Tactile-Based Pantomime Grasping: Knowledge of Results is Not Enough to Support an Absolute Calibration

Tactile-based pantomime-grasping requires that a performer use their right hand to ‘grasp’ a target previously held in the palm of their opposite hand – a task examining how mechanoreceptive (i.e., tactile) feedback informs the motor system about an object property (i.e., size). Here, we contrasted pantomime-grasps performed with (H+) and without (H?) haptic feedback (i.e., thumb and forefinger position information derived from the grasping hand touching the object) with a condition providing visual KR (VKR) related to absolute target object size. Just-noticeable-difference (JND) scores were computed to determine whether responses adhered to – or violated – Weber's law. JNDs for H+ trials violated the law, whereas H? and VKR trials adhered to the law. Accordingly, results demonstrate that haptic feedback – and not KR – supports an absolute tactile-haptic calibration.     

Egocentric and allocentric visual cues influence the specification of movement distance and direction

The authors investigated whether visuomotor transformations that support the computation of movement distance (i.e., extent) and movement direction rely differentially on integration of egocentric and allocentric visual information. To accomplish that objective, the authors factorially arranged 17 participants' open-loop reaching movements from 2 movement-start locations with mediolateral (ML) and anteroposterior (AP) variants of the induced Roelofs effect (IRE). The 2 movement-start locations in combination with the 2 IRE configurations enabled the authors to examine the impact of illusory movement pertaining to distance (i.e., AP-IRE) and direction (i.e., ML-IRE) information. AP-IRE and ML-IRE configurations across the 2 movement-start locations reliably influenced reaching endpoints in a direction consistent with the perceptual effects of the illusion. These findings suggest that unitary visual information involving interactive egocentric and allocentric visual cues supports the specification of both movement distance and movement direction.     

Searching for an environmental effect of parental alcoholism on offspring alcohol use disorder: a genetically informed study of children of alcoholics

The children-of-twins design was used to isolate a potentially causal environmental impact of having an alcoholic parent on offspring alcohol use disorder, by an examination of whether the children of alcoholics were at a higher risk for alcohol use disorders than were the children of nonalcoholic parents, even after correlated familial factors were controlled. Participants were 1,224 male and female twins from 836 twin pairs selected from the Australian Twin Registry, 2,334 of the twins' 18-39-year-old offspring, and 983 spouses of the twins. Lifetime histories of Diagnostic and Statistical Manual of Mental Disorders (4th ed.) alcohol use disorders were obtained by structured, psychiatric, telephone interviews conducted individually with each of the family members. Comparisons of the offspring of twins who were discordant for alcoholism indicated that there was no longer a statistically significant difference between the children of alcoholics and the children of nonalcoholics after genetic and family environmental factors correlated with having an alcoholic parent were controlled. The results of this study suggest that the direct causal effect of being exposed to an alcoholic parent on offspring alcohol use disorder is modest at best.     

The genetic and environmental relationship between Cloninger's dimensions of temperament and character

The purpose of this study was to determine whether Cloninger's revised 7-factor model of personality showed incremental validity over his four dimensions of temperament. A sample of 2517 Australian twins aged over 50 between 1993 and 1995 returned completed self-reported measures of Self-directedness, Cooperativeness, and Self-transcendence from Cloninger's Temperament and Character Inventory. Many of these twins had participated in a 1988 study containing Cloninger's temperament measures of Harm Avoidance, Novelty Seeking, Reward Dependence and Persistence. Contrary to theoretical expectations, univariate analyses revealed that familial aggregation for the character dimensions could be entirely explained by additive gene action alone. Although temperament explained 26, 37 and 10% of additive genetic variance in Self-directedness, Cooperativeness and Self-transcendence, respectively, seven genetic factors were required to explain the genetic variance among the TPQ dimensions, and almost all of the non-shared environmental variance was unique to each dimension of character. Our results indicate that the inclusion of all seven dimensions in a taxonomy of personality is warranted.     

The differential processing of price in gains and losses: the effects of frame and need for cognition

Perhaps the most fundamental principle of decision theory is that more money is preferred to less: the principle of desired wealth. Based on this and other principles such as reference dependence and loss aversion, researchers have derived and demonstrated mental accounting (MA) rules for multiple outcome situations. Experiment 1 tested the invariance of the desired wealth principle and two mental accounting rules (mixed gain, e.g. $100 gain and a $50 loss; mixed loss, e.g. $100 loss and a $50 gain) across types of decision maker and frame. The desired wealth principle and the MA rule for mixed gains were found to vary depending upon (1) the thoughtfulness of the decision maker (need for cognition, NC), and (2) the frame used to describe gains and losses (e.g. a gain of $x versus a gain of y%). The MA rule for mixed losses, however, was found to be immune to framing effects, even among people who are generally less thoughtful. The differential processing of gains and losses across frames (dollar versus percentage) and individuals (less versus more thoughtful) was tested further in Experiment 2 where evaluations of mixed losses were made at the level of the gestalt as well as the constituent (the gain and the loss being evaluated separately). Framing effects were evidenced only among subjects lower in NC and only when the constituent gain was evaluated. Evaluations of the overall mixed loss and the constituent loss were comparable across situation and individual, suggesting that losses motivate greater processing among people otherwise inclined toward cognitive miserliness. Copyright © 2000 John Wiley & Sons, Ltd.     

Imitative violence in the real world: A reanalysis of homicide rates following championship prize fights

Recently, Phillips [Am Soc Rev, 1983; 48:560–568] reported that the homicide rate increases on the third day after heavyweight championship prize fights. The present paper reports a reanalysis of Phillips's data using more sophisticated statistical techniques and examining several theoretically important variables not discussed by Phillips or his critics. Using a conservative analysis strategy, our results suggest that the increases in homicides reported by Phillips were not a methodological artifact as suggested by Baron and Reiss [Am Soc Rev 1985; 50:347–363, 372–376]. The homicide increases only occur on the first weekend or holiday after prize fights that receive the greatest publicity.