Bo S. Johansson

The activity trace in immediate memory: A re-evaluation

Both Hebb and Melton have shown that the ability to repeat a given nine-digit number improved when this number recurred several times in a series of such numbers. Learning had taken place. This improvement was also found by the present authors using approximately the same procedure as Hebb, but only where an overt response was involved. Where no overt response was involved, no improvement in performance was found. When recognition rather than reproduction was used, some evidence of learning was found in the absence of an overt response, but this result should be treated with caution since the majority of Ss, on their own admission, concentrated on trying to recognize only the first, or the first and the last, digit. The attempted retention of subspan units (first or first and last digit) in immediate memory cannot be compared with that of supraspan units (all nine digits).

Preschool children's understanding of the coordinators “and” and “or”

Abstract The development of the understanding of the words and and or was studied. Children in the age interval 2:0–7:6 received two tests of word understanding, varying in the degree to which the context of the test items contributed in determining the meaning of the connectives, and one test of spontaneous usage. The results from the tests of word understanding showed that the context variable facilitated small childrens responding, and that most reponses were correct at the age of four and beyond. The results from the production test indicated that and was used to express enummerations and or to express alternatives. The difference between the linguistic and the logical meaning of the connectives was discussed.

Some relevant factors in the transfer of material from short-term to long-term memory.

The relationship between short-term memory (STM) and long-term memory (LTM) for digits was investigated by means of a Hebb-type experiment, viz. a presentation of a series of nine-digit numbers, in which a certain number recurs at intervals. Improvement in performance, with regard to the critical, or recurring, number was found when the rehearsal grouping was three-three-and-three, but was absent when there were no opportunities for rehearsal or when the rehearsal strategy was grouping five-and-four or searching for systematic numbers. However, if an overt recall response was given on each occasion the recurring number was presented, improved performance was found even with rehearsal strategy five-and-four. The conclusion was drawn that rehearsal is the main transferring mechanism from STM to LTM, with the occurrence of an over recall response as a subsidiary factor.

Numeral writing skill and elementary arithmetic mental calculations

The paper reports three studies addressing the role of numeral writing for arithmetic performance. About 650 children in the age range 5–7 years participated in the studies. The results demonstrate a positive correlation between number of digits correctly written and number of arithmetic problems solved. The correlations between number of reversed digits (i.e., written backward) and arithmetic performance were also positive, in particular for the youngest children. A study of procedures used to solve the arithmetic problems showed strong correlations between correctly written numbers (two‐ to four‐digit numbers) and the reports of decomposition and immediate retrieval solution procedures. The results support the conclusion that the acquisition of the number‐word sequence and numeral writing skills provide the ground for the development of a mental number sequence that allows quantity value solution procedures.

Effects of encoding strategy, presentation modality, and scoring method on STM performance with the Peterson and Peterson technique*

The Peterson and Peterson (1959) STM experiment was replicated with variation of presentation modality and encoding strategy. The effect of various scoring criteria was also analyzed. The recall data showed that a Peterson and Peterson type forgetting curve was obtained using auditory presentation and instructions to rehearse vocally the trigrams when scoring only completely correct recall within the first 3 sec of the recall interval. With visual presentation and instructions to find meaningful trigram interpretations, the forgetting curve was higher and much more flat, especially when scoring position correct recall within the total 0-10-sec recall interval. In a buildup of PI experiment, no buildup of PI could be detected when visual presentation was used together with instructions to find meaningful trigram interpretations. The importance of the different encoding activities for recall performance was discussed.

Influence of pet ownership on opinions towards the use of animals in biomedical research

Abstract The present study investigated the relationship between pet ownership and opinions on the use of animals in medical research. A questionnaire was answered by 484 schoolteacher students and 156 pre-school teacher students from Uppsala University, Sweden. Animal use was found to be of significant importance for developing treatments for human disease by 59 percent of respondents, but 15 percent did not agree. Forty-four percent thought that it was morally acceptable to use animals in biomedical research, while 25 percent did not. A significantly higher proportion of those who reported experience in the use of animals in research from university teaching morally accepted and understood the importance of using animals in biomedical research, compared with students without this background. Fifty-eight percent of the students were pet owners and the most common species owned were the cat and the dog. A lower proportion of pet owners (39%) found it acceptable to use pet species in biomedical research than did non-pet owners (52%).

Informal Parental Traffic Training and Children's Traffic Accidents

The aims of the present study were (a) to assess the relationship between informal traffic training by parents and their childrens involvement in traffic accidents and (b) to identify factors contributing to this relationship. The first two studies involved questionnaires on informal parental traffic education, the childs exposure to traffic and traffic-related accidents. Both studies showed that rate of accidents increased with training, particularly for outdoor training. An accident analysis indicated that most accidents involved the use of the bicycle, and that the major part of the accidents resulted in light injuries and occurred when the child was practicing the act of manoeuvring the bicycle. An interview study with 10 preschool teachers identified two quite disparate traffic education goals: emphasis on cautiousness versus emphasis on independence. The major implications of the study are that efforts in traffic training should give more emphasis to bicycle use and should be planned and carried out in cooperation with the parents.