Pigeons perceive a reversed Zöllner illusion

Pigeons are susceptible to several size and length illusions, but in some cases the bias has been shown to be opposite to that seen in humans. To further investigate how their perceptual system works, we asked how pigeons perceive orientation illusions. We used the Zöllner illusion, in which parallel lines look non-parallel due to series of short crosshatches superimposed on the lines. First, we trained six birds to peck at the narrower (or wider) of the two gaps at the end of a pair of non-parallel target lines. After adapting the subjects to target lines with randomly oriented crosshatches (which result in no illusion at least to humans), we tested the pigeons’ responses on randomly inserted probe trials, in which crosshatches that should induce the standard Zöllner-like illusion for humans replaced the random-oriented ones. The results suggested that pigeons do perceive an illusion from Zöllner figures, but in the direction opposite to that of humans. We propose that pigeons, contrary to humans, may assimilate the two lines of different orientations (each main line and crosshatch), which results in underestimation of acute angles, and this in turn may lead to a reversed Zöllner illusion. Such assimilation dominance appears consistent with previous reports obtained for line length and size illusions in this species.     

Hemodynamic and electrophysiological connectivity in the language system: Simultaneous near-infrared spectroscopy and electrocorticography recordings during cortical stimulation

We applied near-infrared spectroscopy (NIRS) and electrocorticography (ECoG) recordings during cortical stimulation to a temporal lobe epilepsy patient who underwent subdural electrode implantation. Using NIRS, changes in blood concentrations of oxyhemoglobin (HbO(2)) and deoxyhemoglobin (HbR) during cortical stimulation of the left language areas were measured in each hemisphere. NIRS revealed that 2Hz stimulation with 5mA produced no significant hemodynamic changes in either hemisphere. By contrast, 50Hz stimulation elicited significant increases in both HbO(2) and HbR at the stimulation site. Furthermore, with 50Hz stimulation of the left superior temporal gyrus, the increases in HbO(2) and HbR were observed not only at the stimulation site but also concurrently at the left inferior frontal gyrus. This suggests the existence of functional connectivity in the language system. The present study demonstrates that simultaneous NIRS and ECoG studies during cortical stimulation allow a novel analysis of cerebral connectivity.     

Relationship between masculinity-femininity and concession in an experimental collaborative eyewitness testimony

The present study examined the relationships of masculinity and femininity with concession in an experimental collaborative eyewitness testimony task, using the MORI technique. Participants formed same sex or mixed sex pairs and watched a videotaped event. Their eyewitness memories were assessed three times: immediately after watching, after discussing the event together, and individually 1 week later . The participants' self-confidence in their recalled memories and percentages of concessions were also examined. The Masculinity-Humanity-Femininity Scale was administered to the participants at the end of the experiment. The results showed that masculinity negatively correlated with concession, and that both masculinity and femininity were associated with inaccuracy in collaborative memory recall.     

The dynamics of daily events and well-being across cultures: when less is more

The authors examined cultural and individual differences in the relation between daily events and daily satisfaction. In a preliminary study, they established cross-cultural equivalence of 50 daily events. In the main study, participants in the United States, Korea, and Japan completed daily surveys on the 50 events and daily satisfaction for 21 days. The multilevel random coefficient model analyses showed that (a) the within-person association between positive events and daily satisfaction was significantly stronger among Asian American, Korean, and Japanese participants than among European American participants and (b) the within-person association between positive events and daily satisfaction was significantly weaker among individuals high in global life satisfaction than among those low in global life satisfaction. The findings demonstrate a weaker effect of positive events on daily well-being among individuals and cultures high in global well-being.     

Sexual communication and domestication may give rise to the signal complexity necessary for the emergence of language: An indication from songbird studies

For language to be a vehicle of thought, protolanguage must develop a degree of complexity that allows for the syntactic manipulation of symbol sequences. Thus, before language emerged, a process in which signals became complex must have occurred. Here, we submit a scenario describing the process in which courtship songs gained in complexity during the course of domestication of Bengalese finches. By comparing domesticated Bengalese finches with their wild strain, white-rumped munias, we found that female preferences for complex songs were coupled with domesticated relaxed environments to give rise to song complexity. Furthermore, we found that the outcomes of domestication in Bengalese finches include decreased psychological and physiological stress reactions, decreased aggressiveness, and changed plumage colors. These characteristics are consistent with “domestication syndrome,” originally proposed for mammals but now possibly applicable to birds. Our finding that domestication was a cause of signal complexity might be helpful in considering the process of signal evolution in human language.     

Cross-situational consistency of affective experiences across cultures

This study examined cross-situational consistency of affective experiences using an experience-sampling method in Japan, India, and the United States. Participants recorded their moods and situations when signaled at random moments for 7 days. The authors examined relative (interindividual) consistency and absolute (within-person) consistency. They found stable interindividual differences of affective experiences across various situations (mean r =.52 for positive affect.51 for negative affect) and cultural invariance of the cross-situational consistency of affective experiences. Simultaneously, the authors found a considerable degree of within-person cross-situational variation in affective experiences, and cultural differences in within-person cross-situational consistency. Thus, global affective traits exist among non-Western samples, but the degree to which situations exert an influence on the absolute level of affective experience varies across cultures.     

Personality and life satisfaction: a facet-level analysis

At the global level of the Big Five, Extraversion and Neuroticism are the strongest predictors of life satisfaction. However, Extraversion and Neuroticism are multifaceted constructs that combine more specific traits. This article examined the contribution of facets of Extraversion and Neuroticism to life satisfaction in four studies. The depression facet of Neuroticism and the positive emotions/cheerfulness facet of Extraversion were the strongest and most consistent predictors of life satisfaction. These two facets often accounted for more variance in life satisfaction than Neuroticism and Extraversion. The findings suggest that measures of depression and positive emotions/cheerfulness are necessary and sufficient to predict life satisfaction from personality traits. The results also lead to a more refined understanding of the specific personality traits that influence life satisfaction: Depression is more important than anxiety or anger and a cheerful temperament is more important than being active or sociable.     

The relative importance of spatial versus temporal structure in the perception of biological motion: an event-related potential study

We investigated how the spatiotemporal structure of animations of biological motion (BM) affects brain activity. We measured event-related potentials (ERPs) during the perception of BM under four conditions: normal spatial and temporal structure; scrambled spatial and normal temporal structure; normal spatial and scrambled temporal structure; and scrambled spatial and temporal structure. As in a previous study, we identified two negative components at both occipitotemporal regions: N210 reflected general motion processing while N280 reflected the processing of BM. We analyzed the averaged ERPs in the 200-300 ms response time window and found that spatial structure had a substantial effect on the magnitude of the averaged response amplitude in both hemispheres. This finding suggests that spatial structure of point-lights elicits a stronger response in the occipitotemporal region than temporal structure for the BM perception.     

Culture and well-being: the cycle of action, evaluation, and decision

Two studies were conducted to examine how European and Asian Americans experience and remember their task performance, make a decision about a future task, and how that decision affects enjoyment of the task. In Study 1, although Asians solved as many anagrams as European Americans, Asians remembered solving fewer than did European Americans at Time 2. European Americans' Time 2 choice of task was predicted from Time 1 performance, but Asians' Time 2 choice was not. In Study 2, European Americans chose the same task if they had previously done well and a different task if they had not. Their actual enjoyment of the Time 2 task, furthermore, was significantly higher than at Time 1. In contrast, there was no change in actual enjoyment of the task at Time 2 among Asians because their choice was not based on their performance at Time 1.