I know you are not looking at me: capuchin monkeys’ (<Emphasis Type="Italic">Cebus apella</Emphasis>) sensitivity to human attentional states

The present study asked whether capuchin monkeys recognize human attentional states. The monkeys requested food from the experimenter by extending an arm (pointing) toward the baited one of two transparent cups. On regular trials the experimenter gave the food immediately to the monkeys upon pointing but on randomly inserted test trials she ignored the pointing for 5 s during which she displayed different attentional states. The monkeys looked at the experimenter's face longer when she looked at the monkeys than when she looked at the ceiling in Experiment 1, and longer when she oriented her head midway between the two cups with eyes open than when she did so with eyes closed in Experiment 2. However, the monkeys showed no differential pointing in these conditions. These results suggest that capuchins are sensitive to eye direction but this sensitivity does not lead to differential pointing trained in laboratory experiments. Furthermore, to our knowledge, this is the first firm behavioral evidence that non-human primates attend to the subtle states of eyes in a food requesting task.     

A reversed Ebbinghaus–Titchener illusion in bantams (Gallus gallus domesticus)

A disk surrounded by smaller disks looks larger, and one surrounded by larger disks looks smaller than reality. This visual illusion, called the Ebbinghaus–Titchener illusion, remains one of the strongest and most robust illusions induced by contrast with the surrounding stimuli in humans. In the present study, we asked whether bantams would perceive this illusion. We trained three bantams to classify six diameters of target disks surrounded by inducer disks of a constant diameter into “small” or “large”. In the test that followed, the diameters of the inducer disks were systematically changed. The results showed that the Ebbinghaus–Titchener figures also induce a strong illusion in bantams, but in the other direction, that is, bantams perceive a target disk surrounded by smaller disks to be smaller than it really is and vice versa. Possible confounding factors, such as the gap between target disk and inducer disks and the weighted sum of surface of these figural elements, could not account for the subjects’ biased responses. Taken together with the pigeon study by Nakamura et al. (J Exp Psychol Anim Behav Process 34:375–387 2008), these results show that bantams as well as pigeons perceive an illusion induced by assimilation effects, not by contrast ones, for the Ebbinghaus–Titchener types of illusory figures. Perhaps perceptual processes underlying such illusory perception (i.e., lack of contrast effects) shown in bantams and pigeons may be partly shared among other avian species.     

Tensile properties of precracked tempered martensitic steel specimens tested at ultralow strain rates in high-pressure hydrogen atmosphere

Tensile tests were performed on precracked Cr–Mo martensitic steel (C: 0.38, Si: 0.22, Mn: 0.84, P: 0.024, S: 0.021, Ni: 0.08, Cr: 1.11, Mo: 0.15, Cu: 0.12, Fe: bal. (wt%)) specimens at various strain rates (ranging from 6.5 × 10^?8 s^?1 to 1.0 × 10^?4 s^?1) in high-pressure (95 MPa) hydrogen and helium atmospheres. Irrespective of the strain rate, the tensile strength in the helium atmosphere was 1400 MPa. In the hydrogen atmosphere, the tensile strength decreased to less than 600 MPa at a strain rate of 2.0 × 10^?5 s^?1. However, the tensile strength increased to 900 MPa when the strain rate was decreased to 6.5 × 10^?8 s^?1. This recovery of the tensile strength was because of the decrease in the local stress in the vicinity of the precrack because of hydrogen.     

Confluence Proofs of Lambda-Mu-Calculi by Z Theorem

Studia Logica - This paper applies Dehornoy et al.’s Z theorem and its variant, called the compositional Z theorem, to prove confluence of Parigot’s $$\lambda \mu $$ -calculi extended...     

Multichannel fNIRS assessment of overt and covert confrontation naming

Confrontation naming tasks assess cognitive processes involved in the main stage of word production. However, in fMRI, the occurrence of movement artifacts necessitates the use of covert paradigms, which has limited clinical applications. Thus, we explored the feasibility of adopting multichannel functional near-infrared spectroscopy (fNIRS) to assess language function during covert and overt naming tasks. Thirty right-handed, healthy adult volunteers underwent both naming tasks and cortical hemodynamics measurement using fNIRS. The overt naming task recruited the classical left-hemisphere language areas (left inferior frontal, superior and middle temporal, precentral, and postcentral gyri) exemplified by an increase in the oxy-Hb signal. Activations were bilateral in the middle and superior temporal gyri. However, the covert naming task recruited activation only in the left-middle temporal gyrus. The activation patterns reflected a major part of the functional network for overt word production, suggesting the clinical importance of fNIRS in the diagnosis of aphasic patients.     

Change we can believe in: using perceptions of changeability to promote system-change motives over system-justification motives in information search

People are motivated to defend and rationalize the status quo, a phenomenon known as system justification. We propose the existence of a second, countervailing system-level motivation: system-change motivation, which is concerned with bettering the status quo over time. The opportunity to receive diagnostic information about the status quo pits the two system-level motives against each other. Whereas system justification promotes a preference for positive information about the status quo, system-change motivation promotes a preference for negative information about the status quo. In three experiments, we found that people preferred negative over positive feedback about the status quo when it was presented as being changeable. Our findings are the first to suggest the operation of a system-change motive.     

Capuchin monkeys (<Emphasis Type="Italic">Cebus apella</Emphasis>) use conspecifics’ emotional expressions to evaluate emotional valence of objects

Emotional expressions provide important clues to other individuals’ emotional states, as well as the environmental situations leading to such states. Although monkeys often modify their behavior in response to others’ expressions, it is unclear whether this reflects understanding of emotional meanings of expressions, or simpler, non-cognitive processes. The present study investigated whether a New World monkey species, tufted capuchin monkeys, recognize objects as elicitors of others’ expressions. Observer monkeys witnessed another individual (demonstrator) reacting either positively or negatively to the contents of one of two containers and were then allowed to choose one of the containers. The observer preferred the container that evoked positive expressions in the demonstrator and avoided the container that evoked negative expressions. Thus, the monkeys appropriately associated the emotional valence of others’ expressions with the container. This finding supports the view that the ability to represent others’ emotions is not limited to humans and apes.     

Effects of the Central Executive on Postural Control

The authors focused on individual working memory (WM) capacity and examined its effect on postural control. Participants were 79 young volunteers split into two groups of low- and high WM span, based on scores from the Reading Span Test. The length of unrest was measured in the following conditions: double-leg standing as a single (D-S) task, single-leg standing as a single (S-S) task, double-leg standing as a dual (D-D) task, and single-leg standing as a dual (S-D) task. Regarding inte-group comparisons, total length was prolonged significantly between the low- and the high-span groups but only on the S-D task. The present results revealed that dual-task interference emerged in the low-span group when in a more unstable posture.     

Database of synesthetic color associations for Japanese kanji

Synesthesia is a neurological phenomenon in which certain types of stimuli elicit involuntary perceptions in an unrelated pathway. A common type of synesthesia is grapheme–color synesthesia, in which the visual perception of letters and numbers stimulates the perception of a specific color. Previous studies have often collected relatively small numbers of grapheme–color associations per synesthete, but the accumulation of a large quantity of data has greater promise for uncovering the mechanisms underlying synesthetic association. In this study, we therefore collected large samples of data from a total of eight synesthetes. All told, we obtained over 1000 synesthetic colors associated with Japanese kanji characters from each of two synesthetes, over 100 synesthetic colors form each of three synesthetes, and about 80 synesthetic colors associated with Japanese hiragana, Latin letters, and Arabic numerals from each of three synesthetes. We then compiled the data into a database, called the KANJI-Synesthetic Colors Database (K-SCD), which has a total of 5122 colors for 483, 46, and 46 Japanese kanji, hiragana, and katakana characters, respectively, as well as for 26 Latin letters and ten Arabic numerals. In addition to introducing the K-SCD, this article demonstrates the database’s merits by using two examples, in which two new rules for synesthetic association, “shape similarity” and “synesthetic color clustering,” were found. The K-SCD is publicly accessible (www.cv.jinkan.kyoto-u.ac.jp/site/uploads/K-SCD.xlsm) and will be a valuable resource for those who wish to conduct statistical analyses using a rich dataset in order to uncover the rules governing synesthetic association and to understand its mechanisms.     

Flexible route selection by pigeons (Columba livia) on a computerized multi-goal navigation task with and without an "obstacle"

The ability to select efficient routes while reaching several locations, in situations addressed as the "traveling salesperson problem (TSP)", seems to play an important role in the lives of nonhuman species as well as humans. One of our previous studies with pigeons (Columba livia) used different variations of computerized navigation tasks to move a target to one or more goals, and showed that the birds consistently exhibited tendencies to visit the nearest goal first (Miyata & Fujita, 2010). Is this inflexible tendency consistent across all situations, or is it abandoned if it leads to a nonefficient strategy? The present study compared pigeons' route selection strategies in two-goal navigation tasks with and without having an L-shaped line as an obstacle barrier between the starting location of the target and the nearer goal. The pigeons frequently started by visiting the nearer goal in trials with no obstacles, whereas in trials having obstacles the birds often visited the farther goal first. For the detour trials with obstacles, the birds started from visiting the farther goal significantly more often than chance, even though disparity between the two traveling sequences was relatively small. The data demonstrated a case in which a tendency to visit the nearest goal was flexibly abandoned when the route required a detour behavior. Detailed analyses of the movement paths further suggest that the pigeons made decisions to choose a farther goal during the initial few steps, although a past history of reinforcement to avoid the barrier might have guided the birds' behavior.