Gaze following in the red-footed tortoise (Geochelone carbonaria)

Gaze following refers to the ability of an animal to orient its gaze direction to that of another organism. Such a behavior may be adaptive as it alerts the observer to important objects in the environment such as food or predators. This behavior has been shown in mammals and birds, but the evolutionary history and the distribution of this behavior throughout the animal kingdom remain unclear. Here, we show that a reptile, the red-footed tortoise (Geochelone carbonaria), is able to follow the gaze of a conspecific in a lookup task. Controls revealed that neither the mere presence of a conspecific nor the presentation of a light stimulus (without a demonstrator present) controlled the tortoises’ behavior. The findings indicate that the ability to follow gaze may be found in mammals, birds and reptiles and could have evolved before the amniotic line diverged, or may result from a general ability to learn.     

Visual and response-based navigation in the tortoise (Geochelone carbonaria)

Much research has investigated spatial cognition in mammals and birds. Evidence suggests that the hippocampus plays a critical role in this; however, reptiles do not possess a hippocampus. It has been proposed that the reptilian medial cortex plays a similar role, yet little behavioral research has directly investigated this. Consequently, this study examined the role of extramaze cues in spatial navigation by the red-footed tortoise (Geochelone carbonaria) using an eight-arm radial maze. In Experiment 1 the maze was surrounded by a black curtain on which geometrical shapes were attached. After the tortoise reached above-chance performance we introduced test sessions in which the cues were removed. Performance was unaffected by cue removal. The tortoise appeared to have developed a “turn-by-one-arm” strategy. In a second experiment the curtain was removed and the tortoise was allowed access to a rich-cue environment. The use of the turn-by-one-arm strategy was significantly reduced and the tortoise appeared to be using the extramaze cues to navigate around the apparatus. This type of response-based strategy, and the specific contexts in which it was used, has not been observed in mammals and birds, suggesting that the mechanisms served by the reptilian medial cortex do not parallel exactly those of the hippocampus.     

Factor analysis of the frontal systems behavior scale (FrSBe)

The Frontal Systems Behavior Scale (FrSBe), formerly called the Frontal Lobe Personality Scale (FLOPS), is a brief behavior rating scale with demonstrated validity for the assessment of behavior disturbances associated with damage to the frontal-subcortical brain circuits. The authors report an exploratory principal factor analysis of the FrSBe-Family Version in a sample including 324 neurological patients and research participants, of which about 63% were diagnosed with neurodegenerative diseases (Huntington's, Parkinson's, and Alzheimer's diseases). The three-factor solution accounted for a modest level of variance (41%) and confirmed a factor structure consistent with the three subscales proposed on the theoretical basis of the frontal systems. Most items (83%)from the FrSBe subscales of Apathy, Disinhibition, and Executive Dysfunction loaded saliently on three corresponding factors. The FrSBe factor structure supports its utility for assessing both the severity of the three frontal syndromes in aggregate and separately.     

A dialogue on Zeno's paradox of Achilles and the tortoise

The five participants in this dialogue critically discuss Zeno of Elea's paradox of Achilles and the tortoise. They consider a number of solutions to and restatements of the paradox, together with their philosophical implications. Among the issues investigated include the appearance-reality distinction, Aristotle's distinction between actual and potential infinity, the concept of a continuum, Cantor's continuum hypothesis and theory of transfinite ordinals, and, as a solution to Zeno's puzzle, the distinction between infinite and indeterminate or inexhaustible divisibility.     

Changing rational-emotive therapy (RET) to rational emotive behavior therapy (REBT)

Reasons are given for changing the name of Rational-Emotive Therapy (RET) to Rational Emotive Behavior Therapy (REBT) and for bringing its behavioral aspects into more prominence. Excerpted from “Changing Rational-Emotive Therapy (RET) to Rational Emotive Behavior Therapy (REBT).Behavior Therapist, 1994,16(10), 1–2, and fromReason and Emotion in Psychotherapy, Rev ed. updated. New York Carol Publishing, 1994. Reprinted with permission.     

Ontogeny of social behavior in the megapode Australian brush-turkey (Alectura lathami)

Megapodes meet conspecifics at an unpredictable age, and it is unknown how their social behavior develops under such conditions. The authors induced encounters between 2-day-old socially naive hatchlings and up to 49-day-old chicks of the Australian brush-turkey (Alectura lathami) in a large outdoor aviary. All social behavior patterns found in older chicks were present in hatchlings and did not change in form or the frequency in which they occurred thereafer; the frequency of calling was the only feature that changed significantly with age. Chicks stayed only 0.3-2.0 m (medians) apart and synchronized their feeding activity from the age of 20 days. These results indicate that megapode chicks show social behavior without social experience and that this requires no postnatal leaning.     

Life-span changes in the copulatory behavior of male rats (Rattus norvegicus)

The copulatory behavior of 5-, 10-, 15-, and 20-month-old sexually naive male rats (Long-Evans) was studied during 2-hr tests with receptive females. There was no apparent change in sexual arousal as measured by latency to initiate copulation across age, with subjects from all groups exhibiting comparable latencies to first mount and first mount with intromission. The numbers of ejaculations achieved were also similar across ages. Significant age differences were found for frequency of mounts, with 20-month-olds having the highest mean frequency. The persistent mounting by older males appeared to account for significant group differences in interintromission interval and ejaculation latency. It is suggested that motor deficits may impair the ability of older males to achieve intromission, increasing the number of mount bouts as well as the number of mounts per bout, thus extending the length of each copulatory series.     

Effects of toxicosis on the predatory behavior of the golden hamster (Mesocricetus auratus)

The purpose of this study was to measure the effects that toxicosis had on the hamster's predatory behavior and to compare these results with those found in previous studies with grasshopper mice. A 0.15 M LiCl injection caused hamsters to develop a greater aversion and to inhibit their feeding and attack responses more frequently toward a house cricket than did a similar injection of NaCl. The added presence of an almond coating on the cricket prolonged the number of days that a hamster exhibited an aversion toward the prey and an inhibition to attack. Essentially, the inhibitory effects from toxicosis in the hamster paralleled those found with the grasshopper mouse. The differences in these inhibitory effects are attributed to inherent differences in the attack responses of the two rodents.     

Attributions of behavior in the pediatric mild closed head injury (CHI) population

Forty-one children between the ages of 6 and 11 years with a history of a mild closed head injury and 23 age-, gender-, and IQ-matched typically developing control children participated. All of the children in the CHI sample were referred for a magnetic resonance imaging (MRI) scan at 3 months post-injury and children in the CHI sample were further divided into MRI-Negative (n=31) and MRI-Positive (n=10) conditions according to the MRI results. Parents and teachers completed behavioral checklists at three points, including just prior to the MRI and 6 months post-injury. Prior to the MRI (Time 2), in both samples of children with a CHI, parents reported an increase in externalizing symptoms after the CHI. At 6 months post-injury (Time 3: post-MRI), parents of children in the MRI-Positive group did not report any significant changes in their child's externalizing behaviors when compared with pre-MRI, yet parents of children in the MRI-Negative group reported a further increase in externalizing behaviors. Parent attributions also changed as a function of group membership; whereas no changes were noted in the other two groups, parents of children in the MRI-Negative sample ascribed more controllability at Time 3 when compared with Time 2.