No abstract

Shortly after viewing a video of a theft, 5-and 7-year-old children and adults were interviewed with free recall and either misleading or unbiased-leading questions. After a 2-day delay, participants were interviewed with free recall and recognition questions administered by either the same or a dierent interviewer. Results from day 1 replicate previous ®ndings with levels of recall and resistance to suggestibility increasing with age. Counter to predictions, correct recognition performance on day 2 was greater for some participants interviewed by the same as opposed to a dierent interviewer, and incorrect recognition was greater for all groups of participants for those interviewed by a dierent as opposed to the same interviewer. Results are discussed in terms of the role of context dependence on memory performance.There has been an avalanche of research in the past decade on children's susceptibility to suggestion, and results have shown that younger children are more likely to agree with misinformation provided or suggested by an interviewer than are older children and adults (see Ceci and Bruck, 1993 for reviews). However, young children's compliance with the suggestion of an interviewer is not necessarily an indication that they actually changed their memory of the event. Rather, young children's erroneous responses can often be attributed to the social-demand characteristics of the interview (i.e. telling the interviewer what he or she wants to hear), and not to underlying changes in the memory representation, per se.The importance of demand characteristics on young children's suggestibility was illustrated in a study by Cassel et al. (1996). In their study, kindergarten, grade-2 and grade-4 children, and college students were shown a video depicting the theft of a bicycle. One week later, participants were asked for free recall of the event (e.g.`Tell

In adults, the neural substrate associated with encoding memories connected to a specific time and place include the prefrontal cortex and medial temporal lobe (MTL). Using functional magnetic resonance imaging, this research studied the developmental trajectory of this frontal-MTL system by comparing 7- and 8-year-old children to those who were 10 or older in conditions that promoted episodic encoding. In 1 condition, participants generated verbs from nouns heard; in another, they listened to short stories for comprehension. Regions in which brain activation predicted subsequent recognition memory performance were identified. These included the left prefrontal cortex, but not MTL, in the verb generation condition for both age groups. In the story comprehension condition, activation in left posterior MTL predicted subsequent memory performance in both age groups, and activation in left anterior MTL (including the hippocampus proper) and left prefrontal cortex predicted subsequent memory only for the older children. These results illustrate both similarities and differences in how brain systems interact in development to mediate the formation of episodic memories.

No abstract

In order to detect regions of DNA containing tumor suppressor genes involved in the development of gastric cancer, we performed an allelotype study on 78 gastric adenocarcinomas from a population composed largely of Texan Hispanics and Anglos, two ethnic groups that have a ratio of incidence rates of gastric cancer of approximately 2:1. In total, 42 microsatellite markers were employed, which detected at least one site per arm of each autosome in the human genome. These included several markers linked to known tumor suppressor genes (TP53, APC, DCC, RB1, and BRCA1). Sites showing quantitative allelic imbalance (AI) greater than 30% were located on 3p (36%), 11q (31%), 12q (38%), 13q (33%), 17p near TP53 (74%), and 17q near BRCAI (32%). Among the 22% of cases showing microsatellite instability (MI), a subset (4 of 17) showed instability at 59% or more of sites tested. No ethnic bias was detected in cases showing MI or in cases with AI at sites with rates of AI above 30%. Tumors of the intestinal subtype were significantly more likely than diffuse tumors to show AI at DI3S170 (P = 0.01). A deletion map of chromosome arm 3p was prepared for tumors with AI at D3S1478. These data indicate that a tumor suppressor gene on chromosome arm 3p is involved in the development of a subset of gastric cancers.