Unified framework for recognition, localization and mapping using wearable cameras

Monocular approaches to simultaneous localization and mapping (SLAM) have recently addressed with success the challenging problem of the fast computation of dense reconstructions from a single, moving camera. Thus, if these approaches initially relied on the detection of a reduced set of interest points to estimate the camera position and the map, they are currently able to reconstruct dense maps from a handheld camera while the camera coordinates are simultaneously computed. However, these maps of 3-dimensional points usually remain meaningless, that is, with no memorable items and without providing a way of encoding spatial relationships between objects and paths. In humans and mobile robotics, landmarks play a key role in the internalization of a spatial representation of an environment. They are memorable cues that can serve to define a region of the space or the location of other objects. In a topological representation of the space, landmarks can be identified and located according to its structural, perceptive or semantic significance and distinctiveness. But on the other hand, landmarks may be difficult to be located in a metric representation of the space. Restricted to the domain of visual landmarks, this work describes an approach where the map resulting from a point-based, monocular SLAM is annotated with the semantic information provided by a set of distinguished landmarks. Both features are obtained from the image. Hence, they can be linked by associating to each landmark all those point-based features that are superimposed to the landmark in a given image (key-frame). Visual landmarks will be obtained by means of an object-based, bottom-up attention mechanism, which will extract from the image a set of proto-objects. These proto-objects could not be always associated with natural objects, but they will typically constitute significant parts of these scene objects and can be appropriately annotated with semantic information. Moreover, they will be affine covariant regions, that is, they will be invariant to affine transformation, being detected under different viewing conditions (view-point angle, rotation, scale, etc.). Monocular SLAM will be solved using the accurate parallel tracking and mapping (PTAM) framework by Klein and Murray in Proceedings of IEEE/ACM international symposium on mixed and augmented reality, 2007.     

Minimizing sleep deprivation effects in healthy adults by differential outcomes

Sleep deprivation reduces vigilance or arousal levels, affecting the efficiency of certain cognitive functions such as learning and memory. Here we assessed whether the differential outcomes procedure (DOP), a learning procedure that has proved useful to ameliorate episodic memory deficits, can also improve memory performance in sleep-deprived participants. Photographs were presented as sample faces. A probe face was then presented for recognition after either short or long delays. In the differential outcomes condition a unique reinforcer followed correct responses. In the non-differential outcomes condition reinforcers were provided in a random manner. The results indicated that the DOP prevented the recognition memory to decrement during the long delay in the control group, replicating previous findings. The sleep-deprived group showed DOP benefits mainly with the short delay, when working memory could be affected by low arousal. These findings confirm that the DOP can overcome impaired recognition memory due to sleep deprivation conditions.     

The multidimensional nature and multicultural validity of a new measure of social anxiety: the Social Anxiety Questionnaire for Adults

Much has been written about the situations most often feared by persons with social phobia, and several self-report measures are frequently used to assess such feared situations. However, it is not clear whether the situations feared by persons with social phobia form unidimensional or multidimensional factors. If these situations are multidimensional, reliance on a total score of feared situations would not reflect important differences between those dimensions. This research examined the multidimensional nature and multicultural validity of a newly developed instrument (the Social Anxiety Questionnaire for Adults [SAQ-A]) in two studies with a total of 539 patients diagnosed with social phobia and 15,753 nonpatients from 20 different countries. The structure (five clear and solid factors) and psychometric properties of the final instrument (the SAQ-A30) support the multidimensional nature of social anxiety and provide a new perspective in the assessment of social phobia.     

Self-concept and psychosocial adjustment in adolescence

This study analyses the relationship between a multidimensional measure of self-concept, Self-concept Form-5 Questionnaire (AF5), and a broad set of adolescents' psychosocial adjustment indicators. From the responses of 1,281 participants (53.7% females) aged 12 to 17 years ( M = 14.98 years, SD = 1.74 years), results indicated that higher self-concept scores corresponded to better psychological adjustment, good personal skills and fewer behavioral problems. Although a positive relationship between social self-concept and drug use was found, this significant relationship disappeared once the adolescent's age and sex was controlled for. These results support the idea that the self-concept is a basic theoretical construct closely related to the psychosocial adjustment in adolescence. Also this study helps explain some contradictory results reported in the literature (i.e., a positive relationship between social self-concept and drug use), by showing how the statistical control of a third variable effect (i.e., age) avoids reaching conclusions based on spurious relationships.     

Donation after circulatory death: burying the dead donor rule

Despite continuing controversies regarding the vital status of both brain-dead donors and individuals who undergo donation after circulatory death (DCD), respecting the dead donor rule (DDR) remains the standard moral framework for organ procurement. The DDR increases organ supply without jeopardizing trust in transplantation systems, reassuring society that donors will not experience harm during organ procurement. While the assumption that individuals cannot be harmed once they are dead is reasonable in the case of brain-dead protocols, we argue that the DDR is not an acceptable strategy to protect donors from harm in DCD protocols. We propose a threefold alternative to justify organ procurement practices: (1) ensuring that donors are sufficiently protected from harm; (2) ensuring that they are respected through informed consent; and (3) ensuring that society is fully informed of the inherently debatable nature of any criterion to declare death.     

Associations between parental educational/occupational levels and cognitive performance in Spanish adolescents: the AVENA study

We examined the associations between parental educational/occupational levels and cognitive performance in Spanish adolescents. Cognitive performance was measured by a validated Scholar Aptitudes test in 2,162 participants. Parental educational and occupational levels were positively associated with all specific cognitive abilities and the overall score (p<001 to .04). The odds ratios of having a high cognitive performance (top quartile) in adolescents with high parental educational level were 1.6 to 1.7 times higher than for those with a low parental educational level. Similarly, the odds ratios were 1.9 to 2.4 times higher for adolescents with high parental occupational level. These findings suggest an association between parental educational/occupational levels and cognitive performance in Spanish adolescents and support the parents' role in the creation of a stimulating intellectual environment.     

Regulation of memory accuracy with multiple answers: the plurality option

We report two experiments that investigated the regulation of memory accuracy with a new regulatory mechanism: the plurality option. This mechanism is closely related to the grain-size option but involves control over the number of alternatives contained in an answer rather than the quantitative boundaries of a single answer. Participants were presented with a slideshow depicting a robbery (Experiment 1) or a murder (Experiment 2), and their memory was tested with five-alternative multiple-choice questions. For each question, participants were asked to generate two answers: a single answer consisting of one alternative and a plural answer consisting of the single answer and two other alternatives. Each answer was rated for confidence (Experiment 1) or for the likelihood of being correct (Experiment 2), and one of the answers was selected for reporting. Results showed that participants used the plurality option to regulate accuracy, selecting single answers when their accuracy and confidence were high, but opting for plural answers when they were low. Although accuracy was higher for selected plural than for selected single answers, the opposite pattern was evident for confidence or likelihood ratings. This dissociation between confidence and accuracy for selected answers was the result of marked overconfidence in single answers coupled with underconfidence in plural answers. We hypothesize that these results can be attributed to overly dichotomous metacognitive beliefs about personal knowledge states that cause subjective confidence to be extreme.     

Low diversity and low frequency of participation in leisure activities compromise working memory efficiency in young adults

People perform leisure activities (LA) every day; pursuits that entail applying cognitive, physical and social abilities. As in old age, doing LA during early and middle adulthood is related to a reduced risk of dementias, probably by generating a cognitive reserve. As it is possible that a relation between doing LA and working memory (WM) efficiency exists in young adults, we assessed whether the diversity and frequency of LA are related to WM efficiency in this population. Ninety-three healthy young subjects solved the n-back task at two levels of difficulty (2, 3), and answered an LA questionnaire on the activities in which they had participated in the month prior to the experiment. Subjects were classified separately on their scores for (1) diversity (high/low) and (2) frequency (high/low) in order to test the relation between each variable and WM efficiency. Though no differences were found, a subsequent analysis of the average of diversity and frequency ratios of LA performance taken together-the diversity/frequency index-showed that low diversity plus low frequency was significantly associated with reduced WM efficiency at this age; results that suggest that frequent participation in diverse LA during youth is related to WM efficiency.