A stabilometer computerized analog recording system for studying gross motor skill learning

The stabilomotor computerized analog recording system (SCARS) presents a unique data analysis and storage system for studying motor learning strategies. Graphic computer printouts, total time in balance, total number of contacts, time between contacts, standard deviation of the time between contacts, mean angle of balance, and standard deviation of the angle of balance for each trial are derived.     

Influence of the movement parameter to be controlled on manual RT asymmetries in right-handers

In this experiment we test whether the effects of manual asymmetries on movement preparation depend on the parameter (amplitude or direction) to be programmed. In two experiments, only the amplitude, or the direction, of aiming movements was constrained. Reaction and movement times were measured. Results show that RTs are always shorter for left-hand than for right-hand movements. There is an effect of target extent in the amplitude condition, but not in the direction one. RTs for ipsilateral movements are shorter than RTs for contralateral movements. These results are discussed in the light of the processes involved in setting the amplitude or direction of the movement and with regard to the competency of the two hemispheres regarding these processes.     

The construction of large number representations in adults

What is the nature of our mental representation of quantity? We find that human adults show no performance cost of comparing numerosities across vs. within visual and auditory stimulus sets, or across vs. within simultaneous and sequential sets. In addition, reaction time and performance in such tasks are determined by the ratio of the numerosities to be compared; absolute set size has no effect. These findings suggest that modality-specific stimulus properties undergo a non-iterative transformation into representations of quantity that are independent of the modality or format of the stimulus.     

Non-symbolic arithmetic in adults and young children

Five experiments investigated whether adults and preschool children can perform simple arithmetic calculations on non-symbolic numerosities. Previous research has demonstrated that human adults, human infants, and non-human animals can process numerical quantities through approximate representations of their magnitudes. Here we consider whether these non-symbolic numerical representations might serve as a building block of uniquely human, learned mathematics. Both adults and children with no training in arithmetic successfully performed approximate arithmetic on large sets of elements. Success at these tasks did not depend on non-numerical continuous quantities, modality-specific quantity information, the adoption of alternative non-arithmetic strategies, or learned symbolic arithmetic knowledge. Abstract numerical quantity representations therefore are computationally functional and may provide a foundation for formal mathematics.     

Chimpanzees’ (Pan troglodytes) use of gaze cues in object-choice tasks: different methods yield different results

To assess the influence of different procedures on chimpanzees' performance in object-choice tasks, five adult chimpanzees were tested using three experimenter-given cues to food location: gazing, glancing, and pointing. These cues were delivered to the subjects in an identical fashion but were deployed within the context of two distinct meta-procedures that have been previously employed with this species with conflicting results. In one procedure, the subjects entered the test unit and approached the experimenter (who had already established the cue) on each trial. In the other procedure, the subjects stayed in the test unit throughout a session, witnessed the hiding procedure, and waited for a delay of 10 s during which the cue was provided. The subjects scored at high levels far exceeding chance in response to the gaze cue only when they approached the experimenter for each trial. They performed at chance levels when they stayed inside the test unit throughout the session. They scored at chance levels on all other cues irrespective of the procedure. These findings imply that (a) chimpanzees can immediately exploit social gaze cues, and (b) previous conflicting findings were likely due to the different meta-procedures that were used.