Call-note discriminations in black-capped chickadees (Poecile atricapillus).

Bioacousticians (M. S. Ficken, S. R. Ficken, & S. R. Witken, 1978) classified black-capped chickadee call notes from the chick-a-dee call complex into 4 note types (A, B, C, and D) identified from sound spectrograms. In Experiment 1, chickadees (Poecile atricapillus) learned operant auditory discriminations both within and between the 4 note types but learned the between note-type discrimination significantly faster. In Experiment 2, when the original, unrewarded between-category exemplars were replaced with novel, rewarded exemplars of these same categories, chickadees showed transfer of inhibitory stimulus control to the novel exemplars. In Experiment 3, when novel exemplars were replaced by the original exemplars, chickadees showed propagation of positive stimulus control back to the original exemplars. This evidence suggests that chickadees and bioacousticians accurately sort conspecific call notes into the same open-ended categories (R. J. Hernstein, 1990). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acoustic Mechanisms of Note-Type Perception in Black-Capped Chickadee (Poecile atricapillus) Calls.

Acoustic communication in black-capped chickadees (Poecile atricapillus) has been studied intensively, the "chick-a-dee" call being among the most well described. This call consists of 4 note types; chickadees perceive these notes as open-ended categories and do so in a continuous manner, with As more similar to Bs and Bs more similar to Cs. Acoustic features contributing to the note-type differentiation are unknown. Recent analyses suggested that certain acoustic features may play a role in note-type classification. Here, the authors tested black-capped chickadees in an operant-conditioning paradigm to determine which features were controlling note-type perception. The results suggest that the note pitch and the frequency modulation in the initial portion of the note control the perception of note types. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Open-ended categorization of chick-a-dee calls by black-capped chickadees (Poecile atricapilla).

The authors trained black-capped chickadees (Poecile atricapilla) in an operant discrimination with exemplars of black-capped and Carolina chick-a-dee calls, with the goal of determining whether the birds memorized the calls of conspecifics and heterospecifics or classified the calls by species. Black-capped calls served as both rewarded (S+) and unrewarded (S-) stimuli (the within-category discrimination), whereas Carolina chick-a-dee calls served as S-s (the between-category discrimination) in the black-capped chick-a-dee call S+ group. The Carolina call S+ group had Carolina calls as S+s and S-s (within-category) and black-capped calls as S-s (between-category). Both groups discriminated between call categories faster than within a call category. In 2 subsequent experiments, both S+ groups showed transfer to novel calls and propagation back to between-category calls. The results favor the hypothesis that the acoustically similar social calls of the 2 species constitute separate open-ended categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group size and social interactions are associated with calling behavior in Carolina chickadees (Poecile carolinensis).

The complexity of a social group may influence the vocal behavior of group members. Recent evidence in Carolina chickadees, Poecile carolinensis, indicated that one component of social complexity, group size, influenced the complexity of the "chick-a-dee" call, a vocalization functioning in social cohesion. Individuals in larger social groups used calls with greater information than did individuals in smaller social groups. Here, the authors review this earlier work, and describe a recent study indicating that social interactions between females and males within female-male pairs of chickadees were associated with rates of chick-a-dee call production in the males. Together, these studies suggest that the nature and complexity of social interactions among members of chickadee social groups influence chick-a-dee calling behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Statistical classification of black-capped (Poecile atricapillus) and mountain chickadee (Poecile gambeli) call notes.

Both black-capped (Poecile atricapillus) and mountain chickadees (Poecile gambeli) produce a chick-a-dee call that consists of several distinct note types. In some regions, these 2 species live sympatrically, and it has been shown that 1 species will respond weakly to songs of the other. This suggests that chickadee song, and potentially other of their vocalizations, contains species-specific information. We tested the possibility that call notes were acoustically sufficient for species identification. Black-capped and mountain non-D notes were summarized as a set of 9 features and then analyzed by linear discriminant analysis. Linear discriminant analysis was able to use these notes to identify species with 100% accuracy. We repeated this approach, but with black-capped and mountain D notes that were summarized as a set of 4 features. Linear discriminant analysis was able to use these notes to identify species with 94% accuracy. This demonstrates that any of the note types in these chickadee calls possesses sufficient information for species classification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neural network modeling of developmental effects in discrimination shifts

This paper presents neural network simulations of developmental phenomena in discrimination shifts. The discrimination shift literature is reviewed in order to identify the empirical regularities. Leading theoretical accounts of the development of shift learning are reviewed, and the lack of a thorough account is highlighted. Recent unsuccessful neural network simulations of shift learning are also reviewed. New simulations, using the cascade-correlation algorithm, show that networks can capture the regularities of the discrimination shift literature better than existing psychological theories. Manipulation of the amount of training that networks receive, which affects depth of learning, simulates developmental phenomena. It is suggested that human developmental differences in shift learning arise from spontaneous overtraining by older participants, an interpretation consistent with the overtraining literature.     

Pitch discrimination in field- and isolation-reared black-capped chickadees (Parus atricapillus).

Prior research has shown that male black-capped chickadees (Parus atricapillus) raised in the field produce constant relative pitch cues (frequency ratios) in their songs, whereas males reared in isolation from adult song do not. In this study, the authors found that field-reared male chickadees needed fewer than half as many sessions to learn an operant (go/no-go) auditory discrimination that linked S+ note pairs with a constant-frequency ratio than a discrimination that varied the frequency ratio of S+ pairs randomly. Most important, isolation-reared males needed over 5 times as many sessions to learn the constant-ratio discrimination compared with field-reared males. This is, to the authors' knowledge, the first report of impaired pitch discrimination in isolate songbirds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of species identification in ducklings: IV. Change in species-specific perception caused by auditory deprivation.

Four experiments attempted to identify the change in species-specific perception that underlies aurally deprived Peking ducklings' (Anas platyrhynchos) lack of preference or discrimination in the mallard vs chicken call test. Among other acoustic differences, the mallard and chicken maternal calls differed in repetition rate (3.7 and 2.3 notes/sec, respectively). Results show the dimension of repetition rate to be uppermost in the perceptual hierarchy underlying the auditory aspect of species identification in Peking ducklings. The relatively narrow species-typical repetition-rate preferences of normal Peking ducklings (about 4–6 notes/sec) were lacking in the aurally deprived ducklings, and they responded to lower rates than usual (2.3 notes/sec). This broadening of the range of responsiveness on a perceptual dimension (repetition rate) that is basic to species identification accounts for the devocal ducklings' lack of discrimination in the mallard vs chicken call test. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Peak shift: A review.

Reviews the peak-shift literature in relation to operant and classical conditioning procedures, errorless discrimination training, and physiological studies. Results indicate that peak shift is a reliable behavioral phenomenon affected by stimulus dimension, positive-negative stimulus separation, training procedure, and testing procedure. There are many concepts (e.g., inhibition and excitation), behavioral phenomena (e.g., behavioral contrast and negative peak shift), and experimental procedures (e.g., reinforcement density-frequency, successive training, and simultaneous training) interwoven throughout the peak-shift literature. Many questions have been raised regarding these aspects of peak shift yet few questions have been answered to date. (96 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do ability-performance relationships differentiate age and practice effects in visual search?

Investigated relationships between abilities and performance in visual search for 70 young (aged 17–31 yrs) and 70 old adults (aged 65–80 yrs). Ss received extensive practice on a category search task. A consistent version allowed development of an automatic attention response; a varied version allowed general performance improvements. Transfer conditions assessed learning. General ability, induction, semantic knowledge, working memory, perceptual speed, semantic memory access, and psychomotor speed were assessed. LISREL models revealed that general ability and semantic memory access predicted initial performance for both age groups. Improvements on both the consistent and the varied tasks were predicted by perceptual speed. Ability–performance relationships indexed performance changes but were not predictive of learning (i.e., automatic process vs general efficiency). Qualitative differences in the ability-transfer models suggest age differences in learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Location serves as a conditional cue when harp seals (Pagophilus groenlandicus) solve object discrimination reversal problems.

We examined the capacity of harp seals (Pagophilus groenlandicus) to use spatial context (i.e., their tank) as a conditional cue to solve a two-choice visual discrimination reversal task. Seals were trained to touch one of two 3D objects. Two of four seals experienced a context shift that coincided with each of five reversals in the reward value of the two stimuli (i.e., a reversal of S+ and S-); these seals solved the six discriminations in significantly fewer trials than did seals that did not experience a context shift with the contingency reversal. Thus, harp seals use contextual cues when encoding information. The findings are discussed in terms of harp seals' adaptations to the pack-ice environment, the constraints of the learning tasks, and the nature of the subjects that were raised in captivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Crystallized verbal skills in schizophrenia: Relationship to neurocognition, symptoms, and functional status.

Objective: To study the relationship of superior (i.e., ≥ 90th percentile), average (11th?89th percentile) or extremely low (i.e., ≤ 10th percentile) crystallized verbal skills to neurocognitive profiles, symptoms and everyday life function in schizophrenia. Method: Crystallized verbal skill was derived from Vocabulary subtest scores from the Wechsler Adult Intelligence Scale (WAIS). Out of a sample of 165 stable outpatients with schizophrenia we identified 25 participants with superior crystallized verbal skill, 104 participants with average verbal skill, and 36 participants with extremely low crystallized verbal skill. Each participant was administered measures of attention, working memory, verbal learning and memory, problem-solving and processing speed, as well as symptom and performance-based adaptive life skill assessments. Results: The magnitude of neuropsychological impairment across the three groups was different, after adjusting for group differences in education and duration of illness. Working memory, and verbal learning and memory skills were different across all three groups, while processing speed differentiated the extremely low verbal skill group from the other two groups and problem-solving differentiated the very low verbal skill group from the superior verbal skill group. There were no group differences in sustained attention. Capacity measures of everyday life skills were different across each of the three groups. Conclusion: Crystallized verbal skill in schizophrenia is related to the magnitude of impairment in neurocognitive function and performance-based skills in everyday life function. Patterns of neuropsychological impairment were similar across different levels of crystallized verbal skill. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Suicide notes of adolescents: A life-span comparison.

Utilizing suicide notes as the data source, this study begins to explore some psychological dimensions in adolescent suicide and to identify the differences and similarities of suicide across the life span. 80 notes, representing 4 developmental ages (i.e., adolescents, young adults, middle adults, old adults) were analyzed for specific protocols on 8 categories (i.e., unbearable pain, cognitive constriction, indirect expressions, inability to adjust, ego, interpersonal relations, rejection-aggression, and identification-egression). Despite similarities, the results identify that the suicide of teens may be more highly related to cognitive constriction, indirect expressions, rejection-aggression, and identification-egression, than other age groups. Further research beyond the suicides' own narratives (e.g., third-party interviews, study of attempters) is needed to replicate and extend the current findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individualistic and collectivistic worldviews: Implications for understanding perceptions of racial discrimination in African Americans and British Caribbean Americans.

Cultural worldviews and perceived racial discrimination were examined among Americans (n = 106) and British Caribbean Americans (n = 95), both of African descent, who were recruited through university student organizations, community organizations, and snowball sampling. Consistent with public perceptions of differences in the experience of race among these 2 groups, multiple regression analyses revealed African Americans were more likely than British Caribbean Americans to perceive racial discrimination in the United States. In addition, a cultural worldview focus on individuality and equality (i.e., horizontal individualism) moderated the relationship between ethnic group and perceived racial discrimination. British Caribbean Americans who endorsed greater agreement with horizontal individualism were less likely to perceive racial discrimination. The same worldview was unrelated to African Americans' perceptions of racial discrimination. The results are discussed with respect to within-group heterogeneity among persons of African descent. Implications for counseling persons of African descent and future research directions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reaction to punishment, reflectivity, and passive avoidance learning in extraverts.

Passive avoidance learning occupies a central role in accounts of disinhibited behavior, ranging from psychopaths' persistent criminality (Hare, 1970) to extraverts' gregariousness (Gray, 1972). To explore the mechanism underlying passive avoidance deficits, we assessed the relation of extraversion, neuroticism, and response latency after punishment to passive avoidance learning by using two successive go/no go discrimination tasks. The tasks were designed to examine two aspects of subjects' reactions to punishment: response speed on trials immediately following punishment (Experiment 1) and time to terminate punishment feedback between successive trials (i.e., reflectivity; Experiment 2). Consistent with previous findings, the results of Experiment 1 showed that extraverts commit more passive avoidance errors than introverts do (Newman, Widom, & Nathan, 1985) and fail to pause following punished errors (Nichols & Newman, 1986). In Experiment 2, only neurotic extraverts displayed this pattern of performance differences. In both experiments, longer pausing following punishment predicted better learning from punishment for both introverts and extraverts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency-range discriminations and absolute pitch in black-capped chickadees (Poecile atricapillus), mountain chickadees (Poecile gambeli), and zebra finches (Taeniopygia guttata).

The acoustic frequency ranges in birdsongs provide important absolute pitch cues for the recognition of conspecifics. Black-capped chickadees (Poecile atricapillus), mountain chickadees (Poecile gambeli), and zebra finches (Taeniopygia guttata) were trained to sort tones contiguous in frequency into 8 ranges on the basis of associations between response to the tones in each range and reward. All 3 species acquired accurate frequency-range discriminations, but zebra finches acquired the discrimination in fewer trials and to a higher standard than black-capped or mountain chickadees, which did not differ appreciably in the discrimination. Chickadees' relatively poorer accuracy was traced to poorer discrimination of tones in the higher frequency ranges. During transfer tests, the discrimination generalized to novel tones when the training tones were included, but not when they were omitted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of prestriate, inferotemporal, and superior temporal sulcus lesions on attention and gaze shifts in rhesus monkeys.

Studied the role of extrastriate cortical areas in selective attention in 12 rhesus monkeys. Ss learned a series of color–form pattern discrimination problems, with either color or form cues relevant. After each problem was mastered, correct behavior required a shift in attention (i.e., that responses be made to the previously irrelevant dimension). On some problems shifting attention required that the S maintain the same fixation; on other problems the color and form cues were separated in space, and the attention shift presumably required a shift in gaze. Matched groups of Ss with inferotemporal, prestriate, or superior temporal sulcus lesions, and normal controls, differed significantly in their ability to shift attention. Analyses of inferred stages in attention shift showed that different processes were disturbed in the 3 lesion groups. Results are discussed in terms of cortical substrates for "looking" and "seeing." (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What is learned in note taking?

Two experiments with 130 undergraduates investigated the effects of note taking and reviewing on learning from text. Findings support the encoding function of note taking and demonstrate that unguided elaboration hindered performance on teacher-made tests. When delayed tests were based on S's own notes, average scores were nearly twice as high as when test were based on either teacher selection of test material or on other Ss' notes (for all reviewing treatments). Interpretations are in terms of metacognitions related to taking notes, transfer-appropriate processing, and the requirements necessary for elaboration to be an effective learning strategy. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Somatosensory Processing and Schizophrenia Liability: Proprioception, Exteroceptive Sensitivity, and Graphesthesia Performance in the Biological Relatives of Schizophrenia Patients.

In the present study, the authors examined somatosensory processing in 30 biological relatives of persons with schizophrenia (hereafter called "schizophrenia relatives"), 30 biological relatives of persons with bipolar affective disorder (psychiatric family control subjects), and 30 healthy control subjects with no family history of psychopathology. All 3 groups completed a weight discrimination task, a 2-point discrimination task, and a complex cognitive somatosensory task (i.e., graphesthesia). The schizophrenia relatives performed significantly worse on all 3 somatosensory tasks compared with both the healthy control subjects and the bipolar relatives. The healthy control subjects and psychiatric family control subjects showed no significant differences on any of the somatosensory tasks. Within the weight discrimination and 2-point discrimination tasks, schizophrenia relatives showed group differences on the d' index, the measure of sensitivity, whereas all 3 groups did not differ on lnβ, the measure of response bias, suggesting a genuine difference in weight and touch sensitivity. The d' value of the weight discrimination task was significantly associated with both the cognitive-perceptual factor and negative symptom factor of the clinical questionnaire (e.g., Schizotypal Personality Questionnaire; SPQ), whereas the 2-point discrimination d' value and graphesthesia scores were significantly associated only with the cognitive-perceptual factor of the SPQ. Implications for the possible relation between somatosensory task performance and schizophrenia liability are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correction to Rushton and Jensen (2005).

Reports an error in the original article by J. Philippe Rushton and Arthur R. Jensen (Psychology, Public Policy, and Law, 2005[Jun], Vol 11[2], pp. 235-294). An equation on p. 271 was incorrect. In the note to Table 5 on p. 273, a similar equation was incorrect. Finally, on p. 274, the last line of the first paragraph was incorrect. Corrections are published here. (The following abstract of this article originally appeared in record 2005-03637-001.) The culture-only (0% genetic-100% environmental) and the hereditarian (50% genetic-50% environmental) models of the causes of mean Black-White differences in cognitive ability are compared and contrasted across 10 categories of evidence: the worldwide distribution of test scores, g factor of mental ability, heritability, brain size and cognitive ability, transracial adoption, racial admixture, regression, related life-history traits, human origins research, and hypothesized environmental variables. The new evidence reviewed here points to some genetic component in Black-White differences in mean IQ. The implication for public policy is that the discrimination model (i.e., Black-White differences in socially valued outcomes will be equal barring discrimination) must be tempered by a distributional model (i.e., Black-White outcomes reflect underlying group characteristics). (PsycINFO Database Record (c) 2010 APA, all rights reserved)