The development of visual cognition: The emergence of spatial congruency bias.

In adults, spatial location plays a special role in visual object processing. People are more likely to judge two sequentially presented objects as being identical when they appear in the same location compared to in different locations (a phenomenon referred to as Spatial Congruency Bias [SCB]). However, no comparable Identity Congruency Bias (ICB) is found, suggesting an asymmetric location-identity relationship in object binding. What gives rise to this asymmetric congruency bias? This paper considered two possible hypotheses. Hypothesis 1 suggests that the asymmetric congruency bias results from an inherently special role of location in the visual system. In contrast, Hypothesis 2 suggests that the asymmetric congruency bias is a product of development, reflecting people's experience with the world. To distinguish the two hypotheses, we tested both adults' and 5-year-old children's SCB and ICB by Identity Judgment Experiments and Spatial Judgment Experiments, respectively. The study found that adults only exhibited a SCB, but no ICB. However, young children exhibited both SCB and ICB, suggesting a symmetric congruency bias and reciprocal influences between location and identity in early development. The results indicate that the asymmetric location-identity relationship develops as object identity's influence on location gets pruned away, while location's influence on identity is preserved, possibly due to people's gained experiences with regularities of the world. RESEARCH HIGHLIGHTS: Adults exhibit Spatial Congruency Bias-an asymmetric location-identity relationship with location biasing their judgment of object identities, but not vice versa. Asymmetric congruency bias may result from an inherently special role of location in visual system (Hypothesis 1) or accumulated experiences with the world (Hypothesis 2). To distinguish the two hypotheses, the study investigated the Spatial Congruency Bias and Identity Congruency Bias in both adults and 5-year-old children. Unlike adults who exhibited only Spatial Congruency Bias, 5-year-old children exhibited both Spatial Congruency Bias and Identity Congruency Bias.

The influence of object-location binding mental load effects on the visual N1 and N2 Event-related Potentials.

OBJECTIVE: This study aimed to analyze the effect of object-location binding on the visual working memory workload. For this study, thirty healthy subjects were recruited, and they performed the "What was where" task, which was modified to evaluated object-location binding memory. We analyzed their ERP and behavior response. RESULTS: Object memory and location memory were preserved during the task, but binding memory decreased significantly when more than four objects were presented. These results indicate that the N1 amplitude is related to the object-only load effect, and the posterior N2 amplitude is a binding-dependent ERP component.

Differences in Encoding Strategy as a Potential Explanation for Age-Related Decline in Place Recognition Ability.

The ability to recognise places is known to deteriorate with advancing age. In this study, we investigated the contribution of age-related changes in spatial encoding strategies to declining place recognition ability. We recorded eye movements while younger and older adults completed a place recognition task first described by Muffato et al. (2019). Participants first learned places, which were defined by an array of four objects, and then decided whether the next place they were shown was the same or different to the one they learned. Places could be shown from the same spatial perspective as during learning or from a shifted perspective (30° or 60°). Places that were different to those during learning were changed either by substituting an object in the place with a novel object or by swapping the locations of two objects. We replicated the findings of Muffato et al. (2019) showing that sensitivity to detect changes in a place declined with advancing age and declined when the spatial perspective was shifted. Additionally, older adults were particularly impaired on trials in which object locations were swapped; however, they were not differentially affected by perspective changes compared to younger adults. During place encoding, older adults produced more fixations and saccades, shorter fixation durations, and spent less time looking at objects compared to younger adults. Further, we present an analysis of gaze chaining, designed to capture spatio-temporal aspects of gaze behaviour. The chaining measure was a significant predictor of place recognition performance. We found significant differences between age groups on the chaining measure and argue that these differences in gaze behaviour are indicative of differences in encoding strategy between age groups. In summary, we report a direct replication of Muffato et al. (2019) and provide evidence for age-related differences in spatial encoding strategies, which are related to place recognition performance.

Evidence for age-related deficits in object-location binding during place recognition.

Deciding whether a place is the same or different than places encountered previously is a common task in daily navigation which requires to develop knowledge about the locations of objects (object-location binding) and to recognize places from different perspectives. These abilities rely on hippocampal functioning which is susceptible to increasing age. Thus, the question of the present study is how they both together impact on place recognition in aging. Forty people aged 20-29, 44 aged 60-69, and 32 aged 70-79 were presented with places consisting of four different objects during the encoding phase. In the test phase, they were then presented with a second place and had to decide whether it was the same or different. Test places were presented from different perspectives (0°, 30°, 60°) and with different object conditions (same, a swap of two objects, a substitution with a novel object). The sensitivity for detecting changes (d') decreased from 20-29 to 60-69 and to 70-79 years old, and with increasing perspective shifts. Importantly, older adults were less sensitive to object swapping than to object substitution, while young participants did not show any difference. Overall, these results suggest specific age-related difficulties in object-location binding in the context of place recognition.

The effects of changes in object location on object identity detection: A simultaneous EEG-fMRI study.

Object identity and location are bound together to form a unique integration that is maintained and processed in visual working memory (VWM). Changes in task-irrelevant object location have been shown to impair the retrieval of memorial representations and the detection of object identity changes. However, the neural correlates of this cognitive process remain largely unknown. In the present study, we aim to investigate the underlying brain activation during object color change detection and the modulatory effects of changes in object location and VWM load. To this end we used simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) recordings, which can reveal the neural activity with both high temporal and high spatial resolution. Subjects responded faster and with greater accuracy in the repeated compared to the changed object location condition, when a higher VWM load was utilized. These results support the spatial congruency advantage theory and suggest that it is more pronounced with higher VWM load. Furthermore, the spatial congruency effect was associated with larger posterior N1 activity, greater activation of the right inferior frontal gyrus (IFG) and less suppression of the right supramarginal gyrus (SMG), when object location was repeated compared to when it was changed. The ERP-fMRI integrative analysis demonstrated that the object location discrimination-related N1 component is generated in the right SMG.

Sex differences of cognitive load effects on object-location binding memory.

In this study, we investigated where the sex differences of object-location binding memory performance were influenced by the cognitive load. We used the fractal objects version of the 'What was where?' task to measure object memory, location memory and objection-location binding memory. Cognitive load was controlled by task difficulty presented two sessions: one session randomly displayed three or four fractal objects (Session 34) and the other session four or five objects (Session 45). The results showed that females outperformed males on object-location binding memory. Interestingly, even when the four object trials were compared between Session 34 and Session 45, in which we believed that the level of difficulty was similar while cognitive load varied, the swap error of males was significantly increased in Session 45 compared to females. In conclusion, there may be sex differences in object-location binding memory and the males could be more sensitive about the cognitive load than females.

Feature-location binding in 3D: Feature judgments are biased by 2D location but not position-in-depth.

A fundamental aspect of human visual perception is the ability to recognize and locate objects in the environment. Importantly, our environment is predominantly three-dimensional (3D), but while there is considerable research exploring the binding of object features and location, it is unknown how depth information interacts with features in the object binding process. A recent paradigm called the spatial congruency bias demonstrated that 2D location is fundamentally bound to object features, such that irrelevant location information biases judgments of object features, but irrelevant feature information does not bias judgments of location or other features. Here, using the spatial congruency bias paradigm, we asked whether depth is processed as another type of location, or more like other features. We initially found that depth cued by binocular disparity biased judgments of object color. However, this result seemed to be driven more by the disparity differences than the depth percept: Depth cued by occlusion and size did not bias color judgments, whereas vertical disparity information (with no depth percept) did bias color judgments. Our results suggest that despite the 3D nature of our visual environment, only 2D location information - not position-in-depth - seems to be automatically bound to object features, with depth information processed more similarly to other features than to 2D location.

The effect of gaze direction on the different components of visuo-spatial short-term memory.

Cerebral asymmetries and cortical regions associated with the upper and lower visual field were investigated using shifts of gaze. Earlier research suggests that gaze shifts to the left or right increase activation of specific areas of the contralateral hemisphere. We asked whether looking at one quadrant of the visual field facilitates the recall in various visuo-spatial tasks. The different components of visuo-spatial memory were investigated by probing memory for a stimulus matrix in each quadrant of the screen. First, memory for visual images or patterns was probed with a matrix of squares that was simultaneously presented and had to be reconstructed by mouse click. Better memory performance was found in the upper left quadrant compared to the three other quadrants indicating that both laterality and elevation are important. Second, positional memory was probed by subsequently presenting squares which prevented the formation of a visual image. Again, we found that gaze to the upper left facilitated performance. Third, memory for object-location binding was probed by asking observers to associate objects to particular locations. Higher performance was found with gaze directed to the lower quadrants irrespective of lateralization, confirming that only some components of visual short-term memory have shared neural substrates.