Panum’s fusional area estimated with a criterion-free technique

It has been reported that criterion-free estimates of the upper disparity limits for fusion of line targets are small enough to be accounted for by monocular vernier sensitivity. However, targets such as lines, which contain high spatial frequencies, may ensure small fusion limits, since fusion limits obtained with criterion-dependent methods for narrow-band targets, such as sinusoids or difference-of-Gaussian luminance profiles, are proportional to target spatial periods. Experiment 1 therefore explored whether criterion-free methods give fusion limits for narrow-band targets that can be accounted for by vernier sensitivity. Vertical fusion limits were estimated by a method that forced observers to discriminate a disparate sinusoidal grating from an immediately adjacent zero-disparity grating. Fusion limits were too large to be explained by monocular vernier thresholds obtained for the same targets. In addition, fusion limits were not affected by large changes in target contrast, whereas vernier thresholds increased as contrast was decreased. The results of Experiment 1 also argued against interocular suppression as the cause of single vision, since vernier offsets that were visible when viewed monocularly were invisible under binocular viewing conditions. In Experiment 2, manual adjustment of disparities yielded fusion limits little different from those obtained with the forced-choice method of Experiment 1, demonstrating that it is possible to design adjustment methods for assessing fusion limits that are as sensitive as forced-choice methods. In Experiment 3, large reductions in target contrast, which have the effect of decreasing disparity sensitivity, did not alter fusion limits, disconfirming the idea that fusion limits estimated with discriminative procedures represent disparity-detection thresholds. In Experiment 4, disparities were adjusted until a just noticeable difference in grating contrast appeared. These disparities were larger than fusion limits, indicating that fusion limits did not represent a change in apparent contrast arising from disparity limitations of binocular summation. Together, the four experiments support the existence of binocular fusion as a unique category of sensory performance, disconfirm several nonfusional explanations of single vision, and support the use of criterion-free as well as adjustment methods in measuring fusion limits.     

Panum's fusional area estimated with a criterion-free technique

It has been reported that criterion-free estimates of the upper disparity limits for fusion of line targets are small enough to be accounted for by monocular vernier sensitivity. However, targets such as lines, which contain high spatial frequencies, may ensure small fusion limits, since fusion limits obtained with criterion-dependent methods for narrow-band targets, such as sinusoids or difference-of-Gaussian luminance profiles, are proportional to target spatial periods. Experiment 1 therefore explored whether criterion-free methods give fusion limits for narrow-band targets that can be accounted for by vernier sensitivity. Vertical fusion limits were estimated by a method that forced observers to discriminate a disparate sinusoidal grating from an immediately adjacent zero-disparity grating. Fusion limits were too large to be explained by monocular vernier thresholds obtained for the same targets. In addition, fusion limits were not affected by large changes in target contrast, whereas vernier thresholds increased as contrast was decreased. The results of Experiment 1 also argued against interocular suppression as the cause of single vision, since vernier offsets that were visible when viewed monocularly were invisible under binocular viewing conditions. In Experiment 2, manual adjustment of disparities yielded fusion limits little different from those obtained with the forced-choice method of Experiment 1, demonstrating that it is possible to design adjustment methods for assessing fusion limits that are as sensitive as forced-choice methods. In Experiment 3, large reductions in target contrast, which have the effect of decreasing disparity sensitivity, did not alter fusion limits, disconfirming the idea that fusion limits estimated with discriminative procedures represent disparity-detection thresholds. In Experiment 4, disparities were adjusted until a just noticeable difference in grating contrast appeared. These disparities were larger than fusion limits, indicating that fusion limits did not represent a change in apparent contrast arising from disparity limitations of binocular summation. Together, the four experiments support the existence of binocular fusion as a unique category of sensory performance, disconfirm several nonfusional explanations of single vision, and support the use of criterion-free as well as adjustment methods in measuring fusion limits.     

Visual acuity improvement following fading and feedback training—II. Relationship to changes in refractive error

The present study evaluated the effects of behavioral training on visual acuity and refractive error in myopic adults. Twenty volunteers were matched on the basis of refractive error and one member of each matched pair was randomly assigned to either Fading and Feedback training or a no-treatment control condition. Visual acuity was measured with both recognition and resolution measures. Refractive error was measured subjectively using the LaserSpec optometer, and objectively by two retinoscopic examinations performed by an ophthalmologist with and without cycloplegia. The results indicated significant increases in recognition visual acuity, but not resolution visual acuity for trained subjects compared to the no-treatment controls. Trained subjects did not show improvement in refractive error on any measure, and refractive error changes were not correlated with changes in either measure of visual acuity. These data suggest that the visual acuity improvements typically found with behavioral training are not associated with changes in refractive error.     

Vernier acuity with opposite-contrast stimuli

Vernier acuity has usually been tested with stimuli of the same contrast polarity (SC). This traditional vernier acuity was compared to that obtained with stimuli of opposite-contrast (OC) in which one target was brighter than the background and the other was darker. For both bar and dot targets vernier acuity with OC stimuli was about half as good as with SC stimuli. There were large individual differences in the size of the disadvantage with OC stimuli, although thresholds remained within the hyperacuity range. There were also individually-differing biases to see a dark vernier stimulus on one or the other side of a bright stimulus. Differences between OC and SC vernier acuities persisted over a wide range of interstimulus spacings, widths, and contrasts. At extremes of these spatial manipulations acuities became similar, but only because SC acuities were degraded to the level of OC acuities. Subjects showed little improvement in OC vernier acuity, even after 50,000 trials. It is concluded that finest judgements of spatial position arise in a level of the visual system at which light and dark stimuli are treated independently.     

Behavioral Telehealth: Emerging Practice,Research, and Policy Opportunities

Behavioral telehealth, the use of electronic and communication technologies to provide and support behavioral health care when distance separates the participants, has the potential to address the nationally significant problems of access, cost, and distribution of behavioral health care and providers. Using examples of developing behavioral clinical practice, research, and policy opportunities, this article outlines the promise of this field while discussing the barriers to the development of behavioral telehealth networks, including the lack of clinical protocols, solid evaluative research, payment for telehealth/telemedicine services, uniform state licensure, and uniform privacy/confidentiality policy. It is argued that behavioral practitioners, researchers, and advocates must actively participate in this rapidly developing field, and these professionals are ideally suited to supply ongoing federal and state policy initiatives with much needed empirical clinical data and evaluative research that will help to generate sound policy.     

Switching binding states

Recently, we introduced two illusions: Feature inheritance and shine-through (Herzog & Koch, 2001). In both cases, a vernier precedes a grating for a short time. In feature inheritance the grating comprises a small number of elements to which properties of the foregoing vernier are bound. The vernier itself remains invisible. In shine-through, a grating comprising a larger number of elements follows the foregoing vernier. Surprisingly, the vernier becomes visible as an entity in its own right and does not bequeath its features to the grating. Two “objects” are perceived each preserving its properties. Therefore, each of the two illusions represents a different state of feature binding. Our results suggest that feature binding is based on an antecedent segmentation process that might be viewed as a binding process itself.     

Engineering technology and behavior analysis for interdisciplinary environmental protection

Engineering strategies for saving environmental resources have been widespread. However, many of those engineering advances have not been widely accepted nor generally applied by large segments of the general population. This paper considers the need to examine behavioral/environmental variables in the application of engineering technology, with particular reference to specific behavioral strategies for encouraging the use of engineering technology from an interdisciplinary perspective. A model for the study of factors contributing to the solution of ecological/environmental problems is presented and examples of interdisciplinary research are described. The model implies a need for the examination of the effects of antecedent and consequent manipulation of a variety of variables including: behavioral, physiological, environmental, technical and legal conditions. It is concluded that while interdisciplinary research efforts between engineering technologists and behavioral analysts are necessary, they have not received sufficient attention in the literature nor have they focused on the comprehensive study of antecedents and consequences as they relate to ecological/environmental problems. Thus, an extended "family" of research efforts is important for the success of these efforts.     

发展行为遗传学简介

发展行为遗传学是发展心理学与行为遗传学的交叉学科, 旨在探明遗传与环境对人类心理与行为发展是否存在影响, 如何产生影响, 以及该影响及其作用机制是否随年龄增长而发展变化的问题。该学科与行为遗传学在研究对象、设计和内容等方面存在不同; 开展发展行为遗传学研究需要综合运用心理测量法和行为遗传学研究方法; 未来研究应拓宽和深化候选基因与行为关联性的考察, 并着力探析基因与环境的相互作用机制。     

A critique of the usefulness of inferential statistics in applied behavior analysis

Researchers continue to recommend that applied behavior analysts use inferential statistics in making decisions about effects of independent variables on dependent variables. In many other approaches to behavioral science, inferential statistics are the primary means for deciding the importance of effects. Several possible uses of inferential statistics are considered. Rather than being an objective means for making decisions about effects, as is often claimed, inferential statistics are shown to be subjective. It is argued that the use of inferential statistics adds nothing to the complex and admittedly subjective nonstatistical methods that are often employed in applied behavior analysis. Attacks on inferential statistics that are being made, perhaps with increasing frequency, by those who are not behavior analysts, are discussed. These attackers are calling for banning the use of inferential statistics in research publications and commonly recommend that behavioral scientists should switch to using statistics aimed at interval estimation or the method of confidence intervals. Interval estimation is shown to be contrary to the fundamental assumption of behavior analysis that only individuals behave. It is recommended that authors who wish to publish the results of inferential statistics be asked to justify them as a means for helping us to identify any ways in which they may be useful.     

Effect of stimulus duration on stereo and vernier displacement thresholds

Stereo and vernier thresholds were determined as a function of stimulus duration in both misalignment and displacement paradigms. All four thresholds increase as stimulus duration decreases. The increase is greatest for the stereo displacement threshold, less for the vernier displacement threshold, and least for the misalignment thresholds. The results are consistent with the hypothesis that depth signals are averaged over time.     

Serial and parallel search in pattern vision?

The nature of the processing of combinations of stimulus dimensions in human vision has recently been investigated. A study is reported in which visual search for suprathreshold positional information--vernier offsets, stereoscopic disparity, lateral separation, and orientation--was examined. The initial results showed that reaction times for visual search for conjunctions of stereoscopic disparity and either vernier offsets or orientation were independent of the number of distracting stimuli displayed, suggesting that disparity was searched in parallel with vernier offsets or orientation. Conversely, reaction times for detection of conjunctions of vernier offsets and orientation, or lateral separation and each of the other positional judgements, were related linearly to the number of distractors, suggesting serial search. However, practice has a significant effect upon the results, indicative of a shift in the mode of search from serial to parallel for all conjunctions tested as well as for single features. This suggests a reinterpretation of these and perhaps other studies that use the Treisman visual search paradigm, in terms of perceptual segregation of the visual field by disparity, motion, color, and pattern features such as colinearity, orientation, lateral separation, or size.     

Letters of Recommendation: Controversy and consensus from expert perspectives

Letters of recommendation (LORs) are a widely used selection tool with many issues associated with their use. To address some of these issues, 575 professionals in personnel‐related professions reported their experiences with LORs. We separated items into consensus, polarized, or neither categories. Experts reached consensus that letter inflation is a problem that may never be alleviated and that more weight is placed on letters written by someone the reader knows or from a prestigious institution or organization. Most items were polarized, suggesting substantial controversy in the field regarding LORs. Some items originally polarized reached consensus within profession (academic vs applied). Academic professionals reported using LORs more and placing more weight on their contents than applied professionals. Implications discussed include recommendations for future research and practice, such as the appropriate use of LORs, LOR formats, and training.     

The oblique effect in a vernier acuity situation

Observers viewed either vertical or obliquely oriented vernier targets from either an upright position or with their heads tilted. Vernier acuity was consistently better for retinally vertical than for gravitationally vertical targets, even when presented against a background context of vertical stripes designed to aid veridical perception of gravitational orientation. These results indicate that vernier acuity depends on retinal image orientation rather than on perceived orientation. The high contrast of the vernier lines ensures that their gravitational orientation is clearly perceived. Thus the present results provide a stronger basis for ruling out the effects of perceptual orientation than previous studies involving grating contrast-threshold measurements. Since the vernier targets were presented as brief flashes, it is unlikely that the measured oblique effect is attributable to differences in eye-movement patterns.     

POTENTIAL APPLICATIONS OF BEHAVIORAL DECISION RESEARCH TO TREATMENTS FOR DRUG ABUSE, RELATED RISKY BEHAVIORS, AND OTHER PROBLEMS:

Abstract— This commentary highlights potential applications of behavioral decision research to treatments for substance abuse and related risky behaviors. Some research questions are suggested to help determine how risk information developed with behavioral decision methods could be used with maximal impact to treat and prevent substance use The relevance of behavioral decision research treatments for other problems such as anxiety is briefly discussed. The important and direct applicability of behavioral decision methods to informed consent far research participants also is noted.     

From multimodal programs to a new cognitive–interpersonal approach in the rehabilitation of offenders

A considerable amount of meta-analytic research supports the effectiveness of cognitive–behavioral psychoeducational programs in reducing recidivism rates, in youths and adults with antisocial behavior. These same studies suggest that programs including a cognitive component are as twice as more effective in reducing recidivism rates. This paper reviews outcome studies sustaining the use of structured interventions in forensic settings. It introduces a new program, Growing Pro-Social (GPS), currently in use in several Portuguese youth rehabilitation centers and prisons. GPS is a multimodal structured group program designed for the rehabilitation of individuals with antisocial behavior. It includes 40 weekly sessions, organized into 5 sequential modules. Based on a cognitive–interpersonal theoretical framework, GPS focuses on cognitive, emotional, and behavioral change, assuming as an ultimate goal the modification of dysfunctional core beliefs underlying antisocial behavior.     

Positional acuity without monocular cues

The accuracy with which human observers can determine the spatial location of a shape boundary was measured by vernier alignment. The vernier targets were presented as random-dot stereograms, with varying amounts of camouflage in the monocular image. Camouflage decreased vernier acuity, but when the camouflage was broken by stereoscopic disparity, acuity was improved. In the limiting case when the shape boundaries were defined by disparity information alone, vernier thresholds (75% correct, binary forced-choice) were in the region of 40 s visual angle. This is poor acuity in comparison to vernier thresholds with monocular contour, but if the limited resolution acuity for stereopsis is taken into account, cyclopean and monocular positional acuities can be considered quite similar in relation to their respective resolution limits.     

Accommodation fatigue and dark focus: The effects of accommodation-free visual work as assessed by two psychophysical methods

Past studies of accommodation fatigue have yielded inconsistent results, partly because they have not used direct measures of accommodation, and partly because they may have been based on a misleading conception of the nature of accommodation. The dual-innervation theory of accommodation suggests that the resting position of accommodation may be neuromuscular rather than just muscular, and that it lies not at optical infinity, as assumed by older conceptions, but at some intermediate position (dark focus). Among the predictions that may be deduced from this theory is that long-term visual work not requiring active accommodation will not induce fatigue. The present study involved continuous measurements of dark focus for 10 young adults over a 3-h period, using the laser optometer with two psychophysical procedures Ibracketing and staircase. Consistent with the prediction, no changes in dark focus were found, in spite of the demanding visual task. Furthermore, it was found that both psychophysical methods yielded essentially identical results. The practical and theoretical implications of these results are discussed, and recommendations are given regarding situations in which each of the psychophysical methods is likely to be most useful.     

Actions Can Speak as Loud as Words: Measuring Behavior in Psychological Science

It has been argued that there is a growing trend in personality and social psychological science concerning the preference of self‐report measures over the use of direct observations of behavior for the outcome variables of interest. Augmenting the use of self‐reports with measures of behavior helps achieve methodological pluralism that allows researchers to triangulate on the phenomenon of interest and have increased confidence in understanding the phenomenon. To facilitate this process, we discuss a sample of social psychological and personality studies published during APA’s ‘Decade of Behavior’ that use straightforward and innovative ways of measuring behavioral outcome variables. Specifically, we identify three different strategies for incorporating behavior in a study: behavioral traces, behavioral observations, and behavioral choice. In each case, we show how measures of behavior complement self‐report measures. By making a conscientious effort to include more behavior measures in our research, we can broaden the appeal of psychological science by enhancing our understanding of the causes and antecedents of human behavior.     

Evaluating programs in applied settings through behavioral consultation

A behavioral consultation school psychology service model is presented which provides a vehicle for services and communication of process and outcome measures in program evaluation research. Within the context of the problem-solving perspective of applied behavior analysis, the consultation model (a) promotes process and outcome evaluation across a wide variety of settings, situations, and time; (b) leads to use of an applied research technology with wide applicability in educational settings; and (c) provides a communication technology for the program evaluation process through a four-stage problem-solving strategy. It is argued that the professional behavioral school psychologist can provide technical expertise to function as a system change agent within this evaluation model.     

Grouping in the shine-through effect

How the elements of a visual scene are grouped into objects is one of the most fundamental but still poorly understood questions in visual neuroscience. Most investigations of perceptual grouping focus on static stimuli, neglecting temporal aspects. Using a masking paradigm, we show that the neural mechanisms underlying grouping seem to be both fast and complex. For example, a vernier target was followed by, first, a briefly presented grating and, then, a long-lasting, extended grating. Under these conditions, the briefly presented grating is hardly visible. Still, vernier discrimination strongly changed with the number of elements of the briefly displayed grating being worst for small gratings. In accordance with a neural network model of masking, we propose that the edges of the briefly presented grating and the vernier interfere in spite of the short presentation time. We suggest that this fast edge processing is a first step for unconscious grouping processes.