The avian hippocampus and short-term memory for spatial and non-spatial information

Three experiments investigated the role of the pigeon hippocampal formation (the hippocampus and area-parahippocampalis) in short-term memory for non-spatial and spatial information. The acquisition of delayed matching-to-sample and the short-term retention of non-spatial visual information, using a small set of sample stimuli, were unaffected by aspiration lesions of the hippocampus or the neostriatum (Experiment 1). Similarly, acquisition and short-term retention of non-spatial information using a successive, trial-unique, delayed non-matching-to-sample procedure were unaffected by hippocampal damage; the same birds had, however, displayed a profound autoshaping impairment (Experiment 2). Acquisition of a spatial delayed matching-to-sample task was unimpaired by hippocampal damage. However, lesioned animals were impaired following the introduction of retention intervals on this procedure (Experiment 3). The correspondence between the behavioural effects of hippocampal lesions in birds and mammals on short-term memory is discussed, and the implications of these results for avian hippocampal function are considered.     

The Malicious Serpent: Snakes as a prototypical stimulus for an evolved module of fear

As reptiles, snakes may have signified deadly threats in the environment of early mammals. We review findings suggesting that snakes remain special stimuli for humans. Intense snake fear is prevalent in both humans and other primates. Humans and monkeys learn snake fear more easily than fear of most other stimuli through direct or vicarious conditioning. Neither the elicitation nor the conditioning of snake fear in humans requires that snakes be consciously perceived; rather, both processes can occur with masked stimuli. Humans tend to perceive illusory correlations between snakes and aversive stimuli, and their attention is automatically captured by snakes in complex visual displays. Together, these and other findings delineate an evolved fear module in the brain. This module is selectively and automatically activated by once-threatening stimuli, is relatively encapsulated from cognition, and derives from specialized neural circuitry.     

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.     

威胁性刺激蛇一定会被更快觉察吗?蛇与蜥蜴的对比

大量运用视觉搜索范式的研究发现,在进化过程中对人类生存具有威胁的蛇会被人们更快地觉察。但已有研究采用动物（蛇）植物（花）配对搜索的方式,而很少直接采用近似的动物配对搜索。本研究选取成人大学生被试,通过视觉搜索范式和眼动追踪,对比了蛇和同为爬行类动物、却不具有进化上威胁性的蜥蜴的视觉搜索过程,以探究蛇的威胁性和动物特征相似性在威胁性刺激注意偏向中的作用。实验1采用蛇和蜥蜴互为目标物和干扰物,发现相对于蛇,被试对蜥蜴的行为反应时更短;首次注视到达时间也更短。实验2-4分别采用黑白和线画刺激、恒定干扰物（花和青蛙）、使用自然背景材料对比蛇和蜥蜴的觉察,发现了一致的结果,即被试对蜥蜴的视觉搜索时间和行为反应时间都要快于蛇。在视觉搜索任务中当两种视觉刺激材料的属性接近时,蛇在进化上的威胁性不一定导致更快的搜索时间,而刺激物的视觉特征对目标物的觉察会产生重要的影响。     

Outline of the evolution of behavioral and nonbehavioral patterns of parental care among the vertebrates: critical characteristics of mammalian and avian parental behavior

An outline of the evolution of parental care among the vertebrates is presented, leading to a characterization of critical features of parental care among the mammals and birds. Among the lower vertebrates (fishes, amphibia) and reptiles there are a variety of patterns of parental care. These can be divided into those that involve parental behavior and those that are nonbehavioral. Among extant species, parental behavior is not the predominant form of parental care, although it is present in many species of fish, frog and reptile. Nonbehavioral patterns of parental care predominate and are equally effective as parental behavior. Parental behavior is based on reciprocal stimulus interaction (trophallaxis) between the parent and the offspring and includes behavior directed at the nest, eggs, and developing young. Among lower vertebrates and reptiles there are increases in the complexity and completeness of parental behaviors but only among the mammals and birds has parental behavior been elaborated as the only form of parental care. Critical characteristics of mammalian parental behavior are: simultaneous onset of birth, lactation, and maternal care, rapid formation of an attachment of the mother to her offspring, synchrony in the behavioral interaction between mother and young during their development until weaning, and the significance of the mother-offspring unit as the basis of social organization. Among birds there is the period of egg incubation in the nest preceding hatching of the young, in addition to the above characteristics of mammals, but the mother-offspring unit is not the basis for social organization.     

Attributing human characteristics: Developmental changes in over- and underattribution

Twenty each 4-year-olds, 5-year-olds, second-graders, fourth-graders, and college students were asked to attribute seven unobservable animate properties to each of seven phylogenetically varied animate objects, including a person, and a stone as a typical inanimate object. For anatomical/physiological properties (e.g., heart), there was a progression from preschoolers' similarity-based attribution, that is, attributing the properties to the target object according to its similarity to people, toward category-based attribution by adults via similarity-based inference constrained by categorical knowledge. Thus, preschoolers made many underattribution errors and some overattribution errors, but such errors decreased markedly with age and were seldom found among adults. For mental properties (e.g., feeling), subjects in all age groups still made similarity-based attribution. Thus, not a few overattribution errors, though restricted mostly to advanced animals, still existed even among adults (Experiment 1). Experiment 2, in which 20 5-year-olds and 20 college students were asked to attribute four animate properties to five objects each belonging to categories of mammals, birds, fish, insects, and plants, as well as a person and a stone, confirmed the above group data results through analyses of individual data.     

Rapid detection of visually provocative animals by preschool children and adults

The ability to detect dangerous animals rapidly in complex landscapes has been historically important during human evolution. Previous research has shown that snake images are more readily detected than images of benign animals. To provide a stringent test of superior snake detection in preschool children and adults, Experiment 1 consisted of two parts using a touch-screen visual search task. Reaction times to detect different target snakes embedded in matrices of lizards were compared with reaction times to detect target lizards embedded in matrices of snakes. Experiment 2 compared the visual salience of lions with that of similarly colored antelopes. This experiment tested the prediction that historically dangerous felid predators would also engender rapid detection. Results from the two experiments revealed that both preschool children and adults located snakes and lions more quickly than their nonthreatening counterparts. Experiment 3 examined the ability of children and adults to distinguish between similar appearing cows and horses. Preschool children and adult men exhibited no reliable differences in detecting the two animal types. Adult women located horses reliably faster than cows, suggesting that visual biases for some animals can be acquired after childhood.     

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.     

Snakes and cats in the flower bed: fast detection is not specific to pictures of fear-relevant animals

The observation that snakes and spiders are found faster among flowers and mushrooms than vice versa and that this search advantage is independent of set size supports the notion that fear-relevant stimuli are processed preferentially in a dedicated fear module. Experiment 1 replicated the faster identification of snakes and spiders but also found a set size effect in a blocked, but not in a mixed-trial, sequence. Experiment 2 failed to find faster identification of snake and spider deviants relative to other animals among flowers and mushrooms and provided evidence for a search advantage for pictures of animals, irrespective of their fear relevance. These findings suggest that results from the present visual search task cannot support the notion of preferential processing of fear relevance.     

The evil eye effect: vertical pupils are perceived as more threatening

Popular culture has many examples of evil characters having vertically pupilled eyes. Humans have a long evolutionary history of rivalry with snakes and their visual systems were evolved to rapidly detect snakes and snake-related cues. Considering such evolutionary background, we hypothesised that humans would perceive vertical pupils, which are characteristics of ambush predators including some of the snakes, as threatening. In seven studies (aggregate N?=?1458) conducted on samples from American and Turkish samples, we found that vertical pupils are perceived as more threatening on both explicit (Study 1) and implicit level (Studies 2–7) and they are associated with physical, rather than social, threat (Study 4). Findings provided partial support regarding our hypothesis about the relevance of snake detection processes: Snake phobia, and not spider phobia, was found to be related to perceiving vertical pupils as threatening (Study 5), however an experimental manipulation of saliency of snakes rendered no significant effect (Study 6) and a comparison of fears of snakes, alligators, and cats did not support our prediction (Study 7). We discuss the potential implications and limitations of these novel findings.     

Children's understandings of the attributes of life

Previous investigations of children's understandings of the life concept have focused on their classifications of the life status of familiar objects. In this study, we attempted to examine more directly the processes by which children infer life status by examining their reasoning about unfamiliar objects. In Experiment 1, 4- to 11-year-olds and adults were asked to name attributes of living things to establish which attributes they associated most closely with life. Children age 7 and younger most often named attributes true only of animals but not of plants; older children more often named attributes true of both animals and plants. However, movement was the single attribute cited most frequently by children of all ages tested. In Experiment 2, 4- to 11-year-olds and adults were presented information about attributes of imaginary objects on a distant planet and were asked to infer if those objects were alive. Again, young children relied relatively heavily on qualities true only of animals but not of plants, whereas older children relied more on attributes true of both plants and animals. Also as before, movement was viewed as indicative of life at all ages tested. In Experiment 3, we examined the hypothesis that children discriminate among different types of motion and that the types of motion they associate with life are in fact typical of living things. Children ranging from age 5 through 11 were found to discriminate among different types of motion and to infer that objects were alive only when they showed the types of motion typical of living beings. The results of Experiment 3 allowed interpretation of seemingly conflicting results that have arisen in previous studies, as well as in Experiments 1 and 2 of the present study.     

Context and Animal Behavior III: The Relationship Between Early Development and Evolutionary Persistence of Ground Squirrel Antisnake Behavior

California ground squirrel pups are frequent prey of northern Pacific rattlesnakes and Pacific gopher snakes. Although pups innately recognize that snakes are dangerous, they exhibit adult-like antisnake behaviors that are perilous. For the most part, adults apply antisnake behaviors to directly or indirectly protect pups. Two experiments using video investigated the evolutionary and developmental stability of antisnake behavior with the aim of identifying genetic and epigenetic factors that could account for its precocious, but dangerous expression. In Experiment 1, adult squirrels from Folsom Lake where rattlesnake and gopher snakes are abundant were compared with squirrels from Lake Tahoe and Mount Shasta where these snakes are absent and whose ancestors may have experienced relaxed selection from snakes spanning an estimated 300,000 years. Squirrels interacted with a caged rattlesnake or gopher snake for alternate 5-min trials in a laboratory setting. The results of this experiment revealed that the antisnake behaviors of Lake Tahoe and Mount Shasta squirrels were not substantially different from the Folsom Lake squirrels, a finding that suggests low heritability. In Experiment 2, lab-born pups from Folsom Lake were alternately exposed for 5-min trials to a caged gopher snake and guinea pig. The findings from this experiment indicated that visual recognition of snakes had a sharp onset at 40 to 41 days of age, the first day each pup showed evidence of pattern vision. In other rodents, this developmental period shortly after eye opening coincides with major dendritic growth and leveling off interneural connectivity in visual cortex. In ground squirrels, the early expression of antisnake behaviors that function more effectively in adults than in pups could reflect the requirements shaped by natural selection for the reliable emplacement of neural circuitry subserving snake recognition during the initial, less variable period of neuronal outgrowth.     

An Experimental Analysis of Operant Learning in the Parakeet

Twenty-five parakeets were used as subjects in a study involving food-rewarded operant learning. The parakeet behaved essentially in the same way as other birds (Leghorn chicken, Wyandotte chicken, pigeon, quail, turkey, etc.) with respect to number of rewarded reactions to criterion and percentage of animals learning. Parakeets, however, learned significantly faster than all other birds. These findings have implications within the framework of evolutionary comparative learning hypotheses.     

ATTITUDES TOWARD THE USE OF ANIMALS IN PSYCHOLOGICAL RESEARCH AND EDUCATION:

Abstract— This article reports the results of a national survey in which psychology majors were asked about the use of animals in psychological research and teaching. In general, the attitudes of psychology majors closely resembled the attitudes of practicing psychologists. Students tended to (a) support animal experiments involving observation or confinement, but disapprove of studies involving pain or death, (b) support mandatory pain assessments and the federal protection of rats, mice, pigeons, and reptiles, and (c) support the use of animals in teaching, but oppose an animal laboratory requirement for the psychology major. Opposition to the use of animals was greatest among women, among students at selective schools, and among students living in the Northeast/Mid-Atlantic region of the country.     

Selective associations in the observational conditioning of fear in rhesus monkeys

Three experiments explored the issue of selective associations in the observational conditioning of fear. Experiment 1 results indicated that observer rhesus monkeys acquired a fear of snakes through watching videotapes of model monkeys behaving fearfully with snakes. In Experiment 2, observers watched edited videotapes that showed models reacting either fearfully to toy snakes and nonfearfully to artificial flowers (SN+/FL-) or vice versa (FL+/SN-). SN+/FL- observers acquired a fear of snakes but not of flowers; FL+/SN- observers did not acquire a fear of either stimulus. In Experiment 3, monkeys solved complex appetitive discriminative (PAN) problems at comparable rates regardless of whether the discriminative stimuli were the videotaped snake or the flower stimuli used in Experiment 2. Thus, monkeys appear to selectively associate snakes with fear.     

Scanning the "Fringe" of consciousness: what is felt and what is not felt in intuitions about semantic coherence

In intuitions concerning semantic coherence participants are able to discriminate above chance whether a word triad has a common remote associate (coherent triad) or not (incoherent triad). These intuitions are driven by increased fluency in processing coherent triads compared to incoherent triads, which in turn triggers a brief and short positive affect. The present work investigates which of these internal cues, fluency or positive affect, is the actual cue underlying coherence intuitions. In Experiment 1, participants liked coherent word triads more than incoherent triads, but did not rate them as being more fluent in processing. In Experiment 2, participants could intuitively detect coherence when they misattributed fluency to an external source, but lost this intuitive ability when they misattributed affect. It is concluded that the coherence-induced fluency by itself is not consciously experienced and not used in the coherence intuitions, but the fluency-triggered affective consequences.     

The convergent evolution of neural substrates for cognition

This review describes a case of convergence in the evolution of brain and cognition. Both mammals and birds can organize their behavior flexibly over time and evolved similar cognitive skills. The avian forebrain displays no lamination that corresponds to the mammalian neocortex; hence, lamination does not seem to be a requirement for higher cognitive functions. In mammals, executive functions are associated with the prefrontal cortex. The corresponding structure in birds is the nidopallium caudolaterale. Anatomic, neurochemical, electrophysiologic and behavioral studies show these structures to be highly similar, but not homologous. Thus, despite the presence (mammals) or the absence (birds) of a laminated forebrain, ‘prefrontal’ areas in mammals and birds converged over evolutionary time into a highly similar neural architecture. The neuroarchitectonic degrees of freedom to create different neural architectures that generate identical prefrontal functions seem to be very limited.     

Developmental "Roots" in Mature Biological Knowledge

ABSTRACT— Young children tend to claim that moving artifacts and nonliving natural kinds are alive, but neglect to ascribe life to plants. This research tested whether adults exhibit similar confusions when verifying life status in a speeded classification task. Experiment 1 showed that undergraduates encounter greater difficulty (reduced accuracy and increased response times) in determining life status for plants, relative to animals, and for natural and moving nonliving things, relative to artifacts and nonmoving things. Experiment 2 replicated these effects in university biology professors. The professors showed a significantly reduced effect size for living things, as compared with the students, but still showed greater difficulty for plants than animals, even as no differences from the students were apparent in their responses to nonliving things. These results suggest that mature biological knowledge relies on a developmental foundation that is not radically overwritten or erased with the profound conceptual changes that accompany mastery of the domain.     

Emotion and intuition

We investigated effects of emotional states on the ability to make intuitive judgments about the semantic coherence of word triads. Participants were presented word triads, consisting of three clue words that either were weakly associated with a common fourth concept (coherent triads) or had no common associate (incoherent triads). In Experiment 1, participants in a neutral mood discriminated coherent and incoherent triads reliably better than chance level even if they did not consciously retrieve the solution word. In Experiment 2, the induction of a positive mood reliably improved intuitive coherence judgments, whereas participants in a negative mood performed at chance level. We conclude that positive mood potentiates spread of activation to weak or remote associates in memory, thereby improving intuitive coherence judgments. By contrast, negative mood appears to restrict spread of activation to close associates and dominant word meanings, thus impairing intuitive coherence judgments.     

Lateralized cognition: asymmetrical and complementary strategies of pigeons during discrimination of the "human concept"

This study was aimed at revealing which cognitive processes are lateralized in visual categorizations of "humans" by pigeons. To this end, pigeons were trained to categorize pictures of humans and then tested binocularly or monocularly (left or right eye) on the learned categorization and for transfer to novel exemplars (Experiment 1). Subsequent tests examined whether they relied on memorized features or on a conceptual strategy, using stimuli composed of new combinations of familiar and novel humans and backgrounds (Experiment 2), whether the hemispheres processed global or local information, using pictures with different levels of scrambling (Experiment 3), and whether they attended to configuration, using distorted human figures (Experiment 4). The results suggest that the left hemisphere employs a category strategy and concentrates on local features, while the right hemisphere uses an exemplar strategy and relies on configuration. These cognitive dichotomies of the cerebral hemispheres are largely shared by humans, suggesting that lateralized cognitive systems already defined the neural architecture of the common ancestor of birds and mammals.