Neuropharmacological aspects of cognitive neurorehabilitation in epilepsy

The role of CNS neuromodulators in cognitive neurorehabilitation can be related to two main issues: 1) the negative impact on cognition of drug categories prescribed for different neurologic symptoms, such as spasticity, extrapyramidal symptoms, or epileptic seizures; 2) their possible role in neuroprotection and amelioration of the cognitive status of the patient, especially attention and memory. This paper reviews different pharmacological aspects of cognitive neurorehabilitation in epilepsy.     

A computational model of the Simon effect

Even though stimulus location is task irrelevant, reaction times are faster when the location of the stimulus corresponds with the location of the response than when it does not. This phenomenon is called the Simon effect. Most accounts of the Simon effect are based on the assumption that it arises from a conflict between the spatial code of the stimulus and that of the response. In this paper a computational model of this hypothesis is presented. It provides a computationally explicit mechanism of the Simon effect. Consistent with human performance, the model provides reaction times that indicate both an advantage for the ipsilateral, corresponding response (i.e., facilitation) and a disadvantage of the contralateral, noncorresponding response (i.e., inhibition). In addition, the model accounts for the fact that the size for the effect depends on task difficulty.     

Is there a modality effect? Evidence for visual recency and suffix effects

In Experiment 1, four groups of 16 subjects performed ordered recall of six-syllable lists in both suffix and nonsuffix conditions. Sequential presentation of the lists varied for each group. In the auditory presentation, the syllables were delivered from one location only and were read aloud by the subjects. For the visual, spatially nondistributed presentation, the syllables appeared in one location only and were read silently. For visual, spatially distributed presentations, the syllables were spread out either vertically or horizontally and were read silently. Very robust recency and suffix effects were found in the auditory presentation, as well as in visual, spatially distributed presentations. In Experiment 2, 16 subjects performed ordered recall of visually presented lists with the items spread out vertically and conflicting spatial and temporal orders. A reliable recency effect was found for the final block of trials. In Experiment 3, 16 subjects performed ordered recall in the same conditions as in Experiment 2, except that they were instructed to recall the temporal order in which the spatial positions would be filled in. A bow-shaped curve and a strong recency effect were obtained.     

A Tower Unto Heaven: Toward an Expanded Framework for Psychopathology

I respond to commentaries on my target article “An Evolutionary Life History Framework for Psychopathology.” I start by addressing criticism of my basic assumptions about life history strategies and their implications for individual differences in human behavior. Next, I examine the theoretical structure of the proposed framework and respond to the commentators’ challenges to its generality and flexibility. I show how the framework can be expanded to include multiple levels of analysis and to integrate behavioral control with neurological functionality; I also reinterpret the recent finding of a general factor of psychopathology in the context of the expanded framework. In the last section I discuss specific psychopathological conditions, namely attention deficit/hyperactivity disorder, borderline personality disorder, substance abuse, autism spectrum disorders, schizophrenia spectrum disorders, obsessive-compulsive disorder, eating disorders, and depression. For each condition, I reply to the commentators’ criticism of my life history analysis, integrate their suggestions and insights, highlight the present weaknesses of the theory, and indicate promising directions for future research.     

Relative size perception at a distance is best at eye level

Relative size judgments were collected for two objects at 30.5 m and 23.8 m from the observer in order to assess how performance depends on the relationship between the size of the objects and the eye level of the observer. In three experiments in an indoor hallway and in one experiment outdoors, accuracy was higher for objects in the neighborhood of eye level. We consider these results in the light of two hypotheses. One proposes that observers localize the horizon as a reference for judging relative size, and the other proposes that observers perceive the general neighborhood of the horizon and then employ a height-in-visual-field heuristic. The finding that relative size judgments are best around the horizon implies that information that is independent of distance perception is used in perceiving size.