Early Electrophysiological Markers of Navigational Affordances in Scenes

Scene perception and spatial navigation are interdependent cognitive functions, and there is increasing evidence that cortical areas that process perceptual scene properties also carry information about the potential for navigation in the environment (navigational affordances). However, the temporal stages by which visual information is transformed into navigationally relevant information are not yet known. We hypothesized that navigational affordances are encoded during perceptual processing and therefore should modulate early visually evoked ERPs, especially the scene-selective P2 component. To test this idea, we recorded ERPs from participants while they passively viewed computer-generated room scenes matched in visual complexity. By simply changing the number of doors (no doors, 1 door, 2 doors, 3 doors), we were able to systematically vary the number of pathways that afford movement in the local environment, while keeping the overall size and shape of the environment constant. We found that rooms with no doors evoked a higher P2 response than rooms with three doors, consistent with prior research reporting higher P2 amplitude to closed relative to open scenes. Moreover, we found P2 amplitude scaled linearly with the number of doors in the scenes. Navigability effects on the ERP waveform were also observed in a multivariate analysis, which showed significant decoding of the number of doors and their location at earlier time windows. Together, our results suggest that navigational affordances are represented in the early stages of scene perception. This complements research showing that the occipital place area automatically encodes the structure of navigable space and strengthens the link between scene perception and navigation.

Divided attention impairs detection of simple visual features

Covert spatial attention allows us to prioritize processing at relevant locations. There is substantial evidence that perception is poorer when attention is distributed across multiple locations than when attention is focused on a single location. However, recent work suggests that may not always be the case: divided attention does not appear to impair detection of simple visual features that are represented in primary visual cortex. Here, we re-examined this possibility. In two experiments, observers detected a simple target (a vertical Gabor), and we manipulated whether attention was focused at one location (focal-cue condition) or distributed across two locations (distributed-cue condition). In Experiment 1, targets could appear independently at each location. Thus, observers needed to judge target presence for each location separately in the distributed-cue condition. Under these conditions, we found a robust cost of dividing attention. In this experiment, the cost of dividing attention could reflect either a limit in perceptual processing or a limit in decision making. Therefore, in Experiment 2, we simplified the task to more directly test whether dividing attention impairs perceptual processing of the target. Specifically, only one target could appear on each trial, such that observers made the exact same decision in both conditions (“was a target present?”). Here, we found a marginal cost of dividing attention on performance, that was weaker than the cost in Experiment 1. Together, our results suggest that divided attention does impair detection of simple visual features, but that this cost is primarily due to limits in post-perceptual decision making.

Mini-Review: practice organization beyond memory processes

Background: The benefits of variable practice in motor learning have been traditionally explained by the increased demand for memory processes induced by trial-to-trial changes. Recently, a new perspective associating increased demand for perception with variable practice has emerged. Aim: This revision aims to present and discuss the findings in this exciting topic newly opened. Results / Interpretation: In the second half of 2010’s, a number of studies have pointed out differences in perceptual processing when compared variable and repetitive practices. Different levels of (a) hemodynamic activation, (b) electroencephalographic activity, (c) neurochemical activity, and (d) oculomotor behavior have provided evidence that perceptual processes are affected differently by variable and repetitive practices.

Diverse routes to expertise in facial recognition

Facial recognition errors jeopardize national security, criminal justice, public safety and civil rights. Here, we compare the most accurate humans and facial recognition technology in a detailed lab-based evaluation and international proficiency test for forensic scientists involving 27 forensic departments from 14 countries. We find striking cognitive and perceptual diversity between naturally skilled super-recognizers, trained forensic examiners and deep neural networks, despite them achieving equivalent accuracy. Clear differences emerged in super-recognizers’ and forensic examiners’ perceptual processing, errors, and response patterns: super-recognizers were fast, biased to respond ‘same person’ and misidentified people with extreme confidence, whereas forensic examiners were slow, unbiased and strategically avoided misidentification errors. Further, these human experts and algorithms disagreed on the similarity of faces, pointing to differences in their face representations. Our findings reveal there are multiple types of facial recognition expertise, some of which are better suited to particular real-world facial recognition roles than others.

Visual Self-Misperception in Eating Disorders

Many who suffer from eating disorders claim that they see themselves as “fat”. Despite decades of research into the phenomenon, behavioural evidence has failed to confirm that eating disorders involve visual misperception of own-body size. I illustrate the importance of this phenomenon for our understanding of perceptual processing, outline the challenges involved in experimentally confirming it, and provide solutions to those challenges.

Is Artistic Composition in Abstract Art Detected Automatically?

Most artists who create abstract paintings place the pictorial elements not at random, but arrange them intentionally in a specific artistic composition. This arrangement results in a pattern of image properties that differs from image versions in which the same pictorial elements are randomly shuffled. In the article under discussion, the original abstract paintings of the author’s image set were rated as more ordered and harmonious but less interesting than their shuffled counterparts. The authors tested whether the human brain distinguishes between these original and shuffled images by recording electrical brain activity in a particular paradigm that evokes a so-called visual mismatch negativity. The results revealed that the brain detects the differences between the two types of images fast and automatically. These findings are in line with models that postulate a significant role of early (low-level) perceptual processing of formal image properties in aesthetic evaluations.

Social Meaning Brings Beauty

In the study discussed in this chapter, the authors found that concrete pictographs elicited variable aesthetic appraisals related to the aesthetic qualities of the reference objects. In addition, Chinese characters are also produced in the form of metaphorical writing symbols that convey social concepts (ideographic symbols of oracle bone script). The study investigated whether the reference social meanings altered neural responses in the aesthetic appraisal of oracle bone scripts. Similar to the findings of pictographs, the beauty judgment of positive oracle bone scripts activated the occipital lobe for perceptual processing, frontal lobe for cognitive judgment, and right putamen for rewarding experience. However, only perceptual processing regions were found in the ugly judgment of negative oracle bone scripts. Results indicated that aesthetic appraisal of oracle bone scripts mainly depended on the valence of the reference social meanings and was in accordance with the stereotype of “what is good is beautiful, and bad is ugly.”

Visual Self-Misperception in Eating Disorders

Many who suffer from eating disorders claim that they see themselves as “fat”. Despite decades of research into the phenomenon, behavioural evidence has failed to confirm that eating disorders involve visual misperception of own-body size. I illustrate the importance of this phenomenon for our understanding of perceptual processing, outline the challenges involved in experimentally confirming it, and provide solutions to those challenges.