Anticipation of cognitive demand during decision-making

An abundance of evidence indicates that action selection is guided, at least in certain contexts, by anticipation of action outcomes. In one particularly clear demonstration of this principle, Bechara and colleagues, studying a gambling task, observed phasic skin conductance responses just prior to actions associated with a relatively high risk of monetary loss (Bechara et al. in J Neurosci 19:5473–5481, 1999; Bechara et al. in Science 275:1293–1295, 1997; Bechara et al. in Cereb Cortex 6:215–225, 1996). In the present work, we tested for the same effect in a paradigm where choices resulted not in differential monetary outcomes, but in differential requirements for subsequent mental effort. In two experiments, we observed an anticipatory skin conductance response prior to actions resulting in a high level of cognitive demand. This finding indicates that requirements for effortful cognitive control are anticipated during action selection. We argue, based on convergent evidence, that such anticipation may not only trigger preparation; it may also play a direct role in effort-based decision-making.     

Validating a “spurning scale” for nurses in Hong Kong

Based on a model on spumed helpers’ reactions, a spurning scale for nurses was constructed with items to assess the extent to which practicing nurses experience recurrent rejection of their help by patients and colleagues. Three approaches were employed to examine the validity of the scale: the relationship of the spurning scores with job satisfaction and turnover scores; the relationships of the spurning scores with burnout scores; and the relationships of the spurning scores with scores indicative of stress arising from interactions with one's patients, colleagues, and supervisor. Practicing nurses in Hong Kong (N = 212) who were enrolled in a refresher program of studies responded to a questionnaire containing the variables of interest. The results offered promising evidence for the validity of the scale.     

Sinusoidal plucks and bows are not categorically perceived,either

Cutting and Rosner (Perception & Psychophysics, 1974,16, 564–570) reported that two acoustic nonspeech continua varying in rise time were categorically perceived. We have already shown (Rosen & Howell,Perception & Psychophysics, 1981,30, 156–168) that the reason their sawtooth continuum was perceived in such a way, and in particular why it exhibited a midcontinuum peak in the discrimination function, was entirely due to the stimuli not having the intended rise times. The other nonspeech continuum that varied in rise time and was reported to be categorically perceived used a sinusoidal carrier. Although the labeling functions obtained were not as sharp as those obtained with sawtooth stimuli, the characteristic midcontinuum discrimination peak was found. We generated such a set of sinusoidal stimuli and found no evidence of categorical perception. Just as we have previously found for sawtooth stimuli, discrimination is best at the short rise-time end of the continuum and decreases monotonically with increasing rise time.     

Alice in Rorschachland

Misconceptions and misuse of the Rorschach technique are parodied in this Alice in Wonderland story. Alice falls down a rabbit Whole and journeys through the Rorschach Plates until she is tried at an Inquiry on Card X. The story can be interpreted as critical of Rorschach practitioners who: search only for pathology, not health; ignore the free associative instructions to the client of test procedures; and restructure reality along Rorschach dimensions of personality and terminology.     

Dissociation of Hippocampal and Striatal Contributions to Spatial Navigation in the Water Maze

Two experiments were conducted to compare the effects of fornix/fimbria and caudate-putamen lesions in Long–Evans hooded rats (Rattus norvegicus) trained on two water maze tasks that differed in the type of spatial localization required for optimum solution. In Experiment 1, the lesioned rats and surgical controls were trained on the standard place task in the water maze (Morris, 1981) and given two postacquisition tests (a platform removal probe and platform relocation test). In Experiment 2, rats with similar lesions and control rats were trained on a modified cue navigation task. Fornix/fimbria lesions impaired a late stage of place task acquisition but did not impair acquisition of the cue task. Caudate-putamen lesions resulted in a severe place acquisition impairment and a transient cue acquisition impairment, both of which were characterized by an initial tendency to swim near the wall of the pool. Post-hoc analyses of the direction and angles of departure from the start points suggested that rats with fornix/fimbria lesions used non-allocentric spatial strategies to solve the place task. These rats also demonstrated a significantly weakened spatial bias for the former training quadrant on the platform removal probe and reduced flexibility in navigating to a novel platform location on the platform relocation test. In contrast, rats with caudate-putamen lesions showed a significant spatial bias for the former training quadrant but failed to cross the exact location within the quadrant where the platform was formerly positioned. The results suggest that the hippocampus mediates the allocentric spatial component of the water maze place task while the dorsomedial striatum may play an important role in the acquisition of the procedural aspects of both place and cue versions of the task.