A paradoxical dissociation in the effects of midazolam on recollection and automatic processes in the process dissociation procedure

This study used midazolam-induced amnesia to explore the plausibility of the estimates provided by the process dissociation procedure (PDP), which is designed to estimate the contributions of recollection (R) and automatic (A) processes to implicit memory performance. In a double-blind, placebo-controlled, within-subject design with 24 participants, single midazolam doses were administered intravenously, and word stem completion performance was used to calculate PDP estimates. A dissociation was observed such that midazolam decreased R but increased A estimates relative to placebo. Given that a manipulation that induces amnesia would not be expected to facilitate a memory process, these results add to the accumulating body of evidence suggesting that PDP estimates are not always theoretically plausible. Such evidence raises important questions about the use of the PDP.     

A Film Unfinished. Directed by Yael Heronski

Journal of Religion and Health -     

Gay males’ intimate relationship quality: The roles of attachment security,gay identity,social support,and income

Past research of relationship quality in same–sex couples has emphasized similarities with heterosexual couples. The present study examined both general and gay–specific intra– and interpersonal factors as predictors of gay men's relationship durability and relationship satisfaction. Our proposed path model postulated effects of contextual variables on self and relationships (i.e., social support/acceptance as context for attachment security, self–acceptance, and intimate relationships). The data, collected from an Israeli sample of gay men (N = 121), supported this model. All hypothesized paths were significant: Attachment security mediated the association of perceived friends’ support and self–acceptance with relationship quality, self–acceptance mediated the association of self–definition and perceived friends’ acceptance with relationship quality, and income had a direct association with relationship quality.     

The picture superiority effect: support for the distinctiveness model

The form change paradigm was used to explore the basis for the picture superiority effect. Recognition memory for studied pictures and words was tested in their study form or the alternate form. Form change cost was defined as the difference between recognition performance for same and different form items. Based on the results of Experiment 1 and previous studies, it was difficult to determine the relative cost for studied pictures and words due to a reversal of the mirror effect. We hypothesized that the reversed mirror effect results from subjects' basing their recognition decisions on their assumptions about the study form. Experiments 2 and 3 confirmed this hypothesis and generated a method for evaluating the relative cost for pictures and words despite the reversed mirror effect. More cost was observed for pictures than words, supporting the distinctiveness model of the picture superiority effect.     

Neighborhood effects in visual word recognition: Facilitatory or inhibitory?

In five experiments, in which subjects were to identify a target word as it was gradually clarified, we manipulated the target's frequency of occurrence in the language and its neighborhood size—the number of words that can be constructed from a target word by changing one letter, while preserving letter position. In Experiments 1–4, visual identification performance to screen-fragmented words was measured. In Experiments 1 and 2, we used the ascending method of limits, whereas Experiments 3 and 4 presented a fixed-level fragment. In Experiment 1, there was no relation between overall accuracy and neighborhood size for-words-between three and six letters in length. However, more errors of commission (guesses) were made for high-neighborhood words and more errors of omission (blanks) were made for low-neighborhood words. Letter errors within guesses occurred at serial positions having many neighbors, and these positions were also likely to contain consonants rather than vowels. In Experiment 2, a smallfacilitatory effect of neighborhood size on bothhigh- and low-frequency words was found. In contrast, in Experiments 3 and 4, using the same set of words,inhibitory effects of neighborhood size, but only for low-frequency words, were found. Experiment 5, using a speeded identification task, showed results parallel to those of Experiments 3 and 4. We suggest that whether neighborhood effects are facilitatory or inhibitory depends on whether feedback allows subjects to disconfirm initial hypotheses that the target is a high-frequency neighbor.     

The occurrence of different intrusive errors in patients with Alzheimer's disease, multiple cerebral infarctions, and major depression.

Recent evidence suggests that specific types of intrusive errors may occur more often in the protocols of Alzheimer's disease (AD) patients than in those of patients diagnosed with other types of dementia. Using the FULD Object Memory Evaluation, we documented the occurrence of five qualitatively different types of intrusive errors for mildly and moderately impaired patients with AD and multiple cerebral infarctions (MCI). Depressed and normal elderly controls were also studied. Despite an equivalent degree of impairment on a broad array of neuropsychological measures, mildly impaired AD patients evidenced greater deficits on a measure tapping retrieval from semantic memory and demonstrated a higher occurrence of specific types of intrusive errors relative to their mildly impaired MCI counterparts. Further, both of these measures were highly correlated, suggesting that these indices may be particularly sensitive to semantic dysfunction associated with early AD.     

Differential effects of scopolamine and lorazepam on working memory maintenance versus manipulation processes

Between-study comparisons of benzodiazepine and anticholinergic drugs on working memory suggest that anticholinergics may produce greater impairment in maintenance processes, whereas benzodiazepines may produce greater impairment in manipulation processes. This study directly compared acute effects of the benzodiazepine lorazepam (1.0 and 2.0 mg/70 kg, orally administered) and the anticholinergic scopolamine (0.25 and 0.50 mg/ 70 kg, subcutaneously administered) on working memory maintenance (storage and rehearsal) and manipulation processes in a placebo-controlled, double-dummy, double-blind, crossover design in 20 healthy volunteers. Using a modified Sternberg paradigm, storage, rehearsal, and manipulation processes were parametrically manipulated by varying memory load, delay between stimulus presentation and test, and number of operations performed on the letter strings, respectively, while controlling for drug effects on nonmemory processes. As predicted, the results suggested greater impairment in maintenance processes (rehearsal) with scopolamine than with lorazepam and greater impairment in manipulation processes with lorazepam than with scopolamine. In addition, the results suggested greater overall slowing of working memory processes with lorazepam.     

Acute effects of triazolam on false recognition

Neuropsychological, neuroimaging, and electrophysiological techniques have been applied to the study of false recognition; however, psychopharmacological techniques have not been applied. Benzodiazepine sedative/anxiolytic drugs produce memory deficits similar to those observed in organic amnesia and may be useful tools for studying normal and abnormal memory mechanisms. The present double-blind, placebo-controlled repeated measures study examined the acute effects of orally administered triazolam (Halcion; 0.125 and 0.25 mg/70 kg), a benzodiazepine hypnotic, on performance in the Deese (1959)/Roediger-McDermott (1995) false recognition paradigm in 24 healthy volunteers. Paralleling previous demonstrations in amnesic patients, triazolam produced significant dose-related reductions in false recognition rates to nonstudied words associatively related to studied words, suggesting that false recognition relies on normal memory mechanisms impaired in benzodiazepine-induced amnesia. The results also suggested that relative to placebo, triazolam reduced participants' reliance on memory for item-specific versus list-common semantic information and reduced participants' use of remember versus know responses.