Are individual or consecutive letters the unit affected by repetition blindness?

When 2 similar words (e.g., react reach) are briefly sequentially displayed, the 2nd word may be omitted from the report, a phenomenon known as repetition blindness (RB). Previous researchers have suggested that consecutive letters are the unit affected by RB. Six experiments provided new data on orthographic RB. Two letters at the beginning or end of words resulted in RB, as did alternating interior letters (tactile earthly) and 3 letters with different relative positions (arid bird). However, no RB was found with a single final letter (show view). Observed RB may reflect pattern completion because RB for pairs like throat theory was reduced when the nonrepeated letters (eory) were consistent with only a single word. The experiments point to a model of orthographic RB in which both individual letters and letter sequences of length 2 or more play a role.     

Spontaneous allocation of visual attention: dominant role of uniqueness

Common sense suggests that unique or abruptly changing (transient) elements in a visual scene often draw attention involuntarily. Visual search studies paint a seemingly different picture, however: Unique items usually draw attention involuntarily only when observers seek a unique target. One type of transient— abrupt onsets—draws attention involuntarily, but only when the observer is seeking an onset (Folk, Remington, & Johnston, 1992). One way of reconciling common-sense with these findings is to suppose that when people view a scene with no specific goal or task, they adopt adefault set, which might prioritize novelty and/or transients. In two experiments, 336 subjects saw a single display of six items for 900 msec, expecting to have to describe it (Experiment 1) or make an aesthetic judgment about it (Experiment 2). One item in the display was either uniquely flashing (surrounded by static items) or uniquely static (surrounded by flashing items). In both studies, the unique item, even if static, was more often reported than the nonunique item, with flashing items enjoying an additional advantage.     

Adult attention-deficit/hyperactivity disorder: neuropsychological correlates and clinical presentation

We compared the neuropsychological test performance of adult ADHD patients to the neurocognitive profiles of control subjects recruited from the general population. We administered a neuropsychological test battery consisting of measures considered sensitive to either orbitofrontal or dorsolateral-prefrontal (DLPF) dysfunction. Orbitofrontal hypoarousal is associated with behavioral disinhibition and a relative indifference to punishment. The DLPF region may function as a central executive system. Indeed, DLPF dysfunction may underlie many of the cardinal symptoms associated with ADHD. We tested the following hypotheses: (1) adult subjects meeting DSM-IV criteria for ADHD, predominantly hyperactive-impulsive type, would display neuropsychological deficits on tasks sensitive to orbitofrontal dysfunction; (2) adult subjects meeting DSM-IV criteria for ADHD, predominantly inattentive type, would perform poorly on measures sensitive to DLPF dysfunction; and (3) adult subjects meeting DSM-IV criteria for ADHD, combined type, would exhibit performance deficits on orbitofrontal measures and on DLPF tasks. Results partially confirmed our hypotheses. Subtyping ADHD patients revealed important group differences. Distinct neurocognitive and clinical profiles were observed.     

Self-injurious behavior: gene-brain-behavior relationships

This paper summarizes a conference held at the National Institute of Child Health and Human Development on December 6-7, 1999, on self-injurious behavior [SIB] in developmental disabilities. Twenty-six of the top researchers in the U.S. from this field representing 13 different disciplines discussed environmental mechanisms, epidemiology, behavioral and pharmacological intervention strategies, neurochemical substrates, genetic syndromes in which SIB is a prominent behavioral phenotype, neurobiological and neurodevelopmental factors affecting SIB in humans as well as a variety of animal models of SIB. Findings over the last decade, especially new discoveries since 1995, were emphasized. SIB is a rapidly growing area of scientific interest to both basic and applied researchers. In many respects it is a model for the study of gene-brain-behavior relationships in developmental disabilities.     

A sublexical locus for repetition blindness: evidence from illusory words.

Six experiments used an illusory words paradigm to demonstrate that repetition blindness (RB) in orthographically similar words affects only the words' shared letters. Rapid serial visual presentation streams of words and word fragments allowed the unique letters of the 2nd critical word to combine with a subsequent fragment to create a word, as in rock shock ell. The illusory word shell was reported 2-3 times as frequently in RB conditions as in control conditions. Further experiments ruled out letter migration, contour summation, and differences in processing load as explanations for the results. These findings are inconsistent with current proposals that orthographic RB represents similarity inhibition or lexical competition or that it reflects problems with word-level token individuation.     

Look Who's Talking: Measuring Self-Disclosure in MFT

While self-disclosure plays a prominent role in the development and maintenance of the therapeutic relationship, most marriage and family therapy clinical research fails to include measures of self-disclosure. A factor analysis of Chelune's (1976) Self Disclosure Situations Survey (SDSS) reduces the number of items in this measure from 20 to six. Researchers are encouraged to consider conducting clinical research with specific attention to the construct of self-disclosure. The revised SDSS could easily be added as part of the self-report information collected in clinical studies.     

What’s in a name? Lexical knowledge drives infants’ visual preferences in the absence of referential input

Seventeen-month-old infants were presented with pairs of images, in silence or with the non-directive auditory stimulus ‘look!’. The images had been chosen so that one image depicted an item whose name was known to the infant, and the other image depicted an image whose name was not known to the infant. Infants looked longer at images for which they had names than at images for which they did not have names, despite the absence of any referential input. The experiment controlled for the familiarity of the objects depicted: in each trial, image pairs presented to infants had previously been judged by caregivers to be of roughly equal familiarity. From a theoretical perspective, the results indicate that objects with names are of intrinsic interest to the infant. The possible causal direction for this linkage is discussed and it is concluded that the results are consistent with Whorfian linguistic determinism, although other construals are possible. From a methodological perspective, the results have implications for the use of preferential looking as an index of early word comprehension.