Cross-cultural perspectives on pitch memory

We examined effects of age and culture on children's memory for the pitch level of familiar music. Canadian 9- and 10-year-olds distinguished the original pitch level of familiar television theme songs from foils that were pitch-shifted by one semitone, whereas 5- to 8-year-olds failed to do so (Experiment 1). In contrast, Japanese 5- and 6-year-olds distinguished the pitch-shifted foils from the originals, performing significantly better than same-age Canadian children (Experiment 2). Moreover, Japanese 6-year-olds were more accurate than their 5-year-old counterparts. These findings challenge the prevailing view of enhanced pitch memory during early life. We consider factors that may account for Japanese children's superior performance such as their use of a pitch accent language (Japanese) rather than a stress accent language (English) and their experience with musical pitch labels.     

On the primacy of molecular processes in determining response rates under variable-ratio and variable-interval schedules

This study focused on variables that may account for response-rate differences under variable-ratio (VR) and variable-interval (VI) schedules of reinforcement. Four rats were exposed to VR, VI, tandem VI differential-reinforcement-of-high-rate, regulated-probability-interval, and negative-feedback schedules of reinforcement that provided the same rate of reinforcement. Response rates were higher under the VR schedule than the VI schedule, and the rates on all other schedules approximated those under the VR schedule. The median reinforced interresponse time (IRT) under the VI schedule was longer than for the other schedules. Thus, differences in reinforced IRTs correlated with differences in response rate, an outcome suggestive of the molecular control of response rate. This conclusion was complemented by the additional finding that the differences in molar reinforcement-feedback functions had little discernible impact on responding.     

Impairment in judgement of the moral emotion guilt following orbitofrontal cortex damage

Although neuroimaging studies have provided evidence for an association between moral emotions and the orbitofrontal cortex, studies on patients with focal lesions using experimental probes of moral emotions are scarce. Here, we addressed this topic by presenting a moral emotion judgement task to patients with focal brain damage. Four judgement tasks in a simple pairwise choice paradigm were given to 72 patients with cerebrovascular disease. These tasks consisted of a perceptual line judgement task as a control task; the objects’ preference task as a basic preference judgement task; and two types of moral emotion judgement task, an anger task and a guilt task. A multiple linear regression analysis was performed on each set of task performance scores to take into account potential confounders. Performance on the guilt emotion judgement task negatively correlated with the orbitofrontal cortex damage, but not with the other variables. Results for the other judgement tasks did not reach statistical significance. The close association between orbitofrontal cortex damage and a decrease in guilt emotion judgement consistency might suggest that the orbitofrontal cortex plays a key role in the sense of guilt, a hallmark of morality.     

The copyist model of response emission

The variety of different performances maintained by schedules of reinforcement complicates comprehensive model creation. The present account assumes the simpler goal of modeling the performances of only variable reinforcement schedules because they tend to maintain steady response rates over time. The model presented assumes that rate is determined by the mean of interresponse times (time between two responses) between successive reinforcers, averaged so that their contribution to that mean diminishes exponentially with distance from reinforcement. To respond, the model randomly selects an interresponse time from the last 300 of these mean interresponse times, the selection likelihood arranged so that the proportion of session time spent emitting each of these 300 interresponse times is the same. This interresponse time defines the mean of an exponential distribution from which one is randomly chosen for emission. The response rates obtained approximated those found on several variable schedules. Furthermore, the model reproduced three effects: (1) the variable ratio maintaining higher response rates than does the variable interval; (2) the finding for variable schedules that when the reinforcement rate varies from low to high, the response rate function has an ascending and then descending limb; and (3) matching on concurrent schedules. Because these results are due to an algorithm that reproduces reinforced interresponse times, responding to single and concurrent schedules is viewed as merely copying what was reinforced before.     

The effect of semantic plausibility on sentence comprehension in aphasia

Tested were 50 aphasic patients (16 Broca's, 15 Wernicke's, 10 global, and 9 amnesic), 13 nonaphasic brain damaged patients, and 13 normal adults to evaluate the effect of semantic plausibility on sentence comprehension in active affirmative declarative sentences with a sentence-picture matching task. A plate of two pictures was provided for each stimulus sentence, and the subject was required to choose the picture corresponding to the sentence presented auditorily. Two types of sentences in terms of plausibility were prepared, i.e., probable sentences (P) describing common events in our daily life and improbable sentences (I) describing rare events. There were four kinds of combinations of a picture with the other to make a correct/(distractor) set, i.e., P/(P), P/(I), I/(P), and I/(I) constructions. The results indicated that probable sentences were more comprehensible than improbable sentences, and that the effect of semantic plausibility did not differ among aphasic types.     

Time-shrinking: the process of unilateral temporal assimilation

Our previous research on auditory time perception showed that the duration of empty time intervals shorter than about 250 ms can be underestimated hugely if they are immediately preceded by shorter time intervals. We named this illusion 'time-shrinking' (TS). This study comprises four experiments in which the preceding interval, t1, was followed by a standard interval, t2. When t1 < or = 200 ms, and t1 < or = t2, the underestimation of t2 came into view clearly. The absolute difference between t2 and t1 was the crucial factor for the illusion to appear. The underestimation increased when t2 increased from t1 to t1 + 65 ms, stayed at about 45 ms when t2 was between t1 + 65 ms and t1 + 95 ms, and disappeared suddenly when t2 exceeded t1 + 95 ms. This pattern of results was observed across all values of t1 < or = 200 ms. A model was fit to the data to elucidate the underlying process of the illusion. The model states that the perceived duration difference between t1 and t2 is reduced by cutting mental processing time for t2; in other words, that t2 assimilates to t1.     

Can we talk to robots? Ten-month-old infants expected interactive humanoid robots to be talked to by persons

As technology advances, many human-like robots are being developed. Although these humanoid robots should be classified as objects, they share many properties with human beings. This raises the question of how infants classify them. Based on the looking-time paradigm used by [Legerstee, M., Barna, J., & DiAdamo, C., (2000). Precursors to the development of intention at 6 months: understanding people and their actions. Developmental Psychology, 36, 5, 627-634.], we investigated whether 10-month-old infants expected people to talk to a humanoid robot. In a familiarization period, each infant observed an actor and an interactive robot behaving like a human, a non-interactive robot remaining stationary, and a non-interactive robot behaving like a human. In subsequent test trials, the infants were shown another actor talking to the robot and to the actor. We found that infants who had previously observed the interactive robot showed no difference in looking-time between the two types of test events. Infants in the other conditions, however, looked longer at the test event where the second experimenter talked to the robot rather than where the second experimenter talked to the person. These results suggest that infants interpret the interactive robot as a communicative agent and the non-interactive robot as an object. Our findings imply that infants categorize interactive humanoid robots as a kind of human being.     

Children perseverate to a human's actions but not to a robot's actions

Previous research has shown that young children commit perseverative errors from their observation of another person's actions. The present study examined how social observation would lead children to perseverative tendencies, using a robot. In Experiment 1, preschoolers watched either a human model or a robot sorting cards according to one dimension (e.g. shape), after which they were asked to sort according to a different dimension (e.g. colour). The results showed that children's behaviours in the task were significantly influenced by the human model's actions but not by the robot's actions. Experiment 2 excluded the possibility that children's behaviours were not affected by the robot's actions because they did not observe its actions. We concluded that children's perseverative errors from social observation resulted, in part, from their socio-cognitive ability.     

The Other Shoe: An Early Operant Conditioning Chamber for Pigeons

We describe an early operant conditioning chamber fabricated by Harvard University instrument maker Ralph Gerbrands and shipped to Japan in 1952 in response to a request of Professor B. F. Skinner by Japanese psychologists. It is a rare example, perhaps the earliest still physically existing, of such a chamber for use with pigeons. Although the overall structure and many of the components are similar to contemporary pigeon chambers, several differences are noted and contrasted to evolutionary changes in this most important laboratory tool in the experimental analysis of behavior. The chamber also is testimony to the early internationalization of behavior analysis.