Psychoanalytic dream theory and recent neurobiological findings about REM sleep

I have reviewed Hobson and McCarley's activation-synthesis hypothesis of dreaming which attempts to show that the instigation and certain formal aspects of dreaming are physiologically determined by a brainstem neuronal mechanism, their reasons for suggesting major revisions in psychoanalytic dream theory, and neurophysiological data that are inconsistent with their hypothesis. I then discussed the concept of mind-body isomorphism pointing out that they use this concept inconsistently, that despite their denials they regularly view physiology as primary and psychological processes as secondary, and that they frequently make the error of mixing the languages of physiology and psychology in their explanatory statements. Finally, in order to evaluate Hobson and McCarley's claim that their findings require revision of psychoanalytic dream theory, I examined their discussions of chase dreams, flying dreams, sexual dreams, the formal characteristics of dreams, the forgetting of dreams, and the instigation of dreams. I concluded that although their fascinating physiological findings may be central to understanding the neurobiology of REM sleep, they do not alter the meaning and interpretation of dreams gleaned through psychoanalytic study.     

Judging interevent relations: From cause to effect and from effect to cause

Stimulus competition was studied in college students' correlational judgments in a medical decision-making setting. In accord with prior findings, subjects making cause-to-effect (predictive) judgments discounted a stimulus event that was moderately correlated with a target event when rival stimuli were more highly correlated with the effect. However, subjects making effect-to-cause (diagnostic) judgments were not at all disposed to discount a stimulus event which was moderately correlated with a target event when rival stimuli were more highly correlated with the cause. The theoretical implications of these results are considered in connection with associative and mentalistic models of causal attribution.     

Two asymmetries governing neural and mental timing

Mental timing studies may be influenced by powerful cognitive illusions that can produce an asymmetry in their rate of progress relative to neuronal timing studies. Both types of timing research are also governed by a temporal asymmetry, expressed by the fact that the direction of causation must follow time's arrow. Here we refresh our earlier suggestion that the temporal asymmetry offers promise as a means of timing mental activities. We update our earlier analysis of Libet's data within this framework. Then we consider the surprises which often occur on those rare occasions when neural timing experiments parallel mental timing work exactly. Together, these surprises and asymmetries prescribe a relentlessly meticulous and fully transparent exposition of timing methods, terms, and concepts which shuns plausible narratives, even when buttressed by rigorous formal models, unless guided by opposite empirical evidence.     

Brief presentations are sufficient for pigeons to discriminate arrays of same and different stimuli

Four pigeons first learned to discriminate 16-item arrays of same from different pictorial stimuli. They were then tested with reduced exposure to the pictorial arrays, brought about by changes in the stimulus viewing requirement under fixed-ratio (FR) and fixed-interval (FI) schedules. Increasing the FR requirement enhanced discriminative performance up to 10 pecks; increasing the FI requirement enhanced discriminative performance up to 5 s. Exposures to the stimulus arrays averaging only 2 s supported reliable discrimination. Pigeons thus discriminate same from different stimuli with considerable speed, suggesting that same-different discrimination behavior is of substantial adaptive significance.     

Detecting variety: what's so special about uniformity?

People and pigeons were taught to make 1 of 2 responses to 16-icon arrays that differed in their visual variability. In 2 experiments, participants had to (a) discriminate a collection of identical items from a collection in which 2 or more items were different or (b) discriminate a collection of different items from a collection in which 2 or more items were identical. In Experiment 1, humans found it much easier to discriminate uniformity from all levels of diversity. In Experiment 2, pigeons also found it easier to discriminate uniformity from all levels of diversity, but the size of this effect was smaller than that observed in people. These and other results suggest that both species are predisposed to notice differences rather than similarities.     

Paper and voice MAYSI-2: format comparability and concordance with the voice DISC-IV

The authors examine the comparability of paper and voice formats of the Massachusetts Youth Screening Instrument-Second Version (MAYSI-2) as well as each format's concordance with the Voice Diagnostic Interview Schedule for Children (DISC) among adjudicated youth. Comparability is assessed among 248 youths admitted to a South Carolina Assessment Center. Mean scores and alpha coefficients are calculated, and area under the curve and positive and negative predictive values are used to compare concordance to the DISC. Paper and voice formats are significantly correlated, have similar alpha coefficients, and have comparable concordance with the DISC, suggesting that the MAYSI-2 paper and voice formats are comparable instruments. The voice format may be preferable to the paper format for screening justice youth for mental health problems because it may reduce incomplete data and increase reporting of stigmatized behaviors and because of its ability to automatically generate scored reports and aggregate data.     

Same-different conceptualization by baboons (Papio papio): the role of entropy

The authors trained 6 baboons (Papio papio) to make 1 of 2 report responses to 16-icon same arrays versus 16-icon different arrays. In the same arrays, the icons were all the same as one another, whereas in the different arrays the icons were all different from one another. In Experiment 1, the baboons discriminated the same arrays from the different arrays, and they transferred their discriminative responding to arrays of novel icons. In Experiments 2 and 3, the baboons exhibited strong sensitivity to the degree of display variability when they were shown mixed arrays that comprised some same and some different items. The information theoretic measure "entropy" systematically described these results and outperformed several rival metrics. Finally, in Experiments 4 and 5, the baboons' responses to displays that contained jittered and blurred icons suggested that their same-different conceptual behavior was not based on the spatial orderliness of the visual arrays.