Instrumentation for an electrocutaneous communication device

The device described is a prototype that uses spatiotemporal resolution for electrocutaneous stimulation. Signals initiated through a keyboard activate a matrix of four electrodes that may be applied to the fingers, forearm, abdomen, back, or other parts of the integument. The instrumentation described includes a pulse generator, the active time and delay time controls, the control of the total length of a pulse train, and the constant-current generators whose output is fed into the electrodes. This device may be used as an interface with an alphanumeric device (e.g., a calculator or computer) and as a basic instrument in research investigating the spatial and temporal resolving capacities of the skin senses.     

The helping alliance and premature termination

The study was conducted to determine the relationship between strength of the helping alliance and type of client termination (premature or with mutual knowledge of client and counselor). Participants were 102 client-counselors dyads at a university counseling center. After an average of 8 sessions, clients and couneselors completed Alexander & Luborsky's (1986) Helping Alliance Questionnaires. Clients terminated after an average of 19 sessions. Clients who later terminated with mutual knowledge of their counselors gave significantly higher strength of helping alliance ratings than did clients who later terminated unilaterally and prematurely. Counselors' ratings of strength of helping alliance were only modestly related to clients' ratings and unrelated to type of client termination.     

Book reviews

Abstract

Boff, K. R., Kaufmann, L., &; Thomas, J. P. (Eds) (1986). Handbook of perception and human performance, Vols 1 and 2. Chichester: John Wiley. ISBN 0-471-88544-4 and 0-471-82957-9. £85.00 and £77.50.

Garnham, A. (1988). Artificial intelligence: An introduction. London: Routledge and Kegan Paul. Pp. 277. ISBN 0-7102-1416-2. £8.95.     

Secular declines in Spearman's g: some evidence from the United States

The Flynn Effect (J. Flynn, 1987) refers to the apparent increases in intelligence quotient (IQ) observed over the past few decades. A related phenomenon is that the variance in test scores accounted for by Spearman's g (C. Spearman, 1904) varies according to IQ level. That is, g accounts for less variance in high IQ groups than in low IQ groups. Spearman termed this variant aspect of g the "law of diminishing returns." This study extends prior research on the Flynn Effect and the law of diminishing returns by examining changes in the statistical importance of Spearman's g that may accompany secular increases in IQ. Based on the standardization data from the United States versions of the Wechsler scales (i.e., Wechsler Preschool and Primary Scales of Intelligence, D. Wechsler, 1967; Wechsler Intelligence Scale for Children, D. Wechsler, 1949; Wechsler Adult Intelligence Scale, D. Wechsler, 1955), this study indicated that, in most cases, the statistical significance of Spearman's g has indeed declined over the past several years. A. R. Jensen (1998) suggested that the components of the Flynn Effect warrant special investigation. The present study addresses this issue, in part by analyzing the Verbal and Performance subscales of the Wechsler scales. Additionally, this study further confirms the law of diminishing returns as applicable to different ages and time periods.     

Working memory capacity and fluid intelligence are strongly related constructs: comment on Ackerman, Beier, and Boyle (2005)

The authors agree with P. L. Ackerman, M. E. Beier, and M. O. Boyle (2005; see record 2004-22408-002) that working memory capacity (WMC) is not isomorphic with general fluid intelligence (Gf) or reasoning ability. However, the WMC and Gf/reasoning constructs are more strongly associated than Ackerman et al. (2005) indicate, particularly when considering the outcomes of latent-variable studies. The authors' reanalysis of 14 such data sets from 10 published studies, representing more than 3,100 young-adult subjects, suggests a strong correlation between WMC and Gf/reasoning factors (median r=.72), indicating that the WMC and Gf constructs share approximately 50% of their variance. This comment also clarifies the authors' "executive attention" view of WMC, it demonstrates that WMC has greater discriminant validity than Ackerman et al. (2005) implied, and it suggests some future directions and challenges for the scientific study of the convergence of WMC, attention control, and intelligence.     

Lack of association between negative priming and Necker Cube reversals

50 undergraduates were tested on two tasks presented in a counterbalanced fashion: their ability to inhibit irrelevant information measured on a negative priming task involving letter case information and on the number of Necker Cube reversals produced in a specific time period. Since number of reversals presumably reflects a person's ability to see various interpretations of the Necker Cube, this assumes that multiple interpretations are available to a subject and no one interpretation dominates over another. If true, then more reversals could indicate an ability to inhibit irrelevant information. That is, observing one reversal at the expense of another reversal indicates a subject can adequately inhibit these various interpretations successfully, with more reversals indicating a higher ability to inhibit information successfully. Although it was predicted that negative priming performance would be related to the number of Necker Cube reversals, this was not the case (r = -.07).