Different slopes for different folks: Process analysis of spatial aptitude

Adults differing in spatial ability were tested on problems involving the mental rotation of familiar alphanumeric stimuli and unfamiliar stimuli drawn from the Primary Mental Abilities Space Test. Individual differences in spatial ability were associated with speed rather than accuracy of mental rotation processes. Ability differences were correlated with the time to rotate familiar alphanumerics and the additional time to encode, compare, and rotate unfamiliar stimuli. The results are discussed in terms of differences in elementary information processes associated with the representation and transformation of visual information.     

Weeping: Evidence for a cognitive theory

According to a two-factor cognitive theory of weeping, schema-incongruent information and efforts to assimilate it create arousal; resolution, giving up of the schema, and cessation of the assimilation efforts result in arousal reduction and may be associated with emotional tears. To assess these predictions, female subjects were shown an emotional film under one of two conditions. In one condition only schema-induction and incongruity phases were viewed, while the other condition viewed the complete film (i.e., schema-induction, incongruity, and resolution). Consistent with expectations, incongruity was associated with increased stress and depressed mood. Only subjects who viewed the complete film reported significant decreases in these states. The final scene, assumed to trigger schema change, produced the greatest amount of weeping.This paper is adapted from a portion of a doctoral dissertation conducted by the first author. We gratefully acknowledge the assistance of Walter Katkovsky and Raymond Ditrichs. A version of this paper was presented at a meeting of the Western Psychological Association, May 1986.     

Baroreflex responses to the stress of severe hemorrhage in the rat

In two groups of anesthetized (sodium pentobarbital), mature Sprague-Dawley rats, 1) aged 2 years and weighing 300–400 grams, 2) aged 6 months weighing 200–300 grams, baroreflex-induced circulatory responses to pressor (graded doses phenylephrine) and depressor (graded doses nitroglycerine) agents were compared to those occurring during progressive hemorrhage in the same animals. Graded withdrawals of blood from the femoral artery elicited progressive hypotension accompanied by bradycardia rather than expected tachycardia. Graded doses of phenylephrine (2.5 ug to 40 ug bolus, via femoral vein) regularly induced elevations in arterial blood pressurewith associated reflex bradycardia. Similarly graded doses of nitroglycerine induced a marked decline in arterial blood pressure,without expected tachycardia. As hypotension became more severe (during hemorrhage), atrioventricular conduction slowed and A-V block developed, resulting in statistically greater slowing in ventricular than in atrial excitation and contractile cycles. Heart failure during hemorrhage in the rat is characterized sequentially by severe bradycardia, depressed atrial contractile force, impaired conduction and A-V block, terminating in ventricular, atrial, and finally, in pacemaker failure. Baroreceptor reflexes were blunted or even absent in both young and old animals during induced hypotension.     

Inhibition of return in location- and identity-based choice decision tasks

Three experiments were conducted to determine whether inhibition of return can be best characterized as an attentional or a motor phenomenon. In the first experiment, subjects made choice key-press responses to the location of a target (left or right) or the identity of the target (X or +) by pressing a left or right response key. In the second experiment, the display was rotated 90° so that there was no direct spatial mapping between the vertically aligned stimulus display and the horizontally aligned response keys. In both experiments, inhibition of return was observed for location-based and identity-based choice responses, although more inhibition was seen in the identity-based responses. The results of the third experiment suggested that this larger inhibitory effect may be specific to the covert orienting of reflexive attention in response to the sudden appearance of a single peripheral stimulus in the identity tasks. Overall, the results are consistent with the attentional, not the motor, explanation of inhibition of return.     

Autonomic nervous control of heart rate orienting and alpha responses in dog

The object of this experiment is to study the autonomic nervous control of alpha responses elicited in classical conditioning. Twenty-two mongrel dogs were trained in classical discriminative conditioning. Typical two-phase tachycardic responses were observed in positive (CS+) trials while only the earliest, phase 1, response was observed in negative (CS-) trials. The phase 1 response, which was identical in CS+ and CS-trials, was compared in dogs before and after selective SA-nodal parasympathectomy (N=7) and beta-adrenergic blockade (N=11). The phase 1 tachycardic response was eliminated by selective SA-nodal parasympathectomy but not by beta-adrenergic blockade. We conclude that the phase 1 response observed in both CS+ and CS-trials with similar time sequence and magnitude is an alpha response. The heart rate orienting response results from a withdrawal of parasympathetic activity with little or no change in sympathetic tone.     

Age differences in encoding and retrieving details of a pediatric examination

Baker-Ward, Gordon, Ornstein, Larus, and Clubb (1993) showed that recall improves over ages 3–7 for events experienced during a physical examination. We used a joint multinomial model to ask whether the improvement was due to encoding, to retrieval, or to likelihood to report. The model fit the Baker-Ward et al. data well and showed that (1) retrieval and reporting cannot be distinguished and (2) the observed effects were due primarily to age-related improvement in retrieval reporting rather than in encoding.     

On people’s understanding of the diagnostic implications of probabilistic data

Two lines of prior research into the conditions under which people seek information are examined in light of two statistical definitions of diagnosticity. Five experiments are reported. In two, subjects selected information in order to test a hypothesis. In the remaining three, they selected information in order to convince someone else of the truth of a known hypothesis. A total of 567 university students served as subjects. The two primary conclusions were as follows: (1) When the task is highly structured by the environment, subjects select information diagnostically, and (2) when the task is less structured, so that subjects must seek relevant information not manifest, they select information pseudodiagnostically. Possible relations to other laboratory inference tasks and to clinical judgment are discussed.