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.

Forest Before Trees: Letter Stimulus and Sex Modulate Global Precedence in Visual Perception

The global precedence effect (GPE), originally referring to processing hierarchical visual stimuli composed of letters, is characterised by both global advantage and global interference. We present herein a study of how this effect is modulated by the variables letter and sex. The Navon task, using the letters “H” and “S,” was administered to 78 males and 168 females (69 follicular women, 52 luteal women, and 47 hormonal contraceptive users). No interaction occurred between the letter and sex variables, but significant main effects arose from each of these. Reaction times (RTs) revealed that the letter “H” was identified more rapidly in the congruent condition both in the global and the local task, and the letter “S” in the incongruent condition for the local task. Also, although RTs showed a GPE in both males and females, males displayed shorter reaction times in both global and local tasks. Furthermore, luteal women showed higher d’ index (discrimination sensitivity) in the congruent condition for the local task than both follicular women and hormonal contraceptive users, as well as longer exploration time of the irrelevant level during the global task than males. We conclude that, according to the linear periodicity law, the GPE is enhanced for compound letters with straight vs. curved strokes, whereas it is stronger in males than in females. Relevantly, luteal phase of the menstrual cycle seems to tilt women to rely on finer grained information, thus exhibiting an analytical processing style in global/local visual processing.

The Influence of Inhibition of Return and Level-Priming on the Global Precedence Effect

The aim of the reported experiment was to investigate the effects of inhibition of return (IOR) and level-priming on the global precedence effect (GPE). The classical hierarchical stimuli combined with IOR and the level-priming paradigm were used. The participants selectively attended to the global or local features of compound numerals. The results showed that IOR inhibited the response to the global and local features; moreover, the inhibition effect on the perception of the global features was stronger than that of the local features in the stage of inhibitory processing, resulting in the disappearance of GPE. However, level-priming promoted the response to global and local features, and the promotion effect was stronger on local features, leading to the disappearance of GPE as well. These findings suggested that hierarchical processing was affected by IOR and level-priming, which were correlated with selective attention. Thus, it indicated that global precedence could be involved in attentional mechanisms.

Reasons of Diagnostic Errors and the Ways to Overcome among Medical Residents

Arriving at an accurate diagnosis is one of the competencies prime of the medical practitioner. Errors may occur in the diagnostic process anywhere from the point of patient’s initial assessment and interpretation of diagnostic tests, and even during follow-up and patient referral. Patient safety is gaining global precedence and in this context diagnostic errors are speculate as an important cause of harm to the patients.1 An awareness of the possible underlying factors leading to diagnostic errors, along with a repertoire of strategies to improve can be of great help to both junior and senior medical residents

C-07 Global Precedence: Examining Contributing Effects of Age and Cognitive Functioning

Objective Global precedence (GP) is an individual’s ability to readily identify global (gestalt) features when both global and local (internal) details are presented. Prior research shows that both age and neurodegenerative diseases, such as Alzheimer’s, affect GP. The goal of the current study is to examine differences in GP between individuals with early-onset Alzheimer’s disease (EOAD; before age 65) and healthy controls (HC). Method Fourteen EOAD patients and 6 HC’s recruited from Behavioral Neurology at an academic medical center were included in the current analysis. EOAD participants were diagnosed by clinical history, routine labs, neuroimaging, and neurological examination. Exclusion criteria included unstable medical conditions and history of severe head injury, psychotic disorder, or psychoactive substance use. All participants completed a Mini Mental Status Examination (MMSE) to assess overall cognitive functioning and a 4-item Navon's paradigm task (consisting of a larger letter whose shape is composed of smaller repeats of a different letter) to assess for GP. Results Linear regression analysis was performed, with the total score on Navon task as the dependent variable and age, MMSE score, and study group as predictor variables. Analysis yielded significant findings, suggesting a difference in GP performance between the two groups. However, coefficients suggested that while age did not contribute to the between-group difference, MMSE scores significantly accounted for our findings. In fact, when effects of MMSE scores were controlled, the between-group difference was no longer significant. Conclusion Findings suggest that individuals with EOAD perform worse on tasks of GP, which may be secondary to overall cognitive decline.