Object Retrieval Task Research Articles

Integrated vision-based system for efficient, semi-automated control of a robotic manipulator

Purpose – The purpose of this paper is to develop an integrated, computer vision-based system to operate a commercial wheelchair-mounted robotic manipulator (WMRM). In addition, a gesture recognition interface system was developed specially for individuals with upper-level spinal cord injuries including object tracking and face recognition to function as an efficient, hands-free WMRM controller. Design/methodology/approach – Two Kinect® cameras were used synergistically to perform a variety of simple object retrieval tasks. One camera was used to interpret the hand gestures and locate the operator's face for object positioning, and then send those as commands to control the WMRM. The other sensor was used to automatically recognize different daily living objects selected by the subjects. An object recognition module employing the Speeded Up Robust Features algorithm was implemented and recognition results were sent as a commands for “coarse positioning” of the robotic arm near the selected object. Automatic face detection was provided as a shortcut enabling the positing of the objects close by the subject's face. Findings – The gesture recognition interface incorporated hand detection, tracking and recognition algorithms, and yielded a recognition accuracy of 97.5 percent for an eight-gesture lexicon. Tasks’ completion time were conducted to compare manual (gestures only) and semi-manual (gestures, automatic face detection, and object recognition) WMRM control modes. The use of automatic face and object detection significantly reduced the completion times for retrieving a variety of daily living objects. Originality/value – Integration of three computer vision modules were used to construct an effective and hand-free interface for individuals with upper-limb mobility impairments to control a WMRM.

Efficacy of selective PDE4D negative allosteric modulators in the object retrieval task in female cynomolgus monkeys (Macaca fascicularis).

Cyclic adenosine monophosphate (cAMP) signalling plays an important role in synaptic plasticity and information processing in the hippocampal and basal ganglia systems. The augmentation of cAMP signalling through the selective inhibition of phosphodiesterases represents a viable strategy to treat disorders associated with dysfunction of these circuits. The phosphodiesterase (PDE) type 4 inhibitor rolipram has shown significant pro-cognitive effects in neurological disease models, both in rodents and primates. However, competitive non-isoform selective PDE4 inhibitors have a low therapeutic index which has stalled their clinical development. Here, we demonstrate the pro-cognitive effects of selective negative allosteric modulators (NAMs) of PDE4D, D159687 and D159797 in female Cynomolgous macaques, in the object retrieval detour task. The efficacy displayed by these NAMs in a primate cognitive task which engages the corticostriatal circuitry, together with their suitable pharmacokinetic properties and safety profiles, suggests that clinical development of these allosteric modulators should be considered for the treatment of a variety of brain disorders associated with cognitive decline.

Age-related changes in feature-based object memory retrieval as measured by event-related potentials

To investigate neural mechanisms that support semantic functions in aging, we recorded scalp EEG during an object retrieval task in 22 younger and 22 older adults. The task required determining if a particular object could be retrieved when two visual words representing object features were presented. Both age groups had comparable accuracy although response times were longer in older adults. In both groups a left fronto-temporal negative potential occurred at around 750ms during object retrieval, consistent with previous findings (Brier, Maguire, Tillman, Hart, & Kraut, 2008). In only older adults, a later positive frontal potential was found peaking between 800 and 1000ms during no retrieval. These findings suggest younger and older adults employ comparable neural mechanisms when features clearly facilitate retrieval of an object memory, but when features yield no retrieval, older adults use additional neural resources to engage in a more effortful and exhaustive search prior to making a decision.

System Design and Implementation of UCF-MANUS—An Intelligent Assistive Robotic Manipulator

This paper reports on the system design for integrating the various processes needed for end-to-end implementation of a smart assistive robotic manipulator. Specifically, progress is reported in the empowerment of the UCF-MANUS system with a suite of sensory, computational, and multimodal interface capabilities so that its autonomy can be made accessible to users with a wide range of disabilities. Laboratory experiments are reported to demonstrate the ability of the system prototype to successfully and efficiently complete object retrieval tasks. Benchmarking of the impact of the various interface modalities on user performance is performed via empirical studies with healthy subjects operating the robot in a simulated instrumental activities of daily living tasks setup. It is seen through a analysis of the collected quantitative data that the prototype is interface neutral and shows robustness to variations in the tasks and the environment. It is also seen that the prototype autonomous system is quantitatively superior to Cartesian control for all tested tasks under a “number of commands” metric, however, under a “time to task completion” metric, the system is seen to be superior for “hard” tasks but not for “easy” tasks.

An early fMRI marker of semantic memory deficits in people with amnestic mild cognitive impairment

Semantic memory deficits in Alzheimer's disease have often been reported. However, the nature of changes in semantic memory at pre-dementia stage is less extensively studied. By acquiring functional magnetic resonance imaging (fMRI) during a semantic memory task, we examined brain activity that could be affected by early disease processes in patients with amnestic Mild Cognitive Impairment (aMCI). We applied fMRI during the Semantic Object Retrieval Task (SORT), a task where subjects answered at each trial whether a pair of words presented would bring to mind a particular object. Trials of “Binds” probe object memory (e.g., humps and desert) whereas “NonBinds” do not (e.g., humps and mirror). We thus compared blood oxygen level dependent (BOLD) signal recorded from aMCI patients (N=6; mean age: 72.7±8.3 yr; CDR=0.5) to that of age-matched normal control (NC) subjects (N=6; mean age: 67.3±9.8 yr; CDR=0). Participants in both groups took longer to respond to NonBinds compared to Binds. No group differences in reaction time or accuracy were observed (p > .05). FMRI data showed that NC subjects demonstrated greater BOLD signal during Binds compared to NonBinds in left supramarginal gyrus and precuneus whereas no such differences were observed in the aMCI group (FWE < .05). Overall, NC subjects had greater activations than aMCI patients during Binds in bilateral medial frontal lobe, left insula, left caudate, and left post-central gyrus (p < .005, corrected at cluster size > 50 voxels), but NonBind-associated activations did not differ between groups. NC subjects had greater brain response elicited by trials that required retrieval of object memory compared to trials that did not. In contrast, aMCI patients showed no such differential brain activation while demonstrating less brain activity than NC subjects during memory retrieval. Our findings suggest that neural integrity in the regions involved in object memory retrieval is compromised in individuals with aMCI even when behavioral performance is not impaired. Presumably, changes in these brain regions indicate an early sign of semantic memory deficits that may become behaviorally measurable only at a later stage.

Intranasal GDNF for Parkinson's Disease: Next steps in preclinical development

We have shown that glial cell line‐derived neurotrophic factor (GDNF) given by the nasal route of administration provides significant protection of substantia nigra (SN) dopamine neurons in the rat 6‐hydroxydopmaine model of Parkinson's Disease (PD). The next step in preclinical development is to test the efficacy of intranasal GDNF in a primate model of PD. Eighteen common marmosets (Callithrix jacchus) were given three doses of MPTP (2 mg/kg on day 1 and 1 mg/kg on days 2 and 3) to induce a partial lesion of the SN dopamine neurons. Nine animals received 5 daily doses of intranasal GDNF (100 μg in 50 μl saline) and nine received an equivalent volume of saline. Doses were administered on consecutive days with the first given 1 day prior to the start of MPTP, the next three doses given 1 hr prior to each dose of MPTP, and the last dose given 1 day after the last dose of MPTP. Animals recovered for 2 months before sacrifice. Lesions severity was assessed using locomotor activity monitoring, performance on an object retrieval task, motor disability scoring, and by tyrosine hydroxylase (TH) immunohistochemistry (IH) of the SN and striata of each animal. The study concluded in October 2012, and analyses of the behavioral and TH‐IH data were ongoing at the time of abstract submission. Final results will be presented.

Impairment in Semantic Retrieval is Associated with Symptoms in Schizophrenia but not Bipolar Disorder

The Semantic Object Retrieval Task (SORT) requires participants to indicate whether word pairs recall a third object. Schizophrenia individuals (SZ) tend to report associations between nonassociated word pairs; this overretrieval is related to formal thought disorder (FTD). Since semantic memory impairments and psychosis are also found in bipolar disorder (BP), we examined whether SORT impairments and their relationship to symptoms are also present in BP. Participants (n = 239; healthy control subjects [HC] = 133; BP = 32; SZ = 74) completed SORT while undergoing functional magnetic resonance imaging (fMRI) scanning. Retrieval accuracy negatively correlated with negative symptoms and no-retrieval accuracy negatively correlated with FTD severity in SZ but not BP. Retrieval versus no-retrieval trials activated a distributed fronto-parieto-temporal network; bilateral inferior parietal lobule (IPL) activity was larger in HC versus SZ and HC versus BP, with no difference in SZ versus BP. Right IPL activity positively correlated with positive and general psychosis symptoms in SZ but not BP. SZ reported more associations between unrelated word pairs than HC; this overretrieval increased with FTD severity. Schizophrenia individuals were also more likely to fail to find associations between related word pairs; this underretrieval increased with negative symptom severity. fMRI symptom correlations in IPL in SZ are consistent with arguments that IPL abnormality relates to loosening of associations in SZ. By comparison, BP showed intermediate impairments on SORT, uncorrelated with symptoms, suggesting that the relationship between SORT performance, fMRI activity, and psychotic symptoms is schizophrenia-specific.

Precursors of Executive Function in Infants With Sickle Cell Anemia

Executive dysfunction occurs in sickle cell anemia, but there are few early data. Infants with sickle cell anemia (n = 14) and controls (n = 14) performed the “A-not-B” and Object Retrieval search tasks, measuring precursors of executive function at 9 and 12 months. Significant group differences were not found. However, for the A-not-B task, 7 of 11 sickle cell anemia infants scored in the lower 2 performance categories at 9 months, but only 1 at 12 months (P = .024); controls obtained scores at 12 months that were statistically comparable to the scores they had already obtained at 9 months. On the Object Retrieval task, 9- and 12-month controls showed comparable scores, whereas infants with sickle cell anemia continued to improve (P = .027); at 9 months, those with lower hemoglobin oxygen saturation passed fewer trials (R s = 0.670, P = .024) and took longer to obtain the toy (R s = –0.664, P = .013). Subtle delays in acquiring developmental skills may underlie abnormal executive function in childhood.

Direct touches to clear barriers: Developmental sensitivity of a new measure of the production of ineffective responses in infancy

Current interpretation of the object retrieval task (Diamond, 1990) as an infant assessment of response inhibition requires evidence that younger infants make more ineffective attempts to retrieve toys through clear barriers. On two 30-second trials, infants (9 or 11 months of age) saw an inaccessible toy in the front or back of a clear box. The location of the infants touches corresponded with the toy's location and, on the second trial, the younger infants touched the box more. In previous research nonhuman primates with orbital-frontal, but not dorsa-lateral, lesions also made ineffective barrier touches. The current developmental decreases in barrier touches may selectively tap developmental increases in inhibitory control supported by the developing orbital-frontal cortex.

Bimanual strategies for object retrieval in infants and young children

Age differences in goal-directed bimanual coordination were studied in typically developing infants aged 9-29months, compared to a group of children aged 4-6years and a group of adults, using an object retrieval task. This task required one hand to open and hold the lid of a transparent box, while the second hand retrieved a small toy from inside the box. Well-coordinated retrieval strategies with differentiated use of the two hands were not established in the majority of infants until 18months of age. Temporal analysis of the hand actions revealed that, unlike adults who perform the task with close synchronization of the hands at the start, the infants performed the task sequentially and did not activate the second hand until the first hand had started to lift the lid. The children's hand preferences for the two-hand actions also contrasted with those of adults. In children aged 27-29months and 4-6years, there was a preference for using the right-hand to lift the lid while in right-handed adults, the reverse pattern was observed. The results suggest that although bimanual coordination starts to develop in the second year of life, the adult pattern of performance on this task is not observed before 6years of age. It is likely that further maturation of the brain networks involved in bimanual coordination, and in particular functional interhemispheric transfer via the corpus callosum, is required before automatization of bimanual hand actions is achieved.

Object retrieval through observational learning in 8- to 18-month-old infants

Observational learning was studied in 8-, 10-, 12-, 15- and 18-month-old infants. Using object-retrieval tasks of relatively comparable difficulty for each age group, we showed that between 10 and 12 months there is a change in the capacity to learn a new skill by observation.

Trajectory Tree as an Object-Oriented Hierarchical Representation for Video

This paper presents the trajectory tree as a hierarchical region-based representation for video sequences. Motion, as well as spatial features from multiple frames are used to generate a set of temporal regions structured within a hierarchy of scale and motion coherency. The resulting representations offer a global description of the entire video sequence and enhance semantic analysis potential. A multiscale segmentation strategy is proposed whereby region-merging criteria of progressively greater complexity are used to define partition layers of increasing aptitude for object detection. A novel data structure, called the trajectory adjacency graph, is defined for the long-term analysis of partition sequences. Furthermore, mechanisms for assessing connectivity, verifying temporal continuity, and proposing merging operations based on color, affine, and translational motion homogeneity characteristics over the entire sequence are also introduced. Finally, as demonstrated through experimental results, the trajectory tree offers a concise yet versatile support for video object segmentation, description and retrieval tasks.

Temporal sequence of hemispheric network activation during semantic processing: A functional network connectivity analysis

To explore the temporal sequence of, and the relationship between, the left and right hemispheres (LH and RH) during semantic memory (SM) processing we identified the neural networks involved in the performance of functional MRI semantic object retrieval task (SORT) using group independent component analysis (ICA) in 47 healthy individuals. SORT requires participants to determine whether word pairs describing object features combine to retrieve an object. Functional network connectivity (FNC) was used to assess the correlations between components’ time courses. Results showed that semantic left and right hemisphere networks comprise two independent ICA components. The components’ time courses were highly correlated and RH activation preceded that of the LH. Moreover, this correlation was significantly stronger in better vs. poorer performers of the SORT. These results indicate an early activation of the RH that is closely followed by activation of the LH, to facilitate performance during word retrieval from SM.

Delayed self-recognition in 2.5-year-old children: Evidence of a restricted sense of self?

In two experiments, we explored whether 2.5-year-olds can use delayed video information to locate objects placed somewhere covertly after first being given pre-test video experience. Our findings revealed that children had little difficulty passing a surprise-object task, that is, a teddy bear hidden in a box that was placed behind the child and hence only visible in the delayed video. In contrast, the children did not pass the surprise-mark task or delayed self-recognition (DSR) task, even with pre-test video training. Similarly, delayed self-image experience and pre-test video training did not facilitate DSR performance in 2.5-year-olds. Children were also just as likely to fail a live video self-recognition task, suggesting that object-retrieval tasks pertaining to self using video information are difficult for children at this age. The findings are discussed in light of possible changes in representational capabilities; the implications for the development of a temporally extended self are also noted.

Cognitive preconditions for responses to fairness: An object retrieval test of inhibitory control in capuchin monkeys (Cebus apella).

The authors explore the evolution of one cognitive mechanism required for altruistic behavior: the capacity to inhibit prepotent responses. Specifically, the authors used an object retrieval task to investigate whether capuchins (Cebus apella) can inhibit a prepotent strategy of reaching directly for a food reward. Success in this task varies across species and across development, but is also known to depend critically on the maturity of dorsolateral prefrontal cortex, the cortical area implicated in rejecting small payoffs in an Ultimatum Game. Capuchins easily inhibit the tendency to reach directly for food in the object retrieval task, successfully employing an alternative reaching strategy even in the first session of performance. This contrasts with the performance of closely related tamarin monkeys, who performed less well despite extensive training. These results provide the first evidence that capuchins likely exhibit human-like inhibitory control in tasks previously linked to the function of the dorsolateral prefrontal cortex, such as the Ultimatum Game.

Executive Functioning Demands of the Object Retrieval Task for 8-month-old Infants

At 8 to 11 months of age, infants are more successful in negotiating opaque relative to transparent barriers. However, 7-month-old infants have more difficulty with opaque barriers relative to semitransparent barriers. Here, 8-month-old infants spent more time in ineffective direct reaches with more the transparent barriers (Experiments 1 & 2) and were faster with the fully opaque barrier (Experiment 2). This demonstration of the graded effects of transparency confirms the working memory and/or response inhibition demands of the object retrieval task.

RO4938581, a novel cognitive enhancer acting at GABAA α5 subunit-containing receptors

GABAA alpha5 subunit-containing receptors are primarily expressed in the hippocampus and their role in learning and memory has been demonstrated recently by both genetic and pharmacological approaches. The objective of the study is to evaluate the cognitive effects of a novel GABAA alpha5 receptor inverse agonist, RO4938581 in rats and monkeys. The in vitro profile was determined using radioligand binding and electrophysiological assays for the GABAA alpha1, alpha2, alpha3, and alpha5 receptors. Long-term potentiation (LTP) was performed in mouse hippocampal slices. Cognitive effects were assessed in rats in the delayed match to position (DMTP) task and the Morris water maze. In monkeys, the object retrieval task was used. Pro-convulsant and anxiogenic potentials were evaluated in mice and rats. In vivo receptor occupancy was determined using [3H]-RO0154513. RO4938581 is a potent inverse agonist at the GABAA alpha5 receptor, with both binding and functional selectivity, enhancing hippocampal LTP. RO4938581 reversed scopolamine-induced working memory impairment in the DMTP task (0.3-1 mg/kg p.o.) and diazepam-induced spatial learning impairment (1-10 mg/kg p.o.). RO4938581 improved executive function in monkeys (3-10 mg/kg p.o.). Importantly, RO4938581 showed no anxiogenic and pro-convulsive potential. RO4938581 dose-dependently bound to GABAA alpha5 receptors and approximately 30% receptor occupancy was sufficient to produce enhanced cognition in the rat. The data further support the potential of GABAA alpha5 receptors as a target for cognition-enhancing drugs. The dual binding and functional selectivity offers an ideal profile for cognition-enhancing effects without the unwanted side effects associated with activity at other GABAA receptor subtypes.

Cognitive control factors in speech perception at 11 months.

The development of speech perception during the 1st year reflects increasing attunement to native language features, but the mechanisms underlying this development are not completely understood. One previous study linked reductions in nonnative speech discrimination to performance on nonlinguistic tasks, whereas other studies have shown associations between speech perception and vocabulary growth. The present study examined relationships among these abilities in 11-month-old infants using a conditioned head-turn test of native and nonnative speech sound discrimination, nonlinguistic object-retrieval tasks requiring attention and inhibitory control, and the MacArthur-Bates Communicative Development Inventory (L. Fenson et al., 1993). Native speech discrimination was positively linked to receptive vocabulary size but not to the cognitive control tasks, whereas nonnative speech discrimination was negatively linked to cognitive control scores but not to vocabulary size. Speech discrimination, vocabulary size, and cognitive control scores were not associated with more general cognitive measures. These results suggest specific relationships between domain-general inhibitory control processes and the ability to ignore variation in speech that is irrelevant to the native language and between the development of native language speech perception and vocabulary.

Naturalistic Experience and the Early Use of Symbolic Artifacts

Experience with a variety of symbolic artifacts has been proposed as a mechanism underlying symbolic development. In this study, the parents of 120 2-year-old children who participated in symbolic object retrieval tasks completed a questionnaire regarding their children's naturalistic experience with symbolic artifacts and activities. In separate regressions predicting children's use of video and pictures for information in experimental tasks, predictor variables such as children's exposure to live video and their emerging understanding of graphic representation were significant, even after accounting for the effects of children's vocabulary and birth order and parents' education and occupation. The results support the role of experience in children's early detection of symbolic relations.

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We present a system for inserting new objects into existing photographs by querying a vast image-based object library, pre-computed using a publicly available Internet object database. The central goal is to shield the user from all of the arduous tasks typically involved in image compositing. The user is only asked to do two simple things: 1) pick a 3D location in the scene to place a new object; 2) select an object to insert using a hierarchical menu. We pose the problem of object insertion as a data-driven, 3D-based, context-sensitive object retrieval task. Instead of trying to manipulate the object to change its orientation, color distribution, etc. to fit the new image, we simply retrieve an object of a specified class that has all the required properties (camera pose, lighting, resolution, etc) from our large object library. We present new automatic algorithms for improving object segmentation and blending, estimating true 3D object size and orientation, and estimating scene lighting conditions. We also present an intuitive user interface that makes object insertion fast and simple even for the artistically challenged.