Photographic Stimuli Research Articles

Revisiting Snodgrass and Vanderwart in photograph form: The Keele Photo Stimulus Set (KPSS)

Over the last 40 years, object recognition studies have moved from using simple line drawings, to more detailed illustrations, to more ecologically valid photographic representations. Researchers now have access to various stimuli sets, however, existing sets lack the ability to independently manipulate item format, as the concepts depicted are unique to the set they derive from. To enable such comparisons, Rossion and Pourtois (2004) revisited Snodgrass and Vanderwart’s (1980) line drawings and digitally re-drew the objects, adding texture and shading. In the current study, we took this further and created a set of stimuli that showcase the same objects in photographic form. We selected six photographs of each object (three color/three grayscale) and collected normative data and RTs. Naming accuracy and agreement was high for all photographs and appeared to steadily increase with format distinctiveness. In contrast to previous data patterns for drawings, naming agreement (H values) did not differ between grey and color photographs, nor did familiarity ratings. However, grey photographs received significantly lower mental imagery agreement and visual complexity scores than color photographs. This suggests that, in comparison to drawings, the ecological nature of photographs may facilitate deeper critical evaluation of whether they offer a good match to a mental representation. Color may therefore play a more vital role in photographs than in drawings, aiding participants in judging the match with their mental representation. This new photographic stimulus set and corresponding normative data provide valuable materials for a wide range of experimental studies of object recognition.

Exploring the Influence of Race in Mate Copying Using Former Partner Evaluations

Human mate choice is a complex, nuanced process that incorporates factors including physical attractiveness, race, culture, and social values. Choosing the wrong partner can be a risky and costly affair; hence, mate choosers may copy the choices of others to inform their own decisions about the mate quality of a potential partner. This phenomenon is known as mate copying (MC). Consistent with previous research methods, the current study presented a sample of 461 Australian women with photographic stimuli of target men of one of three races paired with a description of a former female partner evaluating the target man either positively or negatively. Racial similarity between participants and the target man was statistically controlled for. As hypothesised, positive evaluations elicited MC whereas negative evaluations elicited mate avoidance. Racial similarity was also shown to influence measures of desirability and MC propensity. Results were discussed within the context of existing human MC literature, with particular emphasis on exploring how new factors affect the expression of MC intent within the Australian female demographic. Recommendations for further research based on these outcomes were also made.

Recognition Memory for Interior Spaces with Biomorphic or Non–Biomorphic Interior Architectural Elements

In our study, the primary goal was to gain insights into cognition by measuring spatial memorability for two different types of approaches to geometry in interior design (biomorphic design and non–biomorphic rectilinear design). To better understand the processes behind the memorability differences, we also looked at how spatial memorability interacted with visual attention and spatial pleasantness. After extensive pre–testing, two standardized photographic stimulus sets were created and used during the experiment, controlling for variables such as novelty, complexity, pleasantness, and the number and density of interior architectural elements. Each stimulus set contained equal numbers of photographs with biomorphic elements and photographs with non–biomorphic elements. Subjects ( N = 68 students, mean age = 25.4 years) viewed the first stimulus set, then were given a “distractor” task. Next, subjects viewed the second stimulus set, and for each photograph indicated whether the image was one they had seen or whether it was new. Visual attention for each photograph was monitored using eye–tracking technology, and subjects also rated the pleasantness of each environment. The data were analyzed to test for the relative strength of memorability between environments with biomorphic elements and non–biomorphic elements, as well as the links between recognition memory, visual attention, and pleasantness. The results suggest that interior spaces with biomorphic elements positively contribute to spatial memorability, are found to be more pleasant, and increase visual attention.

Visual Object Recognition From Single-Trial EEG Signals Using Machine Learning Wrapper Techniques.

Responses of the human brain to different visual stimuli elicit specific patterns in electroencephalography (EEG) signals. It is confirmed that by analyzing these patterns, we can recognize the category of the visited objects. However, high levels of noise and artifacts in EEG signals and the discrepancies between the recorded data from different subjects in visual object recognition task make classification of cognitive states of subjects a serious challenge. In this research, we present a framework for evaluating machine learning and wrapper channel selection algorithms used for classifying single-trial EEG signals recorded in response to photographic stimuli. It is shown that by correctly mapping the entire EEG data space to informative feature spaces (IFS), the performance of the classification methods can improve significantly. Results outperform the state-of-the-art results and confirm efficiency of the proposed feature selection methods in capturing the most informative EEG channels. This can help to achieve high separability of object categories in single-trial visual object recognition task.

Iridescence untwined: honey bees can separate hue variations in space and time

Abstract Iridescence is a phenomenon whereby the hue of a surface changes with viewing or illumination angle. Many animals display iridescence but it currently remains unclear whether relevant observers process iridescent color signals as a complex collection of colors (spatial variation), or as moving patterns of colors and shapes (temporal variation). This is important as animals may use only the spatial or temporal component of the signal, although this possibility has rarely been considered or tested. Here, we investigated whether honey bees could separate the temporal and spatial components of iridescence by training them to discriminate between iridescent disks and photographic images of the iridescent patterns presented by the disks. Both stimuli therefore contained spatial color variation, but the photographic stimuli do not change in hue with varying angle (no temporal variation). We found that individual bee observers could discriminate the variable patterns of iridescent disks from static photographs during unrewarded tests. Control experiments showed that bees reliably discriminated iridescent disks from control silver disks, showing that bees were processing chromatic cues. These results suggest that honey bees could selectively choose to attend to the temporal component of iridescent signals to make accurate decisions.

Examining Face Validity of Visual Stimuli Used in Preference Assessments for Older Adults With Communication Impairments

Preference assessment is integral to person-centered treatment planning for older adults with communication impairments. There is a need to validate photographs used in preference assessment for this population. Therefore, this study aimed to establish preliminary face validity of photographs selected to enhance comprehension of questions from the Preferences for Everyday Living Inventory-Nursing Home (PELI-NH) and describe themes in older adults' recommendations for revising photographic stimuli. This qualitative, cognitive interviewing study included 21 participants with an average age of 75 years and no known cognitive or communication deficits. Photographic stimuli were randomized and evaluated across one to two interview sessions. Participants were asked to describe what the preference stimuli represented to them. Responses were scored to assess face validity. Participants were then shown the PELI-NH written prompt and asked to evaluate how well the photograph(s) represented the preference. A semideductive thematic analysis was conducted on interview transcripts to summarize themes in participant feedback. Forty-six (64%) stimuli achieved face validity criteria without revisions. Six (8%) stimuli achieved face validity after one partial revision. Twenty (28%) stimuli required multiple revisions and reached feedback saturation, requiring team review for finalization. Thematic analysis revealed challenges interpreting stimuli (e.g., multiple meanings) and participant preferences for improving photographs (e.g., aesthetics). Cognitive interviewing was useful for improving face validity of stimuli pertaining to personal care topics. Abstract and subjective preferences (e.g., cultural traditions) may be more challenging to represent. This study provides a framework for further testing with older adults with cognitive, communication, and hearing impairments.

Naming Images in Aphasia: Effects of Graphic Representations and Photographs on Naming Performance in Persons With and Without Aphasia

ABSTRACT Background Picture naming is a common tool in aphasia diagnosis and therapy. However, opinions differ as to which type of image (e.g., photographs, drawings) is most suitable for naming tasks and whether there is a difference on naming correctness and latencies based on image type. Moreover, recent studies have mainly analysed colour photographs and black-and-white line drawings leaving out image types like graphic representations that apply image features that can facilitate naming such as colour, controlled size, or texture. Aims To shed more light on appropriate image types for persons with aphasia, we created graphic representations depicting nouns and verbs and compared them to photographic stimuli in a naming task including persons with aphasia (PWA) and a control group (CG). Methods & Procedures 33 PWA and 33 age matched persons (CG) participated in the study. Naming correctness and latencies were measured in two different conditions: concepts depicted as coloured photographs vs. as graphic representations. 128 pictures of linguistically controlled German-language concepts (64 nouns, 64 verbs) had to be named. The designed graphic stimuli were developed by professional designers based on photographs. The photographs were selected from stock image databases according to a defined image concept. This image concept was based on empirical findings regarding image features that facilitate naming (e.g., colour, texture, shading) and was applied to the selection of the photographs as well as to the creation of the graphic representations. The images were presented in pseudo-randomized sequences on a tablet and all reactions of the participants were videotaped. The data from the main study was analysed using generalized linear mixed models (GLMM) and linear mixed models (LMM). Outcomes & Results Our analysis showed no significant difference in naming correctness and latencies between photographic and graphic stimuli. On average, PWA named terms presented as graphical representations more correctly than the photographs. But this difference was below the significance level. Conclusions In our study we showed that graphic representations, when including image features that facilitate naming like colour, texture, and shading, can evoke the same naming performance as photographs. Graphic representations can thus be used in combination with photographs in an image set, especially when depicting concepts that benefit from reduced representation, e.g., verbs. We therefore advocate the transparent and methodologically stringent implementation of image features that facilitate naming when creating image stimuli.

Insular activation and functional connectivity in firefighters with post-traumatic stress disorder.

Firefighters are frequently exposed to stressful situations and are at high risk of developing post-traumatic stress disorder (PTSD). Hyperresponsiveness to threatening and emotional stimuli and diminishment of executive control have been suggested as manifestations of PTSD. To examine brain activation in firefighters with PTSD by conducting an executive control-related behavioural task with trauma-related interferences. Twelve firefighters with PTSD and 14 healthy firefighters underwent functional magnetic resonance imaging (fMRI) while performing a Stroop match-to-sample task using trauma-related photographic stimuli. Seed-based functional connectivity analysis was conducted using regions identified in fMRI contrast analysis. Compared with the controls, the participants with PTSD had longer reaction times when the trauma-related interferences were presented. They showed significantly stronger brain activation to interfering trauma-related stimuli in the left insula, and had weaker insular functional connectivity in the supplementary motor area and the anterior cingulate cortex than the controls. They also showed a significant correlation between left insula-supplementary motor area connectivity strength and the hyperarousal subscale of the Clinician-Administered PTSD Scale. Our findings indicate that trauma-related stimuli elicit excessive brain activation in the left insula among firefighters with PTSD. Firefighters with PTSD also appear to have weak left insular functional connectivity with executive control-related brain regions. This aberrant insular activation and functional connectivity could be related to the development and maintenance of PTSD symptoms in firefighters.

Cued recall: Using photo-elicitation to examine the distributed processes of remembering with photographs

In studies of cued recall, responses to photographic stimuli have often been examined in isolation of related photography practices (e.g. taking, organising, or sharing images), and without considering how photographs are used. In contrast, photo-elicitation methods position photographs not simply as cues, but as meaningful artefacts around which accounts of the past are constructed. Drawing on photo-elicitation interviews, I examine cued recall from a distributed cognition perspective, proposing that it consists of varying combinations of several, potentially-distributed processes. First, looking at photographs can catalyse remembering by surfacing relevant ideas, followed by: stimulation (of feelings and emotions), simulation and narrative production, association, inference, and meaning-making. Using examples from my interviews, I consider how each process is socially and materially configured. I then discuss the role of diverse photographic practices in the convergence of these processes, and the implications for conceptions of cueing, recall, and autobiographical memory.

E-Inclusion: Defining Basic Image Properties for Illustrated Stimuli in Aphasia Treatment

Word production is stimulated by images in treatment processes for people with aphasia (Heuer & Hallowell, 2007). Although stimulation through pictorial stimuli has a long tradition in aphasia therapy, there is a lack in research on which image stimuli are the most suitable for this purpose (Brown & Thiessen, 2018). Current research assumes that stimulation via photographic images evokes better and more direct retrieve of searched words, than stimulation by illustrations (Heuer, 2016). However, the illustrations investigated so far mostly comprise black and white line drawings and there are hardly any studies investigating possible effects of different image parameters as style, image cropping or perspective in relation to clear naming. We developed a visual concept of illustrated images enabling clear determinability of activities and objects. The 128 designed stimuli that meet linguistic research criteria were named by 62 students regarding "name agreement" and evaluated on a 5-point scale with respect to "visual complexity" and "image agreement". The illustrated images will be examined in a following study regarding the correctness of the naming by persons with aphasia and be compared with corresponding photographic stimuli. The analysis presented here is part of the study E-Inclusion, an interdisciplinary project that includes researchers in life science technology, linguistics and speech therapy as well as image research from the University of Applied Sciences and Art Northwestern Switzerland (FHNW).

Positional inference in rhesus macaques.

Understanding how organisms make transitive inferences is critical to understanding their general ability to learn serial relationships. In this context, transitive inference (TI) can be understood as a specific heuristic that applies broadly to many different serial learning tasks, which have been the focus of hundreds of studies involving dozens of species. In the present study, monkeys learned the order of 7-item lists of photographic stimuli by trial and error, and were then tested on "derived" lists. These derived test lists combined stimuli from multiple training lists in ambiguous ways, sometimes changing their order relative to training. We found that subjects displayed strong preferences when presented with novel test pairs, even when those pairs were drawn from different training lists. These preferences were helpful when test pairs had an ordering congruent with their ranks during training, but yielded consistently below-chance performance when pairs had an incongruent order relative to training. This behavior can be explained by the joint contributions of transitive inference and another heuristic that we refer to as "positional inference." Positional inferences play a complementary role to transitive inferences in facilitating choices between novel pairs of stimuli. The theoretical framework that best explains both transitive and positional inferences is a spatial model that represents both the position of each stimulus and its uncertainty. A computational implementation of this framework yields accurate predictions about both correct responses and errors on derived lists.

Concurrent electrophysiological recording and cognitive testing in a rodent touchscreen environment

Challenges in therapeutics development for neuropsychiatric disorders can be attributed, in part, to a paucity of translational models capable of capturing relevant phenotypes across clinical populations and laboratory animals. Touch-sensitive procedures are increasingly used to develop innovative animal models that better align with testing conditions used in human participants. In addition, advances in electrophysiological techniques have identified neurophysiological signatures associated with characteristics of neuropsychiatric illness. The present studies integrated these methodologies by developing a rat flanker task with electrophysiological recordings based on reverse-translated protocols used in human electroencephalogram (EEG) studies of cognitive control. Various touchscreen-based stimuli were evaluated for their ability to efficiently gain stimulus control and advance to flanker test sessions. Optimized stimuli were then examined for their elicitation of prototypical visual evoked potentials (VEPs) across local field potential (LFP) wires and EEG skull screws. Of the stimuli evaluated, purple and green photographic stimuli were associated with efficient training and expected flanker interference effects. Orderly stimulus-locked outcomes were also observed in VEPs across LFP and EEG recordings. These studies along with others verify the feasibility of concurrent electrophysiological recordings and rodent touchscreen-based cognitive testing and encourage future use of this integrated approach in therapeutics development.

The Relation Between Anti-Fat Stereotypes and Anti-Fat Prejudices: The Role of Gender as a Moderator

Research suggests that people attribute more negative traits to individuals with obesity than to non-obese individuals, and that females with obesity are seen more negatively than males. The theory also suggests that stereotypes are cognitive predecessors of prejudices. The aims of this research were to examine the latent structure underlying anti-fat stereotypical traits, differences in perceiving individuals with obesity and non-obese individuals, male and female individuals with obesity, as well as the role of anti-fat stereotypes in anti-fat prejudices. The sample consisted of 106 respondents (Male = 16; Female = 86; Mean age = 19.98), who graded stimuli photographs of male and female individuals (with obesity and average-weight) on series of anti-fat stereotypical traits on two occasions, and filled in Anti-fat prejudices questionnaire. The data were analyzed through EFA and CFA, ANOVA, and structural equation modeling (moderation). Four factors behind stereotypical traits were extracted: Positive social image, Perceived lack of self-care, Perceived persistence, and Antipathy. It has been shown that respondents gave stimuli photographs of individuals with obesity lower scores on Positive social image and Perceived persistence, and higher scores on Perceived lack of self-care and Antipathy. The same results were obtained for females within the subsample of individuals with obesity. Furthermore, it has been shown that certain anti-fat stereotypes (Positive social image, Perceived lack of self-care, and Perceived persistence) predict anti-fat prejudices, and that gender was a significant moderator of the effect of Perceived lack of self-care on anti-fat prejudices. We can conclude that individuals with obesity are indeed seen in a more negative light than non-obese individuals, and that this is more pronounced for females with obesity, which is in accordance with previous studies. Moreover, the results suggest the possible role of anti-fat stereotypes as cognitive predecessors of anti-fat prejudices, and that gender of individuals with obesity has an effect on this relationship.

Global Saccadic Eye Movements Characterise Artists’ Visual Attention While Drawing

Previous research has shown that artists employ flexible attentional strategies during offline perceptual tasks. The current study explored visual processing online, by tracking the eye movements of artists and non-artists (n=65) while they produced representational drawings of photographic stimuli. The findings revealed that it is possible to differentiate artists from non-artists on the basis of the relative amount of global-to-local saccadic eye movements they make when looking at the target stimulus while drawing, but not in a preparatory free viewing phase. Results indicated that these differences in eye movements are not specifically related to representational drawing ability, and may be a feature of artistic ability more broadly. This eye movement analysis technique may be used in future research to characterise the dynamics of attentional shifts in eye movements while artists are carrying out a range of artistic tasks.

The Varying Coherences of Implied Motion Modulates the Subjective Time Perception.

Previous research has demonstrated that duration of implied motion (IM) was dilated, whereas hMT+ activity related to perceptual processes on IM stimuli could be modulated by their motion coherence. Based on these findings, the present study aimed to examine whether subjective time perception of IM stimuli would be influenced by varying coherence levels. A temporal bisection task was used to measure the subjective experience of time, in which photographic stimuli showing a human moving in four directions (left, right, toward, or away from the viewer) were presented as probe stimuli. The varying coherence of these IM stimuli was manipulated by changing the percentage of pictures implying movement in one direction. Participants were required to judge whether the duration of probe stimulus was more similar to the long or short pre-presented standard duration. As predicted, the point of subjective equality was significantly modulated by the varying coherence of the IM stimuli, but not for no-IM stimuli. This finding suggests that coherence level might be a key mediating factor for perceived duration of IM images, and top-down perceptual stream from inferred motion could influence subjective experience of time perception.

The Costs and Benefits of Goal-Directed Attention in Deep Convolutional Neural Networks

People deploy top-down, goal-directed attention to accomplish tasks, such as finding lost keys. By tuning the visual system to relevant information sources, object recognition can become more efficient (a benefit) and more biased toward the target (a potential cost). Motivated by selective attention in categorisation models, we developed a goal-directed attention mechanism that can process naturalistic (photographic) stimuli. Our attention mechanism can be incorporated into any existing deep convolutional neural networks (DCNNs). The processing stages in DCNNs have been related to ventral visual stream. In that light, our attentional mechanism incorporates top-down influences from prefrontal cortex (PFC) to support goal-directed behaviour. Akin to how attention weights in categorisation models warp representational spaces, we introduce a layer of attention weights to the mid-level of a DCNN that amplify or attenuate activity to further a goal. We evaluated the attentional mechanism using photographic stimuli, varying the attentional target. We found that increasing goal-directed attention has benefits (increasing hit rates) and costs (increasing false alarm rates). At a moderate level, attention improves sensitivity (i.e. increases d^{prime }) at only a moderate increase in bias for tasks involving standard images, blended images and natural adversarial images chosen to fool DCNNs. These results suggest that goal-directed attention can reconfigure general-purpose DCNNs to better suit the current task goal, much like PFC modulates activity along the ventral stream. In addition to being more parsimonious and brain consistent, the mid-level attention approach performed better than a standard machine learning approach for transfer learning, namely retraining the final network layer to accommodate the new task.

Correction to: Using a Touchscreen Paradigm to Evaluate Food Preferences and Response to Novel Photographic Stimuli of Food in Three Primate Species (Gorilla gorilla gorilla, Pan troglodytes, and Macaca fuscata)

Understanding captive animals’ preferences is important for their care and management. However, pairwise testing for preference can be time consuming, open to bias, and typically restricted to stimuli that can be presented manually. We tested the efficacy of using touchscreens to test zoo-housed primates’ food preferences and evaluated the primates’ understanding and interpretation of photographic stimuli. We showed 18 subjects (six gorillas, five chimpanzees, and seven Japanese macaques) four food stimuli (digital photographs of familiar foods presented via touchscreens) to test their preferences in a forced-choice paradigm. We presented preliminary single-food training trials before paired forced-choice test trials, which revealed subjects’ relative preferences for the four foods. To distinguish whether the primates’ responses represented conditioned associations between the stimuli and rewards, or a true understanding of the food photographs, we ran a follow-up study with novel stimuli (novel photographs of familiar foods). We combined the two novel stimuli with the four stimuli presented in the first experiment in pairwise forced-choice trials (importantly, without training trials). Subjects did not preferentially select or avoid the novel stimuli, suggesting they spontaneously interpreted the stimuli without training. While there was interindividual variation in preferences, subject choices were consistent across studies, even with the addition of novel stimuli. These results suggest that preferences for a variety of stimuli could be tested quickly, efficiently, and accurately using touchscreens.

Can compassion, happiness and sympathetic concern be differentiated on the basis of facial expression?

ABSTRACT Recent research has demonstrated the importance of positive emotions, and especially compassion, for well-being. Via two investigations, we set out to determine if facial expressions of happiness, “kind” compassion and sympathetic concern can be distinguished, given limitations of previous research. In investigation one, prototypes of the three expressions were analysed for similarities and differences using the facial action coding system (FACS) by two certified independent coders. Results established that each expression comprised distinct FACS units. Thus, in investigation 2, a new photographic stimulus set was developed using a gender/racially balanced group of actors to pose these expressions of “kind” compassion, happiness, sympathetic concern, and the face in a relaxed/neutral pose. 75 participants were then asked to name the FACS generated expressions using not only forced categorical quantitative ratings but, importantly, free response. Results revealed that kind compassionate facial expressions: (i) engendered words associated with contented and affiliative emotions (although, interestingly, not the word “kind”); (ii) were labelled as compassionate significantly more often than any of the other emotional expressions; but (iii) in common with happiness expressions, engendered happiness word groupings and ratings. Findings have implications for understandings of positive emotions, including specificity of expressions and their veridicality.

Neural mechanisms of perceptive and affective processing of body stimuli in anorexia nervosa – are there developmental effects?

Different components of body image processing seem to be reflected by different neural mechanisms. A core symptom of Anorexia nervosa (AN) is a disturbance of body image with correlates found on a neural level. The present study focuses on the neural processing of visual body stimuli of different weight categories in adolescent and adult AN patients.Thirty-three adolescents aged 12–18 years (15 AN patients, 18 control participants) and 36 adult women (19 AN patients, 17 control participants) underwent functional magnetic resonance imaging (fMRI) while performing a perceptive and an affective body image task involving photographic stimuli of women belonging to different BMI categories.Differential effects on activation, depending on the BMI of the women shown in the pictures, were found in frontal brain regions, the thalamus, the caudate and the fusiform gyrus. Group effects differentiating between AN patients and control participants were seen mainly in the caudate and insula. No significant developmental effect was seen.During a perceptive task, diminished activation of regions involved in perceptive and evaluative functions as well as emotional reasoning was seen in AN. During an affective task there was a tendency towards activation differences reflecting reduced ability of size estimation and impaired integration of visual and body perception with emotions.

Using a Touchscreen Paradigm to Evaluate Food Preferences and Response to Novel Photographic Stimuli of Food in Three Primate Species (Gorilla gorilla gorilla, Pan troglodytes, and Macaca fuscata)

In the original version of our methods, we incorrectly stated the size of the Japanese macaques’ exhibit at Lincoln Park Zoo.