Processing resources and age differences in working memory

This study investigated the performance of young and old subjects on a modified version of the working memory task developed by Baddeley and Hitch (1974). Subjects were required to verify a set of sentences of varying complexity while they repeated aloud zero, two, or four words. The older subjects took longer to verify the sentences, especially when the sentences were grammatically complex, but the effect of concurrent memory load on verification latency was the same in both groups. These results cast doubt on the notion that there is an age-related decline in one general pool of processing resources. They also suggest that older people have greater difficulty with the active processing aspects, rather than with the passive holding aspects, of working memory tasks.     

Alternative scoring system of repeated items on the MMPI: caveat emptor

There are 16 items in the standard MMPI group forms which are included twice. It was found that a number of computerized scoring services use only the first occurrence of repeated items in scoring the MMPI scales, whereas the handscoring templates use an arbitrary combination of the first and second occurrence of these items. Comparison of these conventions suggested a potential for significant differences in score, particularly on the Sc scale. Scoring a set of 126 MMPIs of chronic pain patients by both of these scoring conventions revealed differences of up to 10 T points on the Sc scale. It is recommended that a single scoring convention for the MMPI be adopted by psychologists. For several reasons we suggest that only the first occurrence of repeated items should be used for scoring purposes. In the absence of a single convention, comparisons between Sc scores on different protocols should not be made without first insuring that the protocols were scored in the same manner.     

The effects of divided attention on encoding and retrieval processes: The resiliency of retrieval processes

We have recently cast doubt (Craik, Govoni, Naveh-Benjamin, & Anderson, 1996; Naveh-Benjamin, Craik, Guez, & Dori, 1998) on the view that encoding and retrieval processes in human memory are similar. Divided attention at encoding was shown to reduce memory performance significantly, whereas divided attention at retrieval affected memory performance only minimally. In this article we examined this asymmetry further by using more difficult retrieval tasks, which require substantial effort. In one experiment, subjects had to encode and retrieve lists of unfamiliar name-nouns combinations attached to people's photographs, and in the other, subjects had to encode words that were either strong or weak associates of the cues presented with them and then to retrieve those words with either intra- or extra-list cues. The results of both experiments showed that unlike division of attention at encoding, which reduces memory performance markedly, division of attention at retrieval has almost no effect on memory performance, but was accompanied by an increase in secondary-task cost. Such findings again illustrated the resiliency of retrieval processes to manipulations involving the withdrawal of attention. We contend that retrieval processes are obligatory or protected, but that they require attentional resources for their execution.     

Atypical depression: enhanced right hemispheric dominance for perceiving emotional chimeric faces

Two studies compared hemispatial bias for perceiving chimeric faces in patients having either atypical or typical depression and healthy controls. A total of 245 patients having major depressive disorder (MDD) or dysthymia (164 with atypical features) and 115 controls were tested on the Chimeric Faces Test. Atypical depression differed from typical depression and controls in showing abnormally large right hemisphere bias. This was present in patients having either MDD or dysthymia and was not related to anxiety, physical anhedonia, or vegetative symptoms. In contrast, patients having MDD with melancholia showed essentially no right hemisphere bias. This is further evidence that atypical depression is a biologically distinct subtype and underscores the importance of this diagnostic distinction for neurophysiologic studies.     

A longitudinal study of children's depressive symptoms, self-perceptions, and cognitive distortions about the self

This longitudinal study examined how depressive symptoms relate to children's self-perceptions and to estimates of children's cognitive distortions about the self in a nonclinical sample of children who were followed from 4th grade (n = 248) through 6th grade (n = 227). Report card grades measured children's academic competence, and teachers' ratings of children's level of peer acceptance at school indicated social acceptance. Self-reported depressive symptoms predicted a change in children's negative views of the self. Moreover, the self-perceptions of children who exhibited more symptoms of depression appeared to reflect an underestimation of their actual competence. Children's negative self-perceptions and underestimations about the self were not associated with a subsequent change in depressive symptoms. The implications of the findings for cognitive theories of depression and future research with this population are discussed.     

Naming and categorization in young children: vocal tact training

In three experiments, 2- to 4-year-old children, following pretraining with everyday objects, were presented with arbitrary stimuli of differing shapes. In Experiment 1A, 9 subjects were trained one common tact response, "zag," to three of these and a second tact, "vek," to another three. In category match-to-sample Test 1, 4 subjects sorted accurately when required only to look at the sample before selecting from five comparisons. The remaining 5 subjects succeeded in Test 2, in which they were required to tact the sample before selecting comparisons. Experiment 1B showed, for 2 of these subjects, that tact training with 12 arbitrary stimuli established two six-member classes that were still intact 6 weeks later. In Experiment 2, 3 new subjects participated in a common tact training procedure that ensured that none of the exemplars from the same class were presented together prior to the test for three-member classes. Two subjects passed category Test 1 and the third passed Test 2. Tests showed subjects' listener behavior in response to hearing /zog/ and /vek/ to be in place. These experiments indicate that common naming is effective in establishing arbitrary stimulus classes and that category match-to-sample testing provides a robust measure of categorization.