How does the ecological foraging behavior of desert kangaroo rats (Dipodomys deserti) relate to their behavior on radial mazes?

Experiment 1 showed that laboratory-reared desert kangaroo rats, like domestic Norway rats, efficiently search for food on a radial arm maze (RAM) by avoiding revisiting arms within a trial. By placing an RAM on the floor so the animals could approach food from any direction, Experiment 2 tested whether efficient search by kangaroo rats was based on tactics of distance minimizing, central-place foraging, trail following, or meandering. In contrast to the dominant trail-following tactic of domestic Norway rats (Hoffman, Timberlake, Leffel, & Gont, 1999), kangaroo rats tended to distance minimize, whether maze arms were present or not. Experiment 3 indicated that kangaroo rats treated a floor configuration of eight food cups as two patches of four, based on beeline travel between patches and meandering within them. We conclude that similar performance in an elevated RAM by different species can be based on different tactics, and we suggest that a laboratory apparatus can be used to cast light on niche-related mechanisms.     

When it hurts to be misled: A Stroop-like effect in a simple addition production task

In four experiments, subjects saw simple addition equations (e.g., 3 + 4 = 9) and produced the sums while ignoring the presented answer. If the presented answer was false, subjects took longer to produce the sum, as compared with when the presented answer was true (Experiment 1), when there was no answer presented (blanks; Experiment 2), when a letter was presented (Experiment 3), and when a symbol was presented (Experiment 4). The results suggest that subjects were unable to ignore the presented answers, which raises problems for theories of arithmetic verification (i.e., deciding whether 3 + 4 = 9 is true or false) that claim that subjects verify equations by first producing the sum and then comparing the produced sum with the presented answer. Our results are more compatible with theories that claim that in verification and production, an arithmetic knowledge base is used in different ways.     

Pencil lead diameter affects response sheet completion time

The effect of pencil lead diameter on the completion time of a multiple-choice response sheet was examined. Participants used three pencil lead diameters (.5 mm, .9 mm, and a standard No. 2 pencil) to fill in "bubbles" on response sheets in one experiment; a .7-mm pencil was substituted for the No. 2 pencil in Exp. 2. Participants using a .5-mm pencil completed response sheets more slowly than when using a .7-mm, .9-mm, or a No. 2 pencil.     

Depictions of motion devised by a blind person

A blind man (E.A.) was asked to draw pictures suggesting wheels in various kinds of motion. Six pictures were drawn by E.A. The pictures were shown to sighted subjects, who were asked to assign labels to the pictures, in a multiple-choice format. The labels were assigned at a rate above chance. We argue that the pictures are metaphoric and that pictorial metaphor relies on common properties of the static picture and the kinetic referent.     

Ruminative coping and post-event processing in social anxiety

Cognitive models of social anxiety implicate various factors in the initiation and maintenance of socially anxious states, including anticipatory processing, self-focused attention and post-event processing. The present study focused on post-event processing, which is a post-mortem analysis following a social event that is described as ruminative in nature and serves to maintain social anxiety. Participants (N=112; 64 women, 48 men) were presented with vignettes that involved making mistakes in public and were instructed to record their thoughts to allow for the examination of the content of post-event processing. Ruminative coping and distraction were assessed via self-report. Results indicated that participants high in social anxiety (n=55) were more likely to ruminate and less likely to distract when faced with socially anxious stressors compared to those low in social anxiety (n=57). Further, as hypothesized, participants high in social anxiety recorded more negative thoughts and more upward counterfactual thoughts ('if only' type thoughts on how things could have been better; associated with negative affect) compared to those low in social anxiety. These results are discussed in terms of cognitive models of social anxiety.     

Subjective and reinforcing effects of smoking during negative mood induction

Two notions strongly held by many smokers are that negative mood increases smoking behavior and that this increase is due to the ability of smoking to alleviate negative affect. This study used a modified mood induction procedure to examine both the impact of smoking on induced mood, as well as the effect of induced mood on actual smoking behavior. Forty-eight smokers were randomly assigned to a smoking or a water-drinking comparison group. Each participant attended 3 sessions during which 1 of 3 mood states (positive, negative, or neutral) was induced. Contrary to expectation, smoking did not attenuate negative affect. However, negative mood induction subsequently quickened latency to smoke and increased number of puffs consumed ad lib.     

Perceptions of Dating Violence Following a Sexualor Nonsexual Betrayal of Trust: Effects of Gender, Sexism, Acceptance of Rape Myths, and Vengeance Motivation

College womens (N = 220) and mens (N = 208) perceptions of violence following a betrayal by a romantic partner were studied in an independent groups design that varied gender of the participant, type of betrayal (sexual or nonsexual), and gender of the betrayed individual. Participants read one of four brief vignettes in which the betrayed person slapped his/her partner and made his/her lip bleed. Justification of this action was rated on 10 items. Factor analysis of these items indicated the presence of three factors for men and four for women. Both men and women indicated that hitting the partner, getting even, and being angry were more justifiable following a sexual betrayal. The hitting of a male partner by a betrayed woman was perceived as more justified than the hitting of a female partner by a betrayed man. In absolute terms, hitting and getting even by both women and men were generally viewed as unjustifiable, whereas being angry was viewed as justifiable. For both women and men, scores on the Vengeance Scale (Stuckless & Goranson, 1992) and Rape Myth Acceptance Scale (Lonsway & Fitzgerald, 1995) were related to getting even. For men, the Hostile Sexism Scale (Glick & Fiske, 2001) was related to getting even or being angry and breaking up. Results indicated that perceptions of reactions to betrayal are related to type of betrayal and to the dispositional characteristics of the perceiver.     

Serial recall and presentation schedule: a micro-analysis of local distinctiveness

According to temporal distinctiveness theories, items that are temporally isolated from their neighbours during presentation are more distinct and thus are recalled better. Event-based theories, which deny that elapsed time plays a role at encoding, explain isolation effects by assuming that temporal isolation provides extra time for rehearsal or consolidation of encoding. The two classes of theories can be differentiated by examining the symmetry of isolation effects: Event-based accounts predict that performance should be affected only by pauses following item presentation (because they allow time for rehearsal or consolidation), whereas distinctiveness predicts that items should also benefit from preceding pauses. The first experiment manipulated inter-item intervals and showed an effect of intervals following but not preceding presentation, in line with event-based accounts. The second experiment showed that the effect of following interval was abolished by articulatory suppression. The data are consistent with event-based theories but can be handled by time-based distinctiveness models if they allow for additional encoding during inter-item pauses.