The gap effect for eye and hand movements

A temporal gap between fixation point offset and stimulus onset typically yields shorter saccadic latencies to the stimulus than if the fixation stimulus remained on. Several researchers have explored the extent to which this gap also reduces latencies of other responses but have failed to find a gap effect isolated from general warning effects. Experiment 1, however, showed a robust gap effect for aimed hand movements (which required determination of a precise spatial location), regardless of whether the hand moved alone or was accompanied by a saccadic eye movement. Experiment 2 replicated this aimed hand gap effect and also showed a smaller effect for choice manual keypress responses (which required determination of the direction of response only). Experiment 3 showed no gap effect for simple manual keypress responses (which required no spatial determination). The results are consistent with an interpretation of the gap effect in terms of facilitation of spatially oriented responses.     

Health beliefs and promotion of HIV-preventive intentions among teenagers: a Scottish perspective.

Beliefs concerning the spread of the human immunodeficiency virus (HIV) and preventive behaviors were examined in a sample of 351 sexually active Scottish teenagers. A postal questionnaire, including measures of variables specified by the health belief model (HBM) and preventive intentions, was employed. The relation between HBM measures and reported endorsement of HIV-preventive intentions was investigated. Results indicated that, in general, respondents intended to use condoms with new sexual partners. The majority also intended to carry condoms if they thought they might have sex with a new partner and to ask potential partners about their previous sexual history. Multiple-regression analyses showed that measures of health beliefs, gender, age, sexual experience, and previous condom use accounted for 17.8% to 24.3% of the variance in reported preventive intentions. Perceived barriers to preventive behaviors were found to be important predictors. However, the overall pattern of results raised questions concerning the adequacy of the HBM as a model of the determinants of HIV-preventive intentions, and the need for an extended model is discussed. Separate analyses were conducted for men and women and for 16- and 18-year-olds, and the implications for modeling intention formation in these subgroups are considered. The relevance of these findings to HIV-preventive campaigns is also discussed.     

Negative mood,depressive symptoms,and major depression after smoking cessation treatment in smokers with a history of major depressive disorder

Negative mood, depressive symptoms, and major depressive episodes (MDEs) were examined in 179 smokers with a history of major depression in a trial comparing standard smoking cessation treatment to treatment incorporating cognitive-behavioral therapy for depression (CBT-D). Early lapses were associated with relatively large increases in negative mood on quit date. Mood improved in the 2 weeks after quit date among those returning to regular smoking but not among those smoking moderately. Continuous abstinence was associated with short- and long-term reductions in depressive symptoms. MDE incidence during follow-up was 15.3% and was not associated with abstinence. Unexpected was that CBT-D was associated with greater negative mood and depressive symptoms and increased MDE risk. Results suggest complex bidirectional associations between affect and smoking outcomes.     

Object-based selection within and beyond the focus of spatial attention

In a series of experiments, we examined the effect of perceptual objects on visual attentional processing in the presence of spatially cued attentional selection. Subjects made speeded judgments about two visual elements that were either both on the same object or on two different objects. Judgments were faster when the elements were on the same object than when they were on different objects, revealing an object advantage. Importantly, the object advantage remained even when either exogenous or endogenous spatial cues were used to direct the subjects' attention to a part of the display, contrary to earlier findings of other researchers. The object advantage, however, did disappear when the stimulus duration was shortened substantially. The results show that object-based selection is pervasive and is not diminished by the act of selective attention. The results are discussed in terms of their implications for the mechanisms that underlie attentional selection.     

Does priming specific syllables during tip-of-the-tongue states facilitate word retrieval in older adults?

This experiment investigated whether phonological priming of syllables helps resolve tip-of-the-tongue (TOT) states in young and older adults. Young, young-old, and old-old adults read general knowledge questions and responded "know," "TOT," or "don't know" accordingly. Participants then read a list of 10 words that included 3 phonological primes corresponding solely to the first, middle, or last syllable of the target word. Young and young-old adults resolved more TOTs after first-syllable primes, but old-old adults showed no increase in TOT resolution following any primes. These results indicate that presentation of the first syllable of a missing word strengthens the weakened phonological connections that cause TOTs and increases word retrieval, but not for old-old adults who experience greater deficits in the transmission of priming across these connections.     

Object-based visual attention with endogenous orienting

In a series of experiments, we examined covert orienting using endogenous cuing, in which attention is voluntarily directed toward a peripheral location. In one experiment, subjects were cued to attend to one end of an oblong object. They then detected targets on the cued object or elsewhere. In another experiment, subjects provided judgments of the relative temporal order of two flashes after their attention had moved endogenously. In a third experiment, subjects were directed to attend to an empty spatial location and subsequently discriminated features of objects that appeared at or near the locus of attention. In each of these situations, attentional orienting was object based, in the sense that nonattended locations that were on the cued object had an advantage over nonattended locations that were not on the object. The results are discussed in terms of their implications for object-based representations and the differences between exogenous and endogenous orienting of attention.     

Oculocentric coding of inhibited eye movements to recently attended locations

Results are reported for experiments that examined eye movements directed toward recently cued objects. In 1 experiment participants were slower to initiate saccades toward the earlier location of an object that had been cued, even though the cued object had subsequently moved away from that location. Other experiments involved exploring the reference frame within which the inhibited eye movements are encoded. These experiments revealed that the eye movement that is inhibited is encoded in an oculocentric-rather than an environmental-reference frame. However, simple detection as indexed by manual keypress responses is encoded in an environmental reference frame. The results have implications for inhibition of return, for the link between eye movements and attention, and for the nature of the spatial reference frames in which both covert and overt movements of attention are encoded.     

Parts outweigh the whole (word) in unconscious analysis of meaning

In unconscious semantic priming, an unidentifiable visually masked word (the prime) facilitates semantic classification of a following visible related word (the target). Three experiments reported here provide evidence that masked primes are analyzed mainly at the level of word parts, not whole-word meaning. In Experiment 1, masked nonword primes composed of subword fragments of earlier-viewed targets functioned as effective evaluative primes. (For example, after repeated classification of the targets angel and warm , the nonword anrm acted as an evaluatively positive masked prime.) Experiment 2 showed that this part-word processing was potent enough to oppose analysis at the whole-word level. Thus, smile functioned as an evaluatively negative (!) masked prime after repeated classification of smut and bile . Experiment 3 found no priming when masked word primes contained no parts of earlier targets. These results suggest that robust unconscious priming (a) is driven by analysis of part-word information and (b) requires previous classification of visible targets that contain the fragments later serving as primes. Contrary to a widely held view, analysis of subliminal primes appears not to function at the level of analysis of complete words.     

Onset but not offset of irrelevant motion disrupts inhibition of return

In seven experiments, subjects were slower to detect targets in cued static objects than in uncued static objects, revealing inhibition of return (IOR). This occurred regardless of the presence or absence of continuous motion of other, task-irrelevant objects in the display. However, if the motion of the irrelevant objects began during the interval between cue and target, the amount of IOR was considerably reduced. Offset of motion during the cue-target interval had no effect. Implications for IOR, object perception, and attentional capture are discussed.     

Genetic Counseling for Fragile X Syndrome: Updated Recommendations of the National Society of Genetic Counselors

These recommendations describe the minimum standard criteria for genetic counseling and testing of individuals and families with fragile X syndrome, as well as carriers and potential carriers of a fragile X mutation. The original guidelines (published in 2000) have been revised, replacing a stratified pre- and full mutation model of fragile X syndrome with one based on a continuum of gene effects across the full spectrum of FMR1 CGG trinucleotide repeat expansion. This document reviews the molecular genetics of fragile X syndrome, clinical phenotype (including the spectrum of premature ovarian failure and fragile X-associated tremor-ataxia syndrome), indications for genetic testing and interpretation of results, risks of transmission, family planning options, psychosocial issues, and references for professional and patient resources. These recommendations are the opinions of a multicenter working group of genetic counselors with expertise in fragile X syndrome genetic counseling, and they are based on clinical experience, review of pertinent English language articles, and reports of expert committees. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. The professional judgment of a health care provider, familiar with the facts and circumstances of a specific case, will always supersede these recommendations.