Fourier analysis of movement patterns in pigeons

Fourier analysis describes the amount of variation in a time series by partitioning it into sinusoids of different amplitudes and wavelengths and quantifying the extent to which these waves are synchronized. The importance of a given wave is represented by its contribution to the explained variance of the time series. To illustrate its potential application to the study of movement, Fourier analysis was used to quantify the movement patterns of 2 pigeons on a variable-interval (VI) and a variable-time (VT) schedule of reinforcement. For comparison, the movements of 2 pigeons that did not receive reinforcement were similarly analyzed. Characteristic frequencies were higher during VI than during VT, and relatively low during nonreinforcement. We concluded that Fourier analysis can be used to represent movement patterns compactly, study their periodicity, stereotypy, and resonance, and assist in computer simulations and models of movement.     

Pupillometry system for use in social psychology

It is now relatively easy to implement pupillometry in social psychological research. We describe a system in which a Macintosh computer presents visual and auditory stimuli to subjects while monitoring an infrared pupillometer. The computer records information on subject, task, and pupil diameter into a data file for input into standard statistical analysis programs. Pupil diameter is measured continuously while subjects respond to stimuli that last for several seconds or minutes. A demonstration experiment verifies the usefulness of the system. The ability of the Macintosh computer to easily handle visual and auditory stimuli and to record responses lasting a considerable length of time makes the system well suited for studying pupil responses to complex social stimuli. This system is also well suited for the researcher initiating a research program using pupillometry. Ease of operation makes using a large number of subjects feasible.     

Requiem for “schizophrenia”

In this article a brief overview of the treatment of chronic psychosis for the last two centuries is covered, with particular emphasis on many scientifically demonstrated causes of chronic organic psychosis and their medically successful treatment, including recent neurotransmitter manipulations. With respect for the important contributions of Bleuler, the term “schizophrenic” is considered as an unscientific and unprovable nosological construct, which has hampered the successful resolution of chronic psychosis and has outlived its usefulness in the lexicon of modern psychiatry.     

The Effects of Intra-amygdala Infusion of the AMPA Receptor Antagonist CNQX on Retention Performance Following Aversive Training

The aim of these experiments was to determine whether impaired retention performance in aversively motivated tasks, induced by blockade of amygdala AMPA receptors, is due to influences on mechanisms underlying memory retrieval or to other influences on performance. Rats received either footshock escape training (1 or 10 trials), or no foot shock, in a two-compartment straight alley and bilateral intra-amygdala infusions of the AMPA receptor antagonist CNQX (0.5 μg) were subsequently administered prior to inhibitory avoidance retention testing 8 days later. The CNQX impaired, but did not block, inhibitory avoidance retention performance as indicated by the initial latencies to enter the shock compartment. The animals were then retained in the alley until they remained in the starting compartment for 100 consecutive s and entries into the shock compartment were recorded as errors. In both the controls and CNQX-treated groups, increases in amount of original training resulted in fewer errors, indicating memory for the escape training. Furthermore, regardless of the amount of original training (i.e., 0, 1, or 10 trials), CNQX-treated groups made more errors. Other experiments examined intra-amygdala CNQX effects on reactivity to footshock, locomotor activity, and anxiety. CNQX decreased reactivity to footshock, blocked shock-induced decreases in locomotor activity, and had an anxiolytic effect in an elevated plus maze comparable to that induced by midazolam (0.5 μg). These findings suggest that intra-amygdala infusions of CNQX prior to retention testing affect inhibitory avoidance retention performance following aversive training by altering locomotor activity, reducing sensitivity to footshock, and reducing anxiety. The implications of these findings for hypotheses concerning amygdala function in aversively motivated learning and memory is discussed.     

Social desirability,perceived stress,and PACT ratings in lung transplant candidates: A preliminary investigation

Some aspect of psychosocial criteria is commonly utilized by most transplant programs in assessing candidates' acceptability for transplantation. However, regardless of the assessment methodology, information obtained in pretransplant assessments may be limited given the evaluative nature of the assessment as well as the sensitive nature of the contents. Indeed, transplant candidates may present themselves in a favorable fashion, minimizing any negative traits or psychological dysfunction which they perceive might prevent transplantation. Unfortunately, there are limited data addressing the extent to which transplant candidates may present themselves in an overly positive light. This investigation surveys the prevalence of social desirability in lung transplant candidates as well as its association with self-reports of perceived stress. Further, the relationship between social desirability and interviewer ratings of transplant candidacy is examined. Subjects included 24 patients in end-stage organ failure being evaluated for lung transplant candidacy. Subjects completed the Perceived Stress Scale and a brief version of the Marlowe-Crowne Social Desirability Scale. Additionally, subjects were interviewer-rated on the Psychosocial Assessment of Candidates for Transplantation. Results indicate social desirability is a prevalent phenomenon in lung transplant candidates, with more than half of the sample scoring at or above the 84th percentile on the social desirability measure. Further, self-reports of perceived stress are moderately and inversely associated with social desirability (r=–.55,p .01). Social desirability was unrelated to interviewer-ratings of transplant candidates acceptability (r=.13,p .56). Future research might include larger samples of subjects, other organ transplant candidates, and more detailed assessments of symptom distress.     

On the time course of negative priming: Another look

In two experiments, the pattern of persistence of negative priming effects across delay intervals of 500 and 2,500 msec was assessed using a within-subjects, random sequencing of delays. Neill and Valdes (1992; Neill, Valdes, Terry, & Gorfein, 1992) have argued that a within-subject experimental design is required for decay of negative priming to be seen, in contrast to results reported elsewhere (e.g., Tipper, Weaver, Cameron, Brehaut, & Bastedo, 1991) showing stable negative priming effects across delays. In neither experiment was substantial evidence of decay detected, raising questions for the notion that suppression necessarily declines across brief temporal intervals and for the assertion that episodic retrieval is the sole source of negative priming.     

The visual perception of rigid motion from constant flow fields

Four experiments investigated observers’ judgments of rigidity for different types of optical motion. The depicted structural deformations were of two types: (1) those with nonparallel image trajectories that are detectable from the first-order spatiotemporal relations between pairs of views; and (2) those with parallel image trajectories that can only be detected from higher order relations among three or more views. Patterns were composed of smooth flow fields in Experiments 1 and 3, and of wire frame figures in Experiments 2 and 4. For both types of display, the nonrigidity detectable from the first-order spatiotemporal structure of the motion sequence was much more salient than the deformation detectable only from the higher order spatiotemporal structure. These results indicate that observers’ judgments of rigidity are based primarily on a two-view analysis, but that some useful information can be obtained under appropriate circumstances from higher order spatiotemporal relations among three or more views.     

The effects of situational performance constraints on intrinsic motivation and satisfaction: The role of perceived competence and self-determination

Situational performance constraints, task interest, and pay contingencies were manipulated in a laboratory study in order to investigate the cognitive mechanisms associated with the previously observed detrimental effects of constraints on affective task reactions. It was hypothesized that feelings of task competence and self-determination would account for both the direct and the interactive effects of constraints on motivation and satisfaction. The results of the study indicated that despite the fact that participants' performance was being constrained and they were aware of these constraints, the mere presence of the constraints alone failed to result in lower levels of satisfaction or motivation on a proofreading task. Post hoc analyses suggested that the constraints, in fact, led to negative affective task reactions when they also reduced participants' feelings of competence and self-determination. Interestingly, participants' generalized locus of control was associated with such effects. Internals tended to maintain stronger feelings of competence and self-determination than externals in the presence of constraints, thereby also maintaining greater motivation and satisfaction.