The Handedness Index Practical Task (HI20): An economic behavioural measure for assessing manual preference.

ABSTRACTBecause self-report hand preference measures are limited to investigating cognitive aspects of manual laterality, valid, easy-to-administer and economic behavioural methods are needed for capturing the motoric component of handedness. Therefore, this study introduces the Handedness Index Practical Task (HI20) and tests it in a sample of 206 students (Mage = 23.79 years, SDage = 3.01 years), half of whom were self-specified left-handers. After confirming good reliabilities at the subscale and total scale levels, k-means cluster analysis allowed an empirically based partitioning of test subjects into left- (n = 72), mixed- (n = 23) and right-handers (n = 111). To validate this categorization and the HI20 index, data were compared with the Edinburgh Handedness Inventory (EHI), EHI-short, HI22 and hand grip strength. The congruency between the HI20 clusters and alternative categorizations ranged from 95.6% to 84.0%, while the clusters explained large portions of variance in grip strength differences. The HI20 sub- and total scores showed strong correlations with other measures of lateral preference. Altogether, the freely available HI20 emerges as a reliable and valid alternative for behavioural handedness assessment, whose power lies in explaining differential hand use patterns and enabling fine-grained examinations of handedness.

The development of the University of Jordan word recognition test.

OBJECTIVE: To develop and validate a digitally recorded speech test battery to assess speech perception in Jordanian Arabic-speaking adults. DESIGN: Selected stimuli were digitally recorded and were divided into four lists of 25 words each. Speech audiometry was completed for all listeners. Participants were divided into two equal groups of 30 listeners each with equal male to female ratio. The first group of participants completed speech reception thresholds (SRTs) and word recognition testing on each of the four lists using a fixed intensity. The second group of listeners was tested on each of the four lists at different intensity levels in order to obtain the performance-intensity function. STUDY SAMPLE: Sixty normal-hearing listeners in the age range of 19-25 years. All participants were native speakers of Jordanian Arabic. RESULTS: Results revealed that there were no significant differences between SRTs and pure tone average. Additionally, there were no differences across lists at multiple intensity levels. CONCLUSIONS: In general, the current study was successful in producing recorded speech materials for Jordanian Arabic population. This suggests that the speech stimuli generated by this study are suitable for measuring speech recognition in Jordanian Arabic-speaking listeners.

The virtual maze: A behavioural tool for measuring trust.

Trusting another person may depend on our level of generalised trust in others, as well as perceptions of that specific person's trustworthiness. However, many studies measuring trust outcomes have not discussed generalised versus specific trust. To measure specific trust in others, we developed a novel behavioural task. Participants navigate a virtual maze and make a series of decisions about how to proceed. Before each decision, they may ask for advice from two virtual characters they have briefly interviewed earlier. We manipulated the virtual characters' trustworthiness during the interview phase and measured how often participants approached and followed advice from each character. We also measured trust through ratings and an investment game. Across three studies, we found participants followed advice from a trustworthy character significantly more than an untrustworthy character, demonstrating the validity of the maze task. Behaviour in the virtual maze reflected specific trust rather than generalised trust, whereas the investment game picked up on generalised trust as well as specific trust. Our data suggest the virtual maze task may provide an alternative behavioural approach to measuring specific trust in future research, and we demonstrate how the task may be used in traditional laboratories.

Initiatory and reactive behaviour in young children with a pervasive developmental disorder: Two independent components in communicative behaviour for distinguishing subgroups.

Thirty-three children with a pervasive developmental disorder (PDD) were classified to be either "aloof", "passive", or "active but odd" according to Wing's classification criteria (Wing & Attwood, 1987). These subgroups were compared with each other and to a control group of 33 normally developing children on the basis of behavioural measures derived from direct observation. The children were observed during an individual play session with a child psychiatrist. The comparative measures were frequency counts and transmission indices derived from sequential analysis (Steinberg, 1977; Van Hooff, 1982; De Vries, 1994). Two independent components in the communicative behaviour of the children were found to distinguish the PDD subgroups from each other in different ways: Initiatory behaviour on the one hand appeared to discriminate between all the 3 subgroups with respect to its level of occurrence as well as the effect it had on communicative acts of the child psychiatrist. Reactive behaviour on the other hand only discriminated the aloof group from the other two groups. Discrimination was seen in the frequency of this behaviour and its predictability in response to the child psychiatrist's communicative acts.