Visual perception of biological motion in newly hatched chicks as revealed by an imprinting procedure

Day-old chicks were exposed to point-light animation sequences depicting either a walking hen or a rotating cylinder. On a subsequent free-choice test (experiment 1) the chicks approached the novel stimulus, irrespective of this being the hen or the cylinder. In order to obtain equivalent local motion vectors, in experiments 2 and 3 newly hatched chicks were exposed either to a point-light animation sequence depicting a walking hen, or to a positionally scrambled walking hen (i.e. an animation in which exactly the same set of dots in motion as that employed for the walking hen was presented, but with spatially randomized starting positions). Chicks tested on day 1 (experiment 2) or on day 2 (i.e. after a period in the dark following exposure on day 1 (experiment 3)) proved able to discriminate the two animation sequences: males preferentially approached the novel stimulus, females the familiar one. These results indicate that discrimination was not based on local motion vectors, but rather on the temporally integrated motion sequence. Received: 18 August 1999 / Accepted after revision: 14 March 2000     

Preference for biological motion in domestic chicks: sex-dependent effect of early visual experience

To examine the effects of early visual experience on preference for biological motion (BM), newly hatched chicks were exposed to a point-light animation (a visual stimulus composed of identical light points) depicting the following features of a hen: a walking hen (a BM stimulus), a rotating hen (a non-BM stimulus), a pendulum stimulus, a random motion stimulus and a stationary pattern. Chicks were then tested in a binary choice task, choosing between walking-hen and rotating-hen stimuli. Males exhibited a preference for BM if they had been trained with any animation except the stationary pattern stimulus, suggesting that the BM preference was not learned, but induced by motion stimuli. We found a significant positive correlation between the number of approaches in training and the preference in the test, but locomotion alone did not cause preference for BM. In contrast, females exhibited a particularly strong preference for walking-hen stimuli, but only when they had been trained with it. Furthermore, females (but not males) trained with random motion showed a preference for walking hen over walking cat (a biological motion animation depicting a cat), possibly suggesting that females are choosier than males. Chicks trained with a stationary pattern and untrained controls did not show a significant preference. The induction of BM preference is discussed in terms of possible ecological background of the sex differences.     

Acquaintance and the Problem of the Speckled Hen

This paper responds to Ernest Sosa’s recent criticism of Richard Fumerton’s acquaintance theory. Sosa argues that Fumerton’s account of non-inferential justification falls prey to the problem of the speckled hen. I argue that Sosa’s criticisms are both illuminating and interesting but that Fumerton’s theory can escape the problem of the speckled hen. More generally, the paper shows that an internalist account of non-inferential justification can survive the powerful objections of the Sellarsian dilemma and the problem of the speckled hen.     

Androgen mediation of conditioned rhythmic cloacal sphincter movements in Japanese Quail (Coturnix japonica)

Demonstrations of increased reproductive success due to sexual conditioning in Japanese quail (Coturnix japonica) have been reported, although the mechanisms that underlie these effects have remained elusive. One possible mechanism is conditioned rhythmic cloacal sphincter movements (RCSM). Two experiments were conducted with male quail to determine whether associations between a conditioned stimulus (CS) and a hen would result in the ability of the CS to elicit RCSM, and to explore the androgen mediation of conditioned RCSM. The results suggest that a focal CS paired with visual access to a female will elicit RCSM via a representation of the hen activated by the CS. Further, the available evidence indicates that conditioned RCSM is androgen mediated and that this learning may transfer across breeding seasons.     

Social interaction with siblings is necessary for visual imprinting of species-specific maternal preferences in ducklings (Anas platyrhynchos)

This study was conducted to examine the influence of various social rearing experiences on the development of imprinted visual maternal preferences in domestic mallard ducklings (Anas platyrhynchos) during the first 3 days of postnatal life. Twenty-four-hour-old ducklings were allowed to follow a stuffed mallard hen for 30 min. This experience resulted in a visual preference for the familiar mallard hen over an unfamiliar stuffed redhead (Aythya americana) hen in simultaneous choice tests at 48 hr and 72 hr only if the ducklings were reared in conditions allowing unrestricted social interaction with siblings, as would normally occur in nature. No visual preference for the familiar mallard model was found at 48 hr or at 72 hr if ducklings were reared in social isolation but allowed to see another duckling, reared with one duckling, or reared in a group of ducklings but denied the opportunity for direct social interaction. These results demonstrate the importance of normal social experience in the development of the visual imprinting of filial behavior in ducklings. Imprinting studies have traditionally employed isolation rearing and ignored the precocial bird's natural social context. Thus, the present findings raise doubts about the appropriateness of the usual methods of studying imprinting in the laboratory for an understanding of the process of filial imprinting in nature.     

Neuromagnetic signals associated with reading a kanji character formed by combining two kanji radicals

To find out which brain regions are responsible for the mental construction and recognition of a kanji character initiated by visually presented kanji radicals, rather than by information retained in the memory, a left hen radical and the corresponding right tsukuri radical were simultaneously presented randomly to either the left or right visual field of seven subjects. Thirty left hen radicals and the corresponding right tsukuri radicals were prepared as stimuli; this combination formed over 500 real or pseudo kanji characters. Instead of their usual left and right positions, the left hen radical was always presented above the right tsukuri radical. As quickly and correctly as possible, the subjects released a key when two kanji radicals constituted a single real kanji character and released another key otherwise. We recorded neuromagnetic responses as well as accuracy and reaction time. Left visual field superiority was observed as regards accuracy. This is in good agreement with previous neuropsychological results. Equivalent current dipoles were localized mainly in the left and/or right occipitotemporal regions (ventral visual pathways), the bilateral occipitoparietal regions (dorsal visual pathways) including the supramarginal region, and the areas surrounding the left superior temporal cortex. We suggest that these regions are related to reading and the mental construction of a kanji character from its radicals.     

Maternal hen calls modulate memory formation in the day-old chick: the role of noradrenaline

Facilitation of memory for discriminative learning in young chicks is enhanced following exposure to a synthesized rhythmic auditory stimulus. Increased arousal, mediated by noradrenergic activation, is believed to underlie this effect. In this report we examine whether ethologically relevant rhythmic auditory stimuli produce the same noradrenaline-mediated memory enhancement in neonate chicks (Gallus gallus domesticus). Maternal hen attraction calls which contained a rhythmic pattern were found to facilitate retention. Intracerebral injection of noradrenaline or the beta(2)-adrenergic antagonist propranolol demonstrated that this enhancement is likely to be mediated by noradrenergic activation of central beta(2)-noradrenergic receptors. In contrast, a rhythmic alarm call inhibited retention. Subcutaneous injection of the alpha(1)-adrenergic antagonist prazosin revealed that this impairment may be due to higher arousal levels resulting in activation of alpha(1)-noradrenergic receptors. It is concluded that the maternal hen calls of domestic chickens can influence the memory ability of the offspring via noradrenaline release in the brain. The current data suggest that call meaning and rhythmicity interact to yield the appropriate levels of beta(2)-adrenergic activation required to facilitate retention for a discriminative task.     

Influence of IQ in interpreting MMSE scores in patients with multiple sclerosis

The Mini-Mental State Examination (MMSE) and Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) were administered to 46 outpatients diagnosed with multiple sclerosis (MS). MMSE total raw score was significantly and positively correlated with all WAIS-IV indexes, even when controlling for the effects of participant educational level, with the strongest relationship being with Full Scale IQ. These results suggest that clinicians consider patient intellectual functioning, in particular Full Scale IQ, when diagnosing neurocognitive impairment based on screening with the MMSE in individuals with MS.     

Correlations for number of sunspots, unemployment rate, and suicide mortality in Japan

We studied the correlations among sunspot numbers, business cycles, and suicide mortalitites. Based on data from Japan between 1971 and 2001, a significant negative correlation between sunspot numbers and unemployment rate was found, R= -.17. The correlation between suicide mortality and unemployment rate was positive for males (R=.46) and negative for females (R =-.69). Both are statistically significant. The hypothesis that variation of sun activity may affect the economy and the unemployment rate and hence increase the male suicide mortality is raised.     

Grounding Perceptual Dogmatism: What are Perceptual Seemings?

Perceptual Dogmatism (PD) holds that if it perceptually seems to S that p, then S has immediate prima facie justification for the belief that p. Various philosophers have made the notion of a perceptual seeming more precise by distinguishing perceptual seemings from both sensations and beliefs to accommodate a) the epistemic difference between perceptual judgments of novices and experts, and, b) the problem of the speckled hen. Using somewhat different terminology, perceptual seemings are supposed to be high‐level percepts instead of low‐level sensations. I argue that although it is right that perceptual seemings should not be identified with sensations, they should also not be identified with percepts. There is no strong reason to assume that sensations and percepts exist as separate conscious states, and it appears therefore best to identify perceptual seemings simply with perceptual experiences interpreted as entities incorporating aspects from both sensations and percepts. However, even with this plausible identification in hand, the speckled hen will remain problematic for PD.     

Prejudiced or not? Hidden sectarianism among students in Northern Ireland

The authors developed a new measure of implicit prejudices of students in Northern Ireland, which they derived from a study by G. Haddock, M. Zanna, and V. M. Esses (1993). Using two student surveys, the authors modified and tested the new implicit prejudice measure, which was based on a "Budget Survey." The present study's results indicate that the measure is valid and useful in the student context. Investigators can easily adapt the measure to groups other than students in Northern Ireland, and it may hence be useful for the future investigation of hidden prejudice in a society that experiences low-level ethnopolitical conflict.     

Tacit Integration and Referential Structure in the Language Comprehension of Aphasics and Normals

Aphasics, brain-damaged patients with no language deficit, neurologically intact elderly subjects, and university undergraduates matched pictures to sentences having compelling tacit implications (e.g., the sentence The fox grabs the hen strongly invites one to assume that the fox will eat the hen). All groups made, for the same sentences, qualitatively similar referential errors consisting in choosing a tacit implication picture. Two auxiliary experiments using the same target sentences in other interpretive situations permitted ruling out the possibility that these errors were due to the putative intrinsic semantic properties of the sentences, showing that the sentences which were most liable to elicit integrative error varied from task to task. These results are interpreted within the conceptual framework which posits that reliable directions for interpretation are couched by the speaker in the very structure of his utterances (the utterance's referential structure) providing the hearer with means to restructure the relevant personal knowledge integrated into the interpretive process in accordance with the speaker's communicative intent. The determination of the referential structure (RSD) of utterances thus seems critical to their correct or, more precisely, conventional interpretation, and, along with the tacit integration of relevant sources of personal knowledge, constitutes the principal cognitive device enabling us to understand each other. But this device appears to be easily corruptible. It is suggested that many errors made by aphasics in language interpretation are due to a failure to follow all referential instructions, but that qualitatively similar failures also occur in normal subjects, though to a lesser degree. Language interpretation is a fallible process and aphasic errors provide remarkable clues for the understanding of its subtle referential mechanisms.     

Phenomenal background frequency and the concreteness/imagery effect in verbal discrimination learning

College students gave frequency ratings for concrete and abstract words which were equated on normative frequency. The results replicated the finding of Galbraith and Underwood (1973) that abstract words are perceived to be higher in frequency than concrete words. Different subjects then learned verbal discrimination lists consisting of both abstract and concrete pairs. While the usual concreteness effect was obtained when abstract and concrete items differed widely on phenomenal frequency, it disappeared when these items were equated on perceived frequency. The finding that appropriate frequency manipulations can eliminate the concreteness/imagery effect, coupled with similar findings for other stimulus characteristics, lends strong support to the frequency theory of discrimination learning.     

Principles of Behavioral Assessment and Management of “Life-Threatening Behavior” in Dialectical Behavior Therapy

Dialectical behavior therapy (DBT) in its initial iteration was developed for the treatment of suicidal and self-injuring adults. As a result, the assessment and management of suicidal and nonsuicidal self-injurious (NSSI) behavior was and is central to the conduct of standard DBT. In this paper the authors describe the DBT approach to suicide risk assessment including discussion of both comprehensive and targeted suicide risk assessment and the associated documentation. In addition, it describes when and when not to conduct such assessment. Finally, this article describes management of both imminent and distant suicide risk and the application of DBT treatment strategies that can be applied in session.     

When you and I are "we," you are not threatening: the role of self-expansion in social comparison

Many theories of self-evaluation emphasize the power of social comparison. Simply put, an individual is thought to gain esteem whenever she or he outperforms others and to lose esteem when he or she is outperformed. The current research explored interdependent self-construal as a moderator of these effects. Two studies used a priming task to manipulate the level of self-construal and investigate effects of social comparison in dyadic (Study 1) and group situations (Study 2). Both studies demonstrated that when the target for comparison is construed as part of the self, his or her successes become cause for celebration rather than costs to esteem. Additionally, gender differences in chronic relational and collective self-construals moderated the patterns of social comparison in a form similar to that of priming relational and collective self-construals.     

A meta-analytic study of self-help interventions for anxiety problems

The present study examined the effectiveness of self-help (SH) interventions for individuals with anxiety problems. Thirty-three studies, targeting a variety of anxiety disorders and problems, met criteria for inclusion with 1,582 clinical and subclinical participants. Self-help formats included books, audio/videotapes, and computer/Internet-based programs. The average effect sizes (Cohen's ds) comparing SH interventions to control groups for target symptoms were .62 at posttreatment and .51 at follow-up. When compared to therapist-directed interventions (TDIs), the average effect sizes (Cohen's ds) for target problems were -.42 at posttreatment and -.36 at follow-up. Format of SH materials, type of target disorder, presence of minimal therapist contact, and other study parameters were examined for their effect on treatment outcome. The results were discussed from the perspective of a stepped-care approach for anxiety problems.     

Internal and external factors modulate food-calling in domestic hens

Two series of experiments investigated factors affecting utterance of food calls in the domestic hen, Gallus domesticus. The first series of experiments tested the effect of food preference and the hen’s internal state on the utterance of food calls. Different food types were presented first singly and then in a choice test to 20 hens, first when hens were laying, and then when they were maternal. The second series of experiments tested the effect of hunger level on the utterance of food calls in laying hens, and maternal hens with or without chicks. These two series of experiments showed that laying hens and maternal hens showed a similar marked preference for certain types of food, but laying hens very rarely emitted food calls, in contrast to maternal hens. This shows the effect of the bird’s psychophysiological state on her tendency to emit food calls. The more a maternal hen preferred a food type, the more food calls she emitted. This was observed from the beginning of a test in single-food tests as well as in choice tests. Hunger level positively affected food-call production under certain feeding conditions in maternal hens, but not in laying hens. When maternal hens were tested in the absence of their chicks, utterance of food calls was more sustained than in the presence of chicks. Received: 14 May 1998 / Accepted after revision: 11 October 1998     

Attention and expectation in human predictive learning: the role of uncertainty

Three localized, visual pattern stimuli were trained as predictive signals of auditory outcomes. One signal partially predicted an aversive noise in Experiment 1 and a neutral tone in Experiment 2, whereas the other signals consistently predicted either the occurrence or absence of the noise. The expectation of the noise was measured during each signal presentation, and only participants for whom this expectation demonstrated contingency knowledge showed differential attention to the signals. Importantly, when attention was measured by visual fixations, the contingency-aware group attended more to the partially predictive signal than to the consistent predictors in both experiments. This profile of visual attention supports the Pearce and Hall (1980) theory of the role of attention in associative learning.     

The Unmaking of Prejudice: How Christian Beliefs Relate to Attitudes Toward Homosexuals

We propose that the internalization of orthodox Christian beliefs serves as a basis for a personal moral standard that discourages prejudice against others as well as for self-critical emotions that follow upon behaving in a discriminatory manner. Two correlational studies tested hypotheses derived from our theory. Study 1 demonstrated that to the extent people endorse orthodox Christian beliefs, they report an internal motivation to respond without prejudice toward homosexuals. Study 2 demonstrated that, when controlling for the effects of right-wing authoritarianism (RWA), endorsement of orthodox Christian beliefs was related to positive attitudes toward homosexuals as individuals or as a group, but not toward homosexuality as a behavior or lifestyle.