Memory for action events: findings in neurological patients

Encoding action phrases by enacting leads normally to better memory performance than verbal encoding. In order to gain additional insight into the representational basis of the enactment effect, neurological patients are contrasted with healthy participants. Persons suffering from Parkinson's disease, which primarily impairs the motor system, and patients suffering from Frontal Lobe Syndrome, which primarily affects action-related planning processes, were involved. We investigated whether the enactment effect would be differentially affected by these disorders. In addition, the characteristics of information processing after encoding by enacting was analyzed by varying memory material (unrelated versus clusterable actions) and by adding an encoding condition that included obligatory action planning (director condition). The findings indicate that the impact of motor information for the enactment effect is not dominant compared to the role of action-related cognitive and motivational processes, in particular planning processes. The findings of the two experiments are explained within traditional conceptual memory theories.     

An experimental study of the emergence of human communication systems

The emergence of human communication systems is typically investigated via 2 approaches with complementary strengths and weaknesses: naturalistic studies and computer simulations. This study was conducted with a method that combines these approaches. Pairs of participants played video games requiring communication. Members of a pair were physically separated but exchanged graphic signals through a medium that prevented the use of standard symbols (e.g., letters). Communication systems emerged and developed rapidly during the games, integrating the use of explicit signs with information implicitly available to players and silent behavior-coordinating procedures. The systems that emerged suggest 3 conclusions: (a) signs originate from different mappings; (b) sign systems develop parsimoniously; (c) sign forms are perceptually distinct, easy to produce, and tolerant to variations.     

Introduction

This Introduction to the special issue on ??Skepticism and Justification?? provides a background to the nine articles collected here and a detailed summary of each, which highlights their interconnections and relevance to the debate at the heart of the issue.     

Transformation processes upon the visual code

Seven experiments investigated whether orientation-dependent latency functions for the visual code resemble those observed in studies of mental rotations of visual images. The subjects were required to perform “same-different” classifications of two simultaneously presented letters. The dependent variables considered were reaction time IRT and accuracy. Experiments 1, 2, 4, 5, and 6 showed that subjects could correctly classify two different letters on the basis of the visual code without preceding transformations. Experiments 1, 2, and 7 showed orientationdependent effects for “same“ responses. It appeared, however, that orientation functions for the visual cede were clearly different from those previously observed for visual images. In addition, the findings of Experiments 4, 5, and 6 indicated that a frame that jointly rotated with the disoriented letters could eliminate the orientation-dependent effects for “same” responses. Experiment 7 showed that the results of Experiments 4, 5, and 6 must be attributed to the structural characteristics of the frame and not to a directional cue. The results of Experiment 3 seemed to demonstrate that transformations did not occur when the subjects used the phonetic code to classify the letters. Overall, the results of the seven experiments were considered to provide a demonstration of the importance of the distinction between the operations on visual images and those on the visual code.     

The cost of a strategy

Abstract

Experiment 1 demonstrated a new kind of dual-task interference effect. The primary task was a speeded left-right discrimination of stimulus position (R1). The un speeded secondary task consisted of reporting verbally whether the stimuli were the same or different (R2). Stimulus exposure time was either 150 or 2000 msec. Two groups of subjects performed the primary task only, whereas two other groups performed both tasks and were instructed to emit R1 before R2. It was reasoned that the decision would be made to emit R1 before R2, and that this decision would produce a lengthening of R1. The results supported this prediction. Experiment 2 showed that the interference effect also occurred when the subjects were not explicitly instructed to emit R1 before R2, and was not due to either the mere presence of the second task or to response grouping. Experiments 3 and 4 compared two possible models for explaining the interference effect, i.e. the capacity-sharing model and the postponement model. As predicted by the postponement model, task difficulty did not interact, or interacted underadditively, with task overlap (Experiment 3), and the interference effect was not influenced by the amount of processing resources devoted to the primary task (Experiment 4). It was concluded that this new type of interference effect is best explained by the version of the postponement model that locates the bottleneck at the decision stage.     

The Relationship Between Frustration Intolerance,Unhealthy Emotions,and Assertive Behaviour in Italian Students

The aim of the present research was to investigate the relationship between frustration intolerance and emotional-behavioural problems. Specifically, the study explored whether frustration intolerance beliefs were associated with difficulties in assertive behaviour, anxiety, depression, and anger in a non-clinical student sample (N = 250). For this purpose an Italian version of the Frustration Discomfort Scale (FDS) was developed. The findings supported a multidimensional model of frustration intolerance and the relationship between specific frustration intolerance beliefs and emotional-behavioural problems. Regarding unhealthy emotions, structural equation modeling (SEM) analyses (model A) indicated that discomfort intolerance and emotional intolerance had a significant relationship with state anxiety, trait anxiety, and depression. The discomfort intolerance and entitlement sub-scales had a significant relationship with state anger and trait anger, while entitlement directly predicted trait anger. Regarding assertiveness, SEM analyses (model B) indicated that emotional intolerance had a significant relationship with distress when being assertive. More generally, the FDS full scale score (model C) was significantly related to unhealthy emotions and (model D) unassertive behaviour (distress). The present study provided evidence of the cross-cultural applicability of the FDS.