In a conditioned suppression study with rats, CS modality (light vs. noise) and type of conditioning (on-line vs. off-line training) were manipulated. All rats were then tested on-line with only half the test trials reinforced. Some results and conclusions were as follows: (1) During initial training, suppression following reinforced noise trials was moderately strong at first but weakened over days; for the light, it was weak from the start. It was suggested that this strong influence of CS modality might complicate interpretations of posttrial suppression as a measure of US effectiveness. (2) During testing, posttrial suppression and freezing were greater following nonreinforced trials than following reinforced trials (US-omission effect), and this effect was stronger for noise than for light. Since noise also produced more freezing than light, this result favors the hypothesis that the US-omission effect is due to persistent CS-elicited freezing that is undisrupted by a shock US. (3) Although noise produced more freezing, both noise and light produced similar barpress suppression. This result is consistent with the suggestion that noise and light acquire equal associative strength but elicit different defensive behaviors.In a recent study of conditioned suppression of barpressing in the rat, Ayres and Vigorito (1984) examined their subjects' behavior in a I-min period following each trial. They found that when a white-noise conditioned stimulus (CS) coterminated with a single brief electric-gridshock unconditioned stimulus (US), the rats' barpressing in this l-rnin posttrial period was at first moderately suppressed. With further training, however, this suppression gradually decreased. If a second shock US was then added 1 min after the first, suppression in this same l-min posttrial period (now the period between the two shocks) gradually increased until it approached its original level. If shocks were omitted on some trials but presented on others, posttrial suppression was greater following shock omission than following shock presentation (US-omission effect). Finally, direct observations of the rats' behavior disclosed that the rats froze more following shock omission than following shock presentation. To account for these results, Ayres and Vigorito proposed that two factors were important:First, in the usual conditioned suppression procedure in which trials are widely spaced, the temporal stimuli

Needle localization of breast lesions is commonly performed for surgical guidance when excising nonpalpable lesions. A few reports have specifically addressed complications associated with needle-localized surgical breast biopsy. We present the first reported case of delayed cardiac injury resulting from migration of a guidewire from a needle-localized breast biopsy that occurred 2 years after the procedure. The patient presented with chest pain and cardiac tamponade. It was found that a hook-wire had penetrated the pericardium and left ventricular myocardium through the aortic valve into the ascending aorta. The diagnosis was made by echocardiogram and computed axial tomography scan and subsequent surgical removal was undertaken successfully.

In two preceding papers, data have been presented indicating a lack of relationship between scores on the Taylor Manifest Anxiety Scale (29) and performance on two complex learning tasks: (a) stylus maze learning ( 2) and (b) paired associate learning (14). These findings are somewhat in contrast to earlier studies in which high anxious subjects (Ss) have been found to perform more poorly than low anxious Ss on complex learning tasks involving multiple competing response tendencies (13,17,23,25,30).The present report deals with the relationship between A -scale response and performance on three personality-cognitive measures; perceptual reactivity to "threat expectancy," problem-solving rigidity, and self-regarding attitudes. It evolves from the same basic design as do its two predecessors (2, 14) and accordingly, involves two methodological extensions to earlier studies in the area. Thus, in order to examine the over-the-range discriminatory power of the A scale, we have included a middle anxiety group, consisting of MAS scorers between the 43rd and 56th percentiles. And, secondly, we have utilized the MMPI Lie scale as an additional criterion in order to determine whether differences in performance on the dependent measures are related to variations in £-scale score.For the variable of perceptual reactivity, previous investigations (9, 20) report elevated

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