Cross-sectional and longitudinal patterns of dedifferentiation in late-life cognitive and sensory function: the effects of age,ability, attrition,and occasion of measurement

The dedifferentiation hypothesis is examined with respect to age-group differences, ability-group differences, attrition-group differences, and time. Cognitive and sensory data were analyzed from individuals (n = 1,823) who completed a clinical assessment on at least 1 of 3 occasions of measurement in the Australian Longitudinal Study of Ageing. Inconsistent dedifferentiation effects were associated with low ability and early attrition from the study, but age-related dedifferentiation was not found. Longitudinal analyses confirmed the cross-sectional analyses. Even though instances of dedifferentiation were identified between pairs of sensory and cognitive variables, consistent patterns of dedifferentiation were not found. These results do not support the view that shared biological factors become increasingly important for explaining within-individual change in cognitive and sensory function in later life.     

What you get out of memory depends on the question you ask

Following study, participants received 2 tests. The 1st was a recognition test; the 2nd was designed to tap recollection. The objective was to examine performance on Test 1 conditional on Test 2 performance. In Experiment 1, contrary to process dissociation assumptions, exclusion errors better predicted subsequent recollection than did inclusion errors. In Experiments 2 and 3, with alternate questions posed on Test 2, words having high estimates of recollection with one question had high estimates of familiarity with the other question. Results supported the following: (a) the 2-test procedure has considerable potential for elucidating the relationship between recollection and familiarity; (b) there is substantial evidence for dependency between such processes when estimates are obtained using the process dissociation and remember-know procedures; and (c) order of information access appears to depend on the question posed to the memory system.     

Modeling memory decline in older adults: the importance of preclinical dementia, attrition, and chronological age

This longitudinal study examined memory loss in a sample of 391 initially nondemented older adults. Analyses decomposed observed memory loss into decline associated with preclinical dementia, study attrition, terminal decline, and chronological age. Measuring memory as a function of only chronological age failed to provide an adequate representation of cognitive change. Disease progression accounted for virtually all of the memory loss in the 25% of the sample that developed diagnosable dementia. In the remainder of the sample, both chronological age and study attrition contributed to observed memory loss. These results suggest that much of memory loss in aging adults may be attributable to the progression of preclinical dementia and other nonnormative aging processes that are not captured by chronological age.     

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.     

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.