Improving face identity perception in age-related macular degeneration via caricaturing

The experience of visual art for people living with mild-to-moderate vision loss

BACKGROUND

Visual art can enhance wellbeing and quality-of-life; however, the experience of visual art for people with mild-to-moderate vision loss has not been examined.

METHODS

Eight participants (6 females, 2 males; Mean age = 81 years, SD = 7.9, range 70-91 years; 4 with mild vision loss and 4 with moderate vision loss based on binocular visual acuity) completed a mixed-methods study comprising: a semi-structured interview on visual art experience; an eye examination; and questionnaires about visual functioning and quality-of-life.

RESULTS

Various themes were identified: visual perception of art (e.g. altered colours, visual distortions, etc.), viewing conditions, elements of art, personal preference, deriving meaning, appreciation of art, impact of impaired visual perception, and social aspects of art.

CONCLUSIONS

The overall experience of art is influenced by how an individual sees, perceives, and makes meaning from art. Even mild vision loss can impair this experience and impact emotional and social wellbeing.

Crossmodal benefits to vocal emotion perception in cochlear implant users

Speech comprehension counts as a benchmark outcome of cochlear implants (CIs)-disregarding the communicative importance of efficient integration of audiovisual (AV) socio-emotional information. We investigated effects of time-synchronized facial information on vocal emotion recognition (VER). In Experiment 1, 26 CI users and normal-hearing (NH) individuals classified emotions for auditory-only, AV congruent, or AV incongruent utterances. In Experiment 2, we compared crossmodal effects between groups with adaptive testing, calibrating auditory difficulty via voice morphs from emotional caricatures to anti-caricatures. CI users performed lower than NH individuals, and VER was correlated with life quality. Importantly, they showed larger benefits to VER with congruent facial emotional information even at equal auditory-only performance levels, suggesting that their larger crossmodal benefits result from deafness-related compensation rather than degraded acoustic representations. Crucially, vocal caricatures enhanced CI users' VER. Findings advocate AV stimuli during CI rehabilitation and suggest perspectives of caricaturing for both perceptual trainings and sound processor technology.

Enhancing socio-emotional communication and quality of life in young cochlear implant recipients: Perspectives from parameter-specific morphing and caricaturing

The use of digitally modified stimuli with enhanced diagnostic information to improve verbal communication in children with sensory or central handicaps was pioneered by Tallal and colleagues in 1996, who targeted speech comprehension in language-learning impaired children. Today, researchers are aware that successful communication cannot be reduced to linguistic information—it depends strongly on the quality of communication, including non-verbal socio-emotional communication. In children with cochlear implants (CIs), quality of life (QoL) is affected, but this can be related to the ability to recognize emotions in a voice rather than speech comprehension alone. In this manuscript, we describe a family of new methods, termed parameter-specific facial and vocal morphing. We propose that these provide novel perspectives for assessing sensory determinants of human communication, but also for enhancing socio-emotional communication and QoL in the context of sensory handicaps, via training with digitally enhanced, caricatured stimuli. Based on promising initial results with various target groups including people with age-related macular degeneration, people with low abilities to recognize faces, older people, and adult CI users, we discuss chances and challenges for perceptual training interventions for young CI users based on enhanced auditory stimuli, as well as perspectives for CI sound processing technology.

Caricatured facial movements enhance perception of emotional facial expressions

Although faces “in the wild” constantly undergo complicated movements, humans adeptly perceive facial identity and expression. Previous studies, focusing mainly on identity, used photographic caricature to show that distinctive form increases perceived dissimilarity. We tested whether distinctive facial movements showed similar effects, and we focussed on both perception of expression and identity. We caricatured the movements of an animated computer head, using physical motion metrics extracted from videos. We verified that these “ground truth” metrics showed the expected effects: Caricature increased physical dissimilarity between faces differing in expression and those differing in identity. Like the ground truth dissimilarity, participants’ dissimilarity perception was increased by caricature when faces differed in expression. We found these perceived dissimilarities to reflect the “representational geometry” of the ground truth. However, neither of these findings held for faces differing in identity. These findings replicated across two paradigms: pairwise ratings and multiarrangement. In a final study, motion caricature did not improve recognition memory for identity, whether manipulated at study or test. We report several forms of converging evidence for spatiotemporal caricature effects on dissimilarity perception of different expressions. However, more work needs to be done to discover what identity-specific movements can enhance face identification.

Coarse-to-Fine(r) Automatic Familiar Face Recognition in the Human Brain

At what level of spatial resolution can the human brain recognize a familiar face in a crowd of strangers? Does it depend on whether one approaches or rather moves back from the crowd? To answer these questions, 16 observers viewed different unsegmented images of unfamiliar faces alternating at 6 Hz, with spatial frequency (SF) content progressively increasing (i.e., coarse-to-fine) or decreasing (fine-to-coarse) in different sequences. Variable natural images of celebrity faces every sixth stimulus generated an objective neural index of single-glanced automatic familiar face recognition (FFR) at 1 Hz in participants' electroencephalogram (EEG). For blurry images increasing in spatial resolution, the neural FFR response over occipitotemporal regions emerged abruptly with additional cues at about 6.3-8.7 cycles/head width, immediately reaching amplitude saturation. When the same images progressively decreased in resolution, the FFR response disappeared already below 12 cycles/head width, thus providing no support for a predictive coding hypothesis. Overall, these observations indicate that rapid automatic recognition of heterogenous natural views of familiar faces is achieved from coarser visual inputs than generally thought, and support a coarse-to-fine FFR dynamics in the human brain.

Correlation of Central Versus Peripheral Macular Structure-Function With Acuity in Age-Related Macular Degeneration

Purpose

Patients with advanced age-related macular degeneration (AMD) may have preserved visual function despite significant retinal structural changes. We aimed to evaluate the relationships among retinal thickness, macular sensitivity, and visual acuity (VA) in advanced AMD.

Methods

We examined 43 eyes of 22 patients with advanced AMD (ages 66–93 years), prospectively recruited from the Canberra Hospital Ophthalmology Department. Visual function was measured on participants with low and high contrast visual acuity (LCVA and HCVA) and 10-2 Matrix visual fields. Retinal structure was determined with spectral domain optical coherence tomography (OCT), and customized software mapped the 64 OCT macular thickness regions onto the 44 regions of the 10-2 test.

Results

Median retinal thickness at each 10-2 region was near normal. Just 7 of 88 regions from the OCT analysis that were thicker than the median had sensitivity that declined significantly with increasing thickness (r = −0.698 ± 0.082, mean ± SD), whereas 17 of 88 thinner regions showed significantly decreasing sensitivity with decreasing thickness (r = 0.723 ± 0.078). The absolute value of deviations from median optical coherence tomography thickness (aOCT) outside the central eight degrees was significantly correlated with HCVA (r = −0.34, P = 0.047). Thickness in the central eight degrees was not. Similarly, matrix sensitivities inside the central eight degrees were significantly correlated with outer aOCT (r = −0.49, P = 0.002).

Conclusions

Retinal thickness outside eight degrees were significantly associated with HCVA and macular sensitivity. These results suggest that outer macular thickness may be a useful prognostic indicator in AMD.

Translational Relevance

Retinal structure at the borders of the macula may be a surrogate marker of vision and retinal thickness near fixation.

Why the other-race effect matters: Poor recognition of other-race faces impacts everyday social interactions

What happens to everyday social interactions when other-race recognition fails? Here, we provide the first formal investigation of this question. We gave East Asian international students (N = 89) a questionnaire concerning their experiences of the other-race effect (ORE) in Australia, and a laboratory test of their objective other-race face recognition deficit using the Cambridge Face Memory Test (CFMT). As a 'perpetrator' of the ORE, participants reported that their problems telling apart Caucasian people contributed significantly to difficulties socializing with them. Moreover, the severity of this problem correlated with their ORE on the CFMT. As a 'victim' of the ORE, participants reported that Caucasians' problems telling them apart also contributed to difficulties socializing. Further, 81% of participants had been confused with other Asians by a Caucasian authority figure (e.g., university tutor, workplace boss), resulting in varying levels of upset/difficulty. When compared to previously established contributors to international students' high rates of social isolation, ORE-related problems were perceived as equally important as the language barrier and only moderately less important than cultural differences. We conclude that the real-world impact of the ORE extends beyond previously identified specialized settings (eyewitness testimony, security), to common everyday situations experienced by all humans.

Parameter-Specific Morphing Reveals Contributions of Timbre and Fundamental Frequency Cues to the Perception of Voice Gender and Age in Cochlear Implant Users

Purpose Using naturalistic synthesized speech, we determined the relative importance of acoustic cues in voice gender and age perception in cochlear implant (CI) users. Method We investigated 28 CI users' abilities to utilize fundamental frequency (F0) and timbre in perceiving voice gender (Experiment 1) and vocal age (Experiment 2). Parameter-specific voice morphing was used to selectively control acoustic cues (F0; time; timbre, i.e., formant frequencies, spectral-level information, and aperiodicity, as defined in TANDEM-STRAIGHT) in voice stimuli. Individual differences in CI users' performance were quantified via deviations from the mean performance of 19 normal-hearing (NH) listeners. Results CI users' gender perception seemed exclusively based on F0, whereas NH listeners efficiently used timbre. For age perception, timbre was more informative than F0 for both groups, with minor contributions of temporal cues. While a few CI users performed comparable to NH listeners overall, others were at chance. Separate analyses confirmed that even high-performing CI users classified gender almost exclusively based on F0. While high performers could discriminate age in male and female voices, low performers were close to chance overall but used F0 as a misleading cue to age (classifying female voices as young and male voices as old). Satisfaction with CI generally correlated with performance in age perception. Conclusions We confirmed that CI users' gender classification is mainly based on F0. However, high performers could make reasonable usage of timbre cues in age perception. Overall, parameter-specific morphing can serve to objectively assess individual profiles of CI users' abilities to perceive nonverbal social-communicative vocal signals.