The forest, the trees, and the leaves across adulthood: Age-related changes on a visual search task containing three-level hierarchical stimuli

Selecting relevant visual information in complex scenes by processing either global information or local parts helps us act efficiently within our environment and achieve goals. A global advantage (faster global than local processing) and global interference (global processing interferes with local processing) comprise an evidentiary global precedence phenomenon in early adulthood. However, the impact of healthy aging on this phenomenon remains unclear. As such, we collected behavioral data during a visual search task, including three-levels hierarchical stimuli (i.e., global, intermediate, and local levels) with several hierarchical distractors, in 50 healthy adults (26 younger (mean age: 26 years) and 24 older (mean age: 62 years)). Results revealed that processing information presented at the global and intermediate levels was independent of age. Conversely, older adults were slower for local processing compared to the younger adults, suggesting lower efficiency to deal with visual distractors during detail-oriented visual search. Although healthy older adults continued exhibiting a global precedence phenomenon, they were disproportionately less efficient during local aspects of information processing, especially when multiple visual information was displayed. Our results could have important implications for many life situations by suggesting that visual information processing is impacted by healthy aging, even with similar visual stimuli objectively presented.

Data Extraction and Visualization from Three-dimensional Drawings Made in Immersive Virtual Environments

One approach to characterizing human perceptual organization is to distinguish global and local processing. In visual perception, global processing enables us to extract the ‘gist’ of the visual information and local processing helps us to perceive the details. Individual differences in these two types of visual processing have been found in conditions like autism and ADHD. The Rey-Osterrieth Complex Figure (ROCF) test is commonly used to investigate differences between local and global processing. Whilst Virtual Reality (VR) has become more accessible, cheaper, and widely used in psychological research, no previous study has investigated local vs global perceptual differences using immersive technology. In this study, we investigated individual differences in local and global processing as a function of autistic and ADHD traits. The ROCF was presented in the virtual environment and a standard protocol for using the figure was followed. A novel method of quantitative data extraction was used, which will be described in this paper in greater detail. Whilst some performance differences were found between experimental conditions, no relationship was observed between these differences and participants’ levels of autistic and ADHD traits. Limitations of the study and implications of the novel methodology are discussed.

The Relationship Between Shape Perception Accuracy and Drawing Ability.

Accurate shape perception is critical for object perception, identification, manipulation, and recreation. Humans are capable of making judgements of both objective (physical) and projective (retinal) shape. Objective judgements benefit from a global approach by incorporating context to overcome the effects of viewing angle on an object’s shape, whereas projective judgements benefit from a local approach to filter out contextual information. Realistic drawing skill requires projective judgements of 3D targets to accurately depict 3D shape on a 2D surface, thus benefiting from a local approach. The current study used a shape perception task that comprehensively tests the effects of context on shape perception, in conjunction with a drawing task and several measures of local processing bias, to show that the perceptual basis of drawing skill in neurotypical adults is not due to a local processing bias but to perceptual flexibility, the ability to process local or global information as needed.

Approach for Obtaining Material Mechanical Properties in Local Region of Structure Based on Accurate Analysis of Micro-indentation Test

The hot or cold processing would induce the change and the inhomogeneous of the material mechanical properties in the local processing region of the structure, and it is difficult to obtain the specific mechanical properties in these regions by using the traditional material tensile test. To accurately get actual material mechanical properties in the local region of structure, a micro-indentation test system incorporated by an electronic universal material test device has been established. An indenter displacement sensor and a group of special micro-indenter assemblies are established. A numerical indentation inversion analysis method by using ABAQUS software is also proposed in this study. Based on the above test system and analysis platform, an approach to obtaining material mechanical properties in the local region of structures is proposed and established. The ball indentation test is performed and combined with the energy method by using various changed mechanical properties of 316L austenitic stainless steel under different elongations. The investigated results indicate that the material mechanical properties and the micro-indentation morphological changes have evidently relevance. Compared with the tensile test results, the deviations of material mechanical parameters, such as hardness H, the hardening exponent n, the yield strength σy, and others are within 5% obtained through the indentation test and the finite element analysis. It provides an effective and convenient method for obtaining the actual material mechanical properties in the local processing region of the structure.

Most Findings Obtained With Untimed Visual Illusions Are Confounded

Visual illusions have been studied extensively, but their time course has not. Here we show, in a sample of more than 550 people, that unrestricted presentation times—as opposed to presentations lasting only a single second—weaken the Ebbinghaus illusion, strengthen lightness contrast with double increments, and do not alter lightness contrast with double decrements. When presentation time is unrestricted, these illusions are affected in the same way (decrease, increase, no change) by how long observers look at them. Our results imply that differences in illusion magnitude between individuals or groups are confounded with differences in inspection time, no matter whether stimuli are evaluated in matching, adjustment, or untimed comparison tasks. We offer an explanation for why these three illusions progress differently, and we spell out how our findings challenge theories of lightness, theories of global-local processing, and the interpretation of all research that has investigated visual illusions, or used them as tools, without considering inspection time.

Using HMD Virtual Reality to investigate individual differences in visual processing styles

Global and local processing is part of human perceptual organisation, where global processing enables us to extract the ‘gist’ of the visual information and local processing helps us to perceive the details. Individual differences in these two types of visual processing have been found in autism and ADHD. Virtual Reality (VR) has become a more available method of research in the last few decades. No previous research has investigated perceptual differences using this technology. The standard ROCF test was used as a baseline task to look at a practical aspect of using VR as an experimental platform. 94 participants were tested. Attention-to-Detail, Attention Switching and Imagination subscales of AQ questionnaire were found to be predictors of organisational ROCF scores, whereas only Attention-to?Detail subscale was predictive of perceptual ROCF scores. Current study is an example of how classic psychological paradigms can be transferred into the virtual world. Further investigation of the distinct individual preferences in drawing tasks in VR could lead to a better understanding on how we process visuospatial information. As a result, such findings would inevitably extend to industrial applications.

Local Processing Bias Impacts Implicit and Explicit Memory in Autism

Autism spectrum disorder (ASD) is characterized by atypical perception, including processing that is biased toward local details rather than global configurations. This bias may impact on memory. The present study examined the effect of this perception on both implicit (Experiment 1) and explicit (Experiment 2) memory in conditions that promote either local or global processing. The first experiment consisted of an object identification priming task using two distinct encoding conditions: one favoring local processing (Local condition) and the other favoring global processing (Global condition) of drawings. The second experiment focused on episodic (explicit) memory with two different cartoon recognition tasks that favored either local (i.e., processing specific details) or a global processing (i.e., processing each cartoon as a whole). In addition, all the participants underwent a general clinical cognitive assessment aimed at documenting their cognitive profile and enabling correlational analyses with experimental memory tasks. Seventeen participants with ASD and 17 typically developing (TD) controls aged from 10 to 16 years participated to the first experiment and 13 ASD matched with 13 TD participants were included for the second experiment. Experiment 1 confirmed the preservation of priming effects in ASD but, unlike the Comparison group, the ASD group did not increase his performance as controls after a globally oriented processing. Experiment 2 revealed that local processing led to difficulties in discriminating lures from targets in a recognition task when both lures and targets shared common details. The correlation analysis revealed that these difficulties were associated with processing speed and inhibition. These preliminary results suggest that natural perceptual processes oriented toward local information in ASD may impact upon their implicit memory by preventing globally oriented processing in time-limited conditions and induce confusion between explicit memories that share common details.