Psychophysical features of the transition from pure heat perception to heat pain perception.

The psychophysical features of the transition from the pure heat to the heat pain range were studied in 25 healthy subjects (mean age 28.8 years). Thirty short heat stimuli from -1.6 degrees C to +1.6 degrees C relative to the pain threshold were applied to the thenar of the left hand with an apparatus containing a Peltier thermode (nine different temperatures at 0.4 degrees C intervals). The subjects rated the sensation intensity on a visual analogue scale. The resulting stimulus/sensation intensity relations could be explained equally well (same goodness of fit) by a model with a power function (PF) and by a model with two linear regression lines (TLR), one for stimulus intensities below and one for those above the pain threshold and intersecting at the pain threshold. The slopes of the TLR model were significantly larger above the pain threshold than below it. The PF model produced exponents between 1.8 and 1.9. We conclude that to describe the transition area, it is sufficient to use simple linear models for both the pure heat and the heat pain ranges.     

Psychophysical parameters of the perception of orally-retained liquid bulk

Bulk of liquid held in the mouth may be judged on its subjective volume. Over the range I ml-31 ml, scaling by the constant method and by ratio estimation yielded a Weber fraction which was not constant and decreased with stimulus magnitudes and a psychophysical power function with an exponent of 0.96. A “negative threshold” effect is reported.     

Psychophysical test for the independence of perception and action

Research has suggested that perception and action are independent (see M. A. Goodale & A. Haffenden, 1998). The authors used the Ebbinghaus illusion to test this hypothesis in 2 experiments. Verbal reports of perceived size were compared with maximum grip aperture during grasping (Experiment 1) and manual reports of perceived size (Experiment 2). A multidimensional signal detection analysis was used to distinguish among the possible interactions between the two processes in each experiment (H. Kadlec & J. T. Townsend, 1992a, 1992b). In Experiment 1, the percepts were independent, and there were no interactions between processes for verbal and visuomotor responses. In Experiment 2, the percepts associated with verbal and manual reports were independent, but the processes interacted at the levels of the stimulus information and the decision rules used to transform each percept into a response.     

Human perception of verticality: Psychophysical experiments on the centrifuge and their neuronal implications

The role of the otoliths in the perception of verticality is analyzed in two different gravitational environments, 1 g and 1.5 g , and in different roll body positions between upright and upside down. The subjective visual vertical (SVV) is determined when a subject judges the orientation of an indicator as apparently vertical. An increase of g level hardly affects the SVV in the subject's frontal plane (y-z plane). However, for the first time, a three-dimensionally adjustable indicator was used for the SVV and this revealed a new phenomenon: An increase of g level induces a backward slant of the SVV into subject's median plane (x-z plane). The data are discussed with regard to Mittelstaedt's SVV theory; particular emphasis is given to the otolith-head coordinate transformation and the normalization of afferent otolith components. The results of this study provide evidence that the former is implemented at an earlier level and thus precedes the latter.     

Separating perception time from response time: the slope transition paradigm

This paper describes the slope transition paradigm (STP), a variant of rapid serial visual presentation (RSVP) that separates early (perceptual) processing time from total response time. The paradigm is based on a very simple idea: provide varying amounts of time for perceptual processing and find the moment when the subject begins to waste time waiting for more data. That moment is a measure of how much time was actually needed. The method was used in two experiments. Results are discussed in relation to set-size effects, perceptual capacity limits, attentional dwell times, and some related neurophysiological findings. The method appears to tap aspects of information processing that differ from those tapped in studies of the psychological refractory period, the attentional blink, and repetition blindness.     

婴儿的痛觉

婴儿痛觉对婴儿的生长发育有重要意义, 已经日益引发研究者的兴趣。痛觉本质上是一种不愉悦的感官和情绪体验, 是通过早年与伤害有关的经历习得的。在心理学角度, 在介绍婴儿痛觉概念、神经生理机制、评估工具的基础上, 系统梳理痛觉对婴儿生长发育的影响及其影响因素十分必要。后续研究需继续完善婴儿痛觉的测量方法, 考察疼痛反应在不同文化和不同群体间的差异。     

Neurocognitive aspects of pain perception

The perception of pain is sensitive to various mental processes such as the feelings and beliefs that someone has about pain. It is therefore not exclusively driven by the noxious input. Attentional modulation involving the descending pain modulatory system has been examined extensively in neuroimaging studies. However, the investigation of neural mechanisms underlying more complex cognitive modulation is an emerging field in pain research. Recent findings indicate an engagement of the ventrolateral prefrontal cortex during more complex modulation, leading to a change or reappraisal of the emotional significance of pain. Taking placebo-induced analgesia as an example, we discuss the contribution of attention, expectation and reappraisal as three basic mechanisms that are important for the cognitive modulation of pain.     

Computerizing the perception laboratory: Surviving the transition

A number of problems may be encountered during the transition to a computerized perception laboratory. Although some of these problems are of a technological nature, others have to do with the psychology of the investigator. These problems are discussed in the context of actual incidents taken from various research facilities, and some suggestions for avoiding common difficulties are presented.     

Beautiful faces in pain: Biases and accuracy in the perception of pain

Abstract

The impact of appearance-based information on judgments about the psychological functioning of pain patients was investigated. Video-tapes of low back pain patients experiencing pain were used as stimulus materials. Subjects viewed silent video clips and photographs of the patients' faces and made judgments about the functioning of these patients. These judgments were affected both by patient physical attractiveness and gender. Physically attractive patients and male patients were judged to be functioning better than physically unattractive and female patients. The judgments were reasonably described as biased because the perceived differences about patients varying in attractiveness and sex were not associated with measures of actual patient functioning.     

Effects of attentional focusing on pain perception

Two experiments were conducted to examine the hypothesized differential effectiveness of two attentional focusing strategies in pain perception. In the first experiment, subjects (72 male college students) rated their levels of pain after being exposed to either low- or high-intensity pressure stimulation for 75 s. Subjects were instructed to use either an external or internal focus of attention during the pain induction. Results revealed that external focusing was more effective for coping than internal focusing across both levels of stimulus intensity. The second experiment was a replication of the first, and featured bolstered internal focusing and stimulus intensity manipulations. Results showed that high-intensity stimulation produced higher pain ratings than did low-intensity stimulation for subjects in the internal focusing conditions, but not for those in the external focusing conditions. The findings support the power of distraction strategies for dealing with short-term pain with a rapid onset. Theoretical implications are discussed.The authors thank Darwyn E. Linder and Daniel M. Landers for their help in development of this research. The authors are also indebted to Sarah Colley, Jona Davis, Nanci Neuberger, and Rebecca Roberts for their assistance in data collection.     

Psychophysical dualism from the point of view of a working psychologist

Cognitive neuroscience constitutes the third phase of development of the field of cognitive psychophysiology since it was established about half a century ago. A critical historical overview is given of this development, focusing on recurring problems that keep frustrating great expectations. It is argued that psychology has to regain its independent status with respect to cognitive neuroscience and should take psychophysical dualism seriously. A constructive quantum physical model for psychophysical interaction is presented, based on a new stochastic interpretation of the quantum potential in the de Broglie–Bohm theory. This model can be applied to analyze cognitive information processing in psychological experiments. It is shown that the quantum potential shares several features with Duns Scotus’ notion of contingent causality.     

Cognitive mediators of pain perception and tolerance

A social learning model of pain perception and tolerance was evaluated. Responses to cold-pressor pain were examined in 4 groups of 20 Ss each. One group was given instruction in cognitive coping strategies, the 2nd was given a monetary incentive contingent on tolerance time, the 3rd was given both cognitive training and monetary reinforcement, and a no-treatment control group was given neither. Incentive and coping instructions significantly increased tolerance but did not alter pain perception. A path analysis indicated that pain tolerance was affected by self-efficacy, which in turn was predicted by pain expectancy and the provision of incentives. Incentive also had an impact on tolerance that was independent of self-efficacy. Pain perception was strongly affected by pain expectancy, but was unrelated to self-efficacy.     

Climbing the cortical ladder from sensation to perception

A recent study using displays that are ambiguous for motion direction demonstrates that the current perceptual interpretation of such a stimulus is encoded in the highest areas of visual cortex whereas earlier areas encode only its sensory properties. This finding implies that cortical processing pathways perform a transition from a sensory representation to a representation that emphasizes the input's perceptual interpretation and ultimately the organism's behavioral state.     

疼痛恐惧的形成及其对疼痛知觉的影响

脑岛、杏仁核是疼痛恐惧形成的重要神经网络中心。疼痛恐惧增强了慢性疼痛患者的疼痛知觉体验, 进而加剧抑郁、焦虑情绪和功能损伤程度。脑岛、杏仁核、前额皮层和前扣带回是疼痛恐惧影响疼痛知觉的重要神经基础。通过认知方法干预疼痛恐惧可以改善患者的抑郁、焦虑情绪, 减少功能损伤。未来研究应拓展疼痛恐惧的测量工具, 采用功能磁共振成像技术进一步揭示疼痛恐惧影响慢性疼痛患者疼痛知觉的神经机制。