Effects of Control on the Stress Reactions of Commuters1

The effects of morning, rush hour commuting were examined in a quasi-experimental field study involving government-employed commuters (single and carpool drivers). Commuting stress was measured as a response to variations in how difficult it was for commuters to move from home to work. The mediation of these effects by two sources of control in the commuting situation also were assessed. Control was operationalized as control over the internal environment of the car (single versus carpool driver) and choice over routes taken to get to work. Among commuters with a high impedance route, driving to work was associated with significant increases in systolic and diastolic blood pressure and decreases in behavioral performance. The stress of commuting under high impedance conditions was reduced for single drivers relative to carpoolers. Under similar conditions of high impedance, however, having the option to select more than one route to get to work seemed to be more stressful than having only one route. The practical implications of these results are discussed.     

Response restriction and substitution with autistic children.

Few studies to date have examined time reallocation in naturalistic, multiresponse human repertoires when one or more responses are restricted. For this experiment, free-operant baseline levels of six responses were measured for four autistic children. The high-probability responses were made unavailable, one at a time, such that subjects had access to five, four, three, and two responses in successive restriction conditions. A return to the six-response free-operant baseline condition completed the experiment. Results were compared to predictions made by four time-reallocation models. These results were described accurately only by the selective substitution model. Further analyses examined alternative explanations for the individual reallocation patterns obtained. An expanded selective substitution definition is proposed that may characterize orderly patterns observed in multiresponse repertoires under restriction conditions more accurately than the other existing models.     

Information on response requirements compared with information on food density as a reinforcer of observing in pigeons

On a variable-interval schedule, pecking the key to the pigeon's right (observing response) produced red or green displays relating to the delivery of grain and its dependence on pecking the key to the left (food key). During various blocks of sessions, mixed (no stimulus change) schedules including the following pairs of components were temporarily converted by the observing response to their corresponding multiple (correlated stimuli) schedules: variable-interval 60-s, extinction; variable-interval 60-s, variable-time (response-independent) 60-s; extinction, variable-time 60-s. Differences in food delivery maintained substantial rates of responding on the observing key, without regard to pecking requirements on the food key. Although stimuli correlated with differences in the response requirement on the food key maintained higher observing rates than those maintained by uncorrelated stimuli, they were much lower than those based on food. The value of predictive stimuli as reinforcers is determined by the value of the events predicted. In particular, the cost of pecking appears to be low, and this may place limitations on the applicability of energy-based and economic models of behavior.     

Stimulus-response compatibility in the programming of speech

Subjects chose between sequences of one syllable (e.g.,/gi/vs./bi/), two syllables (e.g.,/gibi/ vs./gubu/), and three syllables (e.g.,/gibidi/ vs. gubudu/), when/i/sequences were signaled by high-pitched tones and/u] sequences were signaled by low-pitched tones (high compatibility), or the reverse (low compatibility). Choice times were additively affected by sequence length and compatibility. A second experiment showed attenuated compatibility effects for sequences with different vowels in the first and second syllables. These results replicate previously reported results for choices between finger sequences, which suggests that the same programming methods are used in both output domains. Evidently, choices between response sequences can be achieved by selecting a distinguishing parameter and assigning it in a serial fashion to partially prepared motor subprograms.     

Cognitive functioning and anxiety

Summary Various possible differences in cognitive functioning between those high and low in trait anxiety are considered. Particular emphasis is paid to the hypothesis that individuals high in trait anxiety tend to approach threatening stimuli, whereas those low in trait anxiety tend to avoid such stimuli. The evidence indicates that there are such differences in the processing of threatening stimuli as a function of trait anxiety. However, these differences are found only under certain conditions, for example, when threatening and nonthreatening stimuli are presented concurrently, and when minor rather than major threat is involved.The differences between those high and low in trait anxiety encompass pre-attentive, attentional, and interpretative mechanisms. As a consequence, any adequate theory of trait anxiety must take proper account of cognitive mechanisms and functioning.     

Motor response information influence on CNV shape and resolution time

This study systematically investigates changes in CNV waveform shape and resolution time that result from the presentation of facilitatory, inhibitory, or no motor response (MR) information simultaneously with the warning (S1) or imperative (S2) stimulus of the S1-S2-MR CNV paradigm. Analyses indicate that the simultaneous presentation of S1 and information to produce or inhibit a MR attenuates initial CNV development. Further, when the S1 information is inhibitive, CNV development is retarded throughout. The contribution of an inhibitory psychological process during CNV development is proposed. The data also indicate that CNV resolution time is not dependent on the presence of a motor response. It is suggested that CNV resolution time is indicative of psychological completion or closure.     

Distance perception as a function of photographic area of view

Distance perception of depicted objects was examined as a function of photographic area of view. Subjects viewed slides of natural outdoor scenes and directly estimated the distances to specified objects. Area of view was manipulated by means of photographing each scene with lenses of five different focal lengths: 135, 80, 48, 28, and 17 mm. Distance perception along the pictorial depth plane was systematically transformed through changing the photographic area of view: the shorter the focal length of the camera lens, the wider the area of view, and the greater the perceived distance. Linear functions for each subject's distance judgments revealed a very high goodness of fit. Both the y-intercepts and the slopes increased as focal length decreased. The increasing y-intercepts suggest that viewers place themselves farther away from the depicted scene as focal length decreases, compensating for the advancing proximal edge. The increasing slopes suggest that distance information throughout the pictorial depth plane appears to change with focal length. The subjects also made direct judgments of foreground truncation, revealing that foreground truncation decreased as focal length decreased, but that this decrease did not account for the considerable expansion in distance perception.     

Ego-involvement leads to positive self-schema activation and to a positivity bias in information processing

Study 1 examined the hypothesis that ego-involvement leads to positive self-schema activation. Ego-involvement was induced by having experimental subjects anticipate a difficult test of intelligence. Noninvolved control subjects did not anticipate the test. All subjects completed a depth-of-processing task, following which incidental recall was assessed. Ego-involved relative to noninvolved subjects tended to recall a greater number of positive and fewer negative words at both the self-referent and semantic processing levels. Study 2 was conducted to address further the self-schema hypothesis and to address the hypothesis suggested by the results of Study 1 that ego-involvement leads to a positivity bias in information processing. The design of Study 2 was similar to that of Study 1. Results revealed that the self-favorability of negative words recalled at the self-referent level was greater for ego-involved than for noninvolved subjects, suggesting positive self-schema activation. In addition, ego-involved subjects recalled a greater number of positive words at the semantic level, suggesting a positivity bias in information processing.Study 2 was conducted by Andrew Howell in partial fulfillment of the requirements of a Master of Arts degree at Concordia University, under the supervision of Michael Conway. The authors thank Karin Stiefenhofer for her work on the project. The research was supported by the Social Sciences and Humanities Research Council of Canada and the Fonds pour la Formation de Chercheurs et l'Aide à la Recherche du Québec grants to Michael Conway.     

Memory deficits before and after temporal lobectomy: Effect of laterality and age of onset

Laterality and age of onset effects on semantic and figural memory were evaluated in 30 right-handed, left speech dominant (amobarbital test) patients with epilepsy before and after temporal lobectomy. There were no effects of focus on WAIS-R IQ scores. Early onset (less than or equal to 5 years) was associated with lower IQ and memory (WMS). Left Temporal (LT) patients showed worse semantic than figural memory preoperatively. Unexpectedly, early onset LT had marked postoperative decline of figural memory, whereas late onset LT patients showed the previously reported worsening of semantic memory. Right Temporal (RT) lobectomy patients, in contrast, improved in both semantic and figural memory regardless of age of onset. A "crowding effect" was suggested by the decline in figural memory following surgery in the early onset LT patients who remained stable or improved in semantic memory. Results indicate the need to incorporate age of onset of seizures into laterality models of memory function following unilateral temporal-hippocampal resection.