Visual aftereffect of texture density contingent on color of frame

An aftereffect of perceived texture density contingent on the color of a surrounding region is reported. In a series of experiments, participants were adapted, with fixation, to stimuli in which the relative density of two achromatic texture regions was perfectly correlated with the color presented in a surrounding region. Following adaptation, the perceived relative density of the two regions was contingent on the color of the surrounding region or of the texture elements themselves. For example, if high density on the left was correlated with a blue surround during adaptation (and high density on the right with a yellow surround), then in order for the left and right textures to appear equal in the assessment phase, denser texture was required on the left in the presence of a blue surround (and denser texture on the right in the context of a yellow surround). Contingent aftereffects were found (1) with black-and-white scatter-dot textures, (2) with luminance-balanced textures, and (3) when the texture elements, rather than the surrounds, were colored during assessment. Effect size was decreased when the elements themselves were colored, but also when spatial subportions of the surround were used for the presentation of color. The effect may be mediated by retinal color spreading (Pöppel, 1986) and appears consistent with a local associative account of contingent aftereffects, such as Barlow’s (1990) model of modifiable inhibition.     

The reverse Stroop effect

In classic Stroop interference, manual or oral identification of sensory colors presented as incongruent color words is delayed relative to simple color naming. In the experiment reported here, this effect was shown to all but disappear when the response was simply to point to a matching patch of color. Conversely, strong reverse Stroop interference occurred with the pointing task. That is, when the sensory color of a color word was incongruent with that word, responses to color words were delayed by an average of 69 msec relative to a word presented in gray. Thus, incongruently colored words interfere strongly with pointing to a color patch named by the words, but little interference from incongruent color words is found when the goal is to match the color of the word. These results suggest that Stroop effects arise from response compatibility of irrelevant information rather than automatic processing or habit strength.     

Perception of visual speed while moving

During self-motion, the world normally appears stationary. In part, this may be due to reductions in visual motion signals during self-motion. In 8 experiments, the authors used magnitude estimation to characterize changes in visual speed perception as a result of biomechanical self-motion alone (treadmill walking), physical translation alone (passive transport), and both biomechanical self-motion and physical translation together (walking). Their results show that each factor alone produces subtractive reductions in visual speed but that subtraction is greatest with both factors together, approximating the sum of the 2 separately. The similarity of results for biomechanical and passive self-motion support H. B. Barlow's (1990) inhibition theory of sensory correlation as a mechanism for implementing H. Wallach's (1987) compensation for self-motion.     

Mixing metaphors in the cerebral hemispheres: what happens when careers collide?

Are processes of figurative comparison and figurative categorization different? An experiment combining alternative-sense and matched-sense metaphor priming with a divided visual field assessment technique sought to isolate processes of comparison and categorization in the 2 cerebral hemispheres. For target metaphors presented in the right visual field/left cerebral hemisphere (RVF/LH), only matched-sense primes were facilitative. Literal primes and alternative-sense primes had no effect on comprehension time compared to the unprimed baseline. The effects of matched-sense primes were additive with the rated conventionality of the targets. For target metaphors presented to the left visual field/right cerebral hemisphere (LVF/RH), matched-sense primes were again additively facilitative. However, alternative-sense primes, though facilitative overall, seemed to eliminate the preexisting advantages of conventional target metaphor senses in the LVF/RH in favor of metaphoric senses similar to those of the primes. These findings are consistent with tightly controlled categorical coding in the LH and coarse, flexible, context-dependent coding in the RH.     

The Wished‐For Always Wins Until the Winner Was Inevitable All Along: Motivated Reasoning and Belief Bias Regulate Emotion During Elections

How do biases affect political information processing? A variant of the Wason selection task, which tests for confirmation bias, was used to characterize how the dynamics of the recent U.S. presidential election affected how people reasoned about political information. Participants were asked to evaluate pundit‐style conditional claims like “The incumbent always wins in a year when unemployment drops” either immediately before or immediately after the 2012 presidential election. A three‐way interaction between ideology, predicted winner (whether the proposition predicted that Obama or Romney would win), and the time of test indicated complex effects of bias on reasoning. Before the election, there was partial evidence of motivated reasoning—liberals performed especially well at looking for falsifying information when the pundit's claim predicted Romney would win. After the election, once the outcome was known, there was evidence of a belief bias—people sought to falsify claims that were inconsistent with the real‐world outcome rather than their ideology. These results suggest that people seek to implicitly regulate emotion when reasoning about political predictions. Before elections, people like to think their preferred candidate will win. After elections, people like to think the winner was inevitable all along.     

Giant African Pouched Rats as Detectors of Tuberculosis in Human Sputum: Comparison of Two Techniques for Sputum Presentation

Previous studies have shown that pouched rats can detect the presence of Mycobacterium tuberculosis, which causes tuberculosis, in human sputum samples obtained from clinical facilities. Although pouched rats evaluate sputum samples quickly, preparing the samples is relatively slow. The present study evaluated whether the rats can detect tuberculosis in microscope slides, which are routinely prepared at these facilities. Results indicate that they can do so, but their accuracy is considerably lower than that of rats exposed to pots containing sputum, as in prior studies.

     

Tuberculosis detection by giant african pouched rats

In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can evaluate many samples quickly, are sufficiently accurate in detecting TB to merit further investigation as a diagnostic tool.     

An imputed dissociation might be an artifact: Further evidence for the generalizability of the observations of Durgin et al. 2010

We recently showed that palm board measures are systematically inaccurate for full-cue surfaces within reach of one's hand, whereas free-hand gestures and reaching actions are quite accurate for such surfaces (Durgin, Hajnal, Li, Tonge, & Stigliani, 2010). Proffitt and Zadra (2010) claim that our demonstration that palm boards are highly inaccurate is irrelevant to interpreting past and present findings concerning dissociations between verbal reports and palm board estimates. In their paper they offer a theoretical representation of the findings of Bhalla and Proffitt (1999) and argue that our analysis is incompatible with their account. We offer here an alternative account of the findings of Bhalla and Proffitt, based on their actual data (which are fully compatible with our original analysis). We further show how our account generalizes to more recent studies that continue (1) to mistakenly describe null statistical effects on (insensitive) palm boards as evidence of a “dissociation” from (more sensitive) verbal measures that show a similar relative magnitude of change and (2) to introduce uncontrolled demand characteristics.     

Perceptual scale expansion: an efficient angular coding strategy for locomotor space

Whereas most sensory information is coded on a logarithmic scale, linear expansion of a limited range may provide a more efficient coding for the angular variables important to precise motor control. In four experiments, we show that the perceived declination of gaze, like the perceived orientation of surfaces, is coded on a distorted scale. The distortion seems to arise from a nearly linear expansion of the angular range close to horizontal/straight ahead and is evident in explicit verbal and nonverbal measures (Experiments 1 and 2), as well as in implicit measures of perceived gaze direction (Experiment 4). The theory is advanced that this scale expansion (by a factor of about 1.5) may serve a functional goal of coding efficiency for angular perceptual variables. The scale expansion of perceived gaze declination is accompanied by a corresponding expansion of perceived optical slants in the same range (Experiments 3 and 4). These dual distortions can account for the explicit misperception of distance typically obtained by direct report and exocentric matching, while allowing for accurate spatial action to be understood as the result of calibration.     

An ostrich on a rock: commentary on Christie and Barresi (2002)

There are problems with both the theoretical logic and the interpretation of data in Christie and Barresi's (2002) interesting article. The general pattern of results (described as Orwellian) is easily incorporated into an information-processing framework compatible with Dennett's analysis. In particular, different aspects of the illusory motion event are queried at different times and these aspects (line extent and manner of appearance) are not in conflict, so no revision of conscious content is necessary. Second, too much interpretive weight is placed on an anomalous pair of data points (described as Stalinesque) that do not seem fully interpretable within the author's framework and are probably susceptible to one of several alternative interpretations proposed here, though further investigation is necessary.