Evocation and characterization of percepts of apparent motion on the face

The percepts evoked by sequential stimulation of sites in close spatial proximity (<2.5 cm) on the face were studied. Both method-of-limits and magnitude-estimation procedures were used to identify and characterize alterations in the percepts produced by systematic changes in the temporal and spatial parameters of the sequence. Each site was stimulated by a vertically oriented row of miniature vibrating probes. Apparent motion was consistently perceived when the delay between the onsets of sequentially activated rows (interstimulus onset interval, or ISOI) fell within a relatively narrow range of values, the lower limit of which approximated 5 msec. Both the upper limit and the perceived smoothness and continuity of the motion percepts (goodness of motion) increased with the duration for which each row stimulated the skin over the range evaluated, 15–185 msec. For the successive activation of only two rows, goodness of motion was not influenced by changes in their separation from 0.4 to 2.5 cm. The ISOI values at which magnitude estimates of goodness of motion were highest increased with the duration for which each row stimulated the skin. As such, maximum goodness of motion decreased with increases in the apparent velocity of motion. When the number of sequentially activated rows was increased from two to four or more, the quality of the motion percepts improved. For the successive activation of multiple closely spaced rows, values of ISOI at which numerical estimates of goodness of motion were highest approximated integral fractions of the duration for which each row stimulated the skin. In this situation, the probes rose and fell in a regular, step-locked rhythm to simulate an edge-like or rectangular object moving across the skin. The goodness of motion so attained was relatively independent of the apparent velocity of motion.     

In defense of a pragmatic picture of belief

Philosophical Studies - In Belief: A Pragmatic Picture, I define “belief” as information poised to guide relatively attentive, controlled action. Though I admit that this is one of...     

Convergent validity of the Beck depression inventory-II with the reynolds adolescent depression scale in psychiatric inpatients

The Beck Depression Inventory-II (BDI-II; Beck, Steer, & Brown, 1996) and the Reynolds Adolescent Depression Scale (RADS; Reynolds, 1987) were administered to 56 female and 44 male psychiatric inpatients whose ages ranged from 12 to 17 years old. The Cronbach coefficient alpha(s) for the BDI-II and RADS were, respectively, .92 and .91 and indicated comparably high levels of internal consistency. The correlation between the BDI-II and RADS total scores was .84,p <.001. Binormal receiver-operating-characteristic analyses indicated that both instruments were comparably effective in differentiating inpatients who were and were not diagnosed with a major depressive disorder; the areas under the ROC curves for the BDI-II and RADS were, respectively, .78 and .76. The results (a) indicate that the BDI-II and the RADS have similar psychometric characteristics and (b) support the convergent validity of the BDI-II for assessing self-reported depression in adolescent inpatients.     

Prisoners of hate

The terrorist attacks in New York and Washington, D.C. on September 11, 2001 as well as domestic terrorism in the United States and elsewhere in the world has prompted an analysis of the psychology of the terrorist. The perpetrators' profound sense of being wronged--their values undermined by foreign powers or a corrupt domestic power structure--has cried out for revolution and revenge. The fanatic ideology of the perpetrators has provided the matrix for a progressively more malevolent representation of the oppressors: the Image of the Enemy. Retribution against the Enemy in the form of mass murder of anonymous civilians becomes an imperative. The counterpart of the image of the Enemy is the idealized collective self-image of members of the movement, faction, or cult. The group narcissism of the white supremacists in the United States, the Aum Shinrikyo in Japan, and the Islamic extremists enhance their collective self-image as pure, righteous, and united. While the foot soldiers, as in any war, gain glory through martyrdom, the instigators and leaders have their own personal narcissistic goals (power and prestige) and plan. For the extremist Islamists the ultimate goal has been overthrow of the moderate Islamic governments; for the domestic terrorists, destabilization of the national government and reinstitution of the traditional values.     

Screening ADHD problems in the sports behavior checklist: factor structure, convergent and divergent validity, and group differences

The Sports Behavior Checklist (SBC) is subjected to a principal components analysis, and subscales are correlated with subscales of the Conners' Revised Parent Form and the Social Skills Rating System. Both of these analyses are conducted to determine the construct validity of the instrument. A subsample of lower socioeconomic status individuals is used to compare ADHD and control group differences on the subscales of the SBC. The authors find that a six-factor solution, as proposed by the original authors, accounted for 71.5% of the variance. As hypothesized, subscales on the SBC are low to moderately related to subscales on the anchor measures. Significant group differences are found on the Aggression, Emotional Reactivity, and Injury subscales. Implications and limitations are discussed.     

Maternal self‐perceptions and reactions to infant crying among intrusive and withdrawn depressed mothers

This study compared intrusive (N =15) and withdrawn (N = 10) mothers' ratings of their own interaction styles with their infants and the behaviors of videotaped models of intrusive and withdrawn mothers. Withdrawn mothers rated themselves as less withdrawn than the model withdrawn mother. Intrusive mothers viewed themselves as more intrusive than the model intrusive mother. Both groups viewed their own infants as more outgoing than the infants of the model intrusive and withdrawn mothers. The withdrawn mothers reported feeling more distressed when they observed an infant (of an intrusive or withdrawn mother) crying, suggesting that they feel more empathy than the intrusive mothers. © 2001 Michigan Association for Infant Mental Health.