Effects of Expectancy and Attention in Vibrotactile Choice Reaction Time Tasks

The orienting of attention in space has not been considered in the tactile domain. This issue is examined using a modified version of a visual paradigm initially adopted by Posner, Snyder, and Davidson (1980), which manipulates the probability of a stimulus occurring at different spatial locations. Slower RTs at an unexpected stimulus location are thought to reflect the time required to shift attention from the expected to the unexpected location. In two experiments involving vibrotactile choice RT between left and right hands, the two hands were either crossed or uncrossed, and the hands were held both on the left side of the body, both on the right, or one on either side of the midline. There was no evidence to suggest that spatial location (left or right) affected the orienting of attention in the tactual modality. As predicted, RTs were slower when the arms were crossed compared with uncrossed, though this effect was smaller for the expected trials. A coding conflict hypothesis may explain both these findings, but the smaller effect in the expected trials may also reflect attentional factors. Both the relative and absolute location of the hands affected the magnitude of the crossed-arm effect and indicated that attention may play a role in the perceptual division of space into left and right sides. Possible reasons for hand or hemispace asymmetries in different simple and choice RT paradigms were discussed.     

The sources of visual recency: Movement and language in serial recall

Four experiments examine the importance of movement—the sequential ordering of stimulus features—in producing recency in the ordered serial recall of visual lists. The written recall of handsigns produced more recency when they were seen moving than still (Experiment I). Number lists presented as moving bar figures showed more recency than numbers which were displayed in the normal way with all features displayed simultaneously (Experiment II). The order in which features of abstract shapes are displayed can, itself, determine recency (Experiment III). However, a final experiment showed that still lip pictures of speech sounds generate more recency than letters representing those speech sounds. Therefore movement of stimulus features need not account for the extensive recency advantage in remembering lipread lists. The theoretical implications of these findings are discussed.     

Reasoning in depression: Impairment on a concept discrimination learning task

Abstract

This study compared depressed and nondepressed undergraduates identified by the Beck Depression Inventory on concept discrimination learning problems. In two experiments, both groups generally performed at ceiling when solving simpler 1- and 2-dimensional problems, but the depressed subjects showed significant impairment on 4-dimensional problems. The first experiment investigated the role of storage in task performance. The second experiment was designed to focus attention at critical stages, and also manipulated storage demands. The depressed subjects in each experiment solved fewer problems correctly and made significantly more errors when listing hypotheses; there was little evidence that the experimental manipulations differentially facilitated their performance. The findings are considered in relation to current models of cognitive function in depression.     

Freud as Philosopher and Metaphysician: The Case of Dora

The Dora case is examined, for its use of psychoanalytic constructs and concomitant reliance on neurological terminology. Boothby and Robertson are cited as commentators, and it is concluded that both Dora and The Interpretation of Dreams point us in the direction of an intriguing, not-quite-materialistic philosophy of mind.