Inaccurate reporting and inappropriate variables: a reply to Vecchio's (1990) examination of cognitive resource theory.

In an article in the Journal of Applied Psychology, Vecchio (1990) purported to test cognitive resource theory (Fiedler, 1986; Fiedler & Garcia, 1987). We present evidence that Vecchio's article seriously misrepresented previous work on cognitive resource theory and also contained several flaws in methodology that call into question his conclusions regarding the validity of cognitive resource theory.     

Evidence for an error deadzone in compensatory tracking

Humans and monkeys show intermittent arm movements while tracking moving targets. This intermittency has been explained by postulating either a psychological refractory period after each movement and/or an error deadzone, an area surrounding the target within which movements are not initiated. We present a technique to detect and quantify the size of this deadzone, using a compensatory tracking paradigm that distinguishes it from a psychological refractory period. An artificial deadzone of variable size was added around a visual target displayed on a computer screen. While the subject was within this area, he received visual feedback that showed him to be directly on target. The presence of this artificial deadzone could affect tracking performance only if it exceeded the size of his intrinsic deadzone. Therefore, the size of artificial deadzone at which performance began to be affected revealed the size of the intrinsic deadzone. Measured at the subjects' eye, the deadzone was found to vary between 0.06 and 0.38 degrees, depending on the tracking task and viewing conditions; on the screen, this range was 1.3 mm to 3.3 mm. It increased with increasing speed of the target, with increasing viewing distance, and when the amplitude of the movement required was reduced. However, the deadzone size was not significantly correlated with the subjects' level of performance. We conclude that an intrinsic deadzone exists during compensatory tracking, and we suggest that its size is set by a cognitive process not simply related to the difficulty of the tracking task.     

Effects of Fluprazine Hydrochloride on Three Aversively Motivated Tasks

The Psychological Record - Treatment with 8.0 mg/kg fluprazine hydrochloride had no effect on the acquisition of a step-down avoidance response but retarded its extinction. The drug also impaired...     

Backward walking: a simple reversal of forward walking?

The purpose of this study was to determine whether backward walking represented a simple temporal reversal of forward walking and, hence, could be controlled by a reversed cycling of the same group of neurons. Electromyographic (EMG), joint angle, joint moment, and joint muscle power patterns were compared for forward and backward walking, in 6 subjects. The joint angle patterns with the time-base of the backward walking reversed were similar, with the exception of the ankle. The moment patterns were similar except for the knee, whereas the joint muscle powers were almost reversed-polarity images of each other. This suggests that somewhat similar muscle activation patterns could be used to produce both modes of locomotion, but the temporal cycling of muscle contraction would be reversed: Concentric muscle activity in forward walking would become eccentric activity in backward walking, and visa versa. The EMG results generally supported these findings.     

What does infant perception tell us about theories of perception?

The article begins with a summary of eight well-substantiated conclusions drawn from research on perception in infants that have implications for theories of perception. The following section examines several traditional and modern theories of perception in the light of these conclusions. Finally, some "big issues" that have divided perceptual and cognitive theories are discussed, with the suggestion that research on infants can help reconcile the divided camps. Research on perception in young infants not only flourishes but also presents a challenge to all theories of perception.     

A collection of 4,741 word fragments that have unique completions with respect to 146,205 words

A collection of 4,741 word fragments that have a unique completion is described. All word fragments are specified by two letters (e.g.,__Q__U__can only be completed by the word LIQUEURS). The words completing these fragments range in length from five to nine letters. The fragments are unique with respect to a pool of 146,205 words, which helps rule out the possibility that obscure words could be used as a completion to the fragments. The collection of fragments as well as the words that complete them is available in ASCII format on computer disks or in printed form.