Human gaze control during real-world scene perception

In human vision, acuity and color sensitivity are best at the point of fixation, and the visual-cognitive system exploits this fact by actively controlling gaze to direct fixation towards important and informative scene regions in real time as needed. How gaze control operates over complex real-world scenes has recently become of central concern in several core cognitive science disciplines including cognitive psychology, visual neuroscience, and machine vision. This article reviews current approaches and empirical findings in human gaze control during real-world scene perception.     

Targeting regressions: Do readers pay attention to the left?

The perceptual span during normal reading extends approximately 14 to 15 characters to the right and three to four characters to the left of a current fixation. In the present study, we investigated whether the perceptual span extends farther than three to four characters to the left immediately before readers execute a regression. We used a display-change paradigm in which we masked words beyond the three-to-four-character range to the left of a fixation. We hypothesized that if reading behavior was affected by this manipulation before regressions but not before progressions, we would have evidence that the perceptual span extends farther left before leftward eye movements. We observed significantly shorter regressive saccades and longer fixation and gaze durations in the masked condition when a regression was executed. Forward saccades were entirely unaffected by the manipulations. We concluded that the perceptual span during reading changes, depending on the direction of a following saccade.     

Semantic Informativeness Mediates the Detection of Changes in Natural Scenes

Three experiments investigated whether the semantic informativeness of a scene region (object) influences its representation between successive views. In Experiment 1, a scene and a modified version of that scene were presented in alternation, separated by a brief retention interval. A changed object was either semantically consistent with the scene (non-informative) or inconsistent (informative). Change detection latency was shorter in the semantically inconsistent versus consistent condition. In Experiment 2, eye movements were eliminated by presenting a single cycle of the change sequence. Detection accuracy was higher for inconsistent versus consistent objects. This inconsistent object advantage was obtained when the potential strategy of selectively encoding inconsistent objects was no longer advantageous (Experiment 3). These results indicate that the semantic properties of an object influence whether the representation of that object is maintained between views of a scene, and this influence is not caused solely by the differential allocation of eye fixations to the changing region. The potential cognitive mechanisms supporting this effect are discussed.     

Using real-world scenes as contextual cues for search

Research on contextual cueing has demonstrated that with simple arrays of letters and shapes, search for a target increases in efficiency as associations between a search target and its surrounding visual context are learned. We investigated whether the visual context afforded by repeated exposure to real-world scenes can also guide attention when the relationship between the scene and a target position is arbitrary. Observers searched for and identified a target letter embedded in photographs of real-world scenes. Although search time within novel scenes was consistent across trials, search time within repeated scenes decreased across repetitions. Unlike previous demonstrations of contextual cueing, however, memory for scene-target covariation was explicit. In subsequent memory tests, observers recognized repeated contexts more often than those that were presented once and displayed superior recall of target position within the repeated scenes. In addition, repetition of inverted scenes, which made the scene more difficult to identify, produced a markedly reduced rate of learning, suggesting semantic information concerning object and scene identity are used to guide attention.     

Dispersion in Cognitive Ability as a Function of Age: A Longitudinal Study of an Elderly Community Sample

This longitudinal study investigated whether age is associated with increased dispersion among major domains of cognitive ability. Three samples were examined: the full sample of 760 elderly community dwellers aged 70 years and older who were tested in 1990; a subset of the original sample who died between testing occasions; and the sample of 426 who survived with full data sets in 1994 (followed up for a mean 3.5 years). Dispersion, as measured by the within-individual standard deviation of ability scores and by the within-individual deviations from crystallized intelligence for speed, memory and spatial functioning, was significantly correlated with age in all three samples at Wave 1 and at Wave 2 (for the longitudinal sample). The rate at which dispersion increased was not significantly correlated with age. In a more detailed analysis of the 426 survivors, dispersion as a function of age was similar for demented persons within this sample, those without dementia, those with poor and excellent educational levels, and those with a physical disability. Activities of daily living was a predictor of larger-than-average changes in dispersion – but not age, education, or activity. Greater dispersion was associated with faster deterioration in memory and speed performance. Contrary to some recent reports, there was evidence for greater within-individual variability among cognitive domains in older individuals.     

Metabolic Syndrome and Cognitive Function in Healthy Middle-Aged and Older Adults without Diabetes

ABSTRACT

Objective: Few studies have addressed whether the metabolic syndrome (MetS) and its individual components are associated with cognitive function in middle-aged and older populations, as well as whether specific areas of cognition are more affected than others. We examined the cross-sectional association between MetS and six areas of cognitive function in healthy cognitively intact adults without diabetes (n?=?853, mean age 61 years) randomized in two intervention trials. Methods: The National Cholesterol Education Program (NCEP) criteria were used to identify subjects with MetS. Cognitive function was assessed with a neuropsychological battery. A principal components analysis was used to extract five uncorrelated factors interpreted to represent five areas of cognition, and a measure of global cognition was calculated. Results: MetS was weakly but non-significantly associated with lower verbal learning (β?=??.14 [SE(β)?=?0.09], p?=?.15). As the number of MetS criteria increased, scores on global cognition (p trend?=?.01), verbal learning (p trend?=?.06) and semantic memory (p trend?=?.04) decreased. Hypertension was the only MetS risk factor that was independently correlated with lower verbal learning (β?=??.17 [SE(β) =?0.08], p?=?.04), semantic memory (β?=??.26 [SE(β)?=?0.08], p?=?.001) and global cognition (β?=??.15 [SE(β)?=?0.07], p?=?.04). Conclusion: This study adds to the evidence of an association between MetS and lower cognitive function among healthy middle-aged and older adults without CVD and diabetes, as well as confirms the correlation between hypertension and lower cognition.     

Jungian analysis: An elder's perspective

Dr. Joseph L. Henderson has the richest and longest history of any analyst who trained with Jung. He is in his 97th year, in excellent health and spirit, and continues to practice daily. He was in Zürich in the 1930s when Jung was developing many of his theories in the seminars Henderson attended. Henderson trained and analyzed with Jung, although he worked with other analysts as well. He received his medical training in London. Jung asked Henderson to write a chapter in Man and His Symbols, and he has been writing ever since. He is the author of Thresholds of Initiation and other books related to Jungian psychology. After World War II, along with the late Joseph Wheelwright, Elizabeth Whitney, Jane Wheelwright, and other analysts, he co-founded the C.G. Jung Institute of San Francisco, one of two Jungian centers in the U.S. at that time. He continues to work with candidates in training to become analysts, and to help research organizations such as the Archive for Research in Archetypal Symbolism (ARAS)     

"Let's work together": what do infants understand about collaborative goals?

Collaboration is fundamental to our daily lives, yet little is known about how humans come to understand these activities. The present research was conducted to fill this void by using a novel visual habituation paradigm to investigate infants’ understanding of the collaborative-goal structure of collaborative action. The findings of the three experiments reported here suggest that 14-month-old infants understand that the actions of collaborative partners are complementary and critical to the attainment of a common collaborative goal. Importantly, 14-month-olds do not interpret the actions of two individuals in terms of a collaborative goal when their actions are not causally related. The implications of our findings for theories of collaboration and folk psychology are discussed.     

Family Functioning, Self-Concept, and Severity of Adolescent Externalizing Problems

We investigated direct and shared effects of family functioning and self-concept on the severity of adolescent externalizing problems in a sample of 224 clinically referred adolescents. Structural equation modeling (SEM) revealed strong, direct relationships between problem behaviors and both family functioning and self-concept. Using R. M. Baron and D. A. Kenny's (1986) and G. N. Holmbeck's (1997) criteria for testing mediation in SEM, family functioning partially mediated the relationship between self-concept and problem behaviors. A moderation model, testing the relationship between externalizing problems and the interaction between family functioning and self-concept, did not yield a significant effect. Our findings indicate that self-concept and family functioning exert direct and shared effects on externalizing problems and suggest that interventions for clinically referred adolescents should target both the individual adolescent and his/her family.