Perception of pictorial eye gaze by baboons (Papio papio)

Pictorial faces looking left or right were presented to baboons (Papio papio) before the display of a target letter in the left or right hemifield of a monitor screen. Baboons had to provide go or no-go responses taking into account the identity of the target letter. The 1st 6 experiments showed no reliable effect of eye gaze on discrimination speed, using either schematic gazes or pictures of real gazes. Experiment 7 showed that eye gazes facilitated target processing when eye cues were perfect predictors of target location. Findings suggest that baboons do not spontaneously process eye-gaze direction but can learn to do so if the gaze has a predictive value. Implications of these findings on baboons' perspective-taking abilities are discussed.     

Accountability as a deterrent to self-enhancement: the search for mechanisms

Although self-enhancement is linked to psychological benefits, it is also associated with personal and interpersonal liabilities (e.g., excessive risk taking, social exclusion). Hence, structuring social situations that prompt people to keep their self-enhancing beliefs in check can confer personal and interpersonal advantages. The authors examined whether accountability can serve this purpose. Accountability was defined as the expectation to explain, justify, and defend one's self-evaluations (grades on an essay) to another person ("audience"). Experiment 1 showed that accountability curtails self-enhancement. Experiment 2 ruled out audience concreteness and status as explanations for this effect. Experiment 3 demonstrated that accountability-induced self-enhancement reduction is due to identifiability. Experiment 4 documented that identifiability decreases self-enhancement because of evaluation expectancy and an accompanying focus on one's weaknesses.     

The psychological bases of ideology and prejudice: testing a dual process model

The issue of personality and prejudice has been largely investigated in terms of authoritarianism and social dominance orientation. However, these seem more appropriately conceptualized as ideological attitudes than as personality dimensions. The authors describe a causal model linking dual dimensions of personality, social world view, ideological attitudes, and intergroup attitudes. Structural equation modeling with data from American and White Afrikaner students supported the model, suggesting that social conformity and belief in a dangerous world influence authoritarian attitudes, whereas toughmindedness and belief in a competitive jungle world influence social dominance attitudes, and these two ideological attitude dimensions influence intergroup attitudes. The model implies that dual motivational and cognitive processes, which may be activated by different kinds of situational and intergroup dynamics, may underlie 2 distinct dimensions of prejudice.     

Naming and categorization in young children: vocal tact training

In three experiments, 2- to 4-year-old children, following pretraining with everyday objects, were presented with arbitrary stimuli of differing shapes. In Experiment 1A, 9 subjects were trained one common tact response, "zag," to three of these and a second tact, "vek," to another three. In category match-to-sample Test 1, 4 subjects sorted accurately when required only to look at the sample before selecting from five comparisons. The remaining 5 subjects succeeded in Test 2, in which they were required to tact the sample before selecting comparisons. Experiment 1B showed, for 2 of these subjects, that tact training with 12 arbitrary stimuli established two six-member classes that were still intact 6 weeks later. In Experiment 2, 3 new subjects participated in a common tact training procedure that ensured that none of the exemplars from the same class were presented together prior to the test for three-member classes. Two subjects passed category Test 1 and the third passed Test 2. Tests showed subjects' listener behavior in response to hearing /zog/ and /vek/ to be in place. These experiments indicate that common naming is effective in establishing arbitrary stimulus classes and that category match-to-sample testing provides a robust measure of categorization.     

Illusory 3-D rotation induced by dynamic image shading

Observers' perceptions of the three-dimensional structure of smoothly curved surfaces defined by patterns of image shading were investigated under varying conditions of illumination. In five experiments, observers judged the global orientation and the motion of the simulated surfaces from both static and dynamic patterns of image shading. We found that perceptual performance was more accurate with static than with dynamic displays. Dynamic displays evoked systematic biases in perceptual performance when the surface and the illumination source were simulated as rotating in opposite directions. In these conditions, the surface was incorrectly perceived as rotating in the same direction as the illumination source. Conversely, the orientation of the simulated surfaces was perceived correctly when the frames making up the apparent-motion sequences of the dynamic displays were presented as static images. In Experiment 6, moreover, the results obtained with the computer-generated displays were replicated with solid objects.     

Tactile "capture" of audition

Previous research has demonstrated that the localization of auditory or tactile stimuli can be biased by the simultaneous presentation of a visual stimulus from a different spatial position. We investigated whether auditory localization judgments could also be affected by the presentation of spatially displaced tactile stimuli, using a procedure designed to reveal perceptual interactions across modalities. Participants made left-right discrimination responses regarding the perceived location of sounds, which were presented either in isolation or together with tactile stimulation to the fingertips. The results demonstrate that the apparent location of a sound can be biased toward tactile stimulation when it is synchronous, but not when it is asynchronous, with the auditory event. Directing attention to the tactile modality did not increase the bias of sound localization toward synchronous tactile stimulation. These results provide the first demonstration of the tactile capture of audition.     

A reversal in the direction of detection asymmetry: effects of spatial density,spatial regularity,and retinal eccentricity

We analyzed detection asymmetry, using openand closed squares as target and contextelements. It was found that varying density, regularity, and target eccentricity not only can modulate the amount of asymmetry, but also can produce a reversal in the direction of the asymmetry. The results suggest that the different stimuli are processed with different grains of analysis,consisting of in some cases, single elements and their properties and, in other cases, larger units of the stimulus array and more globalproperties. A detection task that can utilize the properties that are available with a given grain of analysis would show an advantage over a task for which the given grain of analysis is not as favorable, resulting indetection asymmetry in one direction or another.     

Recognition memory for source and occurrence: The importance of recollection

Previous recognition memory studies indicate that when both recollection and familiarity are expected to contribute to recognition performance (e.g., discriminating studied items from nonstudied items) the dual-process and the unequal-variance signal detection models provide comparable accounts of performance. When familiarity is not expected to be useful (e.g., when items from two equally familiar sources are discriminated between), the dual-process model provides a significantly better account of performance. In the present study, source recognition was tested under conditions in which familiarity could have been used to perform a list-discrimination task; participants were required to discriminate between strong studied items, weak studied items, and new items. The dual-process model provided a better account of performance than did the unequal-variance model. Moreover, the results indicated that the unequal-variance assumption in a single-process signal detection model was not a valid substitution for recollection and that recollection was used to make recognition judgments even when assessments of familiarity were useful.     

Cross-modal re-mapping influences the Simon effect

Tagliabue, Zorzi, Umiltà, and Bassignani (2000) showed that one's practicing of a spatially incompatible task influences performance in a Simon task even when the interval between the two tasks is as long as 1 week. In the present study, three experiments were conducted to investigate whether such an effect could be found in a cross-modal paradigm, whereby stimuli in the two tasks were presented in different modalities. Subjects performed either compatible or incompatible mappings in an acoustic spatial compatibility task and, after an interval of 5 min, 24 h, or 7 days, performed a visual Simon task. Results show that the spatially incompatible mapping task affected performance in the Simon task: The Simon effect was absent for all three intervals. This pattern is similar to the results of the Tagliabue et al. study, in which both tasks were performed in the same (visual) modality. Our findings disprove possible explanations based on episodic/contextual effects and support the hypothesis of a long-lasting spatial remapping that is not modality specific.     

Personally familiar proper names are relatively successfully processed in the human right hemisphere; or, the missing link

Responding to our abstract in Brain and Language (Ohnesorge & Van Lancker, 1999), which proposed that famous proper nouns are successfully processed in both cerebral hemispheres, Schweinberger, Landgrebe, Mohr, and Kaufmann (2001) claimed that the "link" between personal names and the right hemisphere is "illusory." Ohnesorge and Van Lancker (2001) further described six experimental studies in which LVF/RH recognition of famous proper nouns was influenced by task conditions and stimulus familiarity. Here presenting two more experiments performed to explore the refutation presented by Schweinberger et al., this article confirms an ability of the right hemisphere to recognize famous proper nouns and explains why appropriate stimulus development and task conditions are essential in furthering our understanding of the role of the right hemisphere in processing personal relevance.