Object-location Binding Research Articles

Early cognitive assessment in premature infants: the discriminatory value of eye-tracking vs. Bayley Scales.

The testing of visuocognitive development in preterm infants shows strong interactions between perinatal characteristics and cognition, learning and overall neurodevelopment evolution. The assessment of anticipatory gaze data of object-location bindings via eye-tracking can predict the neurodevelopment of preterm infants at the age of 3 years; little is known, however, about the early cognitive function and its assessment methods during the first year of life. The current study presents data from a novel assessment tool, a Delayed Match Retrieval (DMR) paradigm via eye-tracking was used to measure visual working memory (VWM) and attention skills. The eye-tracking task that was designed to measure infants' ability to actively localize objects and to make online predictions of object-location bindings. 63 infants participated in the study, 39 preterm infants and 24 healthy full term infants - at a corrected age of 8-9 months for premature infants and similar chronological age for full term infants. Infants were also administered the Bayley Scales of Infant and Toddler Development. The analysis of the Bayley scores showed no significant difference between the two groups while the eye-tracking data showed a significant group effect on all measurements. Moreover, preterm infants' VWM performance was significantly lower than full term's. Birth weight affected the gaze time on all Areas Of Interest (AOIs), overall VWM performance and the scores at the Cognitive Bayley subscale. Furthermore, preterm infants with fetal growth restriction (FGR) showed significant performance effects in the eye-tracking measurements but not on their Bayley scores verifying the high discriminatory value of the eye gaze data. Visual working memory and attention as measured via eye-tracking is a non-intrusive, painless, short duration procedure (approx. 4-min) was found to be a significant tool for identifying prematurity and FGR effects on the development of cognition during the first year of life. Bayley Scales alone may not pick up these deficits. Identifying tools for early neurodevelopmental assessments and cognitive function is important in order to enable earlier support and intervention in the vulnerable group of premature infants, given the associations between foundational executive functional skills and later cognitive and academic ability.

Dynamic saccade context triggers more stable object-location binding.

Our visual systems rapidly perceive and integrate information about object identities and locations. There is long-standing debate about if and how we achieve world-centered (spatiotopic) object representations across eye movements, with many studies reporting persistent retinotopic (eye-centered) effects even for higher level object-location binding. But these studies are generally conducted in fairly static experimental contexts. Might spatiotopic object-location binding only emerge in more dynamic saccade contexts? In the present study, we investigated this using the spatial congruency bias paradigm in healthy adults. In the static (single-saccade) context, we found purely retinotopic binding, as before. However, robust spatiotopic binding emerged in the dynamic saccade context (multiple frequent saccades and saccades during stimulus presentation). We further isolated specific factors that modulate retinotopic and spatiotopic binding. Our results provide strong evidence that dynamic saccade context can trigger more stable object-location binding in ecologically relevant spatiotopic coordinates, perhaps via a more flexible brain state that accommodates improved visual stability in the dynamic world. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Demands on perceptual and mnemonic fidelity are a key determinant of age-related cognitive decline throughout the lifespan.

Aging results in less detailed memories, reflecting reduced fidelity of remembered compared to real-world representations. We tested whether poorer representational fidelity across perception, short-term memory (STM), and long-term memory (LTM) are among the earliest signs of cognitive aging. Our paradigm probed target-lure object mnemonic discrimination and precision of object-location binding. Across the lifespan, cognitive deficits were observed in midlife when detailed stimulus representations were required for perceptual and short/long-term forced choice mnemonic discrimination. A continuous metric of object-location source memory combined with computational modeling demonstrated that errors in STM and LTM in middle-aged adults were largely driven by a loss of precision for retrieved memories, not necessarily by forgetting. On a trial-by-trial basis, fidelity of item and spatial information was more tightly bound in LTM compared to STM with this association being unaffected by age. Standard neuropsychological tests without demands on memory quality (digit span, verbal learning) were less sensitive to age effects than STM and LTM precision. Perceptual discrimination predicted mnemonic discrimination. Neuropsychological proxies for prefrontal executive functions correlated with STM, but not LTM fidelity. Conversely, neuropsychological indicators of hippocampal integrity correlated with mnemonic discrimination and precision of both STM and LTM, suggesting partially dissociable mechanisms of interindividual variability in STM and LTM fidelity. These findings suggest that reduced representational fidelity is a hallmark of cognitive aging across perception, STM, and LTM and can be observed from midlife onward. Continuous memory precision tasks may be promising for the early detection of subtle age-related cognitive decline. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Extended trajectory of spatial memory errors in typical and atypical development: The role of binding and precision.

Spatial reconstruction, a method for evaluating how individuals remember the placement of objects, has traditionally been evaluated through the aggregate estimation of placement errors. However, this approach may obscure the nature of task errors. Specifically, recent data has suggested the importance of examining the precision of responses, as well as absolute performance on item-context bindings. In contrast to traditional analysis approaches based on the distance between the target and the reconstructed item, in this study we further explored three types of errors (swap error, global error, and local distance) that may all contribute to the distance, with particular emphasis on swap errors and local distance due to their associations with item-context bindings and memory precision, respectively. We examined these errors in children aged 3-18 years, making comparisons between children with typical development (TD) and children with Down syndrome (DS), a population with known memory challenges. As expected, older children outperformed younger children in terms of overall memory accuracy. Of importance is that we measured uneven maturational trajectories of memory abilities across the various error types. Specifically, both remembered locations (irrespective of object identity) and swap errors (object-location binding errors) align with the overall memory accuracy. Memory precision, as measured by local distance in simpler set size 2 trials, mirrored overall memory accuracy. However, for more complex set size 3 trials, local distance remained stable before age 8 and showed age-related change thereafter. The group with DS showed reduced precision compared to a TD matched group, and measures of precision, and to a lesser extent binding errors, correlated with standard neuropsychological outcomes. Overall, our study contributed to a fine-grained understanding of developing spatial memory ability in a large sample of typical developing children and a memory impaired population. These findings contribute to a growing body of research examining precision as a key factor in memory performance.

The influence of task-irrelevant landmarks on spatiotopic localization and object-location binding

The influence of task-irrelevant landmarks on spatiotopic localization and object-location binding

The spatial layout of doorways and environmental boundaries shape the content of event memories

Physical boundaries in our environment have been observed to define separate events in episodic memory. To date, however, there is little evidence that the spatial properties of boundaries exert any control over event memories. To examine this possibility, we conducted four experiments that took manipulations involving boundaries that have been demonstrated to influence spatial representations, and adapted them for use in an episodic object memory paradigm. Here, participants were given 15 min to freely explore an environment that contained 36 objects, equally dispersed among six discriminable buildings. In a subsequent test of object-location binding, participants were required to indicate where they remembered encountering the objects. In Experiment 1 the spatial properties of the building boundaries were identical; however, in Experiment 2 the boundaries were differentiated by their geometric shape and the location of the doorways in the buildings. In the test phases of these experiments, we observed a shift from a bias towards remembering the positions of objects within a building but not the building itself (Experiment 1), to a bias towards remembering which building an object was in but not the location within the building (Experiment 2). In Experiment 3, the buildings shared the same geometry but were differentiated by the locations of doorways, and we observed no significant differences between response types. Finally, in Experiment 4, the buildings were uniquely shaped but shared the same doorway location, and we observed a bias towards remembering the positions of objects within a building. In addition, exploratory analyses of non-spatial interference revealed more correct recall for objects housed in the first building a participant visited during exploration, compared to all other buildings. Together, our data indicates that the location of doorways in boundaries and, to a lesser extent, boundary geometries influence event models, and that a primacy effect can be observed in the recall of multiple object-location bindings.

Evidence for object–place binding in pigeons in a sequence-learning procedure

We studied object–location binding in pigeons using a sequence learning procedure. A sequence of four objects was presented, one at a time at one of four locations on a touchscreen. A single peck at the object ended the trial, and food reinforcement was delivered intermittently. In Experiment 1, a between-subjects design was used to present objects, locations, or both in a regular sequence or randomly. Response time costs on nonreinforced probe tests on which object order, location order, or both were disrupted revealed sequence learning effects. Pigeons encoded location order when it was consistent, but not object order when it alone was consistent. When both were consistent, pigeons encoded both, and showed evidence of object–location binding. In Experiment 2, two groups of pigeons received training on sequences where the same object always appeared at the same location. For some pigeons a consistent sequence was used while for others sequence order was randomized. Only when sequence order was consistent was object–location binding found. These experiments are the first demonstrations of strong and lasting feature binding in pigeons and are consistent with a functional account of learning.

Consumption of a fermented dairy beverage improves hippocampal-dependent relational memory in a randomized, controlled cross-over trial

ABSTRACT Objectives: We aimed to determine whether consumption of a fermented dairy beverage containing probiotic microorganisms influences negative mood states, stress, and hippocampal memory performance in healthy adults. Methods: Adults (25-45 yrs, N = 26) free of gastrointestinal and mental illness were enrolled in a single-blind, randomized, controlled, crossover trial. Participants completed testing prior to and after 4-week consumption, with a 2–4 week washout between treatments of: (1) 8 oz of a dairy-based fermented beverage containing 25–30 billion colony forming units of live and active kefir cultures or (2) 8 oz isocaloric, non-fermented, 1% low-fat lactose-free dairy-based control beverage. Hippocampal-dependent relational memory was assessed using a spatial reconstruction task. Negative mood states of depression and anxiety were assessed using the Depression Anxiety Stress Scales-42 (DASS-42). Pooled 24-hour urine samples were analyzed using an enzyme-linked immunosorbent assay to determine urinary free-cortisol (UFC) concentrations. Fecal microbiota composition was assessed using 16S rRNA gene sequencing. Results: Lactobacillus was increased by 235% following fermented dairy consumption compared to the control (p < .01). Furthermore, the fermented dairy beverage improved performance on two metrics of relational memory, misplacement (p = .04) and object-location binding (p = .03). UFC and DASS-42 scores (all p’s > .08) were not significantly changed by either arm of the intervention. No correlations were observed between the change in Lactobacillus and memory performance. Conclusions: Fermented dairy consumption increased the presence of certain microorganisms in the gut and improved relational memory in healthy adults. However, the benefits observed for relational memory were not related to changes in Lactobacillus. Trial registration: ClinicalTrials.gov identifier: NCT02849275.

Effects of item distinctiveness on the retrieval of objects and object-location bindings from visual working memory.

Visual working memory (VWM) is prone to interference from stored items competing for its limited capacity. Distinctiveness or similarity of the items is acknowledged to affect this competition, such that poor item distinctiveness causes a failure to discriminate between items sharing common features. In three experiments, we studied how the distinctiveness of studied real-world objects (i.e., whether the objects belong to the same or different basic categories) affects the retrieval of objects themselves (simple recognition) and object-location conjunctions (information about which object was where in a display, cued recall). In Experiments 1 and 2, we found that distinctiveness did not affect memories for objects or for locations, but low-distinctive objects were more frequently reported at "swapped" locations that originally contained other objects, showing object-location memory swaps. In Experiments 3 we found that observers swapped the location of a tested object with another object from the same category more frequently than with any of the objects from another category. This suggests that more similar studied objects cause more retrieval competition in object-location judgments than in simple recognition. Additionally, we discuss a possible role of categorical labeling of locations that can support object-location retrieval when the studied objects are highly distinct.

Vividness of visual imagery questionnaire scores and their relationship to visual short-term memory performance

Mechanisms underlying visual imagery, the ability to create vivid mental representations of a scene in the absence of sensory input, remain to be fully understood. Some previous studies have proposed that visual imagery might be related to visual short-term memory (STM), with a common mechanism involving retention of visual information over short periods of time. Other observations have shown a strong relationship between visual imagery and functional activity in the hippocampus and primary visual cortex, both regions also associated with visual STM. Here we examined the relationship of visual imagery to STM and hippocampal and primary visual cortex volumes, first in a large sample of healthy people across a large age range (N = 229 behavioural data; N = 56 MRI data in older participants) and then in patients with Alzheimer's disease and Parkinson's disease (N = 19 in each group compared to 19 age-matched healthy controls).We used a variant of the “What was where?” visual object-location binding task to assess the quality of remembered information over short delays. In healthy people, no evidence of a relationship between the vividness of visual imagery and any visual STM performance parameter was found. However, there was a significant positive correlation between visual imagery and the volumes of the hippocampus and primary visual cortex. Although visual STM performance was significantly impaired in patients with Alzheimer's disease, their vividness of visual imagery scores were comparable to those of age-matched elderly controls and patients with Parkinson's disease. Despite hippocampal volumes also being reduced in Alzheimer's patients, there appeared to be no impact on their self-reported visual imagery. In conclusion, visual imagery was not significantly related to visual STM performance, either in healthy controls or Alzheimer's or Parkinson's disease but it was related to hippocampal and visual cortex volume in healthy people.

Scene grammar facilitates object-location binding in realistic scenes

Scene grammar facilitates object-location binding in realistic scenes

Visual short-term memory impairments in presymptomatic familial Alzheimer's disease: A longitudinal observational study

Visual short-term memory (VSTM) deficits including VSTM binding have been associated with Alzheimer's disease (AD) from preclinical to dementia stages, cross-sectionally. Yet, longitudinal investigations are lacking. The objective of this study was to evaluate VSTM function longitudinally and in relation to expected symptom onset in a cohort of familial Alzheimer's disease. Ninety-nine individuals (23 presymptomatic; 9 symptomatic and 67 controls) were included in an extension cross-sectional study and a sub-sample of 48 (23 presymptomatic carriers, 6 symptomatic and 19 controls), attending two to five visits with a median interval of 1.3 years, included in the longitudinal study. Participants completed the “What was where?” relational binding task (which measures memory for object identification, localisation and object-location binding under different conditions of memory load and delay), neuropsychology assessments and genetic testing. Compared to controls, presymptomatic carriers within 8.5 years of estimated symptom onset showed a faster rate of decline in localisation performance in long-delay conditions (4s) and in traditional neuropsychology measures of verbal episodic memory. This study represents the first longitudinal VSTM investigation and shows that changes in memory resolution may be sensitive to tracking cognitive decline in preclinical AD at least as early as changes in the more traditional verbal episodic memory tasks.

Memory precision of object-location binding is unimpaired in APOE ε4-carriers with spatial navigation deficits.

Research suggests that tests of memory fidelity, feature binding and spatial navigation are promising for early detection of subtle behavioural changes related to Alzheimer’s disease. In the absence of longitudinal data, one way of testing the early detection potential of cognitive tasks is through the comparison of individuals at different genetic risk for Alzheimer’s dementia. Most studies have done so using samples aged 70 years or older. Here, we tested whether memory fidelity of long-term object-location binding may be a sensitive marker even among cognitively healthy individuals in their mid-60s by comparing participants at low and higher risk based on presence of the ε4-allele of the apolipoprotein gene (n = 26 ε3ε3, n = 20 ε3ε4 carriers). We used a continuous report paradigm in a visual memory task that required participants to recreate the spatial position of objects in a scene. We employed mixture modelling to estimate the two distinct memory processes that underpin the trial-by-trial variation in localization errors: retrieval success which indexes the proportion of trials where participants recalled any information about an object’s position and the precision with which participants retrieved this information. Prior work has shown that these memory paradigms that separate retrieval success from precision are capable of detecting subtle differences in mnemonic fidelity even when retrieval success could not. Nonetheless, Bayesian analyses found good evidence that ε3ε4 carriers did not remember fewer object locations [F(1, 42) = 0.450, P = 0.506, BF01 = 3.02], nor was their precision for the spatial position of objects reduced compared to ε3ε3 carriers [F(1, 42) = 0.12, P = 0.726, BF01 = 3.19]. Because the participants in the sample presented here were a subset of a study on apolipoprotein ε4-carrier status and spatial navigation in the Sea Hero Quest game [Coughlan et al., 2019. PNAS, 116(9)], we obtained these data to contrast genetic effects on the two tasks within the same sample (n = 33). Despite the smaller sample size, wayfinding deficits among ε3ε4 carriers could be replicated [F(1, 33) = 5.60, P = 0.024, BF10 = 3.44]. Object-location memory metrics and spatial navigation scores were not correlated (all r < 0.25, P > 0.1, 0 < BF10 < 3). These findings show spared object-location binding in the presence of a detrimental apolipoprotein ε4 effect on spatial navigation. This suggests that the sensitivity of memory fidelity and binding tasks may not extend to individuals with one ε4-allele in their early to mid-60s. The results provide further support to prior proposals that spatial navigation may be a sensitive marker for the earliest cognitive changes in Alzheimer’s disease, even before episodic memory.

Different patterns of short-term memory deficit in Alzheimer's disease, Parkinson's disease and subjective cognitive impairment

It has recently been proposed that short-term memory (STM) binding deficits might be an important feature of Alzheimer's disease (AD), providing a potential avenue for earlier detection of this disorder. By contrast, work in Parkinson's disease (PD), using different tasks, has suggested that the STM impairment in this condition is characterised by increased random guessing, possibly due to fluctuating attention. In the present study, to establish whether a misbinding impairment is present in sporadic late-onset AD (LOAD) and increased guessing is a feature of PD, we compared the performance of these patient groups to two control populations: healthy age-matched controls and individuals with subjective cognitive impairment (SCI) with comparable recruitment history as patients. All participants performed a sensitive task of STM that required high resolution retention of object-location bindings. This paradigm also enabled us to explore the underlying sources of error contributing to impaired STM in patients with LOAD and PD using computational modelling of response error.Patients with LOAD performed significantly worse than other groups on this task. Importantly their impaired memory was associated with increased misbinding errors. This was in contrast to patients with PD who made significantly more guessing responses. These findings therefore provide additional support for the presence of two doubly dissociable signatures of STM deficit in AD and PD, with binding impairment in AD and increased random guessing characterising the STM deficit in PD. The task used to measure memory precision here provides an easy-to-administer assessment of STM that is sensitive to the different types of deficit in AD and PD and hence has the potential to inform clinical practice.

Reduced Dorsal Visual Oscillatory Activity During Working Memory Maintenance in the First-Episode Schizophrenia Spectrum.

Cognitive deficits in people with schizophrenia are among the hardest to treat and strongly predict functional outcome. The ability to maintain sensory precepts in memory over a short delay is impacted early in the progression of schizophrenia and has been linked to reliable neurophysiological markers. Yet, little is known about the mechanisms of these deficits. Here, we investigated possible neurophysiological mechanisms of impaired visual short-term memory (vSTM, aka working memory maintenance) in the first-episode schizophrenia spectrum (FESz) using magnetoencephalography (MEG). Twenty-eight FESz and 25 matched controls performed a lateralized change detection task where they were cued to selectively attend and remember colors of circles presented in either the left or right peripheral visual field over a 1 s delay. Contralateral alpha suppression (CAS) during the delay period was used to assess selective attention to cued visual hemifields held in vSTM. Delay-period CAS was compared between FESz and controls and between trials presenting one vs three items per visual hemifield. CAS in dorsal visual cortex was reduced in FESz compared to controls in high-load trials, but not low-load trials. Group differences in CAS were found beginning 100 ms after the disappearance of the memory set, suggesting deficits were not due to the initial deployment of attention to the cued visual hemifield prior to stimulus presentation. CAS was not greater for high-load vs low-load trials in FESz subjects, although this effect was prominent in controls. Further, lateralized gamma (34–40 Hz) power emerged in dorsal visual cortex prior to the onset of CAS in controls but not FESz. Gamma power in this cluster differed between groups at both high and low load. CAS deficits observed in FESz were correlated with change detection accuracy, working memory function, estimated IQ, and negative symptoms. Our results implicate deficits in CAS in trials requiring broad, but not narrow, focus of attention to spatially distributed objects maintained in vSTM in FESz, possibly due to reduced ability to broadly distribute visuospatial attention (alpha) or disruption of object-location binding (gamma) during encoding/consolidation. This early pathophysiology may shed light upon mechanisms of emerging working memory deficits that are intrinsic to schizophrenia.

Coding of featural information in visual working memory in 2.5-year-old toddlers

The number of objects that infants can remember in visual working memory (VWM) increases rapidly during the first few years of life (Kaldy & Leslie, 2005; Ross-Sheehy, Oakes, & Luck, 2003). However, less is understood about the representational format of VWM: whether storage is determined by fixed-precision memory slots, or the allocation of a limited continuous resource. In the current study, we adapted the Delayed Match Retrieval eye-tracking paradigm (Kaldy, Guillory, & Blaser, 2016), to test 2.5-year-old toddlers’ ability to remember three object-location bindings when the to-be-remembered objects were all unique (Experiment 1) versus when they shared features such as color or shape (Experiment 2). 2.5-year-olds succeeded in Experiment 1, but only performed marginally better than chance in Experiment 2. Interestingly, when incorrect, participants in Experiment 2 were no more likely to select a decoy item that shared a feature with the target item. It seems that the increased similarity of to-be-remembered objects did not impair memory for the objects directly, but instead increased the likelihood of catastrophic forgetting.

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.

Focused attention predicts visual working memory performance in 13-month-old infants: A pupillometric study

Attention turns looking, into seeing. Yet, little developmental research has examined the interface of attention and visual working memory (VWM), where what is seen is maintained for use in ongoing visual tasks. Using the task-evoked pupil response – a sensitive, real-time, involuntary measure of focused attention that has been shown to correlate with VWM performance in adults and older children – we examined the relationship between focused attention and VWM in 13-month-olds. We used a Delayed Match Retrieval paradigm, to test infants’ VWM for object-location bindings – what went where – while recording anticipatory gaze responses and pupil dilation. We found that infants with greater focused attention during memory encoding showed significantly better memory performance. As well, trials that ended in a correct response had significantly greater pupil response during memory encoding than incorrect trials. Taken together, this shows that pupillometry can be used as a measure of focused attention in infants, and a means to identify those individuals, or moments, where cognitive effort is maximized.

Object recognition and location: Which component of object location memory for landmarks is affected by gender? Evidence from four to ten year-old children

Memory for object location requires at least three processes: object recognition, object location, and object-location binding. Gender-related differences during childhood are still a matter of debate, especially concerning memory for object location, where females are expected to outperform males. Memory for object position is pivotal for spatial navigation and its investigation during childhood is crucial in order to understand the roots of gender-related differences in spatial orientation. Actually, environmental objects, namely landmarks, can be located using egocentric and/or allocentric frames of references, as well as using the spatial translation between them. Here, we investigated gender-related differences during childhood in object recognition and location whenever a shift between egocentric and allocentric frame of reference is required. Sixty-three boys and 44 girls (aged between four and ten years old) were asked to egocentrically learn a path on the Walking Corsi Test enriched with three landmarks. Then, children were asked to recognize (object recognition) the landmarks encountered along the path and locate them (object location) on an allocentric configuration of the spatial array. Girls outperformed boys in locating landmarks, whereas no difference occurred in landmark recognition. These results provide insights into the gender-related differences in location memory of landmarks, suggesting that females are better than males in the object location component well before the age of 13.

How does aging affect the human visual short-term memory task for object-location and name-location binding?

How does aging affect the human visual short-term memory task for object-location and name-location binding?