Evidence for disproportionate dual-task costs in older adults for episodic but not semantic memory

Previous research demonstrates that older adults are poor at dual tasking, but there is less agreement on whether their decrement is worse than that predicted from single-task performance. This study investigated whether task domain moderates dual-task costs in old age. In two experiments, young and older adults retrieved either previously learned associates (episodic retrieval) or overlearned category members (semantic retrieval) under single or working-memory load conditions, using cued recall (Experiment 1) and recognition (Experiment 2) procedures. In both experiments the proportional costs of dual tasking were age invariant for semantic retrieval but were particularly marked for episodic retrieval, although the size of the age effect was reduced in recognition compared to cued recall. The data suggest that age effects in dual tasking may be domain specific.     

The effect of varied physician affect on recall, anxiety, and perceptions in women at risk for breast cancer: an analogue study.

Evaluated the effect of varied physician affect on subject recall, anxiety, and perceptions in a simulated tense and ambiguous medical situation. Forty women at risk for breast cancer viewed videotapes of an oncologist presenting--with either worried or nonworried affect--mammogram results. Although the mammogram results and the oncologist were the same in both presentation, analyses indicated that, compared to the women receiving the results from a nonworried physician, the women receiving the results from a worried physician recalled significantly less information, perceived the clinical situation as significantly more severe, reported significantly higher levels of state anxiety, and had significantly higher pulse rates. These results suggest that physician affect plays a critical role in patient reaction to medical information. Implications for compliance research, patient satisfaction, and physician training are discussed.     

On the relation between feeling of knowing and lexical decision: persistent subthreshold activation or topic familiarity?

Experiment 1 replicated Yaniv and Meyer's (1987) finding that lexical decision and episodic recognition performance was better for words previously yielding high-accessibility levels (a combination of feeling-of-knowing and tip-of-the-tongue ratings) in comparison with those yielding low-accessibility levels in a rare word definition task. Experiment 2 yielded the same pattern even though lexical decisions preceded accessibility estimates by a full week. Experiment 3 dismissed the possibility that the Experiment 2 results may have been due to a long-term influence from the lexical decision task to the rare word judgment task. These results support a model in which Ss (a) retrieve topic familiarity information in making accessibility estimates in the rare word definition task and (b) use this information to modulate lexical decision performance.     

Biology of elderly suicide.

Most studies of suicide in younger patients have demonstrated significant alterations in the serotonin system. Although a high percentage of completed suicides occur in late-life, to date very few studies of the biology of suicide have focused on this age group. This chapter describes age-related changes in the central nervous system pertinent to the biology of suicide, then reviews post-mortem biological studies of the brains of suicides and suicide attempters. As suicide attempts in the elderly are characterized by the use of violent means, biologic studies of impulsive violence are discussed. Finally we describe data on the effect of degenerative diseases on the serotonin system and the possible link to increased suicidal behavior in affected patients. This review underscores the need for further study of the biology of suicide in the geriatric age group.     

The recovery of structure from motion: no evidence for a special link with the convergent disparity mechanism

Convergent and divergent stereo mechanisms were compared in their ability to recover structure from motion. Contrary to a recent result reported by Richards and Lieberman, no difference in their performance was found; both mechanisms appeared equally capable of supporting the perception of good structure from motion. Possible reasons for the disparate results are discussed.     

Selective attention and stimulus-reinforcer interactions in the pigeon

The study supplies further evidence that non-associative effects and temporal-spatial similarities between certain combinations of cue and consequence cannot explain all instances of stimulus-reinforcer interactions. Pigeons were trained to press a treadle in the presence of a discriminative compound stimulus either to avoid shock or to obtain a food reinforcer. The compound stimulus was composed of diffuse tone and light cues which had identical temporal patterns of onset, duration and offset. With the avoidance schedule the auditory cue acquired more control than the visual cue; however, when food was the reinforcer, the visual cue exerted more control. This pattern of stimulus control on the appetitive schedule did not change if random shocks were also added, even though these shocks were equal in density to the food presentations and equal in magnitude to those used for the avoidance schedule. Other changes in the appetitive procedure, such as making the tone spatially contiguous with food and removing the light in the food hopper, also failed to alter the relative control by the different cues. Prior training with a food reinforcer did not produce any change in the relative control by the two cues when the birds were retrained on the shock-avoidance schedule. The results suggest that some frequently stated alternatives to selective associability are not adequate explanations of this instance of a stimulus-reinforcer interaction.