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Many previous studies have investigated visual distance perception, especially for small to moderate distances. Few experiments, however, have evaluated the perception of large distances (e.g., 100 m or more). The studies that have been conducted have found conflicting results (diametrically opposite conclusions). In the current experiment, the functions relating actual and perceived distance were obtained for sixteen adult observers using the method of equal appearing intervals. These functions relating perceived and actual distance were obtained for outdoor viewing in a typical University environment-the experiment was conducted along a sidewalk adjacent to a typical street where campus buildings, trees, street signs, etc., were visible. The overall results indicated perceptual compression of distances in depth so that the stimulus distance intervals appeared significantly shorter than the actual (physical) distance intervals. It is important to note, however, that there were sizeable individual differences-the judgments of half of the observers were relatively accurate, whereas the judgments of the remaining half were inaccurate to varying degrees. The results of the experiment demonstrate that there is no single function that describes how human observers visually perceive large distance intervals in outdoor environments., (© 2024. The Author(s).)

It has been known for more than 160 years that highly occluded objects that would normally be visually unrecognizable can be successfully identified when they move. This anorthoscopic perception relies on the visual system's ability to integrate information over time to complete the perception of an entire object's shape. In this experiment, 16 younger and older adults (mean ages were 20.5 and 74.6 years, respectively) were familiarized with the (unoccluded) shapes of five naturally-shaped objects (bell peppers, Capsicum annuum) until they could be easily identified (i.e., with accuracies of at least 90 percent correct). All observers then viewed the stimulus objects anorthoscopically as they moved behind narrow slits; only small object fragments could be seen at any given time, because the objects were almost totally occluded from view. Even though the object identification performance for all observers was equivalent when whole object shapes were visible, a large age-related deficit in object identification emerged during anorthoscopic viewing such that the younger adults' identification performance was 45.4 percent higher than that of the older adults. This first ever study of aging and anorthoscopic perception demonstrates that there is an age-related deficit in performing the temporal integration needed for successful object recognition., (© 2023. Springer Nature Limited.)

The theta rhythm, a quasi-periodic 4-10 Hz oscillation, is observed during memory processing in the hippocampus, with different phases of theta hypothesized to separate independent streams of information related to the encoding and recall of memories. At the cellular level, the discovery of hippocampal memory cells (engram neurons), as well as the modulation of memory recall through optogenetic activation of these cells, has provided evidence that certain memories are stored, in part, in a sparse ensemble of neurons in the hippocampus. In previous research, however, engram reactivation has been carried out using open-loop stimulation at fixed frequencies; the relationship between engram neuron reactivation and ongoing network oscillations has not been taken into consideration. To address this concern, we implemented a closed-loop reactivation of engram neurons that enabled phase-specific stimulation relative to theta oscillations in the local field potential in CA1. Using this real-time approach, we tested the impact of activating dentate gyrus engram neurons during the peak (encoding phase) and trough (recall phase) of theta oscillations. Consistent with previously hypothesized functions of theta oscillations in memory function, we show that stimulating dentate gyrus engram neurons at the trough of theta is more effective in eliciting behavioral recall than either fixed-frequency stimulation or stimulation at the peak of theta. Moreover, phase-specific trough stimulation is accompanied by an increase in the coupling between gamma and theta oscillations in CA1 hippocampus. Our results provide a causal link between phase-specific activation of engram cells and the behavioral expression of memory., Competing Interests: BR, JN, JN, BL, MQ, KG, AP, FF, SR, JW No competing interests declared, (© 2023, Rahsepar, Norman et al.)

Grouping by common fate plays an important role in how human observers perceive environmental objects. In this study, the effect of aging upon the ability to utilize common fate was evaluated. Twenty-two younger and older adults (mean ages were 23.4 and 74.7 years, respectively) participated in two experiments. On any given trial, the participants sequentially viewed two apparent motion sequences and were required to indicate which temporal interval contained a coherently moving dotted line embedded in noisy random background motion. In Experiment 1, the number of dots defining the target was varied, while in Experiment 2, the target interpoint spacing was varied. The younger adults outperformed the older adults by 19.4 percent in Experiment 1 and 50.5 percent in Experiment 2. The older and younger adults were similarly affected by variations in the number of target dots and the target interpoint spacing. The individual older participants' object detection accuracies were highly correlated with their individual chronological ages, such that the performance of the younger old participants was much higher than that exhibited by the older old. Increases in age systematically affect the ability of older adults to detect and visually perceive objects defined by common fate., (© 2022. The Author(s).)

An experiment evaluated the ability of 30 younger and older adults to visually judge object size under three conditions: (1) full cue, (2) in the dark, with linear perspective, and (3) in complete darkness. Each observer made repeated judgments for the same square stimuli (the task was to adjust a separation until it matched the perceived size of the squares), enabling an evaluation of precision as well as accuracy. The judgments were just as accurate in the dark with linear perspective condition as in the full cue condition, indicating that linear perspective serves as an important source of optical information to support the perception of object size). In contrast, in complete darkness (where linear perspective information was unavailable), the accuracy of the observers' judgments was poor. Finally, there was no difference in either the accuracy or the precision of the observers' judgments between the two age groups, despite the fact that the older adults were more than 50 years older than the younger adults (mean age of the younger and older adults was 22.3 and 74.1 years, respectively). The ability to visually perceive object size is well maintained with increasing age, unlike a number of other important visual abilities., (© 2022. The Author(s).)

The ability to visually perceive distances in depth was evaluated in two experiments. In both experiments, the observers were required to bisect a distance interval oriented in depth (8 m total extent in Experiment 1 and 7 m in Experiment 2). The purpose of Experiment 1 was to examine the effects of environmental context (indoors in the dark, indoors in the light, and outdoors) and monocular versus binocular viewing. The purpose of Experiment 2 was to manipulate linear perspective to determine its importance for perceiving depth interval magnitudes. In the outdoor environment, the observers' bisection judgments indicated perceptual compression of farther distances similar to that obtained in many previous studies. In contrast, the observers' judgments in the indoor lighted environment were consistent with the perceptual expansion of farther distances. There was also a beneficial effect of binocular viewing upon the precision of the observers' repeated judgments, but the size of this effect was large only within the dark environment. Finally, linear perspective was found to significantly modulate the observers' bisection judgments such that they became accurate only when perspective was available., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Eighteen younger and older adults (mean ages were 20.4 and 72.8 years, respectively) participated in a tactile speed matching task. On any given trial, the participants felt the surfaces of rotating standard and test wheels with their index fingertip and were required to adjust the test wheel until its speed appeared to match that of the standard wheel. Three different standard speeds were utilized (30, 50, and 70 cm/s). The results indicated that while the accuracy of the participants' judgments was similar for younger and older adults, the precision (i.e., reliability across repeated trials) of the older participants' judgments deteriorated significantly relative to that exhibited by the younger adults. While adverse effects of age were obtained with regards to both the precision of tactile speed judgments and the participants' tactile acuity, there was nevertheless no significant correlation between the older adults' tactile acuities and the precision of their tactile speed judgments., (© 2022. The Author(s).)

Background: Despite exercise being one of few strategies to improve outcomes for individuals with heart failure with preserved ejection fraction (HFpEF), exercise clinical trials in HFpEF are plagued by poor interventional adherence. Over the last 2 decades, our research team has developed, tested, and refined Heart failure Exercise And Resistance Training (HEART) Camp, a multicomponent behavioral intervention to promote adherence to exercise in HF. We evaluated the effects of this intervention designed to promote adherence to exercise in HF focusing on subgroups of participants with HFpEF and heart failure with reduced ejection fraction (HFrEF)., Methods and Results: This randomized controlled trial included 204 adults with stable, chronic HF. Of those enrolled, 59 had HFpEF and 145 had HFrEF. We tested adherence to exercise (defined as ≥120 minutes of moderate-intensity [40%-80% of heart rate reserve] exercise per week validated with a heart rate monitor) at 6, 12, and 18 months. We also tested intervention effects on symptoms (Patient-Reported Outcomes Measurement Information System-29 and dyspnea-fatigue index), HF-related health status (Kansas City Cardiomyopathy Questionnaire), and physical function (6-minute walk test). Participants with HFpEF (n = 59) were a mean of 64.6 ± 9.3 years old, 54% male, and 46% non-White with a mean ejection fraction of 55 ± 6%. Participants with HFpEF in the HEART Camp intervention group had significantly greater adherence compared with enhanced usual care at both 12 (43% vs 14%, phi = 0.32, medium effect) and 18 months (56% vs 0%, phi = 0.67, large effect). HEART Camp significantly improved walking distance on the 6-minute walk test (η 2  = 0.13, large effect) and the Kansas City Cardiomyopathy Questionnaire overall (η 2  = 0.09, medium effect), clinical summary (η 2  = 0.16, large effect), and total symptom (η 2  = 0.14, large effect) scores. In the HFrEF subgroup, only patient-reported anxiety improved significantly in the intervention group., Conclusions: A multicomponent, behavioral intervention is associated with improvements in long-term adherence to exercise, physical function, and patient-reported outcomes in adults with HFpEF and anxiety in HFrEF. Our results provide a strong rationale for a large HFpEF clinical trial to validate these findings and examine interventional mechanisms and delivery modes that may further promote adherence and improve clinical outcomes in this population., Clinical Trial Registration: URL: https://clinicaltrials.gov/. Unique identifier: NCT01658670., (Copyright © 2021 Elsevier Inc. All rights reserved.)

In this study 28 younger and older observers discriminated the global shapes of objects that were defined by differences in texture. The judged stimulus patterns were 3-point micropattern textures. On any given trial, a texture-defined shape (either a vertically- or horizontally-oriented rectangle) was presented; the observers' task was to discriminate between the two rectangles. The task difficulty was manipulated by varying the deviation from colinearity of each of the individual 3-point texture elements between figure and background (the larger the difference in deviation between figure and ground, the higher the discrimination performance). The results revealed a substantial effect of age. In order for the older observers to reliably discriminate the shape of the target rectangle (with a d' value of 1.5), they needed differences from colinearity that were 54.4 percent larger than those required for the younger observers. While older adults can utilize differences in texture to perceive global shape, their ability is nevertheless significantly impaired., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Fluorescence imaging is a widely used technique that permits for cell-type-specific recording from hundreds of neurons simultaneously. Often, to obtain cell-type-specific recordings from more than one cell type, researchers add an additional fluorescent protein to mark a second neuronal subpopulation. Currently, however, no consensus exists on the best expression method for multiple fluorescent proteins., New Method: We optimized the coexpression of two fluorescent proteins across multiple brain regions and mouse lines., Results: The single-virus method, a viral injection in a double transgenic reporter mouse, results in limited fluorescent coexpression. In contrast the double-virus method, injecting a mixture of two viruses in a Cre driver mouse, results in up to 70 % coexpression of the fluorescent markers in vitro. Using the double-virus method allows for population activity recording and neuronal subpopulation determination., Comparison With Existing Method: The standard for expressing two fluorescent proteins is to use a double transgenic reporter mouse with a single viral injection. Injecting two viruses into a Cre driver mouse resulted in significantly higher coexpression compared to the standard method. This result generalized to multiple brain regions and mouse lines in vitro, as well as in vivo., Conclusion: Efficiently coexpressing multiple fluorescent proteins provides population activity while identifying a neuronal subpopulation of interest. The improved coexpression is applicable to a wide breadth of experiments, ranging from engram investigation to voltage imaging., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Two experiments evaluated the importance of temporal integration for the perception and discrimination of solid object shape. In Experiment 1, observers anorthoscopically viewed moving or stationary cast shadows of naturally shaped solid objects (bell peppers, Capsicum annuum) through narrow (4-mm wide) slits. At any given moment, observers could only see a very small portion of the overall object shape (generally less than 10%). The results showed that the observers' discrimination performance for the moving cast shadows was much higher than that obtained for the stationary shadows, demonstrating the ability to temporally integrate the piecemeal momentary information about shape that was available through the narrow apertures. In a second experiment, estimates of the strength of the observers' impressions of solid shapes rotating in depth were obtained as well as discrimination accuracies; perceptions of the original moving condition were compared with a new condition where the frames of the apparent motion sequences depicting solid objects in continuous motion (behind the slits) were randomly scrambled. The observers perceived the anorthoscopic displays as depicting solid objects rotating in depth, but only in the continuous motion condition. Interestingly, the discrimination performance in the scrambled condition remained relatively high-observers were still able to integrate information across the multiple scrambled frames in order to produce discrimination performance that was significantly higher than that obtained in the stationary shadow condition. This study was the first to thoroughly evaluate whether and to what extent human observers can effectively discriminate and perceive solid object shape anorthoscopically.

Aims: A cardiopulmonary exercise (CPX) test is considered the gold standard in evaluating maximal oxygen uptake. This study aimed to evaluate the predictive validity of equations provided by Burr et al., Ross et al., Adedoyin et al., and Cahalin et al. in predicting peak VO 2 from 6 min walk test (6MWT) distance in patients with heart failure (HF)., Methods and Results: New York Heart Association Class I-III HF patients performed a maximal effort CPX test and two 6MWTs. Correlations between CPX VO 2 peak and the predicted VO 2 peak , coefficient of determination (R 2 ), and mean absolute percentage error (MAPE) scores were calculated. P-values were set at 0.05. A total of 106 participants aged 62.5 ± 11.5 years completed the tests. The mean VO 2 peak from CPX testing was 16.4 ± 3.9 mL/kg/min, and the mean 6MWT distance was 419.2 ± 93.0 m. The predicted mean VO 2 peak (mL/kg/min) by Burr et al., Ross et al., Adedoyin et al., and Cahalin et al. was 22.8 ± 8.8, 14.6 ± 2.1, 8.30 ± 1.4, and 16.6 ± 2.8. A significant correlation was observed between the CPX test VO 2 peak and predicted values. The mean difference (0.1 mL/kg/min), R 2 (0.97), and MAPE (0.14) values suggest that the Cahalin et al. equation provided the best predictive validity., Conclusions: The equation provided by Cahalin et al. is simple and has a strong predictive validity, and researchers may use the equation to predict mean VO 2 peak in patients with HF. Based on our observation, equations to predict individual maximal oxygen uptake should be used cautiously., (© 2020 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Two experiments are reported that investigated how the perceptual identification of glass is influenced by banding contours formed by internal specular interreflections within glass materials. Observers made material categorization judgments for images depicting glass, chrome, shiny black and shiny white objects, and for contour drawings that were created by edge filtering images of glass, chrome or textured objects. Observers rated each stimulus by adjusting four sliders to indicate their confidence that the depicted material was glass, metal, shiny black, or something else, and these adjustments were constrained so that the sum of all four settings was always 100%. The results revealed that the rendered images were all categorized correctly with a high level of confidence. The contour drawings of glass and textured materials were also categorized correctly with a high level of confidence. However, the contour drawings of chrome materials were miscategorized as glass, with an average confidence rating that was significantly lower than those obtained for the glass contours. It is hypothesized that these different contour types are perceptually distinguished from one another based on how they align with the pattern of surface curvature on an object and the smoothness of the contours.

Seventy-two older and younger adults haptically discriminated the solid shape of natural objects (bell peppers, Capsicum annuum). Plastic copies of the original-sized fruits were used as experimental stimuli, as well as copies that were reduced in size to 1/8th and 1/27th of the original object volumes. If haptic object shape is represented in a part-based manner, then haptic shape discrimination performance should be at least partly size invariant, since changes only in scale do not affect an object's constituent parts. On any given trial, participants sequentially explored two bell pepper replicas and were required to judge whether they possessed the same shape or had different shapes. For some participants, the objects to be discriminated possessed the same size, while for others, the two objects had different sizes. It was found that variations in scale did significantly reduce the participants' haptic sensitivities to shape. Nevertheless, the discrimination performance obtained for large variations in size was no lower than that obtained for smaller variations in size. The results also demonstrated that increases in age modestly affect haptic shape discrimination performance: the d' values of the older participants were 15.5% lower than those of the younger participants.

The ability of 32 younger (ages ranged from 19 to 32 years) and older adults (ages ranged from 65 to 83 years) to visually perceive outdoor distances was evaluated; we used the method of equal-appearing intervals. On any given trial, the observers adjusted five distance intervals in depth so that they all appeared equivalent in magnitude (and equal to a standard initial egocentric distance of 6 m). The judgments of approximately two thirds of the younger and older observers exhibited varying degrees of perceptual compression, while those of the remaining one third were essentially accurate. Unlike a number of previous studies that evaluated the perception of shorter distances, no significant effects of age were obtained in the current experiment. In particular, there were no significant effects of age upon either accuracy or precision. The ability of human observers to evaluate large-scale distances outdoors is well maintained with increasing age.

A single experiment required 40 younger and older adults to discriminate global shape as depicted by Glass patterns (concentric and radial organizations). Such patterns have been widely used for decades, because in order to successfully perceive the depicted shape, the visual system has to detect both locally oriented features (dipoles) and their alignments across extended regions of space. In the current study, we manipulated the number of constituent dipoles in the stimulus patterns (40 or 200), the noise-to-signal ratio (zero, 1.0, & 5.0), and the pattern size (6.0 & 25.0 degrees visual angle). The observers' shape discrimination accuracies (d' values) decreased markedly as the amount of noise increased, and there were smaller (but significant) effects of both overall pattern size and the number of stimulus dipoles. Interestingly, while there was a significant effect of age, it was relatively small: the overall d' values for older and younger adults were 2.07 and 2.34, respectively. Older adults therefore retain an effective ability to visually perceive global shape, even for sparsely-defined patterns embedded in noise., Competing Interests: The authors have declared that no competing interests exist.

The present research was designed to examine how patterns of illumination influence the perceptual categorization of metal, shiny black, and shiny white materials. The stimuli depicted three possible objects that were illuminated by five possible high-dynamic-range imaging light maps, which varied in their overall distributions of illuminant directions and intensities. The surfaces included a low roughness chrome material, a shiny black material, and a shiny white material with both diffuse and specular components. Observers rated each stimulus by adjusting four sliders to indicate their confidence that the depicted material was metal, shiny black, shiny white, or something else, and these adjustments were constrained so that the sum of all four settings was always 100%. The results revealed that the metal and shiny black categories are easily confused. For example, metal materials with low intensity light maps or a narrow range of illuminant directions are often judged as shiny black, whereas shiny black materials with high intensity light maps or a wide range of illuminant directions are often judged as metal. To discover the visual information on which these judgements are based, we measured several possible image statistics, and we found two that were highly correlated with the observers' confidence ratings in appropriate contexts. We also performed a spherical harmonic analysis on the different light maps to quantitatively predict how they would bias observers' judgments of metal and shiny black surfaces.

Fifty-one adults evaluated visually-perceived emotions from 32 masks. These masks (held in the collection of the Kentucky Museum, located on the campus of Western Kentucky University) were created by artists from a wide variety of cultures spanning multiple continents. Each participant evaluated every mask along six dimensions: happiness, sadness, anger, fear, surprise, and disgust. No previous scientific study has ever studied the general effectiveness of masks (other than Japanese Noh masks) in producing perceptions of human emotion. The results showed that the masks were effective in producing substantial variations in perceived happiness, sadness, anger, fear, surprise, and disgust. The ability of the masks to produce effective perceptions of emotion was due to the artists' inclusion of facial features that reliably signal emotions in everyday life., Competing Interests: The authors have declared that no competing interests exist.

Background: Regular exercise training has beneficial effects on quality of life, physical function, depression and anxiety in individuals with heart failure. Unfortunately, individuals with heart failure have low levels of adherence to exercise. Thus, studies are needed to assess intervention strategies which may enhance clinical outcomes., Aim: The aim of this study was to identify the components of the HEART Camp intervention, which contributed to optimizing clinical outcomes., Methods: The Heart Failure Exercise and Resistance Training Camp (HEART Camp) was a randomized controlled trial to evaluate the effect of a multicomponent intervention on adherence to exercise (6, 12 and 18 months) compared to an enhanced usual care group. This study assessed various components of the intervention on the secondary outcomes of physical function, health-related quality of life, depression, anxiety, and fatigue., Results: Individuals participating ( n =204) in this study were 55.4% men and the average age was 60.4 (11.5) years. A combination of individualized and group-based strategies demonstrated clinical improvements, HEART Camp versus enhanced usual care groups, in physical function, positive trends in health-related quality of life and positive changes in the minimally important differences for depression, anxiety, and fatigue., Conclusions: Individualized coaching by an exercise professional and group-based educational sessions were identified as important components of patient management contributing to improvements in the secondary outcomes of physical function, health-related quality of life, depression, anxiety and fatigue.

Everyday threat detection includes recognizing threat cues in facial expressions found in our peripheral visual field. The current study examined age differences in the detection of emotion in low and high intensity angry and fearful facial expressions presented in younger and older adults' parafoveal (±5°) and peripheral visual field (±10°, ±15°). For both age groups, detection performance was better for higher than for lower intensity stimuli, and detection performance declined with greater peripheral distance. Although younger and older adults displayed a similar pattern of findings for angry facial expressions, younger adults appeared to be more sensitive to lower intensity fearful expressions across all viewing positions. These findings demonstrate that, although threat detection may be partly maintained into older age, neurophysiological changes may accompany aging that selectively reduce older adults' sensitivity to peripheral facial cues of fear., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A single experiment evaluated the haptic-visual cross-modal matching of solid object shape. One set of randomly shaped artificial objects was used (sinusoidally modulated spheres, SMS) as well as two sets of naturally shaped objects (bell peppers, Capsicum annuum and sweet potatoes, Ipomoea batatas ). A total of 66 adults participated in the study. The participants' task was to haptically explore a single object on any particular trial and subsequently indicate which of 12 simultaneously visible objects possessed the same shape. The participants' performance for the natural objects was 60.9 and 78.7 percent correct for the bell peppers and sweet potatoes, respectively. The analogous performance for the SMS objects, while better than chance, was far worse (18.6 percent correct). All of these types of stimulus objects possess a rich geometrical structure (e.g., they all possess multiple elliptic , hyperbolic , and parabolic surface regions). Nevertheless, these three types of stimulus objects are perceived differently: Individual members of sweet potatoes and bell peppers are largely identifiable to human participants, while the individual SMS objects are not. Analyses of differential geometry indicate that these natural objects (e.g., bell peppers and sweet potatoes) possess heterogeneous spatial configurations of distinctly curved surface regions, and this heterogeneity is lacking in SMS objects. The current results therefore suggest that increases in surface structure heterogeneity facilitate human object recognition.

An important phenomenon in the study of human perception is the ability of observers to identify different types of surface materials. The present article will consider a wide range of factors that can influence the perceptual identification of glass, including the structural complexity of an object, whether it is hollow or solid, and the pattern of illumination. Several illumination techniques used in the field of photography are described, and examples are provided to show how they interact with structural complexity. A single psychophysical experiment is reported to evaluate the perceptions of naïve observers using a novel categorization task designed to assess potential confusions among multiple material categories. Finally, the paper will enumerate a number of specific image features that are potentially diagnostic for the identification of glass, and it will evaluate their relative importance for human perception.

Aim: The use of the internet and newer activity monitors such as the Fitbit Charge HR to improve exercise adherence is limited. The primary aim of the Move on Virtual Engagement (MOVE-HF) was to investigate the effects of group social support by internet-based synchronized face-to-face video and objective physical activity feedback on adherence to recommended exercise guidelines., Methods: Thirty stable heart failure patients (New York Heart Association class I-III), aged 64.7±11.5 years, were randomly assigned to an experimental or comparison group. Participants were provided a handout on self-care in heart failure, an exercise routine, a Fitbit Charge HR and were asked to wear the Fitbit Charge HR daily, and record their exercise sessions using both the Fitbit Charge HR and exercise diaries. In addition, participants in the experimental group connected to Vidyo software, once a week, for 8 weeks, for a 45-minute face-to-face online group discussion/education session., Results: Overall Vidyo session attendance was 68%, with 73% of participants attending five or more sessions. Adherence to exercise was 58.8% in the experimental group and 57.3% in the comparison group. The experimental group perceived receiving social support through the internet-based synchronized face-to-face video meetings but due to a small sample size and lack of adequate power, no significant impact on exercise adherence was observed. Participants commented that feedback regarding physical activity from the Fitbit Charge HR was helpful and motivational., Conclusion: Delivering social support by internet-based synchronized face-to-face video is feasible with heart failure patients. However, more investigations are needed to understand its impact on exercise adherence.

In the current study of haptic distance perception, 20 younger (median age: 22 years) and 20 older adults (median age: 72 years) used active touch to estimate distance ratios(one length relative to another). Nine tactile stimuli were created from wooden dowels; each consisted of two perpendicular dowels. The stimulus distance ratios ranged from 1.0 to 5.0. Each participant used both hands (without vision) to actively explore (30 s) a single stimulus object on every trial. The task was to numerically estimate the distance ratio. Overall, the participants’ judgments were precise; the overall magnitude of the Pearson r correlation coefficient was 0.943 and did not differ for younger and older adults. While the participants’ judgments were precise, they were not completely accurate: The average slope (of the relationship between actual and judged distance ratios) for all participants was significantly greater than 1.0 (1.15). Surprisingly, differences in manual dexterity had no apparent effect on distance ratio estimates. Older adults apparently retain an excellent ability to perceive distances using their sense of touch. Our results also demonstrate that the geometry of haptic space (at the scale of the hand) is approximately Euclidean in nature (and certainly not merely topological, projective, or affine).

Competing Interests: All authors have completed and submitted the ICMJE form for disclosure of potential conflicts of interest. William Schaffner reports personal fees from Pfizer, Merck, Dynavax, Seqirus, SutroVax, and Shionogi, outside the submitted work. No other potential conflicts of interest were disclosed.

An experiment was conducted to evaluate the ability of 28 younger and older adults to visually bisect distances in depth both indoors and outdoors; half of the observers were male and half were female. Observers viewed 15-m and 30-m distance extents in four different environmental settings (two outdoor grassy fields and an indoor hallway and atrium) and were required to adjust the position of a marker to place it at the midpoint of each stimulus distance interval. Overall, the observers' judgments were more accurate indoors than outdoors. In outdoor environments, many individual observers exhibited perceptual compression of farther distances (e.g., these observers placed the marker closer than the actual physical midpoints of the stimulus distance intervals). There were significant modulatory effects of both age and sex upon the accuracy and precision of the observers' judgments. The judgments of the male observers were more accurate than those of the female observers and they were less influenced by environmental context. In addition, the accuracies of the younger observers' judgments were less influenced by context than those of the older observers. With regard to the precision of the observers' judgments, the older females exhibited much more variability across repeated judgments than the other groups of observers (younger males, younger females, and older males). The results of our study demonstrate that age and sex are important variables that significantly affect the visual perception of distance.

Background: Use of wrist-worn activity monitors has increased over the past few years; however, the use of the Fitbit® Charge HR (FCHR) in a community setting in patients with heart failure has not been tested., Purpose: The purpose of the study was to assess the feasibility, practicality and acceptability of utilizing the FCHR to validate self-reported exercise diaries and monitor exercise in community dwelling patients with heart failure., Methods: Thirty heart failure patients (12 females and 18 males) aged 64.7 ± 11.5 years were provided with a FCHR. Participants were provided with an exercise routine and for eight weeks, recorded their exercise sessions in self-reported exercise diaries and used the FCHR to record those exercise sessions., Results: Exercise data from the self-reported exercise diaries were validated with data from the FCHR. Participants' perception and acceptance of using the FCHR was positive. Validation of exercise and physical activity interventions using the FCHR appears feasible and acceptable in patients with heart failure., Conclusion: Wrist-worn activity monitors can be useful for objective measurement of exercise adherence and monitoring of physical activity in patients with heart failure in a community setting.

An experiment required younger and older adults to estimate coherent visual motion direction from multiple motion signals, where each motion signal was locally ambiguous with respect to the true direction of pattern motion. Thus, accurate performance required the successful integration of motion signals across space (i.e., accurate performance required solution of the aperture problem) . The observers viewed arrays of either 64 or 9 moving line segments; because these lines moved behind apertures, their individual local motions were ambiguous with respect to direction (i.e., were subject to the aperture problem). Following 2.4 seconds of pattern motion on each trial (true motion directions ranged over the entire range of 360° in the fronto-parallel plane), the observers estimated the coherent direction of motion. There was an effect of direction, such that cardinal directions of pattern motion were judged with less error than oblique directions. In addition, a large effect of aging occurred-The average absolute errors of the older observers were 46% and 30.4% higher in magnitude than those exhibited by the younger observers for the 64 and 9 aperture conditions, respectively. Finally, the observers' precision markedly deteriorated as the number of apertures was reduced from 64 to 9.

The present research was designed to examine how the presence or absence of ambient light influences the appearance of metal. The stimuli depicted three possible objects that were illuminated by three possible patterns of illumination. These were generated by a single point light source, two rectangular area lights, or projecting light onto a translucent white box that contained the object (and the camera) so that the object would be illuminated by ambient light in all directions. The materials were simulated using measured parameters of chrome with four different levels of roughness. Observers rated the metallic appearance and shininess of each depicted object using two sliders. The highest rated appearance of metal and shininess occurred for the surfaces with the lowest roughness in the ambient illumination condition, and these ratings dropped systematically as the roughness was increased. For the objects illuminated by point or area lights, the appearance of metal and shininess were significantly less than in the ambient conditions for the lowest roughness value, and significantly greater than in the ambient condition for intermediate values of roughness. We also included a control condition depicting objects with a shiny plastic reflectance function that had both diffuse and specular components. These objects were rated as highly shiny but they did not appear metallic. A theoretical hypothesis is proposed that the defining characteristic of metal (as opposed to black plastic) is the presence of specular sheen over most of the visible surface area.

In three experiments participants haptically discriminated object shape using unimanual (single hand explored two objects) and bimanual exploration (both hands were used, but each hand, left or right, explored a separate object). Such haptic exploration (one versus two hands) requires somatosensory processing in either only one or both cerebral hemispheres; previous studies related to the perception of shape/curvature found superior performance for unimanual exploration, indicating that shape comparison is more effective when only one hemisphere is utilized. The current results, obtained for naturally shaped solid objects (bell peppers, Capsicum annuum) and simple cylindrical surfaces demonstrate otherwise: bimanual haptic exploration can be as effective as unimanual exploration, showing that there is no necessary reduction in ability when haptic shape comparison requires interhemispheric communication. We found that while successive bimanual exploration produced high shape discriminability, the participants' bimanual performance deteriorated for simultaneous shape comparisons. This outcome suggests that either interhemispheric interference or the need to attend to multiple objects simultaneously reduces shape discrimination ability. The current results also reveal a significant effect of age: older adults' shape discrimination abilities are moderately reduced relative to younger adults, regardless of how objects are manipulated (left hand only, right hand only, or bimanual exploration).

Two experiments were conducted to evaluate the ability of younger and older adults to recognize 3-D object shape from patterns of optical motion. In Experiment 1, participants were required to identify dotted surfaces that rotated in depth (i.e., surface structure portrayed using the kinetic depth effect). The task difficulty was manipulated by limiting the surface point lifetimes within the stimulus apparent motion sequences. In Experiment 2, the participants identified solid, naturally shaped objects (replicas of bell peppers, Capsicum annuum) that were defined by occlusion boundary contours, patterns of specular highlights, or combined optical patterns containing both boundary contours and specular highlights. Significant and adverse effects of increased age were found in both experiments. Despite the fact that previous research has found that increases in age do not reduce solid shape discrimination, our current results indicated that the same conclusion does not hold for shape identification. We demonstrated that aging results in a reduction in the ability to visually recognize 3-D shape independent of how the 3-D structure is defined (motions of isolated points, deformations of smooth optical fields containing specular highlights, etc.).

A total of 36 younger (mean age = 21.3 years) and older adults (mean age = 73.8 years) haptically explored plastic copies of naturally shaped objects (bell peppers, Capsicum annuum) one at a time for 7 s each. The participants' task was to then choose which of 12 concurrently visible objects had the same solid shape as the one they felt. The younger and older participants explored the object shapes using either one, three, or five fingers (there were six participants for each combination of number of fingers and age group). The outcome was different from that of previous research conducted with manmade objects. Unlike Jansson and Monaci (2006) , we found that for most objects, our participants' performance was unaffected by variations in the number of fingers used for haptic exploration. While there was no significant overall effect of the number of fingers, there was a significant main effect of age. The younger adults' shape matching performance was 48.6% higher than that of the older adults. When perceiving naturally shaped objects such as bell peppers, it appears that the usage of a single finger can be as effective as haptic exploration with a whole complement of five fingers.

We conducted an experiment to evaluate the ability of 32 younger and older adults to visually perceive distances in an outdoor setting. On any given trial, the observers viewed 2 environmental distances and were required to estimate the distance ratio-the length of the (usually) larger distance relative to that of the shorter. The stimulus distance ratios ranged from 1.0 (the stimulus distances were identical) to 8.0 (1 distance interval was 8.0 times longer than the other). The stimulus distances were presented within a 26 m × 60 m portion of a grassy field. The observers were able to reliably estimate the stimulus distance ratios: The overall Pearson r correlation coefficient relating the judged and actual distance ratios was 0.762. Fifty-eight percent of the variance in the observers' perceived distance ratios could thus be accounted for by variations in the actual stimulus ratios. About half of the observers significantly underestimated the distance ratios, while the judgments of the remainder were essentially accurate. Significant modulatory effects of sex and age occurred, such that the male observers' judgments were the most precise, while those of the older males were the most accurate.

The ability of 26 younger (mean age was 22.5 years) and older adults (mean age was 72.6 years) to haptically perceive material properties was evaluated. The participants manually explored (for 5 seconds) 42 surfaces twice and placed each of these 84 experimental stimuli into one of seven categories: paper, plastic, metal, wood, stone, fabric, and fur/leather. In general, the participants were best able to identify fur/leather and wood materials; in contrast, recognition performance was worst for stone and paper. Despite similar overall patterns of performance for younger and older participants, the younger adults' recognition accuracies were 26.5% higher. The participants' tactile acuities (assessed by tactile grating orientation discrimination) affected their ability to identify surface material. In particular, the Pearson r correlation coefficient relating the participants' grating orientation thresholds and their material identification performance was -0.8: The higher the participants' thresholds, the lower the material recognition ability. While older adults are able to effectively perceive the solid shape of environmental objects using the sense of touch, their ability to perceive surface materials is significantly compromised.

In two experiments, participants evaluated the perceived beauty of snowflakes and solid objects. The snowflake silhouettes used as experimental stimuli were created from photographs of natural snowflakes. Both the snowflake silhouettes and computer-generated solid objects varied in complexity. In Experiment 1, 204 participants selected the single snowflake and single solid object that was the most beautiful. In Experiment 2, 33 participants rated the perceived complexity and beauty of the entire set of 100 snowflakes and solid objects. When considered as a group, the participants' results for the solid objects replicated previous findings: The most and least complex objects were perceived as being the most beautiful. This pattern did not necessarily occur, however, for individual participants. Some participants in Experiment 2, for example, found only complex solid objects to be most beautiful ( N = 10); other participants found only the simple solid objects to be most beautiful ( N = 11). Additional participants perceived both the most and least complex solid objects to be beautiful ( N = 10), while one participant only found moderately complex solid objects to be most beautiful. The results for the snowflakes were more uniform: 91% of participants perceived only the complex snowflakes as being most beautiful.

Past studies have consistently demonstrated that human observers cannot accurately perceive environmental distances. Even so, we obviously detect sufficient spatial information to meet the demands of everyday life. In the current experiment, ten younger adults (mean age was 21.8years) and ten older adults (mean age was 72.3years) estimated distance ratios in physical space. On any given trial, observers judged how long one distance interval was relative to another. The 18 stimulus ratios ranged from 1.0 to 9.5; the observers judged each stimulus ratio three times. The average correlation coefficient relating actual distance ratios to perceived ratios was identical (r=0.87) for both younger and older age groups. Despite this strong relationship between perception and reality, the judgments of many individual observers were inaccurate. For example, ten percent of the observers overestimated the stimulus ratios, while fifty percent underestimated the stimulus ratios. Although both under- and overestimation occurred in the current experiment, the results nevertheless demonstrate that human adults can reliably compare environmental distances in different directions., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Our tactual perceptual experiences occur when we interact, actively and passively, with environmental objects and surfaces. Previous research has demonstrated that active manual exploration often enhances the tactual perception of object shape. Nevertheless, the factors that contribute to this enhancement are not well understood. The present study evaluated the ability of 28 younger (mean age was 23.1 years) and older adults (mean age was 71.4 years) to discriminate curved surfaces by actively feeling objects with a single index finger and by passively feeling objects that moved relative to a restrained finger. While dynamic cutaneous stimulation was therefore present in both conditions, active exploratory movements only occurred in one. The results indicated that there was a significant and large effect of age, such that the older participants' thresholds were 43.8 percent higher than those of the younger participants. Despite the overall adverse effect of age, the pattern of results across the active and passive touch conditions was identical. For both age groups, the curvature discrimination thresholds obtained for passive touch were significantly lower than those that occurred during active touch. Curvature discrimination performance was therefore best in the current study when dynamic cutaneous stimulation occurred in the absence of active movement.

Dyspnea limits physical activity and functional status in heart failure patients. This feasibility study examined effects of a diaphragmatic breathing retraining (DBR) intervention delivered over 8 weeks with follow-up at 5 months. The intervention group (n = 18) was trained at baseline and received four telephone calls. An attention control group (n = 18) received four telephone calls with general health information. Results from linear mixed model analysis with effect sizes (η(2)) showed dyspnea improved in both groups, with little difference between groups. Compared with attention alone, the intervention increased physical activity (calories expended; η(2) = .015) and functional status (η(2) = .013) across the 5-month follow-up and increased activity counts at 8 weeks (η(2) = .070). This intervention was feasible and demonstrated promising effects on activity and function but not by reducing dyspnea. Patients may have increased physical activity because of instructions to use DBR during activities of daily living. Further exploration of the intervention's underlying physiological effect is needed., (© The Author(s) 2015.)

It is well known that motion facilitates the visual perception of solid object shape, particularly when surface texture or other identifiable features (e.g., corners) are present. Conventional models of structure-from-motion require the presence of texture or identifiable object features in order to recover 3-D structure. Is the facilitation in 3-D shape perception similar in magnitude when surface texture is absent? On any given trial in the current experiments, participants were presented with a single randomly-selected solid object (bell pepper or randomly-shaped "glaven") for 12 seconds and were required to indicate which of 12 (for bell peppers) or 8 (for glavens) simultaneously visible objects possessed the same shape. The initial single object's shape was defined either by boundary contours alone (i.e., presented as a silhouette), specular highlights alone, specular highlights combined with boundary contours, or texture. In addition, there was a haptic condition: in this condition, the participants haptically explored with both hands (but could not see) the initial single object for 12 seconds; they then performed the same shape-matching task used in the visual conditions. For both the visual and haptic conditions, motion (rotation in depth or active object manipulation) was present in half of the trials and was not present for the remaining trials. The effect of motion was quantitatively similar for all of the visual and haptic conditions-e.g., the participants' performance in Experiment 1 was 93.5 percent higher in the motion or active haptic manipulation conditions (when compared to the static conditions). The current results demonstrate that deforming specular highlights or boundary contours facilitate 3-D shape perception as much as the motion of objects that possess texture. The current results also indicate that the improvement with motion that occurs for haptics is similar in magnitude to that which occurs for vision.

The ability of 20 younger (mean age was 21.8years) and older adults (mean age was 71.5years) to visually perceive exocentric distances outdoors was evaluated. The observers adjusted the extent of in-depth spatial intervals until they appeared identical to fronto-parallel intervals of 4 and 8m. The frontal and in-depth intervals were viewed from a distance of 8m. Almost all of the observers' judgments were inaccurate and most reflected perceptual compressions in depth: e.g., an in-depth interval of 10m would appear to have the same extent as a physically smaller 8m frontal interval. Some observers' judgments, however, were consistent with perceptual expansions of in-depth intervals. No significant effects of age were obtained in the current study: both younger and older adults exhibited perceptual compressions and expansions of in-depth intervals. This outcome differs from that of a recent experiment conducted by our laboratory (Vision Research 109 (2015) 52-58) that found the judgments of younger adults to be less accurate than those of older adults. A comparison of the former and current results revealed that while older adults perform similarly outdoors and indoors, the accuracy of younger adults' exocentric judgements improves substantially in outdoor settings (so that the accuracy becomes similar to that exhibited by older adults)., (Copyright © 2015 Elsevier Ltd. All rights reserved.)