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S Sutton

Publications and source records attributed to S Sutton.

At least 37 records · Page 2Linked to original sources
PubMed1986

Terminal CNV in the absence of motor response.

We addressed the question of whether the terminal CNV, or E-wave, can be obtained in the absence of a motor response. In our design, the stimuli served only to reduce uncertainty with respect to a prior prediction, so that no response to S2 was required. In one experiment, the location of uncertainty reducing information was manipulated: in S1 alone or in S2 alone. When S2 reduced uncertainty, the pre-S2 E-wave was larger than when S2 did not reduce uncertainty. Similarly, when S1 reduced uncertainty, a pre-S1 negativity (whose topography did not differ from that of the pre-S2 E-wave) was larger than when S1 did not reduce uncertainty. The pre-S1 results also indicated that a prior experimenter-generated warning signal is not necessary for a non-motoric negativity to be obtained. In another experiment, the S1-S2 interval was manipulated (1 sec versus 3 sec). For the pre-S2 E-wave, onset was later and duration was longer for the longer S1-S2 interval. Peak amplitude and time of termination after S2 did not differ for short and long duration E-waves. Apparently, the timing of the E-wave is related to when in time the process it reflects is 'needed.' The dependence of the amplitude and timing of the pre-stimulus negativity on the temporal location of information, in conjunction with its independence of motor response requirement, suggests that the pre-stimulus negativity reflects some operation in the domain of expectancy, anticipation or 'mental preparation' for the informational stimulus.

Adolescent↗
PubMed1986

Visual flicker in depression: response criteria, confidence ratings and response times.

Differences in response criterion and sensory sensitivity to visual flicker among major depressive patients, dysthymic patients, and normal controls were investigated. Also, signal detection confidence ratings and response times were compared. The results indicated that major depressive patients responded more conservatively (i.e. were less willing to respond 'flicker') than either of the other groups. The groups did not differ significantly on a criterion free measure of flicker sensitivity. The major conclusions are: previously reported visual flicker differences between depressed patients and normal controls were probably due to the more conservative response criterion of the patients and not to flicker sensitivity differences between groups; and confidence ratings and response times yield similar conclusions with respect to visual flicker sensitivity and response criterion. Therefore, interpretations concerning a sensory or perceptual deficit in depression must take into account the differences in response criterion between depressed patients and normal controls.

Adult↗
PubMed1986

Possible risk of invasive pulmonary aspergillosis with marijuana use during chemotherapy for small cell lung cancer.

Bacterial and fungal contaminants have been identified in marijuana samples and thus are a potential risk factor in the immunocompromised patient using it as an antiemetic. We describe the development of an invasive pulmonary aspergillosis in a patient using illicitly obtained marijuana as an antiemetic during combination antitumor therapy for small cell lung cancer. Although this patient had multiple risk factors implicated in the development of invasive pulmonary aspergillosis, the infectious potential of inhaled marijuana must be recognized. Further study of this potential health risk in needed.

Antiemetics↗
PubMed1984

The relation of P3b to prior events and future behavior.

A prediction paradigm was used to explore the relationship of the amplitude of the scalp-recorded event-related potential to the sequence of preceding signals and to preceding and subsequent behavior. P3b was found to be the only component which related systematically to prior sequence of signals. The CNV, P300E and Slow Wave were not affected by signal sequence. The P3b findings were the same for the emitted and evoked P3b, thus ruling out a sensory interpretation of the effect of signal sequence on P3b amplitude. Furthermore, it was found that signal sequence interacts with the subject's predictions in determining P3b amplitude. For signal discontinuations, P3b was large in amplitude regardless of what had been predicted. However, for signal continuations, P3b was small when continuations had been predicted, but large when discontinuations had been predicted. Finally, we found that for both correctly and incorrectly predicted signal continuations, larger P3bs were more likely than smaller P3bs to be followed by a prediction that the signal for the next trial would be different.

Adolescent↗
PubMed1984

The late positive complex. Advances and new problems.

In summary, what we have tried to do in this paper is to present our view of the ways in which the ERP field has become more complex in recent years. It is not an overstatement to say that, in a certain sense, we know less now than we thought we knew five to ten years ago. New advances have brought with them new problems. But they also point, though not yet with complete clarity, to directions for new solutions. Possibly, as we make further progress toward the definition of various generators for different components, our problems may be simplified. But even this prediction cannot be made with certainty. It should be noted that we have tended in this chapter to emphasize the problems. There has also been a positive side to the recent developments. Because we are more aware of the overlap problem, we now work with methods that attempt to deal with it. We now know, for example, that P3b and SW can relate quite differently to behavioral variables. Decision time, which we had thought occurred at P3 latency, can now be assumed on the basis of recent findings to occur earlier, at the N2 component. The separation of the formerly unitary CNV into several components makes it more possible to develop unique functional roles for each of the components. A similar development has occurred with the separation of the poststimulus negativities into several components. Our constructs for various components are still on the fuzzy side, but the field has better tools at its disposal for making them more precise. Finally, the multiplicity of components, which appears overwhelming initially, provides us with more degrees of freedom in attempting to relate electrophysiological activity to behavior. A number of investigators have commented that the complexity of factors that enter into behavior could not be reflected in the relatively few ERP components we were dealing with. Now that more components are coming to be distinguished, the likelihood increases that we may be able to obtain ERP correlates of more of the dimensions involved in behavior.

Arousal↗
PubMed1984

The modality shift effect in schizophrenia: fact or artifact?

We investigated whether the disproportionate slowing of schizophrenic patients on cross-modal relative to ipsimodal sequences in a reaction time task ("modality shift effect") could be attributed to a psychometric artifact, as implied by Chapman and Chapman. Fifteen schizophrenic patients (Research Diagnostic Criteria) and 50 normal controls with no current or past history of psychiatric disorder were tested. Subjects made an identical finger-lift response to brief duration light and sound stimuli of different intensities presented in quasi-random order. The major finding was that psychometric artifact could not account for the disproportionate slowing of the reaction time of schizophrenic patients since the reliabilities and variances of the cross-modal and ipsimodal conditions did not differ in normal controls. Furthermore, the modality shift effect was highly significant for reaction times to both sound and light and for all intensities. Findings were the same when the schizophrenic patients were compared to a matched subgroup of slow-responding normal controls.

Cues↗
PubMed1983

Value of chest computed tomography in genitourinary malignancies.

Fifty-one patients with genitourinary malignancies with normal chest x-ray films all had chest computerized tomography in an attempt to detect metastatic disease. One patient with a hypernephroma and another with a bladder carcinoma had metastatic nodules detected. One patient with a testicular tumor had a histologically confirmed benign nodule. Chest computerized tomography should be performed on patients with tumors that have a high likelihood of metastasizing to the lung.

Female↗
PubMed1980

Emitted P300 and slow wave event-related potentials in guessing and detection tasks.

A comparison was made of evoked and emitted P300 and Slow Wave activity elicited in guessing and signal detection tasks. The stimulus conditions were the same in both tasks. Only the instructions to the subjects were different. Latency corrected averaging was used to compensate for trial-to-trial fluctuation of P300 latency. Principal components-varimax analysis (PCVA) was utilized to deal with overlap among P300, Slow Wave and CNV return-to-baseline. Clear measures (from both conventional and latency corrected averages) of emitted P300 components for correct rejection trials were obtained under the following conditions: (a) stimulus intensity near threshold (detection accuracy approximately equal to 78%, d' approximately equal to 1.9); (b) no simultaneous cueing signal; (c) stimulus presence and absence were equiprobable; (d) estimated contributions of overlap from other event-related potential components were removed from the P300 measurements. A significant difference was found between the Slow Wave topographic profiles elicited in the guessing and detection tasks. For the guessing task Slow Wave was relatively large and positive at vertex whereas in the detection task it was near zero amplitude at vertex. No significant differences due to task were found for the P300s when a PCVA derived estimate of the contribution of Slow Wave overlap was removed from the P300 measures.

Adult↗
PubMed1979

Dichotic perception: evidence for right hemisphere dysfunction in affective psychosis.

The association between lateralized hemispheric dysfunction and psychiatric diagnosis was investigated with a measure of summation of dichotic clicks and with a dichotic competing message task. Ear asymmetries of affective psychotic patients were similar to those of right temporal lesioned controls and differed from those of schizophrenic patients and normal controls. In contrast, schizophrenic patients did not display abnormal auditory perceptual asymmetries.

Adult↗
PubMed1978

The effect of specific antiserum on the resistance of Neisseria gonorrhoeae to intracellular killing by phagocytes of human blood.

The high natural resistance of gonococci showing a characteristic 'double highlight' (DH) colonial morphology (Penn, Veale & Smith, 1977b) to intracellular killing by human phagocytes was markedly reduced by addition of rabbit antiserum to the phagocytosis medium or by preincubation of organisms with antiserum. Antisera raised to three different DH gonococcal strains showed a complex pattern of specificity in phagocytosis tests with the homologous organisms and three other DH strains. The effect of antiserum could be neutralized by adsorption with intact organisms or with extracts, prepared ultrasonically, of the homologous strain. Antiserum also promoted the intracellular killing of a strain which had a 'single highlight' colonial morphology (Penn et al., 1977b) and a low natural resistance to phagocytic killing, but adsorption with this strain neutralized the antiserum less consistently than the DH strain. The neutralization of antiserum-mediated promotion of intracellular killing by extracts of organisms naturally resistant to such killing may provide an assay for the aggressins responsible for this resistance.

Adsorption↗
PubMed1976

Adamantane and protoadamantanealkanamines as potential anti-Parkinson agents.

The synthesis of 2-halo-1-adamantanemethanamines, 4-protoadamantanemethanamines, and 4-protoadamantaneamines is described. The anti-Parkinson activity of these amines in terms of reversal of reserpine-induced catalepsy in rats has been evaluated and compared with amantadine. 2-Bromo- and 2-chloro-1-adamantanemethanamines are shown to be twice as active as amantadine.

Adamantane↗