Revisiting scene primes for object locations

Sanocki and Epstein (1997) provided evidence that an immediate prior experience of a scene, as a prime, can induce representations of its spatial layout, facilitating the subsequent spatial processing of objects in the target scene. In their experiments, observers responded to target scenes by indicating which of two critical objects was closer in the pictorial space. Reaction times to target scenes that were preceded by same-scene primes without the critical objects were faster than reaction times to target scenes that were preceded by different scene or control primes (geometrical figures). By manipulating the nature of the prime and the interval between prime and target, and by cueing the position of the critical objects, we obtain evidence that the facilitating effect of the same-scene primes can also be explained by the sudden appearance of the critical objects in the target scene. In same-scene conditions, the critical objects cause a local onset, whereas in different-scene and control conditions the entire target scene causes a global onset. As a result, the local onset in the same-scene condition produces a shift of attention towards the critical objects, resulting in faster processing of the critical objects.     

Looking away from death: Defensive attention as a form of terror management

Previous research has suggested that the physical aspects of human nature in general, and physical human frailties in particular become disagreeable and repugnant following death primes. The current research tested this hypothesis in two studies using an eye-tracking methodology. Participants were subliminally primed with death or with a control word and then viewed a series of arrays containing four pictures each, during which their eye-movements were monitored. In Study 1, the arrays included pictures of physical injury or neutral objects, and in Study 2 pictures of physical injury, threatening images, and neutral objects. The results indicated that in both studies death primes significantly decreased gaze duration towards pictures of physical injury, and did not have a significant effect on gaze duration towards neutral images. However, in Study 2 death primes increased gaze duration towards threatening images. The discussion examines the role of motivated unconscious attention in terror management processes.     

What is a nice smile like that doing in a place like this? Automatic affective responses to environments influence the recognition of facial expressions

An affective priming paradigm with pictures of environmental scenes and facial expressions as primes and targets, respectively, was employed in order to investigate the role of natural (e.g., vegetation) and built elements (e.g., buildings) in eliciting rapid affective responses. In Experiment 1, images of environmental scenes were digitally manipulated to make continua of priming pictures with a gradual increase of natural elements (and a decrease of built elements). The primes were followed by presentations of facial expressions of happiness and disgust as to-be-recognized target stimuli. The recognition times of happy faces decreased and the recognition times of disgusted faces increased as the quantity of natural/built material present in the primes increased/decreased. The physical changes also influenced the evaluated restorativeness and affective valence of the primes. In Experiment 2, the primes used in Experiment 1 were manipulated in such a way that they were void of any recognizable natural or built elements but contained either similar colours or similar shapes as primes in Experiment 1. This time the results showed no effect of priming. These results were interpreted to give support for a view that the priming effect by environmental pictures is due to the primes representing environmental scenes and not due to the presence of certain low-level colour or shape information in the primes. In all, the present results provide evidence that perception of environmental scenes elicits automatic affective responses and influences recognition of facial expressions.     

Recognising the forest, but not the trees: an effect of colour on scene perception and recognition

Colour has been shown to facilitate the recognition of scene images, but only when these images contain natural scenes, for which colour is 'diagnostic'. Here we investigate whether colour can also facilitate memory for scene images, and whether this would hold for natural scenes in particular. In the first experiment participants first studied a set of colour and greyscale natural and man-made scene images. Next, the same images were presented, randomly mixed with a different set. Participants were asked to indicate whether they had seen the images during the study phase. Surprisingly, performance was better for greyscale than for coloured images, and this difference is due to the higher false alarm rate for both natural and man-made coloured scenes. We hypothesized that this increase in false alarm rate was due to a shift from scrutinizing details of the image to recognition of the gist of the (coloured) image. A second experiment, utilizing images without a nameable gist, confirmed this hypothesis as participants now performed equally on greyscale and coloured images. In the final experiment we specifically targeted the more detail-based perception and recognition for greyscale images versus the more gist-based perception and recognition for coloured images with a change detection paradigm. The results show that changes to images are detected faster when image-pairs were presented in greyscale than in colour. This counterintuitive result held for both natural and man-made scenes (but not for scenes without nameable gist) and thus corroborates the shift from more detailed processing of images in greyscale to more gist-based processing of coloured images.     

The influence of color on the perception of scene gist

In 3 experiments the authors used a new contextual bias paradigm to explore how quickly information is extracted from a scene to activate gist, whether color contributes to this activation, and how color contributes, if it does. Participants were shown a brief presentation of a scene followed by the name of a target object. The target object could be consistent or inconsistent with scene gist but was never actually present in the scene. Scene gist activation was operationalized as the degree to which participants respond "yes" to consistent versus inconsistent objects, reflecting a response bias produced by scene gist. Experiment 1 demonstrated that scene gist is activated after a 42-ms exposure and that the strength of the activation increases with longer presentation durations. Experiments 2 and 3 explored the contribution of color to the activation of scene gist. The results revealed that color has an influence across a wide variety of scenes and is directly associated with scene gist.     

Gist perception requires attention

Four experiments (240 subjects) explored gist perception without attention using the Mack and Rock (1998) cross task. Twelve scenes were flashed under conditions of inattention, divided, and full attention. Subjects described what they saw on critical trials in which a scene was flashed with the cross. In Experiments 3 and 4 subjects also chose the scene from a four scene array. In Experiment 4 the critical scenes were shown twice in the inattention condition. Overall, only 17% reported gist in the inattention condition, 65% did so with divided, and 82% did so with full attention. In Experiment 4 most subjects remained inattentionally blind to the scenes even though they were shown twice, conditions which fostered repetition priming, and we found a suggestion of negative priming. The results of all 4 experiments indicate that gist requires attention.     

The role of higher order image statistics in masking scene gist recognition

In the present article, we investigated whether higher order image statistics, which are known to be carried by the Fourier phase spectrum, are sufficient to affect scene gist recognition. In Experiment 1, we compared the scene gist masking strength of four masking image types that varied in their degrees of second- and higher order relationships: normal scene images, scene textures, phase-randomized scene images, and white noise. Masking effects were the largest for masking images that possessed significant higher order image statistics (scene images and scene textures) as compared with masking images that did not (phase-randomized scenes and white noise), with scene image masks yielding the largest masking effects. In a control study, we eliminated all differences in the second-order statistics of the masks, while maintaining differences in their higher order statistics by comparing masking by scene textures rather than by their phase-randomized versions, and showed that the former produced significantly stronger gist masking. Experiments 2 and 3 were designed to test whether conceptual masking could account for the differences in the strength of the scene texture and phase-randomized masks used in Experiment 1, and revealed that the recognizability of scene texture masks explained just 1% of their masking variance. Together, the results suggest that (1) masks containing the higher order statistical structure of scenes are more effective at masking scene gist processing than are masks lacking such structure, and (2) much of the disruption of scene gist recognition that one might be tempted to attribute to conceptual masking is due to spatial masking.     

Does visual expertise improve visual recognition memory?

In general, humans have impressive recognition memory for previously viewed pictures. Many people spend years becoming experts in highly specialized image sets. For example, cytologists are experts at searching micrographs filled with potentially cancerous cells and radiologists are expert at searching mammograms for indications of cancer. Do these experts develop robust visual long-term memory for their domain of expertise? If so, is this expertise specific to the trained image class, or do such experts possess generally superior visual memory? We tested recognition memory of cytologists, radiologists, and controls with no medical experience for three visual stimulus classes: isolated objects, scenes, and mammograms or micrographs. Experts were better than control observers at recognizing images from their domain, but their memory for those images was not particularly good (D’ ~ 1.0) and was much worse than memory for objects or scenes (D’ > 2.0). Furthermore, experts were not better at recognizing scenes or isolated objects than control observers.     

Cortical dynamics of contextually cued attentive visual learning and search: spatial and object evidence accumulation

How do humans use target-predictive contextual information to facilitate visual search? How are consistently paired scenic objects and positions learned and used to more efficiently guide search in familiar scenes? For example, humans can learn that a certain combination of objects may define a context for a kitchen and trigger a more efficient search for a typical object, such as a sink, in that context. The ARTSCENE Search model is developed to illustrate the neural mechanisms of such memory-based context learning and guidance and to explain challenging behavioral data on positive-negative, spatial-object, and local-distant cueing effects during visual search, as well as related neuroanatomical, neurophysiological, and neuroimaging data. The model proposes how global scene layout at a first glance rapidly forms a hypothesis about the target location. This hypothesis is then incrementally refined as a scene is scanned with saccadic eye movements. The model simulates the interactive dynamics of object and spatial contextual cueing and attention in the cortical What and Where streams starting from early visual areas through medial temporal lobe to prefrontal cortex. After learning, model dorsolateral prefrontal cortex (area 46) primes possible target locations in posterior parietal cortex based on goal-modulated percepts of spatial scene gist that are represented in parahippocampal cortex. Model ventral prefrontal cortex (area 47/12) primes possible target identities in inferior temporal cortex based on the history of viewed objects represented in perirhinal cortex.     

Diagnostic colours contribute to the early stages of scene categorization: Behavioural and neurophysiological evidence

We examined the effects of colour cues on the express categorization of natural scenes. Using a go/no-go paradigm sensitive to fast recognition processes, we measured early event-related potential (ERP) correlates of scene categorization to elucidate the processing stage at which colour contributes to scene recognition. Observers were presented with scenes belonging to four colour-diagnostic categories (desert, forest, canyon and coastline). Scenes were presented in one of three forms: Diagnostically coloured, nondiagnostically coloured, or greyscale images. In a verification task, observers were instructed to respond whenever the presented stimulus matched a previously presented category name. Reaction times and accuracy were optimal when the stimuli were presented as their original diagnostically coloured version, followed by their greyscale version, and lastly by their nondiagostically coloured version. These effects were mirrored in the early (i.e., 150 ms following stimulus onset) ERP frontal correlates. Their onset was delayed for greyscale scenes compared to diagnostically coloured scenes, and for nondiagnostically coloured scenes compared to the other two conditions. Frontal ERP amplitudes also decreased for greyscale and nondiagnostically coloured scenes. Together, the results suggest that diagnostic colours are part of the scene gist responsible for express scene categorization.     

Searching in the dark: Cognitive relevance drives attention in real-world scenes

We investigated whether the deployment of attention in scenes is better explained by visual salience or by cognitive relevance. In two experiments, participants searched for target objects in scene photographs. The objects appeared in semantically appropriate locations but were not visually salient within their scenes. Search was fast and efficient, with participants much more likely to look to the targets than to the salient regions. This difference was apparent from the first fixation and held regardless of whether participants were familiar with the visual form of the search targets. In the majority of trials, salient regions were not fixated. The critical effects were observed for all 24 participants across the two experiments. We outline a cognitive relevance framework to account for the control of attention and fixation in scenes.     

Infants detect changes in everyday scenes: The role of scene gist

When watching physical events, infants bring to bear prior knowledge about objects and readily detect changes that contradict physical rules. Here we investigate the possibility that scene gist may affect infants, as it affects adults, when detecting changes in everyday scenes. In Experiment 1, 15-month-old infants missed a perceptually salient change that preserved the gist of a generic outdoor scene; the same change was readily detected if infants had insufficient time to process the display and had to rely on perceptual information for change detection. In Experiment 2, 15-month-olds detected a perceptually subtle change that preserved the scene gist but violated the rule of object continuity, suggesting that physical rules may overpower scene gist in infants’ change detection. Finally, Experiments 3 and 4 provided converging evidence for the effects of scene gist, showing that 15-month-olds missed a perceptually salient change that preserved the gist and detected a perceptually subtle change that disrupted the gist. Together, these results suggest that prior knowledge, including scene knowledge and physical knowledge, affects the process by which infants maintain their representations of everyday scenes.     

Functions of parahippocampal place area and retrosplenial cortex in real-world scene analysis: An fMRI study

We used functional MRI to investigate several hypotheses concerning the functions of posterior parahippocampal cortex and retrosplenial cortex, two regions that preferentially activate to images of real-world scenes compared to images of other meaningful visual stimuli such as objects and faces. We compared activation resulting from photographs of rooms, city streets, cityscapes, and landscapes against activation to a control condition of objects. Activation in posterior parahippocampal cortex, including parahippocampal place area, was greater for all scene types than objects, and greater for scenes that clearly convey information about local three-dimensional (3-D) structure (city streets and rooms) than scenes that do not (cityscapes and landscapes). Similar differences were observed in retrosplenial cortex, though activation was also greater for city streets than rooms. These results suggest that activation in both cortical areas is primarily related to analysis or representation of local 3-D space. The results are not consistent with hypotheses that these areas reflect panoramic spatial volume, an artificial versus natural category distinction, an indoor versus outdoor distinction, or the number of explicit objects depicted in a scene image.     

Emotional scenes in peripheral vision: selective orienting and gist processing, but not content identification

Emotional-neutral pairs of visual scenes were presented peripherally (with their inner edges 5.2 degrees away from fixation) as primes for 150 to 900 ms, followed by a centrally presented recognition probe scene, which was either identical in specific content to one of the primes or related in general content and affective valence. Results indicated that (a) if no foveal fixations on the primes were allowed, the false alarm rate for emotional probes was increased; (b) hit rate and sensitivity (A') were higher for emotional than for neutral probes only when a fixation was possible on only one prime; and (c) emotional scenes were more likely to attract the first fixation than neutral scenes. It is concluded that the specific content of emotional or neutral scenes is not processed in peripheral vision. Nevertheless, a coarse impression of emotional scenes may be extracted, which then leads to selective attentional orienting or--in the absence of overt attention--causes false alarms for related probes.     

Facilitatory priming of scene layout depends on experience with the scene

Facilitatory scene priming is the positive effect of a scene prime on the immediately subsequent spatial processing of a related target, relative to control primes. In the present experiments, a large set of scenes were presented, each several times. The accuracy of a relational spatial-layout judgment was the main measure (which of two probes in a scene was closer?). The effect of scene primes on sensitivity was near zero for the first presentation of a scene; advantages for scene primes occurred only after two or three presentations. In addition, a bias effect emerged in reaction times for novel scenes. These results imply that facilitatory scene priming requires learning and is top-down in nature. Scene priming may require the consolidation of interscene relations in a memory representation.     

Directed forgetting for categorised pictures: recognition memory for perceptual details versus gist

ABSTRACT

Item-based directed forgetting (DF) was tested using 2-alternative forced-choice recognition to examine the effects of forgetting instructions on memory for perceptual detail and gist of categorised pictures of scenes and objects in three experiments. When the distractor is from the same category as the target (exemplar test condition), discrimination must be based on memory for perceptual details, whereas recognition can be based on gist or general category information when the distractor is from a novel category (novel test condition). Recognition accuracy was greater for Remember-cued than Forget-cued pictures when discrimination must be based on perceptual details in the exemplar test condition but not when discrimination could be based on gist in the novel test condition. Accuracy in scene and object recognition is greater for gist than for perceptual details, and DF instructions serve to reduce recognition memory based on perceptual details.     

Direct versus indirect processing changes the influence of color in natural scene categorization

We examined whether participants would use a negative priming (NP) paradigm to categorize color and grayscale images of natural scenes that were presented peripherally and were ignored. We focused on (1) attentional resources allocated to natural scenes and (2) direct versus indirect processing of them. We set up low and high attention-load conditions, based on the set size of the searched stimuli in the prime display (one and five). Participants were required to detect and categorize the target objects in natural scenes in a central visual search task, ignoring peripheral natural images in both the prime and probe displays. The results showed that, irrespective of attention load, NP was observed for color scenes but not for grayscale scenes. We did not observe any effect of color information in central visual search, where participants responded directly to natural scenes. These results indicate that, in a situation in which participants indirectly process natural scenes, color information is critical to object categorization, but when the scenes are processed directly, color information does not contribute to categorization.     

The cortical basis of visual scene processing

Several lines of evidence suggest that the human brain contains special-purpose machinery for processing information about visual scenes. In particular, a region in medial occipitotemporal cortex—the “parahippocampal place area”, or PPA—represents the geometric structure of scenes as defined primarily by their background elements. Neuroimaging studies have demonstrated that the PPA responds preferentially to scenes but not to the objects within them, while neuropsychological studies have shown that damage to this region leads to an impaired ability to learn new scenes. More recent evidence suggests that the PPA encodes novel scenes in a viewpoint-specific manner and that these codes are more reliable in good navigators than bad navigators. The PPA may be part of a larger network of regions involved in processing navigationally relevant spatial information. The role of this region in place recognition and gist comprehension is also discussed.     

Mental layout extrapolations prime spatial processing of scenes

Four experiments examined whether scene processing is facilitated by layout representation, including layout that was not perceived but could be predicted based on a previous partial view (boundary extension). In a priming paradigm (after Sanocki, 2003), participants judged objects' distances in photographs. In Experiment 1, full scenes (target), partial scenes, and two control primes were used. Partial scenes excluded the target objects' locations, but these areas could be predicted. Full and partial scenes produced equal performance facilitation. In Experiment 2, task-irrelevant partial scene primes were also tested. These primes did not facilitate performance (i.e. simple scene previews did not help). Experiment 3 showed that a partial prime's utility depended on the area of the scene that would be tested; the task-irrelevant primes used in Experiment 2 were useful for other distance judgments. Experiment 4 showed that partial scene facilitation is not limited to the area immediately surrounding the prime. The study demonstrated that perceived and mentally extrapolated layouts are equally effective.