Biomedical subjects

M Gulya

Publications and source records attributed to M Gulya.

4 recordsLinked to original sources

PubMed2001

Infants' long-term memory for a serial list: recognition and reactivation.

Serial lists contain information about item identity and item order. Using a task designed for nonverbal animals, we previously found that 3- and 6-month-olds exhibited a primacy effect after 24 hr, remembering both item identity and item order. Presently, we examined their memory of list information after longer delays. In Experiment 1, the serial-position curve reverted to a U-shape after 1 week at both ages, revealing that the common practice of attributing primacy and recency effects to long- and short-term memory, respectively, is flawed. In Experiment 2, a precuing procedure confirmed that 6-month-olds' memory still contained order information after 1 week, but 3-month-olds' reactivated memory contained none. Experiments 3A and 3B confirmed that increasing the complexity of information that was learned shortened the delay after which it could be retrieved. Testing infants after delays longer than have previously been used with animals or human adults sheds new light on an old phenomenon.

Analysis of Variance↗

PubMed1999

Infants' memory processing of a serial list: list length effects.

Six-month-olds, trained with a three-mobile serial list, exhibit a primacy effect 24 h later. In three experiments, we demonstrated that increasing list length impairs their memory for serial order. In all experiments, 6-month-olds were trained with a five-mobile list. In Experiment 1, infants failed to exhibit a primacy effect on a 24-h delayed recognition test, recognizing mobiles from all serial positions. In Experiment 2, infants did exhibit a primacy effect on a reactivation (priming) test, suggesting that they may originally have encoded serial-order information. Experiment 3 confirmed that serial-order information was represented in infants' training memory. After the reactivation treatment, infants were precued with one list member and tested for recognition of another. When precues specified valid order information, infants recognized test mobiles from the later serial positions. The memory dissociation for serial order on delayed recognition and reactivation tests adds to the growing evidence that young infants possess two functionally distinct memory systems.

Analysis of Variance↗

PubMed1996

Infants' memory for context: timing effects of postevent information.

How infants' memories of the context or place where an event occurred are selectively distorted was studied in 6-month-olds, who kicked to activate a mobile in a distinctive context for 2 days and then saw that mobile in a different context for 2 min either 1 or 6 days later. Infants whose exposure delay was 1 day failed to recognize the mobile in either the original or the exposed context but did so in a completely novel one. Infants whose exposure delay was 6 days--after the details of the original context were forgotten--recognized the mobile in the exposed context and no other, and the mobile could reactivate the forgotten memory only in the exposed context and no other. In effect, the details of the exposed context appeared to have been substituted in memory for the original details that had been forgotten. Thus, when components of an event are encountered later in a new context, that new context may be falsely remembered as being where the event had actually occurred, and the original context may be forgotten altogether. This error is more likely when a memory is older and may underlie some of the inaccuracies of childrens' and adults' recollections of their prior experiences.

Adult↗

PubMed1992

Assessment of the effects of dentifrices on plaque acidogenesis via intra-oral measurement of plaque acids.

Dionex ion chromatography was used for identification and quantification of the plaque acids (formate, lactate, acetate, and propionate) formed in vivo following a sucrose rinse. Consistent with other literature reports, lactate and acetate were the predominant acid species generated by plaque. This micro-analytical technique was used for investigation of the effects of dentifrice formulations containing NaF, xylitol, or NaF/xylitol on plaque acid metabolism. Neither a single nor multiple exposures (three times daily for one week) to the experimental dentifrices significantly altered the profiles of the individual acids or total plaque acidity relative to the placebo dentifrice. The lack of an effect of fluoride and xylitol on plaque acid metabolism is attributed to the variability of dental plaque and the low concentrations of active ingredients reaching the plaque. However, we believe that, with further improvement in sampling technique and study design, this approach may prove useful for the study of the effects of active ingredients (i.e., anticaries agents) on plaque acidogenesis.

Acetates↗