Multiplicative effects of intention on the perception of bistable apparent motion

When viewing ambiguous displays, observers can, via intentional efforts, affect which perceptual interpretation they perceive. Specifically, observers can increase the probability of seeing the desired percept. Little is known, however, about how intentional efforts interact with sensory inputs in exerting their effects on perception. In two experiments, the current study explored the possibility that intentional efforts might operate by multiplicatively enhancing the stimulus-based activation of the desired perceptual representation. Such a possibility is suggested by recent neurophysiological research on attention. In support of this idea, when we presented bistable apparent motion displays under stimulus conditions differentially favoring one motion percept over the other, observers' intentional efforts to see a particular motion were generally more effective under conditions in which stimulus factors favored the intended motion percept.     

Are monkeys aesthetists? Rensch (1957) revisited

Three experiments assessed whether capuchin monkeys (Cebus apella) and squirrel monkeys (Saimiri sciureus) prefer regular and symmetrical visual patterns. Pictorial representations of faces were included in 1 stimulus set. When the monkeys could pick up and manipulate small cards bearing the stimuli, all preferences expressed by capuchins and most of those expressed by squirrel monkeys were for regular stimuli. Symmetry of the patterns was influential but not essential. Some preferences were also found for faces. When images of the patterns were presented on a touch screen, capuchins continued to express preferences especially for regular and symmetrical stimuli, but they showed some avoidance of faces. Squirrel monkeys responded less discriminatingly to the touch screen stimuli. The findings provide support for B. Rensch's (1957) claim that monkeys prefer visual stimuli that humans find aesthetically pleasing.     

What perceptual rules do capuchin monkeys (Cebus apella) follow in completing partly occluded figures?

Capuchin monkeys (Cebus apella) matched a variety of rodlike figures, distinguishable only by their central portions. The monkeys were then tested for perceptual completion rules by examining which comparison figures they would choose as matching the sample with the critical central portion occluded by a horizontal belt. In Experiment 1, the monkeys overwhelmingly chose a straight rod over disconnected rods and rods having irregular shapes at their center, irrespective of the presence-absence of common motion of visible parts of the samples. The monkeys chose a connected rod for relatable rods and disconnected rods for non-relatable ones in Experiment 2. In Experiments 3 and 4, some of the monkeys chose rods specified by the global regularity of the contour, whereas others did not. Experiment 5 showed that humans and capuchin monkeys basically follow similar perceptual rules in completing occluded contours, but the global regularity rule may be stronger in humans.     

Attention to combined attention in new world monkeys (Cebus apella, Saimiri sciureus)

Co-orientation by capuchin (Cebus apella) and squirrel (Saimiri sciureus) monkeys in response to familiar humans abruptly switching the direction of their visual attention was recorded. Co-orientation occurred more frequently overall in capuchins than squirrel monkeys. Capuchins showed a tendency to habituate within trials involving consecutive attention switches performed by 2 different people, whereas squirrel monkeys co-oriented more when the 2nd attention switch was by a 2nd actor. These results suggest variable attention-processing abilities in New World monkeys, including differences in summation of attention by others.     

Novel visual stimuli activate a population of neurons in the primate orbitofrontal cortex

Neurons were found in the rhesus macaque anterior orbitofrontal cortex that respond to novel but not to familiar visual stimuli. Some of these neurons responded to all novel stimuli, and others to only a subset (e.g., to novel faces). The neurons have no responses to familiar reward- or punishment-associated visual stimuli, nor to taste, olfactory or somatosensory inputs. The responses of the neurons typically habituated with repeated presentations of a novel stimulus, and five presentations each 1s was the median number for the response to reach half-maximal. The neurons did not respond to stimuli which had been novel and shown a few times on the previous day, indicating that the neurons were involved in long-term memory. The median latency of the neuronal responses was 120 ms. The median spontaneous firing rate was 1.3 spikes/s, and the median response to novel visual stimuli was 6.0 spikes/s. These findings indicate that the long-term memory for visual stimuli is information that is represented in a region of the primate anterior orbitofrontal cortex.     

Auditory-visual intermodal matching of small numerosities in 6-month-old infants

Recent studies have reported that preverbal infants are able to discriminate between numerosities of sets presented within a particular modality. There is still debate, however, over whether they are able to perform intermodal numerosity matching, i.e. to relate numerosities of sets presented with different sensory modalities. The present study investigated auditory-visual intermodal matching of small numerosities in infancy by using a violation-of-expectation paradigm. After being familiarized with events of a few objects impacting a surface successively, 6-month-old infants were alternatively presented with two and three tones while the movement of each object remained hidden behind an opaque screen. The screen was then removed to reveal either two or three objects. Results showed that the infants looked significantly longer at the numerically nonequivalent events (the three-tone/two-object and the two-tone/three-object events) than at the numerically equivalent events (the two-tone/two-object and the three-tone/three-object events) irrespective of the rate or duration of auditory tones presented. These findings suggest that infants are capable of performing intermodal matching of small numerosities and that they might possess abstract representations of numerosity beyond sensory modalities.     

Baby arithmetic: one object plus one tone

Recent studies using a violation-of-expectation task suggest that preverbal infants are capable of recognizing basic arithmetical operations involving visual objects. There is still debate, however, over whether their performance is based on any expectation of the arithmetical operations, or on a general perceptual tendency to prefer visually familiar and complex displays. Here we provide new evidence that 5-month-old infants recognize basic arithmetic operations across sensory modalities. Using a violation-of-expectation task that eliminated the possibility of the familiarity and complexity preference, 5-month-old infants were presented alternatively with two types of arithmetical events: the expected, correct outcomes of operations (1 object+1 tone=2 objects and 1 object+2 tones=3 objects) and the unexpected, incorrect ones (1 object+2 tones=2 objects and 1 object+1 tone=3 objects). Results showed that subjects looked significantly longer at the unexpected events than at the expected events, suggesting that infants are able to recognize basic arithmetic operations across sensory modalities.     

A Capuchin monkey (<Emphasis Type="Italic">Cebus apella</Emphasis>) recognizes when people do and do not know the location of food

In a previous study, Kuroshima and colleagues demonstrated that capuchin monkeys (Cebus apella) learned to discriminate between a "knower" who inspected a box for food, and a "guesser" who did not. The aim of the present study was to specify whether the subjects learned a simple conditional discrimination or a causal relationship that seeing leads to knowing. In experiment 1, we introduced five types of novel containers to two subjects. Each container was of different shape and color. The subjects gradually learned to reach toward the container the knower suggested. In experiment 2, we diversified the behavior of the knower and the guesser. In experiment 3, in order to eliminate the possibility of discrimination based on differences in the magnitude and the complexity of two trainers, we equated their behaviors. One subject adapted to the novel behaviors of the knower and the guesser, successfully discriminating the two trainers. Thus this monkey clearly learned to use the inspecting action of the knower and the non-inspecting action of the guesser as a discriminative cue to recognize the baited container. This result suggests that one capuchin monkey learned to recognize the relationship between seeing and knowing.     

Validation of the Japanese version of the NEO Five-Factor Inventory in a large community sample

The NEO Five-Factor Inventory is the shortened version of the Revised NEO Personality Inventory. The aim of this study was to examine the reliability and validity of the Japanese version of the shortened version in the general population of Japan. This version was translated into Japanese and then administered to 2,051 adults in a rural town in Akita Prefecture. A total of 1,664 (81.1%) individuals gave valid answers. Internal reliability, assessed by Cronbach alpha for subscales, ranged from .60 to .77. The scales were only weakly correlated both with each other and with age. In a multiple regression analysis, only the Neuroticism scale score was a significant predictor of scores on the General Health Questionnaire. Factor analysis supported the theoretical structure of personality. Overall, the Japanese version showed good reliability and validity in this sample of the general population of Japan.     

The left superior longitudinal fasciculus within the primary sensory area of inferior parietal lobe plays a role in dysgraphia of kana omission within sentences

Functional neurological changes after surgery combined with diffusion tensor imaging (DTI) tractography can directly provide evidence of anatomical localization of brain function. Using these techniques, a patient with dysgraphia before surgery was analyzed at our hospital in 2011. The patient showed omission of kana within sentences before surgery, which improved after surgery. The brain tumor was relatively small and was located within the primary sensory area (S1) of the inferior parietal lobe (IPL). DTI tractography before surgery revealed compression of the branch of the superior longitudinal fasciculus (SLF) by the brain tumor. These results suggest that the left SLF within the S1 of IPL plays a role in the development of dysgraphia of kana omission within sentences.