Attentional balance and intelligence

Recent studies of neuroimaging during cognitive tasks suggest that most tasks involve the activity of widespread areas in both cerebral hemispheres. In many cases, information must be shared between the two hemispheres. The coordination of these areas involves the brain's attentional networks. Unilateral brain damage often causes asymmetries in attention and reduced speed of processing. Based on these findings it was hypothesized that mental processing in normals will be more efficient when normal people can shift attention to either hemisphere with equal efficiency. Attentional balance was measured by the degree of asymmetry found during the covert visual-orienting task. Intelligence was measured by the Raven Standard Progressive Matrices. Data from two experiments suggest that low asymmetry in attention shifting is associated with higher intelligence.     

Mushroom bodies of the honeybee brain show cell population-specific plasticity in expression of amine-receptor genes

Dopamine and octopamine released in the mushroom bodies of the insect brain play a critical role in the formation of aversive and appetitive memories, respectively. As recent evidence suggests a complex relationship between the effects of these two amines on the output of mushroom body circuits, we compared the expression of dopamine- and octopamine-receptor genes in three major subpopulations of mushroom body intrinsic neurons (Kenyon cells). Using the brain of the honeybee, Apis mellifera, we found that expression of amine-receptor genes differs markedly across Kenyon cell subpopulations. We found, in addition, that levels of expression of these genes change dramatically during the lifetime of the bee and that shifts in expression are cell population-specific. Differential expression of amine-receptor genes in mushroom body neurons and the plasticity that exists at this level are features largely ignored in current models of mushroom body function. However, our results are consistent with the growing body of evidence that short- and long-term olfactory memories form in different regions of the mushroom bodies of the brain and that there is functional compartmentalization of the modulatory inputs to this multifunctional brain center.     

Stimulus Classes Formation in Concurrent Discriminations in Rats as a Function of Overtraining

The Psychological Record - The present two experiments conducted a limited parametric study of the overtraining variable using a whole-partial reversal procedure in rats. Rats received two...     

Does religious priming increase the prosocial behaviour of a Japanese sample in an anonymous economic game?

We examined the effect of religious priming on a Japanese sample in an anonymous dictator game whereas previous studies on religious priming on prosociality had mainly been conducted within Western contexts. The current study attempted to examine whether religion increases prosocial behaviour in a Japanese sample through the replication of ‘God is Watching You’ (Shariff & Norenzayan, 2007) where it was found that participants primed with religion‐related words and secular justice‐related words behaved more prosocially than participants primed with neutral words in an anonymous dictator game. The current experiment was conducted with Japanese students (n = 106) to examine whether the results of the original study could be applied to Japanese people. The results showed that among the three priming conditions (control, religion, secular justice), there was no difference in the amount of money participants allocated to anonymous strangers, although in the secular justice priming condition, theists allocated more money than atheists. The results might be due to the fact that the religious priming words used in the original study did not precisely activate the propositional network of religion that Japanese participants have. More culture‐specific studies are necessary to examine how religious priming works for non‐Westerners.     

Behavioural development in a matching-to-sample task and token use by an infant chimpanzee reared by his mother

We investigated the behavioural and cognitive development of a captive male infant chimpanzee, Ayumu, raised by his mother, Ai. Here we report Ayumu's achievements up to the age of 2 years and 3 months, in the context of complex computer-controlled tasks. From soon after birth, Ayumu had been present during an experiment performed by his mother. The task consisted of two phases, a matching-to-sample task in which she received token rewards, and the insertion of these tokens into a vending machine to obtain food rewards. Ayumu himself received no reward or encouragement from humans for any of the actions he exhibited during the experiment. At the age of 9 months and 3 weeks, Ayumu performed his first matching-to-sample trial. At around 1 year and 3 months, he began to perform them consistently. Also during this period, he frequently stole food rewards from his mother. At 2 years and 3 months, Ayumu succeeded for the first time in inserting a token into the vending machine. Once he had succeeded in using a token, he performed both phases of the task in sequence 20 times consecutively. The infant's behaviour was not shaped by food rewards but by a strong motivation to copy his mother's behaviour. Our observations of Ayumu thus mirror the learning processes shown by wild chimpanzees.     

The role of attention in the facilitation effect and another "inhibition of return"

The present study investigated how anticipation of a target's appearance affects human attention to gaze cues provided by a schematic face. Subjects in a 'catch' group received a high number of 'catch' trials, in which no target stimulus appeared. Subjects in the control group did not receive any catch trials. As in previous studies, both groups showed a facilitation effect to the cued location during shorter stimulus onset asynchrony (SOA). In both groups, an analysis of eye movements confirmed that subjects' eyes remained on the fixation point, ruling out the possibility that the facilitation effect was due to shifting eye movements (saccades) as opposed to a shift in covert attention. But while the control group's response time (RT) decreased as SOA increased, the catch group's RT had a U-shaped pattern and the facilitation effect to the cued location was reversed at the longest SOA (1005 ms). These results suggest that subjects in the catch group disengaged their attention during long SOAs because they expected the trial to be a catch trial. This disengagement of attention during long SOAs results in a delay before attention could be re-focused to the previous location regardless of the cue validity ["IOR (inhibition of return)"-like-phenomenon]. Unlike the conventional IOR, we suggest that this "IOR"-like phenomenon caused by an unpredictive central gaze cue is likely to be mediated by an endogenous mechanism.     

Evaluating the Effect of Listeners' Response on Speakers' Later Recollection and Impression of the Story

The purpose of this study was to investigate a listener's role in a speaker's later recollection and impression of the story through a story-retelling method. Two experiments were conducted, and listener responses were manipulated in each experiment in different ways. Experiment 1 examined the effect of a listener's attitude toward story retelling, and Experiment 2 studied the effect of a listener's subtle nonverbal reaction to a specific part of the story's retelling on a speaker's later recollection and impression of that story. Results showed that the listener's verbal empathetic attitude encouraged more word utterances from the speaker, changed the narrative content more positively, and reinforced the speaker's recollection, especially with positive ideas. It also amplified the speaker's emotions more than the non-empathetic attitude (Experiment 1). However, the listener's nonverbal reaction to the specific part of the speaker's story did not appear to have a direct effect upon later recollection nor on the impression of the story (Experiment 2).     

Mirror reading of words and numbers: Practice and transfer effects

It remains unknown whether mirror reading represents a genuine text processing skill or is based on recognition of visual patterns. The present study attempts to determine whether (1) systematic practice with a particular mirrored typography also improves reading performance for other mirrored typographies, and whether (2) this transfer extends from lexical to numerical material and vice versa. The results show that short-term intensive practice with mirror-reversed words significantly improves reading performance not only for the trained typography but also for other mirrored typographies and mirror-reversed Arabic digits. Practice with mirror-reversed Arabic digits showed a mixed pattern of transfer effects with regard to other digit transformations and there were no transfer effects to lexical material. Hence, for lexical material, at least, improvement after training seems to be based on generalized skill with transfer effects beyond lexical material, rather than on mere improvement of visual recognition of the material used in training.