Novel odors evoke risk assessment and suppress appetitive behaviors in mice

The effects of four novel odors on risk assessment by mice (i. e., flat back approach, stretched attention, immobility) and the suppression of appetitive behaviors were examined in two experiments. When novel odors were presented in a straight runway, subjects spent significantly less time in the odor compartment, relative to controls, when it contained sheep wool, chocolate, or citronella (but not cat fur) odors. Risk assessment behaviors occurred at similar levels among all groups and appetitive behaviors were not suppressed by the novel odors. When odorants were scattered over one half of the subjects' home cage floor in Experiment 2, all novel odors increased the duration of at least on e risk assessment measure and/or suppressed appetitive behaviors (i. e., eating, grooming, rearing). The results clearly reveal that a reasonably wide range of novel odors evoke at least some level of risk assessment which presumably reflects increased fearfulness. The odors of sheep wool and cat fur induced a wider range of such responses than did chocolate or cinnamon suggesting that mammalian odors may be particularly effective stimuli. If so, however, it is clear that predator odors are not uniquely effective in this regard. Experiment 1 also underscores the importance of the testing environment in assessing the behavioral effects of novel odors in mice. © 1993 Wiley-Liss, Inc.     

Man The Rational Animal?

This paper considers well known results of psychological researchinto the fallibility of human reason, and philosophical conclusionsthat some have drawn from these results. Close attention to theexact content of the results casts doubt on the reasoning that leadsto those conclusions.     

Some fear-potentiating effects of fluprazine hydrochloride in mice

The fear-potentiating effects of fluprazine hydrochloride were explored in a series of five experiments. The drug was found to strongly inhibit entry into a novel open field, exploration of a complex maze, or approach to a novel object placed in the animal's home cage. Time sampling techniques were used to assess drug effects on frequencies of immobility, activity, and grooming and rearing responses prior to and for 70 min after footshock. There were no group differences during the 10 min immediately following shock but the groups diverged steadily in immobility, activity, and grooming for the remainder of the observations. Post-shock activity and grooming responses increased steadily towards baseline values among control mice but remained at low levels or declined among drug-treated mice. Immobility responses declined steadily among control mice but increased substantially among the fluprazine-treated mice throughout post-shock observations. Pairs of male mice treated with fluprazine were also found to maintain greater intermouse distances in a novel linear runway than pairs of undrugged adult males, juvenile males, or male-female pairs. It is suggested that fluprazine hydrochloride both potentiates fear and alters its time course in addition to interfering in some way with normal olfactory processes.     

Ecstasy and agony: activation of the human amygdala in positive and negative emotion

Considerable evidence indicates that the amygdala plays a critical role in negative, aversive human emotions. Although researchers have speculated that the amygdala plays a role in positive emotion, little relevant evidence exists. We examined the neural correlates of positive and negative emotion using positron emission tomography (PET), focusing on the amygdala. Participants viewed positive and negative photographs, as well as interesting and uninteresting neutral photographs, during PET scanning. The left amygdala and ventromedial prefrontal cortex were activated during positive emotion, and bilateral amygdala activation occurred during negative emotion. High-interest, unusual photographs also elicited left-amygdala activation, a finding consistent with suggestions that the amygdala is involved in vigilance reactions to associatively ambiguous stimuli. The current results constitute the first neuroimaging evidence for a role of the amygdala in positive emotional reactions elicited by visual stimuli. Although the amygdala appears to play a more extensive role in negative emotion, it is involved in positive emotion as well.     

Idiosyncratic profiles of collinearity error using segments and dot pairs

It is well known that judgments of oblique line segments are more variable and less accurate than are judgments of horizontal or vertical segments, i.e., the “oblique effect.” A prior study from our laboratories confirmed these differentials for a task in which the collinearity of segments at various angular positions was judged. Further, that study found that each observer manifests a distinct, idiosyncratic profile of errors across the 360° range. These error tendencies are conspicuous in models derived by harmonic analysis, and we describe significant excursions of a given model as “delta errors.” The present experiments found complex profiles of delta error with various stimulus and test conditions. A given subject manifested similar models of delta error when judging collinearity of dot pairs versus line segments. In the prior work the segments to be judged were asymmetrically positioned upon the test sheet. However, the asymmetric positioning is not responsible for the errors, as the present work found errors excursions with a round display field. Similar profiles of delta error were found when subjects were allowed to mark an open space, versus being required to respond at a specific distance (indicated by a target circle). This addresses questions of whether the error should be measured as an angle. In the two final experiments, we present evidence that the source of delta error within the nervous system is at the point of binocular synthesis of the information from the two eyes, or beyond, and the effects are not due to errors of reaching. Potential neural substrates for these complex, idiosyncratic error tendencies are discussed. Received: 16 June 2000 / Accepted: 10 March 2001     

Associated factors of post-stroke depression among Hong Kong Chinese: a longitudinal study

The aim of this study was to explore associated factors of post-stroke depression (PSD) among Chinese first-time stroke patients. A 6-month prospective design was adopted with data collected by face-to-face interviews and physical assessment at two observation time points: T1, within 48 h of admission to the rehabilitation hospitals and T2, 6 months after the first interview in the subject's current place of residence. The prevalence of PSD at T1 and T2 was found to be 69% and 48% respectively. Backward linear regression showed that five variables explained 55% of the variance of PSD at T2. Participants who had a higher level of depression at T2 tended to have a higher level of functional disability, less social companionship and poorer informational support. Those who had been homemaker at pre-morbid state and those who exhibited a higher level of depressive symptoms at T1 showed a higher level of depression at T2. The results of this study suggest that PSD could be a psychological condition arising from the disabling consequences and altered family roles caused by a stroke.     

Pronouns and quantifier-scope in English

This paper is truly a joint effort and it could not have been written without the contribution of both authors. Garson, though, deserves credit (or blame) for first seeing the need for two kinds of quantifier scope, and also for devising essentials of the positive theory.     

Regulatory fit theory at work: prevention focus' primacy in safe food production

The food‐processing industry emphasizes employee compliance to food‐safety standards to prevent distribution of contaminated foods. Regulatory fit theory was tested to examine the applicability of self‐regulation constructs as potential components of person‐job fit. In contexts emphasizing safety, workers higher in prevention should experience greater person‐job fit, thus prevention focus should relate to desirable outcomes. Poultry‐processing workers (n = 180) completed a work‐related regulatory focus scale as part of a survey including a set of outcome measures. Consistent with theory, prevention focus scores related to self‐reported positive work outcomes (job effectiveness, satisfaction, efficacy, enjoyment, involvement), and relationships were statistically mediated by perceived regulatory fit. Results have implications for selection practices and suggest ways work can be structured to enhance job performance.