Eye movements do not reflect retrieval processes: limits of the eye-mind hypothesis

Abstract— This research investigated whether eye movements are informative about retrieval processes. Participants learned facts about persons and locations, and the number of facts (fan) learned about each person and location was manipulated. During a subsequent recognition test, participants made more gazes to high-fan facts than to low-fan facts, and gazes to high-fan facts had a longer duration than gazes to low-fan facts. However, there was no relation between the order in which items were fixated and the relative effect of person or location fan. The effect of person and location fan on gaze duration also did not differ with whether it was the person or location being fixated. A model assuming that the process of retrieval is independent of eye movements was successfully fit to the data on the distribution of gaze durations. According to this model, the effect of fan on number of gazes and gaze duration is an artifact of the longer retrieval times for high-fan facts.     

Psychophysical magic: rendering the visible 'invisible'

What are the neural correlates of conscious visual awareness? Tackling this question requires contrasting neural correlates of stimulus processing culminating in visual awareness with neural correlates of stimulus processing unaccompanied by awareness. To produce these two neural states, one must be able to erase an otherwise visible stimulus from awareness. This article describes and assesses visual phenomena involving dissociation of physical stimulation and conscious awareness: degraded stimulation, visual masking, visual crowding, bistable figures, binocular rivalry, motion-induced blindness, inattentional blindness, change blindness and attentional blink. No single approach stands above the others, but those producing changing visual awareness despite invariant physical stimulation are clearly preferable. Such phenomena can help lead us ultimately to a comprehensive account of the neural correlates of conscious awareness.     

A nonspatial methodology for the analysis of two-way proximity data incorporating the distance-density hypothesis

This paper presents a nonspatial operationalization of the Krumhansl (1978, 1982) distancedensity model of similarity. This model assumes that the similarity between two objectsi andj is a function of both the interpoint distance betweeni andj and the density of other stimulus points in the regions surroundingi andj. We review this conceptual model and associated empirical evidence for such a specification. A nonspatial, tree-fitting methodology is described which is sufficiently flexible to fit a number of competing hypotheses of similarity formation. A sequential, unconstrained minimization algorithm is technically presented together with various program options. Three applications are provided which demonstrate the flexibility of the methodology. Finally, extensions to spatial models, three-way analyses, and hybrid models are discussed.     

Time limits for completing fixed ratios. IV. Components of the ratio

Pigeons received food after completing a fixed ratio if the temporal properties of responding exceeded minimum duration requirements. In one set of conditions, a minimum time had to elapse before the first response of the ratio (the initial pause). In another set, the minimum duration was the time between the first and last response of the ratio. Obtained times increased as a power function of required times in both conditions. The power function resembled that occurring in experiments involving temporal differentiation of individual responses, interresponse times, latencies, and entire fixed-ratio sequences. Moreover, in all of these experiments individual performances could be described as a function of the base duration (the duration occurring in the absence of temporal requirements) and the specific time requirement. Control conditions indicated that the effects resulted from temporal requirements and not from reinforcer intermittency.     

Tactile stimulation: Psychophysical studies of receptor function

Psychometric functions for the detection of brief tactile pulses were determined at the fingertips and the dorsal forearm. Functions at both lore were shallower than those previously obtained for electrocutaneous pulses. demonstrating the different neural consequences of receptor and afferent nerve stimulation. Detection on the forearm was characterized by steeper slopes of psychometric functions and by lower rates of false alarms than on the fingertips, though absolute sensitivity was better at the latter site. An examination is made of explanations for the differential effects based on receptor type, receptor density, and static tremor.     

Davidson on the Impossibility of Psychophysical Laws

Donald Davidsons classic argument for the impossibility of reducing mental events to physicallistic ones is analyzed and formalized in relational logic. This makes evident the scope of Davidsons argument, and shows that he is essentially offering a negative transcendental argument, i.e., and argument to the impossibility of certain kinds of logical relations. Some final speculations are offered as to why such a move might, nevertheless, have a measure of plausibility.     

Psychophysical scales of apparent heaviness and the size-weight illusion

The apparent heaviness of a set of 40 cylindrical objects was scaled by the method of magnitude estimation. The objects varied in weight, volume. and density. There were three main conclusions: (1) For any constant volume, heaviness grows as a power function of weight; the larger the volume. the larger the exponent of the power function. The family of such power functions converge at a common point in the vicinity of the heaviest weight that can be lifted. (2) For any constant density (i:e., weight proportional to volume), heaviness does not grow as a power function of weight. (3) For any constant weight, heaviness decreases approximately as a logarithmic function of volume; the constants of the log function depend systematically on the weight of the object. The outcome furnishes a broad quantitative picture of apparent heaviness and of the size-weight illusion (Charpentier’s illusion).     

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.     

刺激强度与个体差异对心理生理测谎的影响

探讨不同说谎经验的被试在完成不同刺激强度的任务时,其生理反应和说谎分数的变化。结果表明,在测谎过程中,任务刺激强度不仅影响测试结果的有效性,而且与被试的生理反应和说谎分数成正相关;不同类型被试的说谎分数没有显著差异,测谎应对任何人群都普遍有效。     

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.     

Detecting deception: the scope and limits

With the increasing interest in the neuroimaging of deception and its commercial application, there is a need to pay more attention to methodology. The weakness of studying deception in an experimental setting has been discussed intensively for over half a century. However, even though much effort has been put into their development, paradigms are still inadequate. The problems that bedevilled the old technology have not been eliminated by the new. Advances will only be possible if experiments are designed that take account of the intentions of the subject and the context in which these occur.     

Smoking and pain--a method of limits and sensory decision theory analysis

The effects of tobacco smoking on responses to electrical stimulation were studied according to a Method of Limits (ML) threshold analysis and a Sensory Decision Theory (SDT) analysis. For the ML procedure, Detection Threshold (DT), Pain Threshold (PT) and Tolerance Level (TL) measures were obtained. For the SDT procedure, nonparametric estimates of capacity to discriminate between stimulus intensities (P(A)) and response criterion (B) were calculated. There was no main effect of tobacco smoking on responses to electrical stimulation. Males had consistently higher ML thresholds than females in both the NS and S condition. Males also tended to increase in DT and PT after smoking. From a comparison between the effects of smoking on ML and SDT measures it was suggested that PT is related mainly to sensory factors and TL to response factors.     

Trauma: the seductive hypothesis

In much of contemporary culture, "trauma" signifies not so much terrible experience as a particular context for understanding and responding to a terrible experience. In therapy, in the media, and in international interventions, the traumatized are seen not simply as people who suffer and so are deserving of concern and aid; they are seen also as people who suffer for us, who are given special dispensation. They are treated with awe if they tell a certain kind of trauma story, and are ignored or vilified if they tell another. Trauma has become not simply a story of pain and its treatment, but a host of sub-stories involving the commodification of altruism, the justification of violence and revenge, the entry point into "true experience," and the place where voyeurism and witnessing intersect. Trauma is today the stuff not only of suffering but of fantasy. Historically, trauma theory and treatment have shown a tension, exemplified in the writings of Freud and Janet, between those who view trauma as formative and those who view it as exceptional. The latter view, that trauma confers exceptional status deserving of special privilege, has gained ground in recent years and has helped to shape the way charitable dollars are distributed, how the traumatized are presented in the media, how governments justify and carry out international responses to trauma, and how therapists attend to their traumatized patients. This response to trauma reflects an underlying, unarticulated belief system derived from narcissism; indeed, trauma has increasingly become the venue, in society and in treatment, where narcissism is permitted to prevail.     

Visual and tactual form discrimination: Psychophysical comparison within and between modalities

Intermodal perceptual equivaience was investigated, using visual and tactual oddity discrimination and cross-modal matching-to-sample tasks. Four groups of Ss were presented with 100 problems made up of randomly derived forms from five levels of sidedness. The same quadratic relationship was observed for all tasks as a function of complexity, with optimal performance at eight sides. Comman information utilization, as indicated by intercorrelations of performance variables and by correlational analyses with differences in form measures, was not as pronounced within side classes. Evidence concerning the nature of pattern-feature usage in discrimination was obtained from graphical analyses.     

Psychophysical scales of the olfactory pleasantness of homologous alcohols

A category, a ratio estimation, and three magnitude scales were constructed from the observations of 10 Os who judged the pleasantness of a homologous series of n-aliphatic alcohols. Magnitude scaling indicated that pleasantness generally varies inversely with chain length, which is consistent with the findings of earlier investigators who used different methods; ratio estimation also indicated an inverse relationship. Stable magnitude scales resembled power functions with exponents of ?0.262 to ?0.587; the adjusted ratio estimation’s was ?0.138. Pleasantness seemed to be unexpectedly prothetic, some evidence of which had also been reported in an earlier study involving a more diverse set of odorants. Yet in the present study the hedonic range was small and in the earlier, large. More than the size of range appears to account for the puzzling prothetic evidence.