Perceptual assignment of opacity to translucent surfaces: the role of image blur

In constructing the percept of transparency, the visual system must decompose the light intensity at each image location into two components one for the partially transmissivc surface, the other for the underlying surface seen through it. Theories of perceptual transparency have typically assumed that this decomposition is defined quantitatively in terms of the inverse of some physical model (typically, Metelli's 'episcotister model'). In previous work, we demonstrated that the visual system uses Michelson contrast as a critical image variable in assigning transmittance to transparent surfaces not luminance differences as predicted by Metelli's model [F Metelli, 1974 Scientific American 230(4) 90 98]. In this paper, we study the contribution of another variable in determining perceived transmittance, namely, the image blur introduced by the light-scattering properties of translucent surfaces and materials. Experiment 1 demonstrates that increasing the degree of blur in the region of transparency leads to a lowering in perceived transmittance, even if Michelson contrast remains constant in this region. Experiment 2 tests how this addition of blur affects apparent contrast in the absence of perceived transparency. The results demonstrate that, although introducing blur leads to a lowering in apparent contrast, the magnitude of this decrease is relatively small, and not sufficient to explain the decrease in perceived transmittance observed in experiment 1. The visual system thus takes the presence of blur in the region of transparency as an additional image cue in assigning transmittance to partially transmissive surfaces.     

Information along contours and object boundaries

F. Attneave (1954) famously suggested that information along visual contours is concentrated in regions of high magnitude of curvature, rather than being distributed uniformly along the contour. Here the authors give a formal derivation of this claim, yielding an exact expression for information, in C. Shannon's (1948) sense, as a function of contour curvature. Moreover, they extend Attneave's claim to incorporate the role of sign of curvature, not just magnitude of curvature. In particular, the authors show that for closed contours, such as object boundaries, segments of negative curvature (i.e., concave segments) literally carry greater information than do corresponding regions of positive curvature (i.e., convex segments). The psychological validity of this informational analysis is supported by a host of empirical findings demonstrating the asymmetric way in which the visual system treats regions of positive and negative curvature.     

Parsing silhouettes: The short-cut rule

Many researchers have proposed that, for the purpose of recognition, human vision parses shapes into component parts. Precisely how is not yet known. The minima rule for silhouettes (Hoffman & Richards, 1984) defines boundary points at which to parse but does not tell how to use these points to cut silhouettes and, therefore, does not tell what the parts are. In this paper, we propose the short-cut rule, which states that, other things being equal, human vision prefers to use the shortest possible cuts to parse silhouettes. We motivate this rule, and the well-known Petter’s rule for modal completion, by the principle of transversality. We present five psychophysical experiments that test the short-cut rule, show that it successfully predicts part cuts that connect boundary points given by the minima rule, and show that it can also create new boundary points.     

The cycle of schizoaffective disorder, cognitive ability, alcoholism, and suicidality

In this study we investigated the putative role of cognitive dysfunction, diagnosis (schizoaffective versus schizophrenia disorder), and alcoholism as risk factors for suicidal behavior among individuals with DSM-TV schizophrenia or schizoaffective disorders. Subjects received cognitive tests and medical records were reviewed for evidence of a history of suicide attempts or suicidal ideation. Discriminant analysis was used to identify cognitive test performance measures that distinguished those with versus those without suicidal behavior. None of the cognitive measures discriminated between the two groups. The rates of suicidal behavior (suicidal ideation and suicide attempts) did not differ between participants with versus those without comorbid alcohol use. An association was found between suicidal behavior and the diagnosis of schizoaffective disorder. It was concluded that the history of prominent mood syndromes characteristic of schizoaffective disorder contributes to increased risk of suicidal behaviors. Cognitive dysfunction and/or alcoholism did not contribute additionally to risk in this study.     

Continuous Response Monitoring of Relative Time-to-Contact Judgments: Does Effective Information Change During an Approach Event?

In many previous studies of time-to-contact (TTC) judgments of approaching objects, a response was measured after observers viewed the entire event and was used to infer the informational basis for the judgment. Such measures primarily reflect the information used at the end of the approach event and may not reveal whether observers used different information at different times during the event. Evidence indicates that observers use multiple information sources and that the effectiveness of information varies with distance. We introduce a method in which observers continuously report which of 2 approaching objects would reach them first, throughout the approach. We identified the occurrence and time of response reversals. Most observers changed their relative TTC judgments during the event. The pattern of responses indicated that observers did not use tau early during the approach when objects were far and did not use optical size later when the objects were closer. Most observers relied on either optical size or optical expansion rate early during the approach and expansion rate later during the event, although there were individual differences. A single relative TTC judgment measured after observers view an approach event may not reflect judgments or their informational basis throughout the entire event.     

Detection of change in shape: an advantage for concavities

Shape representation was studied using a change detection task. Observers viewed two individual shapes in succession, either identical or one a slightly altered version of the other, and reported whether they detected a change. We found a dramatic advantage for concave compared to convex changes of equal magnitude. Observers were more accurate when a concavity along the contour was introduced, or removed, compared to a convexity. This result sheds light on the underlying representation of visual shape, and in particular the central role played by part-boundaries. Moreover, this finding shows how change detection methodology can serve as a useful tool in studying the specific form of visual representations.     

Recombinative generalization of within-syllable units in nonreading adults with mental retardation

Two adults with mental retardation demonstrated the recombination of within-syllable units (onsets and rimes) using a spoken-to-printed-word matching-to-sample (MTS) procedure. Further testing with 1 participant showed comprehension of the printed words. Printed-word naming was minimal before, but greater after, comprehension tests. The findings suggest that these procedures hold promise for further basic and applied analyses of word-attack skills.     

Gamification and neuromarketing: A unified approach for improving user experience

Neuroscience and its offshoot as neuromarketing have helped marketers understand neuroscientific aspects of customers while gamification has helped them understand the psyche of consumers. Despite neuromarketing's many potential benefits to businesses, little academic work has been done on the field so far. Most studies have examined consumer shifts during and after pandemics without analyzing them from two critical perspectives: neuroscientific theories and psychology theories. As the two streams of knowledge lean on each other, their interdependence in the field of e-engagement needs exploration. The purpose of this study is to answer an important question – “How do marketers use gamification and neuromarketing to understand online engagement of consumers?”. We used a quantitative empirical research approach to assess the inter-relationship between neuromarketing and gamification. The study collected data from digital marketing strategists of retail firms to propose a theoretical framework for self-determination theory in successfully implementing new age technologies by plugging the cues of gamification and neuromarketing. The framework would be useful for retail firms to design digital marketing strategies for capturing the attention of consumers across different geographies. Findings indicated that, marketers are interested in neuromarketing for two main reasons: first, they think it can help them save money and improve their marketing plans, and second, they think that cutting-edge research techniques such as brain imaging can help them get more accurate findings.     

Trends in presentations at the annual conference of the association for behavior analysis

The present report analyzes trends in attendance and presentations at the annual conference of the Association for Behavior Analysis (ABA). Numbers of registered attendees were plotted over time. The trends show that the number of registered attendees has grown considerably over the last three decades, with the largest proportion of the growth occurring during the last 10 years. This growth is shown to be correlated with the introduction of board certification in behavior analysis (BCBA and BCABA). In addition, conference programs from 1980 through 2007 were coded, and all presentations were categorized into one of four areas (application, basic research, conceptual, and verbal behavior) based on the primary designator codes chosen by the authors at the time of submission. An analysis of the total number of presentations in each category indicates that applied research presentations have always outnumbered the other three categories. The absolute number of presentations related to application has grown faster than presentations in other categories. However, correcting for population growth shows that the relative proportion of presentations in the four areas has remained fairly constant over the last 28 years.     

Do common elements predict class merger: A test of Sidman's theory of equivalence

The study presented here investigated the effect of common and uncommon elements on class merger as predicted by Sidman in his reconceptualization of stimulus equivalence suggesting that common elements among contingencies can facilitate emergent performances (1994, 1997, 2000). Eight adult participants were exposed to a procedure that arranged for stimulus–reinforcer correlations in Phase 1 and response–reinforcer correlations in Phase 2 of a 3-phase study. In the common element group, the visual images serving as reinforcers were the same in Phase 1 and Phase 2. In the uncommon elements group, the images serving as reinforcers were different in Phases 1 and 2. In Phase 3, participants were given an opportunity to respond but no feedback was programmed. The results showed that participants' responding was well differentiated in the common element group and undifferentiated in the uncommon elements group. These results are predicted by Sidman's revised formulation of the provenance and scope of equivalence relations. Specifically, these data support Sidman's (1994, 1997, 2000) suggestion that elements of a contingency enter into an equivalence class and common elements among contingencies are sufficient to produce class mergers. The findings highlight an emergent simple discrimination and raise some interesting considerations about the definition of equivalence under the new formulation.