Repeated failure: a source of helplessness or a factor irrelevant to its emergence?

We tested the validity of the egotism model of human helplessness. In contrast to the original theoretical approach of Seligman and his associates, which points to response-outcome noncontingency as the main source of helplessness, the egotism alternative proposes that repeated failure itself is the critical determinant of helplessness symptoms. Repeated failure threatens the self-esteem of the subject, who supposedly engages in a least-effort strategy during the test phase of a typical learned helplessness study, which results in performance impairment. To examine the egotism explanation, we gave subjects noncontingent-feedback training with or without repeated failure on five consecutive discrimination problems. In two experiments, noncontingent-feedback preexposure produced helplessness deficits in performance on avoidance learning, whereas repeated failure appeared irrelevant to helplessness. This and our other findings from research are inconsistent with the egotism explanation and support instead Seligman's original proposal, in which helplessness is attributed to prolonged experience with noncontingency.     

Changes in energy expenditure and work during response acquisition in rats

The principle of least effort predicts that behavior will tend to maximum efficiency. To test this prediction, changes in the energy expended (VO2) and work performed per reinforcement were monitored continuously as rats learned to press a beam with a criterion force for liquid food rewards. All 12 subjects exhibited significant decreases in energy expended per reinforcement over the 16 days of observation. Of these, 10 subjects also decreased the work performed per reinforcement. Analyses of motor performance were undertaken to determine how motor programs for changing efficiency were generated. The 10 animals showing decreased work reinforcement also exhibited significant decreases in the variability of temporal and kinetic response features and in mean response magnitude (time integral of force or work per response) as a function of practice. Adjustments in work output were primarily accomplished by modifying temporal response features (response duration and, initially, interresponse time). The kinetic features (response recruitment and peak force) remained relatively constant for these animals. The remaining 2 subjects differed in that response recruitment increased after Day 9, resulting in progressively larger amounts of work being performed to earn each reinforcement, and the interval between successive reinforcements decreased.     

Effects of anterior or dorsomedial thalamic ibotenic lesions on learning and memory in rats

Sprague-Dawley rats were used to study the effects of ibotenic acid lesions of the anterior (A.Th.) and the dorsomedial (MD) thalamic nuclei on learning and memory. Memory was assessed by employing a temporal alternation task in a straight alley with varying intertrial intervals. In addition, spatial orientation and response flexibility were evaluated on a radial maze and on a spatial reversal task (SSDR). The results indicated that MD rats required more trials to learn the temporal alternation task and exhibited impaired performance compared to A.Th. and control groups at the shortest delay (15 s). In contrast, compared to the control group, A.Th. subjects which required less trials to master the task and exhibited normal performance at the 15-s delay were impaired when the intertrial interval was increased to 45 s. Whatever the lesion, no impairments were found in the SSDR or the radial maze while only MD lesions were found to result in a night hyperactivity associated with greater food and water consumptions. These findings indicate that A.Th. and MD are differentially involved in learning and memory processes. It is suggested that the MD is mostly involved in registering new information while the A.Th. plays a role in the maintenance of information over time.     

Attenuation of amphetamine-stereotypy by mesostriatal dopamine depletion enhances plasma corticosterone: implications for stereotypy as a coping response

The relationship between amphetamine-induced stereotyped behavior and a neuroendocrine index of arousal, plasma corticosterone (CCS), was investigated. 6-Hydroxydopamine lesions of the caudate-putamen, which produced dopamine depletions of 60%, blocked stereotypy and prolonged the elevation in corticosterone associated with d-amphetamine treatment (5 mg/kg). Similar dopamine depleting lesions of the nucleus accumbens, which attenuated the locomotor, but not the stereotypic, response to AMPH did not have this effect on CCS. This pattern of results supports the hypothesis that stereotypy has a coping function which may serve to alter arousal and further suggests important differences between the nigrostriatal and mesolimbic dopamine projections in modulating the responsiveness of the neuroendocrine system. These results have implications for understanding the function of behavioral stereotypies common to a number of psychopathological conditions, including schizophrenia and childhood autism.     

A flavor paired with lithium chloride blocks the formation of a pentobarbital-lithium chloride association

Thirsty rats were used in order to determine whether a vinegar solution, which had been paired with an injection of lithium chloride, could block the formation of an association between a pentobarbital- and a lithium chloride-induced state. During phase 1 the rats in the blocking group had a 2.0% vinegar solution paired with an injection of 240 mg/kg of lithium chloride, during phase 2 these rats were reexposed to the vinegar prior to each injection of 20 mg/kg of pentobarbital and 240 mg/kg of lithium chloride, and during phase 3 these rats were given access to a novel 0.75% saccharin solution and were injected with pentobarbital after saccharin removal. Animals with this history did not form an association between the pentobarbital- and lithium chloride-induced states during phase 2 as evidenced by their refusal to consume the saccharin solution over repeated pairings of saccharin with pentobarbital during phase 3. Control groups that received forward pairings of pentobarbital and lithium chloride, in the absence of a previously conditioned vinegar solution during phase 2, formed an association between pentobarbital and lithium chloride. These findings indicate that drug states and flavors can interfere with each others' capacity to predict the occurrence of lithium chloride.     

Synaptic plasticity in the hypoglossal nucleus of female canaries: structural correlates of season, hemisphere, and testosterone treatment

The caudal portion of the hypoglossal nucleus (nXIIts) contains the motor neurons that control the syrinx in songbirds. In canaries, song occurs seasonally, is principally produced by males, and appears to be produced predominantly by muscles on the left side of the syrinx. The present study measures the effect of seasonal change and manipulation of testosterone levels on synapse number and morphology in nXIIts in adult female canaries. We find that synapse density is lower in testosterone-treated birds than in control birds and lower in fall than in spring. The number of vesicles per presynaptic profile increases in the spring as a result of a general increase in this measure in all synapses. The number of vesicles per presynaptic profile also increases with testosterone treatment, primarily due to an increase in the proportion of synapses associated with unusually high vesicle counts. Together, these changes suggest that large reserves of neurotransmitter may be necessary to sustain singing. Several ultrastructural differences between hemispheres are found. Postsynaptic thickenings are longer, and postsynaptic processes are larger on the left side than on the right side. In the spring, there are more vesicles per synapse on the left than on the right, but this lateralization is reversed in the fall. Thus, lateralization of song production is associated with lateral asymmetries in synapse morphology. These hemispheric differences are relatively small, like those seen at the light microscope level, encouraging further consideration of peripheral as well as CNS sources of functional lateralization. The seasonal and testosterone-induced changes in synapse number and morphology may be components of the periodic reorganization of canary vocalization.     

The effect of response bias on recall performance, with some observations on processing bias

We explored Roediger and Payne's proposal that response bias does not affect recall performance and that it is therefore not necessary to control for response productivity in recall studies. Two initial experiments, contrary to expectation, corroborated Roediger and Payne's findings: Forced recall did not produce more correct recalls than free recall, even though forced recall produced substantially more false alarms than did free recall. However, in succeeding experiments involving pictorial and verbal stimuli, reliable response-bias effects on recall were demonstrated. The stimuli yielding response-bias effects were those associated with higher probabilities of being guessed by chance. In addition, some of the data suggest that processing-bias effects (differential retrieval effort) may be unintentionally induced by instructions and may significantly affect recall memory. Consequently, it is necessary to assess or to control response-bias effects and, possibly, processing-bias effects in recall experiments in which level of recall is of interest.     

DO PUBLIC SCHOOLS TEACH SECULAR HUMANISM? WHY WE MAY NEVER KNOW

Members of the New Right regularly charge that public schools teach secular humanism. This alleged teaching of secular humanism is held responsible for varied social ills and is perceived as a violation of constitutional prohibitions against the advocacy of one set of religious beliefs over others. Although New Right attacks may be perceived as political tactics, the author explores them as empirical claims that schools are in fact teaching secular humanism. Currently, there is no persuasive body of research supporting the New Right allegations. The author questions whether or not such research could be designed and concludes that it could but, for various reasons, is unlikely ever to be enacted.     

REACTANCE AND INTENTIONALITY ATTRIBUTIONS AS DETERMINANTS OF THE INTENT TO FILE A GRIEVANCE

Experimental studies were conducted in two unions to examine the effects of perceptual variables–namely, reactance and intentionality attributions–on the intent to seek redress from management action. Participants responded to a series of vignettes, each of which described a management action (formal punishment, informal warning, promotion denial) taken against an employee. The vignettes varied systematically in terms of the perceived threat to worker freedom posed by the action and the degree to which the action was motivated by a dispositional rather than an environmental attribution. Both studies demonstrated that greater threat and dispositional attributions provoked stronger intent to file a grievance. Implications of the findings were discussed for investigating and screening grievances.