Thalamic modulation of aggression

Integrative Psychological and Behavioral Science - This experiment extends Pavlov’s method of contrasts for 8 components of aggression were quantitatively evaluated in 11 freely moving adult...     

The relative efficiency of two tests as a function of ability level

A new formula is developed for the relative efficiency of two tests measuring the same trait. The formula expresses relative efficiency solely in terms of the standard errors of measurement and, surprisingly, the frequency distributions of true scores. Approximate methods for estimating relative efficiency may make this function routinely available. A numerical illustration compares new and old estimates of relative efficiency for subtests from the Scholastic Aptitude Test.Research reported in this paper has been supported by grant GB-32781X from National Science Foundation.     

The perception of eye contact

Ss made judgments of whether or not they were being looked in the eye as an E fixated several points on and off their faces.Distance between sender and receiver, sex, and whether the sender made a sequence of fixation sprior to the terminal fixation were variables of interest. The sender-receiver distance produced less effect than predicted from the hypothesis that receiver judgments were determined solely by the discrepancy between the sender’s iris/sclera configuration (ISC) during true eye contact and the current fixation point. There was no stable differencein accuracy as a function of whether the sender’s terminal fixation was preceded by other fixations or not. These findings cast doubt on the belief expressed in recent studies that the ISC can be used to accurately discriminate eye gazes from other gazes. The results also suggest that fixations on some portions of the face yield a judgment of eye contact which might be predicted on the basis of social experience.     

Cocaine-induced brainstem seizures and behavior.

A variety of abnormal sensory/motor behaviors associated with electrical discharges recorded from the bilateral brainstem were induced in adult WKY rats by mechanical (electrode implants) and DC electrical current stimulations and by acute and chronic administration of cocaine. The electrode implant implicated one side or the other of the reticular system of the brainstem but subjects were not incapacitated by the stimulations. Cocaine (40 mg/kg) was injected subcutaneously for an acute experiment and subsequent 20 mg/kg doses twice daily for 3 days in a chronic study. Cocaine generated more abnormal behaviors in the brainstem perturbation group, especially the electrically perturbated subjects. The abnormal behaviors were yawning, retrocollis, hyperactivity, hypersensitivity, "beating drum" behavior, squealing, head bobbing, circling, sniffing, abnormal posturing, and facial twitching. Shifts in the power frequency spectra of the discharge patterns were noted between quiet and pacing behavioral states. Hypersensitivity to various auditory, tactile, and visual stimulation was present and shifts in the brainstem ambient power spectral frequency occurred in response to tactile stimulation. These findings suggest that the brainstem generates and propagates pathological discharges that can be elicited by mechanical and DC electrical perturbation. Cocaine was found to activate the discharge system and thus induce abnormal behaviors that are generated at the discharge site and at distant sites to which the discharge propagates. Cognitive functions may also be involved since dopaminergic and serotonergic cellular elements at the brainstem level are also implicated.     

No-loss gambling shows the speed of the unconscious

This paper investigates the time it takes unconscious vs. conscious knowledge to form by using an improved "no-loss gambling" method to measure awareness of knowing. Subjects could either bet on a transparently random process or on their grammaticality judgment in an artificial grammar learning task. A conflict in the literature is resolved concerning whether unconscious rather than conscious knowledge is especially fast or slow to form. When guessing (betting on a random process), accuracy was above chance and RTs were longer than when feeling confident (betting on the grammaticality decision). In a second experiment, short response deadlines only interfered with the quality of confident decisions (betting on grammaticality). When people are unaware of their knowledge, externally enforced decisions can be made rapidly with little decline in quality; but if given ample time, they await a metacognitive process to complete. The dissociation validates no-loss gambling as a measure of conscious awareness.     

But what about the Empress of Racnoss? The allocation of attention to spiders and Doctor Who in a visual search task is predicted by fear and expertise

If there is a spider in the room, then the spider phobic in your group is most likely to point it out to you. This phenomenon is believed to arise because our attentional systems are hardwired to attend to threat in our environment, and, to a spider phobic, spiders are threatening. However, an alternative explanation is simply that attention is quickly drawn to the stimulus of most personal relevance in the environment. Our research examined whether positive stimuli with no biological or evolutionary relevance could be allocated preferential attention. We compared attention to pictures of spiders with pictures from the TV program Doctor Who, for people who varied in both their love of Doctor Who and their fear of spiders. We found a double dissociation: interference from spider and Doctor-Who-related images in a visual search task was predicted by spider fear and Doctor Who expertise, respectively. As such, allocation of attention reflected the personal relevance of the images rather than their threat content. The attentional system believed to have a causal role in anxiety disorders is therefore likely to be a general system that responds not to threat but to stimulus relevance; hence, nonevolutionary images, such as those from Doctor Who, captured attention as quickly as fear-relevant spider images. Where this leaves the Empress of Racnoss, we are unsure.