Learning and development in neural networks--the importance of prior experience

Infants can discriminate between familiar and unfamiliar grammatical patterns expressed in a vocabulary that is distinct from that used earlier during familiarization (Cognition 70(2) (1999) 109; Science 283 (1999) 77). Various models have captured the data, although each required that discrimination be distinct, in terms of the computational process, from familiarization. This article describes a simple recurrent network (SRN), equipped only with the assumption that it should predict what comes next, which models the data without distinguishing between familiarization and discrimination. To accomplish this, the SRN requires pre-training on a range of sequences instantiating different structures and different vocabulary items to those used subsequently during familiarization and test. Pre-training enables the network to avoid replacing structure acquired during familiarization with structure experienced at test. An equivalent enabling condition may underpin infants' resistance to catastrophic interference between the different structures and vocabulary items to which they are exposed.     

Can the Family Assessment Device (FAD) Be Used with School Aged Children?

This article examines the usefulness of the Family Assessment Device(FAD) in assessing family functioning with school-aged children (under 12 years of age) compared to children 12 and older and mothers. FAD reports from 194 children with asthma (132 under 12 years; 62 12 years and older) were evaluated in comparison to mothers' FAD reports as well as mothers' reports on two other family functioning measures: the Family Inventory of Life Events (FILE) and the Impact on Family (IOF) scale, both relevant to functioning in families with children with asthma. Although FAD scale reliabilities were lowest in younger children (alpha = 48-.79), good concurrent validity was found with mothers' reports on the three different measures of family functioning. Older childrens' FAD scales showed good reliability (> .70) but poorer agreement with the various maternal measures. With modifications to make items more structured and simplified, the FAD could be tried with younger children, although documentation of improved reliability is needed before more widespread use with school-aged children is advocated. The measure already shows good agreement with maternal report in this younger age group, which likely would be strengthened with improved reliability. FAD reports in older children correlated less well with maternal measures, but may represent nonredundant information on family health from an independent perspective and are worth considering in addition to mothers' perspectives.     

Dual-task attention deficits in dysphoric mood

The attentional functioning of nondysphoric, mildly dysphoric, and moderately to severely dysphoric college students was tested using the attentional blink (AB) paradigm. These groups performed equally well at reporting a single target appearing in a rapidly presented stream of stimuli. All groups showed an AB, with report sensitivity for a 2nd target being reduced when the 2 targets were presented less than 0.5 s apart. Nondysphoric and mildly dysphoric participants showed the same size ABs, but the ABs for moderately to severely dysphoric participants were larger and longer. As predicted, the results showed that moderately to severely dysphoric individuals have attentional impairments. These impairments, however, were evident only in the more demanding dual-task condition.     

Psychometric properties of the Chinese version of the Family Awareness Scale

The author examined the reliability and validity of the Chinese Family Awareness Scale (C-FAS) in 2 studies. In Study 1, data from 361 adolescents (a) showed that the C-FAS was temporally stable and internally consistent and (b) supported the concurrent and construct validities of the scale. In Study 2, data from clinical (N = 281) and nonclinical (N = 451) groups of adolescents showed that the C-FAS scores discriminated between the 2 groups. C-FAS scores were also correlated significantly with other measures of family functioning and psychological well-being. Results of the 2 studies suggest that the C-FAS displayed generally good psychometric properties in different samples of Chinese adolescents.     

Acceptability of personal hormone monitoring for contraception: longitudinal and contextual variables

A new contraceptive technology may advance the science of family planning but may do little to affect health if potential users do not deem it an acceptable method. The authors conducted an acceptability study of a newly developed contraceptive method--personal hormone monitoring. A sample of 480 English volunteers present at the 6th month of a 13-month longitudinal study completed surveys regarding their attitudes toward a personal hormone monitor for the purpose of contraception. The authors used the participants' responses to determine (a) the extent to which the participants accepted the monitor, (b) how their ratings of acceptability changed over time, (c) the extent to which contextual variables predicted changes in acceptability over time, and (d) whether those contextual variables predicted final acceptability of the monitor. Results suggested that no single method of family planning is best for everyone and specified the people for whom personal hormone monitoring may be most suitable.     

Effects of caffeine on performance of low intensity tasks

31 college age men and women who consume less than three caffeinated beverages per week agreed to participate as subjects in research on the effects of acute caffeine intake on low intensity task performance. All subjects performed two randomly administered test conditions: (1) caffeine (5 mg/kg) and (2) placebo on separate visits following an initial 1-hr. orientation visit. Subjects were administered the beverage 30 min. prior to performing 12 separate tests assessing basic mathematics, simple response, logical reasoning, hand-eye coordination, and spatial and assembly skills. The Spielberger State Anxiety test was administered immediately after consuming the test beverage and once again at posttest. Analysis showed that caffeine did not significantly affect performance on all tests with the exception of the peripheral awareness (hand-eye coordination) test on which performance was higher after ingesting caffeine. The placebo treatment produced no effect on state anxiety, which contrasted with a significant rise in anxiety after caffeine consumption. State anxiety values were significantly greater after caffeine treatment relative to the placebo at pretest, and this difference persisted at posttest. These results demonstrated that the dose of caffeine increased scores on state anxiety for individuals who consumed less than three caffeinated beverages weekly but had very little effect on performance of low intensity tasks, except for a hand-eye coordination test involving peripheral awareness. Perhaps longer continuous performance of more demanding tasks would be more sensitive.     

Unrealistic optimism and perceived control: role of personal competence

This work analyzed the effects of unrealistic optimism in the interaction between the emotional valence of future events, the perception of control over these events, and the person with whom one compares oneself. It was hypothesized that, if the person of comparison is judged as very competent, a pessimistic bias should be produced. Likelihood of four different types of events (positive and controllable, positive and uncontrollable, negative and controllable, and negative and uncontrollable) were rated by 133 university students (22 men and 111 women) for themselves, for an average student, for their best friend, and for a bright friend. A pessimistic bias was observed on the relative likelihood of the events when the comparison was made between oneself and a competent and bright friend, when events were perceived as controllable, especially positive ones. Not enough is known, however, to provide meaningful interpretation at present; that must await further data and theoretical development.     

Sex differences in communication with close friends: testing Tannen's claims

In 1990 Tannen reported that men have fewer close friends than women, men discuss less intimate topics with their friends than women, and men and women respond differently to close friends' problems. 168 students completed a three-page survey designed to examine Tannen's claims. Consistent with Tannen's observations, men discussed less intimate topics (politics and school or work) with their five closest friends and reportedly were less likely to comfort or listen to their friends' problems than women were. Inconsistent with Tannen's statements, these women and men did not differ in the number of close friends they reported having or in the likelihood of offering advice when presented with a friend's problem. Present self-reports corroborate other researchers who questioned Tannen's findings and concluded that sex differences in interpersonal communication are small.     

Case markers as clause boundary inducers in Japanese

The present paper provides evidence that the processing of verb final clauses proceeds incrementally based on local information that becomes available with each word. The results of three self-paced reading experiments are reported in support of the proposal that NPs in Japanese are associated within clauses before a verb is processed. It is argued that a clause boundary is posited whenever case markers prevent two NPs from being part of the same clause, and slow reading times at the second NP are used as supporting evidence. Moreover, clause boundaries induced by case marking can facilitate processing at later points in the sentence as attested to by faster reading times at relative-clause heads. Contrary to previous findings that argued against a subclass of head-driven parsers, the present results are not easily reconcilable with any type of model that delays parsing decisions until a verb is available in the input sentence.     

Garner and congruence effects in the speeded classification of bimodal signals

The role of attention in speeded Garner classification of concurrently presented auditory and visual signals was examined in 4 experiments. Within-trial interference (i.e., congruence effects) occurred regardless of the attentional demands of the task. Between-trials interference (i.e., Garner interference) occurred only under conditions of divided attention when making judgments about auditory signals. Of importance, the data show congruence effects in the absence of Garner interference. Such a pattern has been rarely reported in studies of the classification of purely visual stimuli and contradicts theoretical accounts asserting that the effects share a common locus. The data question the notion that Garner classification reveals fundamental insights about the nature of the perceptual processing of bimodal stimuli.