Serial,parallel, or holistic identification of single words in the two visual fields?

Subjects made timed manual responses in judging whether laterally presented four-letter words were identical to targets. In Experiment 1, nontargets differed by a single letter from targets. A right-field superiority occurred only for targets (which were detected fastest of all) and for nontargets where a letter changed at Position 2 or Position 3. Changes at initial and final positions were detected faster than the two middle positions, and there were no significant field differences. In Experiment 2, ascenders and descenders were controlled and changes were made in nontargets at all four letter positions, at Positions 1 and 4, at Positions 2 and 3, or at 2 alone. Response times for nontargets varied inversely with the number of differing letters, regardless of position. Significant field differences again only appeared for changes in the two middle positions. Letters at the beginning and end of a word seem to be processed faster than and differently from those within, where field differences are strongest. Vowel-consonant differences probably do not account for these effects, which are more compatible with some form of parallel, rather than either serial or holistic, processing.     

Prevalence and structure of behavior symptoms among children in special education and regular classroom settings

Studied the factor structure of the Behavior Problem Checklist using children from a middle to upper-middle-class suburban school system, determined the extent to which factors generated from children in regular classrooms approximated those generated from children in special education, and examined the effects of class placement, sex, and the interactions of these variables on the average rating children receive on the generated factors. One hundred children from 12 classes for the emotionally disturbed or learning disabled and 527 children from regular forst-through seventh-grade classes were rated by their teachers on the Behaviors Problem Checklist. Following a varimax factor rotation, coefficients of factor congruence and analysis of variance were conducted to test the hypotheses. Results indicated that although teacher ratings of special education and normal children are structurally similar, special education children scored higher on all three factors than did their regular class counterparts. Furthermore, almost all percentages of occurance for individual items were higher for special education children. Further research is suggested to deal with a possible expectancy effect in teacher ratings of problem behaviors.     

The effects of illumination level and retinal size on the apparent strength of subjective contours

The apparent strength of subjective contours was investigated as a function of illumination level, figure size, and viewing distance. Magnitude estimation, with a real contour standard as the modulus, was used to measure the perceived strength of the illusory contours. It was found that illumination level and retinal size are both powerful determinants of the apparent strength of subjective contours, generating magnitude estimates varying from 20% to 96% of the strength of the real contour modulus. Particularly strong subjective contours were reported for figures of small retinal size (1.2 to 4.8 deg) under very dim illumination (.10 log lx).     

Contrasting patterns in the acquisition of spatial/temporal terms

Competing hypotheses about the acquisition of terms that refer to relationships in both time and space are tested. One hypothesis is that the language of time is acquired as a spatial metaphor; consequently, such terms will be acquired in their spatial sense first. The competing hypothesis is that differential experience with the dual senses of each term will result in different patterns of acquisition, depending upon which sense is dominant in actual usage. Comprehension of before-after, first-last, and ahead-behind by 4- to 6-year-olds was assessed in spatial, temporal, and spatial-temporal meaning tasks. Results support the second view: there is no consistent order of acquisition; the sense acquired first is the dominant sense, as determined by both linguistic evidence and empirical survey.     

Poison-enhanced neophobia: Effects of CS-UCSUCS-CS procedures and long-delay training

Experiment 1 (n = 110 male rats) showed that pairing sucrose with toxicosis under forward or backward conditioning procedures yielded reliable poison-enhanced neophobia toward casein hydrolysate. Forward procedures produced reliably greater and more persistent enhancement of neophobia. Experiment 2 (n = 160 male rats) showed that interpolating 10 min, or 1, 4, 8, or 12 hr between sucrose and toxicosis yielded reliable aversion effects to sucrose and poison-enhanced neophobia to casein at each interval except 8 and 12 hr. Generally speaking, the effects of training interval were similar for conditioned aversion and enhanced neophobia but conditioned aversion effects were more enduring.     

Working memory in chess

Three experiments investigated the role of working memory in various aspects of thinking in chess. Experiment 1 examined the immediate memory for briefly presented chess positions from master games in players from a wide range of abilities, following the imposition of various secondary tasks designed to block separate components of working memory. Suppression of the articulatory loop (by preventing subvocal rehearsal) had no effect on measures of recall, whereas blocking the visuospatial sketchpad (by manipulation of a keypad) and blocking the central executive (by random letter generation) had equivalent disruptive effects, in comparison with a control condition. Experiment 2 investigated the effects of similar secondary tasks on the solution (i.e., move selection) of tactical chess positions, and a similar pattern was found, except that blocking the central executive was much more disruptive than in Experiment 1. Experiment 3 compared performance on two types of primary task, one concerned with solving chess positions as in Experiment 2, and the other a sentence-rearrangement task. The secondary tasks in each case were both designed to block the central executive, but one was verbal (vocal generation of random numbers), while the other was spatial in nature (random generation of keypresses). Performance of the spatial secondary task was affected to a greater extent by the chess primary task than by the verbal primary task, whereas there were no differential effects on these secondary tasks by the verbal primary task. In none of the three experiments were there any differential effects between weak and strong players. These results are interpreted in the context of the workingmemory model and previous theories of the nature of cognition in chess.