Before first words: Infants' ability to map words to goals.

Handling the deformations of the lung tissues in successive chest computed tomography (CT) scans of a patient is a vital step in any computer-aided diagnostic (CAD) system for lung cancer diagnosis. In this paper, we propose a new nonrigid registration methodology for the segmented lung region from CT data that involves two steps. The first step globally aligns the target-to-reference CT scans using an affine transformation based on ascent maximization of the estimated mutual information of the calculated distance map using the fast marching level sets method inside the segmented lung for both the target and reference objects. The second step is the local alignment of the target lung object in order to correct for intricate relative deformations due to breathing and heart beats. The local deformations are handled based on displacing each voxel of the target over evolving closed equi-spaced surfaces (iso-surfaces) to closely match the reference object. In order to displace the voxel on the iso-surfaces of the target lung object, the initial voxel-to-voxel match between target and reference lung objects is estimated by solving the 3D Laplace equation between each two corresponding iso-surfaces on the reference and target objects. Finally, the estimation of voxel-to-voxel match is refined through iterative energy minimization using a generalized Gauss-Markov random field (GGMRF) model. Qualitative and quantitative results demonstrate the promise of the proposed nonrigid registration framework.

Localisation of the site of an event after change in egocentric spatial relationship between it and the subject was examined in two experiments with eight-month-old infants. The event always occurred in the one place that was marked by a distinctive visual stimulus. Infants saw the event occur in training trials from two vantage points before being shifted to a third for testing. In the first experiment the effect of rotational shifts was compared with that of translational shifts. Infants looked longer at the site after the former but the pattern of looking was essentially similar in the two conditions. In the second experiment the type of shift differed between training and test trials: Rotational shifts in training trials were followed by translational shifts in test trials and vice versa. In each condition a significant number of infants relocated the site on the first test trial but not on the second. In the third experiment, six-month-old infants were tested in the first of these conditions...

Cholinergic regulation of hippocampal theta oscillations has long been proposed to be a potential mechanism underlying hippocampus-dependent memory encoding processes. However, cholinergic transmission has been traditionally associated with type II theta under urethane anesthesia. The mechanisms and behavioral significance of cholinergic regulation of type I theta in freely exploring animals is much less clear. In this study, we examined the potential behavioral significance of cholinergic regulation of theta oscillations in the object location task in male mice that involves training and testing trials and provides an ideal behavioral task to study the underlying memory encoding and retrieval processes, respectively. Cholinergic regulation of hippocampal theta oscillations and the behavioral outcomes was examined by either intrahippocampal infusion of cholinergic receptor antagonists or knocking out cholinergic receptors in excitatory neurons or interneurons. We found that both muscarinic acetylcholine receptors (mAChRs) and α7 nicotinic AChRs (α7 nAChRs) regulated memory encoding by engaging excitatory neurons and interneurons, respectively. There is a transient upregulated theta oscillation at the beginning of individual object exploration events that only occurred in the training trials, but not in the testing trials. This transient upregulated theta is also the only theta component that significantly differed between training and testing trials and was sensitive to mAChR and α7 nAChR antagonists. Thus, our study has revealed a transient cholinergic-sensitive theta component that is specifically associated with memory encoding, but not memory retrieval, in the object location task, providing direct experimental evidence supporting a role for cholinergic-regulated theta oscillations in hippocampus-dependent memory encoding processes.

Probability issues in locality descriptions based on Voronoi neighbor relationship

Human participants learned to select 1 of 4 distinctively marked corners in a rectangular virtual enclosure. After training, control and test trials were interspersed with training trials. On control and test trials, all markers were equivalent in color, but only during test trials was the shape of the enclosure manipulated. Specifically, for each test trial, a single long wall or short wall of the enclosure increased twice as long as or decreased half as long as that present in the training enclosure. These manipulations produced 8 unique trapezoid-shaped enclosures. Participants were allowed to select 1 corner during control and test trials. Performance during control trials revealed that participants selected the correct and rotationally equivalent locations. Performance during test trials revealed that participants selected locations in trapezoid-shaped enclosures that were consistent with those predicted by global geometry (i.e., principal axis of space) but were inconsistent with those predicted by local geometry (i.e., proportion of rewarded training features present at a location). Results have implications for theoretical accounts of geometry learning.

PD40-03 UTILIZATION OF MEDMEASURE!, A SMARTPHONE-BASED APP, AS A RELIABLE METHOD FOR FLUOROSCOPIC AND ENDOSCOPIC MEASUREMENTS

We propose and analyze an example-based framework for relighting images. In this framework, there are a number of images of reference objects captured under different illumination conditions. Given an input image of a new object captured under one of the previously observed illumination conditions, new images can be synthesized for the input object under all the other illumination conditions that are present in the reference images. It does not require any other prior knowledge on the reference and target objects, except that they share the same albedo. Though it is appreciated if the reference objects have similar shape as the target object, sphere or ellipsoid which has plenty of local geometry samples are sufficient to build up a look-up table, as this method solves the problem locally. Gradient domain methods are introduced to finally generate visual-pleasing results. We demonstrate this framework on synthesized data and real images.

Spatial cognitive performance is linked to thigmotaxis in field crickets

Reference directions and reference objects in spatial memory of a briefly viewed layout

Two experiments studied the effects of intermodality change on electrodermal responses and on reaction time to a secondary task probe stimulus after 24 habituation training trials with either a tone or a vibrotactile stimulus. The probe was a visual stimulus of 500 ms duration, and within-stimulus probes occurred 300 ms following stimulus onset. Experiment 1 crossed change versus no change with modality of the training stimulus. Skin conductance responses (SCRs) were larger in the experimental group than in the control on the test trial, and in the experimental group, test trial responses were larger than those on the first training trial. Probe reaction time was slower on the test trial in the experimental group than in the control, and within-stimulus probe reaction time was slower than interstimulus interval reaction time early in the habituation series. Experiment 2 crossed change versus no change with the presence of a secondary task. Test trial SCRs were larger in the experimental group than in the control, regardless of whether or not the secondary task was present. In addition, test trial responses in the experimental group were larger than those on the first training trial in both the task and no-task conditions. Within the task condition, reaction time was slower in the experimental condition than in the control on the test trial. In addition, reaction time in the experimental condition was slower during the change trial than during the first training stimulus. The data provide difficulties for noncomparator theories of habituation and seem to be most easily explained by theories of habituation that emphasize the importance of an extrapolatory process.

ABSTRACTThe goal of the present study was to investigate the effects of stimulus meaningfulness of sample and comparison stimuli on the acquisition of conditional relations and the emergence of symmetrical relations. Eight college students were trained on two types of baseline conditional discrimination tasks involving meaningful (English words) and non-meaningful (Swahili words) stimuli. One task involved English samples and Swahili comparisons (English–Swahili), whereas the other task involved Swahili samples and English comparisons (Swahili–English). Test trials, without programmed consequences, presented the symmetry probe of the baseline relations trained. That is, the English–Swahili baseline relations presented on the training trials were presented as the Swahili–English symmetrical relations on the test trials. Similarly, the Swahili–English baseline relations on the training trials were presented as the English–Swahili symmetrical relations on the test trials. The results show that the English–Swahili baseline relations were acquired faster than the Swahili–English baseline relations. The results also show that, relative to the acquisition of the baseline relations, the emergence of symmetrical relations was facilitated and delayed, respectively, on the English–Swahili and Swahili–English test trials. The present results suggest that stimulus meaningfulness of untrained successive discrimination of samples and simultaneous discrimination of comparisons on test trials affects the emergence of symmetrical relations, with the former playing a more important role than the latter.

The purpose of this study was to investigate the immediate effects of assisted and resisted training using different weight balls on ball speed and accuracy in baseball pitching. Eight male university baseball players were assigned as subjects. The experiment used a standard 145-gram baseball and two heavier or lighter balls with weights increased or decreased by 10% respectively. The subjects were required to pitch these balls and/or standard ball either six or eighteen times under different training trial conditions: 1) pitching the weighted ball only, 2) pitching the lightened ball only, 3) pitching the standard ball only, and 4) pitching three kinds of balls in order of the weighted, standard and lightened balls. Immediately after each training trial, the standard ball was pitched five times respectively (test trial). The ball speed of each trial was measured with a speed gun, and the distance from the center of target to the position of the ball pitched on the target was calculated using a video digitizing system. The results are summarized as follows: 1) In the training trials, the ball speed increased as the ball weight was decreased. 2) In the test trials, immediately after pitching the lightened ball both six (6Atest) and eighteen times (18Atest), and the three different kinds of balls eighteen times (18Ctest), the ball speeds were seen to be significantly higher than that of other test trials (p<0.01). 3) Although there were no significant differences in the ball speed in the above three test trials, a relatively higher ball speed was observed in 18Atest. 4) As for the distance from the center of target to the position of the ball pitched on the target, there were no significant differences among any trials.

It has been argued that several reported non-visual influences on perception cannot be truly perceptual. If they were, they should affect the perception of target objects and reference objects used to express perceptual judgments, and thus cancel each other out. This reasoning presumes that non-visual manipulations impact target objects and comparison objects equally. In the present study we show that equalizing a body-related manipulation between target objects and reference objects essentially abolishes the impact of that manipulation so as it should do when that manipulation actually altered perception. Moreover, the manipulation has an impact on judgements when applied to only the target object but not to the reference object, and that impact reverses when only applied to the reference object but not to the target object. A perceptual explanation predicts this reversal, whereas explanations in terms of post-perceptual response biases or demand effects do not. Altogether these results suggest that body-related influences on perception cannot as a whole be attributed to extra-perceptual factors.

Six rats were trained to find a previously missing target or 'jackpot' object in a square array of four identical or different objects (the test segment of a trial) after first visiting and collecting sunflower seeds from under the other three objects (the study segment of a trial). During training, objects' local positions within the array and their global positions within the larger foraging array were varied over trials but were not changed between segments within a trial. Following this training, rats were tested on their accuracy for finding the target object when a trial's test array was sometimes moved to a different location in the foraging arena or when the position of the target object within the test array had been changed. Either of these manipulations initially slightly reduced rats' accuracy for finding the missing object but then enhanced it. Relocating test arrays of identical objects enhanced rats' performance only after 10-min inter-segment intervals (ISIs). Relocating test arrays of different objects enhanced rats' performance only after 2-min ISIs. Rats also improved their performance when they encountered the target object in a new position in test arrays of different objects. This enhancement effect occurred after either 2- or 30-min ISIs. These findings suggest that rats separately retrieved a missing (target) object's spatial and non-spatial information when they were relevant but not when they were irrelevant in a trial. The enhancement effects provide evidence for rats' limited retrieval capacity in their visuo-spatial working memory.

This experiment was designed to determine whether intersensory transfer can be demonstrated using form (stars, squares, circles, and parallelograms) concepts as mediators. It was hypothesized that the association of certain sounds with visually presented forms would significantly influence the association of these sounds with the same or different forms when tactually presented. Three groups of subjects were used. During training trials, both experimental groups learned the same sound/form associations (with the forms being visually presented). During test trials, both experimental groups were presented the forms tactually, with Experimental Group 1 being tested with the same sound/form pairings given during training trials and Experimental Group 2 being tested with different sound/form pairings. The control group was exposed to a completely different set of stimuli (four new sounds and four line drawings) during training trials and exactly the same conditions as Experimental Group 1 during the test trials. The results indicated that form concept mediation across modalities can result in considerable transfer.