized (e.g., Whittlesea & Leboe, 2000). In this chapter, we briefly review several prior findings that connect Whittlesea’s (1997) SCAPE framework with face memory. We then describe new results, wherein we hypothesize that long- term struggles from the SCAPE evaluation system may inspire a new heuristic (kindly dubbed the ‘oh… screw it’ heuristic).

Deficits in Other-Race Face Recognition: No Evidence for Encoding-Based Effects

The other-race effect (ORE) in face recognition is typically observed in tasks which require long-term memory. Several studies, however, have found the effect early in face encoding (Lindsay, Jack, & Christian, 1991; Walker & Hewstone, 2006). In 6 experiments, with over 300 participants, we found no evidence that the recognition deficit associated with the ORE reflects deficits in immediate encoding. In Experiment 1, with a study-to-test retention interval of 4 min, participants were better able to recognise White faces, relative to Asian faces. Experiment 1 also validated the use of computer-generated faces in subsequent experiments. In Experiments 2 through 4, performance was virtually identical to Asian and White faces in match-to-sample, immediate recognition. In Experiment 5, decreasing target-foil similarity and disrupting the retention interval with trivia questions elicited a re-emergence of the ORE. Experiments 6A and 6B replicated this effect, and showed that memory for Asian faces was particularly susceptible to distraction; White faces were recognised equally well, regardless of trivia questions during the retention interval. The recognition deficit in the ORE apparently emerges from retention or retrieval deficits, not differences in immediate perceptual processing.

Photo ID verification remains challenging despite years of practice

BackgroundMatching unfamiliar faces to photographic identification (ID) documents occurs across many domains, including financial transactions (e.g., mortgage documents), controlling the purchase of age-restricted goods (e.g., alcohol sales), and airport security. Laboratory research has repeatedly documented the fallibility of this process in novice observers, but little research has assessed individual differences based on occupational expertise (cf. White et al., PLoS One 9:e103510, 2014; White et al., Proceedings of the Royal Society B 282(1814):20151292, 2015). In the present study, over 800 professional notaries (who routinely verify identity prior to witnessing signatures on legal documents), 70 bank tellers, and 35 undergraduate students completed an online unfamiliar face-matching test. In this test, observers made match/nonmatch decisions to 30 face ID pairs (half of which were matches), with no time constraints and no trial-by-trial feedback.ResultsResults showed that all groups performed similarly, although age was negatively correlated with accuracy. Critically, weekly and yearly experience with unfamiliar face matching did not impact performance.ConclusionsThese results suggest that accumulated occupational experience has no bearing on unfamiliar face ID abilities and that cognitive declines associated with aging also manifest in unfamiliar face matching.

RSVPupillometry: Incidental memory and psychophysiology in rapid-serial multiple-target search.

# 56.329 Typically, visual search experiments involve single-target (ST), template-guided search: Observers are shown a picture and look for it embedded among distractors. But real-world search is more difficult. Multiple-target (MT) search is ubiquitous; consider collecting your keys, wallet and phone before departing from home. Also, we rarely have a picture from which to generate a target representation. Rather, we search categorically, by compiling target features from long-term memory. Importantly, MT search incurs speed and accuracy costs, relative to ST search: Observers’ RTs are slowed, they make more (and longer) fixations, and they are more likely to miss and false-alarm (Hout & Goldinger, 2012). Paradoxically, this increased workload creates more robust incidental memory for distractors encountered while viewing (Hout & Goldinger, 2010). In the current investigation, we contrasted template(picture cues) and categorical-search (word cues), using a rapid-serial visual presentation task (Williams, 2010), wherein participants maintained a varying number of targets in working memory (WM) while passively viewing streams of 24 briefly presented images (centrally displayed, one at a time). This task allowed us to ensure equal encoding opportunities across conditions. The target appeared in each quartile of the stream (early, mid-early, mid-late, late) equally often. After search, we administered a surprise, 2AFC recognition memory test for items previously seen; foils were semantically matched. Search accuracy was better under ST conditions, relative to MT, and was better in templaterelative to categorical-search. People also located the target more accurately when it appeared late in the stream, relative to earlier. Recognition memory performance, however, was better for items encountered while searching for multiple targets (and tended to be better for items that appear after the target, relative to before it). The results are discussed with respect to our preliminary model of learning in visual search (SQuEaL; Hout & Goldinger, 2011), which suggests that MT template-guided search may involve a strategy shift, wherein cognitive resources are transferred from maintaining target representations in WM to the faithful encoding of search items. In categorical search, a similar mechanism may come into play, whereby the maintenance of guiding features is less stable in MT search. Finally, we explored pupil diameters in order to examine attentional vigilance and its relation to search performance (e.g., Papesh, Goldinger & Hout, 2012). Pupil dilation was a reliable marker of task difficulty, as well as target identification. Moreover, pupils elucidated existing shortcomings of the SQuEal model; future modeling efforts are revised in keeping with the attentional signatures indicated by pupil dilation. RSVPupillometry: Incidental memory and psychophysiology in rapid-serial multiple-target search. Michael C. Hout , Megan H. Papesh , & Stephen D. Goldinger 1 1 Arizona State University; 2 Louisiana State University 12th Annual Meeting of the Vision Sciences Society