Wernicke''s aphasia in a 10-year-old boy

We report the case of a ten-year-old boy, who, after herpes simplex encephalitis, presented a sensory aphasia having much in common with Wernicke's aphasia in adults. The genesis of neologisms appeared very similar to the mechanisms described by Buckingham and Kertesz (1974, Brain and Language, 1, 43-61). The findings are discussed in the light of theories of hemispheric specialization and of age-related semiologies.     

Priming semantic relations in patients with Huntington's disease

To investigate the hypothesis that Huntington's Disease involves a breakdown in the organization of the lexico-semantic representational system, mildly and moderately demented patients with Huntington's Disease and age-matched normal control subjects were given a brief battery of language tests and a semantic priming free association task. Results of the language tests provided suggestive, but confounded, evidence for a semantic deficit in Huntington's Disease. Less equivocal evidence was yielded by results of the priming task, which showed a decline in the effect of association strength of primed stimulus-target word pairs on target hit rates. This finding was interpreted as a disruption in the system of spreading activation in a lexico-semantic network. This breakdown was contrasted with the more severe language deficits found in dementias which are primarily cortical in origin.     

Benefits from attention depend on the target type in location-precued discrimination.

In previous research, we found that precuing of attention to a target location greatly improved discrimination of targets that differed in line arrangement, but had little effect on discrimination of targets that differed in line orientation. In the present research, a number of other targets that represent various feature differences were used. The new data are consistent with and extend our earlier findings by showing that (1) there is some effect of precuing with all targets tested, and (2) the size of precuing effects varies in a complex way with the nature of the target. Moreover, the difficulty of the discrimination cannot explain the size of the precuing effects. A framework for understanding the events occurring during trials in the location-cuing paradigm is presented and applied to these results.     

Position-linked interference in forming simple visual groups.

Experiments with 2-element visual groups reveal a form of interference that has several interesting properties. Observers judged the orientation of an imaginary line formed by 2 pixels (the target) while attempting to ignore a third pixel (the noise). Noise interfered with performance, even when it was made distinct from the target in various ways. This interference was strongly position linked; a single equation described the interference pattern for many different target-noise configurations. Maximum interference was observed not when the noise was closest to the target but when it was at a distance of half the separation between target pixels. Some initial findings were consistent with the idea that visual grouping reflects the operation of visual channels with Gabor-like receptive-field profiles. But subsequent results implicated processes that automatically construct visual boundaries.     

Attention and nontarget effects in the location-cuing paradigm

Three experiments were conducted in order to determine whether irrelevant items presented outside the focus of attention would affect the identification of a precued target. A peripheral cue indicated one of eight possible locations in a circular array, centered on fixation with a radius of 5.25°. After a variable interval (0–200 msec), eight characters were presented briefly and masked. In each experiment, there was an effect of the identity of the characters at the seven noncued locations (the nontargets) on the accuracy of identification of the target. When there were more nontargets identical to the target, accuracy was higher than when there were fewer nontargets identical to the target. Nontargets consistently affected performance despite incentives to focus only on the target.     

Polydipsia induced by intermittent delivery of salted liquid foods

Food-deprived rats given constant access to water were exposed to fixed-time presentations of soybean milk and diluted sweetened condensed cows' milk. In some conditions these liquid foods were adulterated with varying amounts of sodium chloride. Under a fixed-time 30-sec schedule of food delivery, little water was consumed when the food was soybean milk alone, or soybean milk with sodium chloride added in concentrations of .9, 1.8, or 3.6%. However, schedule-induced polydipsia appeared when soybean milk adulterated with 7.2 or 14.4% sodium chloride was delivered under this schedule. When soybean milk containing 7.2% sodium chloride was presented under fixed-time 15-, 30-, 60-, 120-, and 240-sec schedules, schedule-induced drinking increased with the fixed-time value from 15 to 120 seconds, and decreased at 240 seconds. Like soybean milk, diluted sweetened condensed milk delivered under fixed-time schedules of 30, 60, and 120 seconds failed to evoke schedule-induced polydipsia, but did so when adulterated with 7.2% sodium chloride. Drinking induced by salted liquid foods resembled the polydipsia engendered by spaced dry-food presentations in several ways, including temporal relation to food delivery, persistence within and across sections, sensitivity to interfood interval, and magnitude relative to intake evoked by bulk-food presentation.     

Individual differences in speech fusion: Methodological and theoretical explorations

Day (Note 1) constructed pairs of speech sounds such as “lanket” and “banket” from words (e.g., blanket) by omitting either the first or second consonant. When these two components were presented about the same time, one to each ear, some people appeared to fuse them, reporting they heard the word. Other people rarely fused. Moreover, if asked to report the first letter they heard, a judgment of temporal order, subjects that tended to fuse also reported what would be the first consonant of the word, even when it was not first in the pair of components. From this and other evidence, Day concluded that the perception of some individuals might be “language-bound.” We tested a strong version of the language-boundness view of fusion and were able to reject it. We also examined several other possible causes of individual differences in fusion rate. Our second experiment provides evidence that a more general failure to discriminate temporal order of even nonlinguistic material may be involved.     

Studies involving fathers: Subject refusal, attrition and sampling bias

The reported rates of subject refusal and attrition are reviewed in those studies where data were collected directly from fathers. Only 34 per cent of such studies report on subject refusal rates and 36 per cent on attrition rates. Few studies comment on or give information that would allow an assessment to be made of sampling bias arising from subject refusal and attrition. Nevertheless, studies reporting subject refusal and attrition suggest that fathers are no more difficult to recruit than mothers and that a variety of factors, individually and in combination, may have some impact on recruitment. These include the type of commitment required, the techniques of recruitment used and whether studies are hospital, home or laboratory based. However, if biases due to subject refusal and attrition are to be identified and avoided, studies need to be more open in providing information about the characteristics of refusing and participating subjects. To encourage this, some new data are presented, suggesting a number of trends: (1) extended personal contacts with potential subjects may minimize subject refusal and attrition; (2) attrition may be somewhat higher in middle-class families and families with sons.