Counterexample to the hypothesis of functional similarity between tactile and visual pattern perception

In earlier work, the author has demonstrated that tactile pattern perception and visual pattern perception exhibit many parallels when the effective spatial resolution of vision is reduced to that of touch, thus supporting the hypothesis that the two pattern senses are functionally similar when matched in spatial bandwidth. The present experiments demonstrate a clear counter-example to this hypothesis of functional similarity. Specifically, it was found that the lateral masking effect of a surround on tactile character recognition increases when the surround changes in composition from solid lines to dots, whereas for vision, recognition performance goes in the opposite direction. This finding necessitates some modification of the model of character recognition proposed by the author (Loornis, 1990) as it applies to the sensing of raised tactile patterns. One possible modification would be to incorporate, as the initial stage of pattern transformation, the continuum mechanics model for the skin that was developed by Phillips and Johnson (1981b).     

Is the faith of faith development Christian faith?

The major research with a theological and developmental psychological perspective on the meaning and development of faith has been produced by James Fowler of Emory University and the Candler School of Theology. In this paper, I will present challenges by important critics who pose a significant question. Is this faith of the faith development research Christian faith? To provide an initial answer to the question, I will offer brief summaries of some of Fowler's writings that he has listed as most important for responding to the question. I will also present evidence from his writings and from the writings of other authors that he is indeed interpreting Christian faith.     

Affective deficits and pain insensitivity in schizophrenia

Affective deficits have long been considered a prominent feature of schizophrenia and play a central role in recent theory and research on the pathophysiology of this disorder. However, it has recently been argued that current approaches to the conceptualization and assessment of affective flattening in schizophrenia are confounded by the social and neuromotor deficits that are also prevalent in this disorder. Insensitivity to pain in individuals with schizophrenia — a phenomenon that has been reported frequently but never systematically investigated — provides one approach to examining affective flattening unconfounded by social and neuromotor deficits. Two studies are described in which signal detection theory measures of thermal pain sensitivity were examined in patients with schizophrenia, mood disorder, and normal controls; in addition, in the patients with schizophrenia, the relationships between these measures and measures of affective deficits were examined. Patients with schizophrenia had significantly poorer sensory discrimination of painful thermal stimuli than control subjects, but did not differ from controls with respect to their response criterion for reports of pain; patients with mood disorder had a significantly higher (i.e., more stoical) criterion for reports of pain than controls. As predicted, among the patients with schizophrenia, higher response criterion was significantly correlated with greater affective flattening and less intense affective experience (as well as with fewer positive symptoms and poorer premorbid adjustment). The results of these studies suggest that pain insensitivity in schizophrenia may reflect affective as well as sensory abnormalities, and that pain insensitivity in schizophrenia may provide a method for studying affective flattening in this disorder that is relatively independent of the social and neuromotor deficits that confound existing measures of this symptom. Continued examination of the relationship between pain insensitivity and affective deficits in schizophrenia is also important because numerous clinical reports have suggested that pain insensitivity is detrimental to health and can have life-threatening consequences in individuals with this disorder.This research was supported, in part, by research grants from the National Institute of Neurological Disorders and Stroke to Robert H. Dworkin (NS-30714) and W. Crawford Clark (NS-09263, NS-20248).     

Other-race face perception

The other-race effect (or own-race bias or cross-racial identification effect) refers to the finding that recognition memory tends to be better for faces of members of subjects' own race than for faces of members of other races. The current study was designed to test the hypothesis that perceptual skills specific to identifying faces of particular racial groups contribute to this effect. On each of 50 trials, a photograph of a face was tachistoscopically presented for 120 ms, followed by a pattern mask and then a plain-view test pair composed of the previously presented face and a matched foil. As predicted, an other-race effect was obtained on this perceptual task: White subjects performed significantly more poorly on trials involving African American faces than on trials involving White faces, whereas no such difference was obtained among African American subjects.     

Application of the Generalized Matching Law for Description of Student Behavior in the Classroom

Matching law and theory have applied implications for classroom instruction and student behavior. The Generalized Matching Law (GML) is examined in this exploratory study to assess its utility for quantitatively describing student behavior in the classroom. Data were collected using computer-based observational software. Time-lag sequential analysis was used to identify specific teacher behaviors following specific student behaviors as estimates of reinforcement. Derived rates of student and teacher behaviors were analyzed in a linear regression of the natural logarithmic form of the GML. On average, the GML described over 70% of the variance in two students' behavior in a first-grade regular education classroom. Discussion addresses the potential utility of the GML for observation and intervention in the classroom.     

Children's comprehension of grammatical structures in context

Children from nursery school, kindergarten, and first grade were asked to select pictures which correctly represented the propositional content of six grammatical structures-active, passive, cleft-agent, cleft-patient, prepositional beneficiary, indirect object presented under three context conditions-appropriate, inappropriate, isolation. In the appropriate-context condition the relationship between the target structure and its prior context sentence followed known discourse regularities about the allocation of given and new information, while in the inappropriate-context condition the relationship between the target structure and prior context violated these discourse regularities. Comprehension of two of the grammatical structures tested—the passive and the cleft-patient—was better under the appropriate-context treatment than under the inappropriate-context treatment, indicating that young children are in fact sensitive to discourse regularities about the allocation of given and new information.The research reported herein was part of Gourley's Ph.D. dissertation for Cornell University, which was directed by Catlin. An earlier version of this article was presented by Gourley at the 1974 Summer Meeting of the Linguistic Society of America at Amherst, Massachusetts.Deceased.     

Sensitivity to shifts of a point stimulus: An instance of tactile hyperacuity

The sensitivity of the tactile sense to shifts in the position of a point stimulus was determined at four body loci: the index finger, forehead, belly, and back. Water-jet stimulation was used, a method which allows frictionless travel of a point stimulus over the skin. Three subjects were tested by means of the method of forced choice, with the task being to say whether the stimulus moved to the right or to the left. The shift threshold was defined as that shift excursion which gave rise to 75% correct responding. The basic finding was that shift thresholds were on the order of 10 to 30 times smaller than the corresponding two-point limens obtained by Weinstein (1968) for the same body loci. These unexpectedly small shift thresholds indicate an exquisite sensitivity of the cutaneous sense to rapid changes in position of a point stimulus. A physiological model is presented which accounts for the difference between localization and spatial resolution. nt]mis|This research was supported by Department of Health~ Education, and Welfare Grant 14-P-SS282/9 from the Social and Rehabilitation Services, NIH Research Grant R01-EY-00686 from the National Eye Institute, and the Smith-Kettlewell Eye Research Foundation.     

Some aspects of self aversive stimulation in the hooded rat

Three hooded rats were trained to bar press for variable-ratio liquid reinforcement after which an electric shock was delivered following the response. Initially, the shock was presented on a FR 100 basis but the frequency was gradually increased until all responses were punished. Finally, a partial extinction procedure was conducted to determine if the shock resulted in increased bar pressing. No durable suppression of responding occurred, although one subject's rate was reduced during continuous shock. The overall trend for the three animals was one of increased responding. Changes in the pattern of responding were also observed suggesting that the suppressive effects of the punishment were largely restricted to the first response following reinforcement. Increased responding as a function of shock reintroduction during extinction was also observed.