Acoustic markers associated with impairment in language processing in Alzheimer's Disease

This study broaches in a novel way the analysis of cognitive impairment characteristic of the early stages of Alzheimer's Disease (AD). Specifically, we attempt to determine the acoustic speech parameters that are sensitive to the onset of the disease, and their association with the language deficit characteristic of AD. Speech analysis was carried out on 21 elderly patients with AD using Praat software, which analyzes the acoustic components of speech. The data obtained were subjected to stepwise regression, using the overall scores obtained in the test as the criterion variable, and the scores on the frequency, amplitude and periodicity variables as predictors of performance. We found that the percentage of voiceless segments explains a significant portion of the variance in the overall scores obtained in the neuropsychological test. This component seems to be related mainly to the patient's ability in phonological fluency. This finding could permit the creation of a diagnostic test for AD through analysis of the acoustic speech parameters at very low cost in terms of both time and resources.     

Screening utility of the social anxiety screening scale in Spanish speaking adolescents

The aim of this study was to analyse the screening utility of the Social Anxiety Screening Scale (SASS/EDAS) in a sample of 227 adolescents with social anxiety disorder and 156 Without it (14-17 years). Results showed that the EDAS subscales (Avoidance, Distress and Interference) scores were reliable in terms of internal consistency (alpha > .80). All the subscales discriminated between adolescents with and without the disorder. They also showed a positive and significant correlation with other empirically validated measures of social anxiety. The three subscales indicated relevant sensitivity (69.16-84.14%), specificity (63.46-66.03%) and areas under the curve (.74-.81%). Binary logistic regression analyses indicated the adequate predictive utility of EDAS subscales, with the Distress subscale as the best diagnostic predictor. The data provide empirical evidence of the usefulness of EDAS as a screener for adolescent social anxiety disorder in terms of reliability, convergent and discriminant validity, diagnostic accuracy and clinical usefulness.     

Congruent visual information improves traffic signage

In the last five decades, cognitive scientists and the psychologists of reasoning have dedicated a lot of effort designing usable traffic signs. This study investigated the interference effect produced by the position of the sign elements in traffic signage on response accuracy and reaction time. Sixteen drivers performed a flanker interference reaction time task. Incongruent graphical/space solutions, actually used for the airport stack-type sign, lead to increased reaction time and a reduction in the proportion of correct answers. These results suggest that incongruent visual information should be avoided, as this might impair drivers’ performance. These findings provide important information for the specification of future signage design guidelines and for improving road safety.     

Box for interaction with objects (BIO): A new device to synchronize the presentation of objects with electrophysiological recordings

Brain event-related potentials are a useful tool for investigating visual processing and action planning. This technique requires extremely accurate synchronization of stimulus delivery with recordings. The precision of the onset time of visual stimulus delivery is a major challenge when attempting to use real, three-dimensional objects as stimuli. Here, we present an innovative device, the “box for interaction with objects” (BIO), that is designed to synchronize the presentation of objects with electroencephalographic (EEG) recordings. To reach the required resolution of stimulus-onset timing, the BIO system features an interface with reflective glass and light-emitting diodes (LEDs). When the LEDs inside the BIO are turned on, the object inside becomes visible, and a synchronizing pulse is sent to the recording systems. The BIO was tested in a motivational study that focused on visual and motor event-related potentials. EEG signals were recorded during the presentation of an emotion-laden object that could be grasped and brought close to the participant’s chest. BIO successfully synchronized the appearance of a three-dimensional object with EEG recordings, which would allow for an analysis of visual and motor event-related potentials in the same experiment. The BIO device, through a high-quality psychophysiological approach, offers a new perspective for the study of the motivational factors that drive actions toward relevant stimuli.     

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.     

Effects of non-symbolic numerical information suggest the existence of magnitude-space synesthesia

In number-space synesthesia, numbers are visualized in spatially defined arrays. In a recent study (Gertner et al. in Cortex, doi: 10.1016/j.cortex.2012.03.019 , 2012), we found that the size congruency effect (SiCE) for physical judgments (i.e., comparing numbers' physical sizes while ignoring their numerical values, for example, 8) was modulated by the spatial position of the presented numbers. Surprisingly, we found that the neutral condition, which is comprise solely of physical sizes (e.g., 3), was affected as well. This pattern gave rise to the idea that number-space synesthesia might entail not only discrete, ordered, meaningful symbols (i.e., Arabic numbers) but also continuous non-symbolic magnitudes (i.e., sizes, length, luminance, etc.). We tested this idea by assessing the performance of two number-space synesthetes and 12 matched controls in 3 comparative judgment tasks involving symbolic and non-symbolic stimuli: (1) Arabic numbers, (2) dot clusters, and (3) sizes of squares. The spatial position of the presented stimuli was manipulated to be compatible or incompatible with respect to the synesthetic number-space perceptions. Results revealed that for synesthetes, but not for controls, non-symbolic magnitudes (dot clusters) as well as symbolic magnitudes (i.e., Arabic numbers) interacted with space. Our study suggests that number-space synesthetes might have a general magnitude-space association that is not restricted to concrete symbolic stimuli. These findings support recent theories on the perception and evaluation of sizes in numerical cognition.     

The present projects past behavior into the future while the past projects attitudes into the future: How verb tense moderates predictors of drinking intentions

Three studies examined how the use of the present versus the past tense in recalling a past experience influences behavioral intentions. Experiment 1 revealed a stronger influence of past behaviors on drinking intentions when participants self-reported an episode of excessive drinking using the present tense. Correspondingly, there was a stronger influence of attitudes towards excessive drinking when participants self-reported the episode in the past tense. Experiments 2 and 3 liked this effect to changes in construal level (Liberman, Trope, & Stephan, 2007; Trope & Liberman, 2003), with the present tense being similar to a concrete construal level and the past tense being similar to an abstract construal level.     

Looking at the actor's face: Identity cues and attentional focus in false memories of action performance from observation

Observing another's actions can induce false memories of self-performance. We investigated whether such observation inflation depends on the discriminability between the self and the observed actor. Discriminability was manipulated by presenting actions either with or without a key visual identity cue, i.e., the actor's face. We also examined whether self–other confusions in the face-visible condition depend on attentional focus (directed to the observed action vs. the actor's face). In the action-only condition, observation inflation was significant and greater than in the face-visible conditions, in which the effect was moderated by attentional focus: It persisted under an action focus but was eliminated under a face focus. Findings for correct memories of self-performance suggest that the reduced effect is not merely due to weaker encoding of the actions themselves. We conclude that self–other confusions in action memory are constrained by the availability of distinctive non-self cues during observation, and sustained by a visual focus on observed actions.