In a spatial version of the Stroop task where subjects must attend to the position of a word and ignore the word itself, we argue that interference results because selective attention is only partially successful. If so, then increasing attention to the word should increase interference. Experiment 1 showed increased interference with position naming when subjects must be prepared to attend to either the word or its position. Experiment 2 required subjects to first name the position of the word and then later to recall which word had been presented. This resulted in increased interference with position naming when the word was followed at a short SOA by a pattern mask. Experiment 3 employed both word reading and position naming and showed that a large reverse Stroop effect occurred with both vocal and manual responses when subjects had to be prepared to attend to either dimension of the stimulus.

I . Metabolic balance studies of manganese were made on four young women, using brilliant Retention of an element occurs when the total intake is greater than the total output, and its measurement is dependent upon the accuracy of all experimental procedures. For an element like M n which is believed to be poorly absorbed, calculated retentions of up to 63% of the total intake which have been reported for normal subjects are hardly credible, and are unlikely to be caused solely by an overestimate of the intake. There may be another pathway for the excretion of M n beyond the major output in the faeces and the almost negligible amounts lost in the urine and from the skin. Cotzias (1962), however, emphasized the difficulties in estimating Mn, the questionable specificity of many of the methods, the ubiquitous nature of Mn, and the ease of contamination at each stage of any analytical procedure.This study reports the satisfactory use of atomic absorption spectrophotometry for estimation of Mn in food, faeces and urine, and the measurement of the metabolic balance of Mn for four young women.

The manganese concentrations of breast-milk, liquid and dried cow's milk, and foods widely used in mixed feeding of infants in New Zealand, were measured by atomic absorption spectrophotometry.The dietary supply of Mn to infants during the first 6 months was calculated. This varied from 2.5 to 75 μg/d per kg body-weight depending upon the age of the infant, the type of milk and the quantity of solid foods consumed. Young infants in New Zealand received about as much Mn as has been reported for infants elsewhere.

Priming effects were examined in two experiments using either a pronunciation or lexical decision task. The prime, cither a strong associate of the target, an unrelated word, or a neutral prime, was presented for 200 ms. After an SOA ol 200, 400, or 8(K) ms, a masked target was presented for 33.3, 50, or 66.7 ms. Attention was manipulated by varying the probability that prime and target would be strongly associated. Both experiments showed significant interference in the low attention condition and at the 200-ms SOA, presumably before the onset of consciously directed processing. Two subsequent experiments using a short SOA and the low attention condition attempted to determine the conditions under which this interference will occur by varying the interstimulus interval, target duration, and the mask. It was found that interference occurred only when targets were brief and masked. These results are discussed in terms of a model involving lateral inhibition between nodes in semantic memory. It is suggested that when the target is brief and masked, the node in memory corresponding to the target is much less strongly activated and therefore more susceptible to the inhibitory effects of other activated nodes.RKSUMK On a examine dans deux experiences les effets d'amorcage a l'aide d'unc tache de decision lexicale ou de pronunciation. L'amorce, cjui elail soil une forte association de la cible, soil un mot non relie, ou une amorce neutre etait presentee pendant 200 ins. Apres un SOA de 200, 400, ou 800 ms, une cible masqucc ctait presentee pendant 33.3, 50, ou 66.7 ms. L'atiention etait manipulec en variant la probability que l'amorce et la cible soil fortement associees. Les deux experiences ont montrc une interference significative dans la condition ou I'attcntion ctait basse ct au SOA de 200 ms, prcsumement avant le declenehement d'un processing dirige consciemment. Deux experiences subscquentcs utilisant un SOA court el la condition d'aiiemion basse lemaient de determiner les conditions dans lesquellcs survicndraint cette interference en variant I'intcrvallc cntre les stimuli, la durcc dc la cible ct Ic masque. I/interference survenait seulemcnt quand les cibles elaienl presentees brievement ct avee Ic masque. Les rcsultats sont diseutcs en fonction d'un modelc impliquant 1'inhibition latcralc cntrc les nocuds dans la memoire semanlique. Nous suggcrons que lorsque la cible est breve ct masquees, le noeud dans la memoire corrcspondant a la cible est active beaucoup moins fortement et est ainsi plus sueeptiblc aux effcts inhibitcurs d'autres nocuds actives.

No abstract