An investigation of reversal learning in octopus vulgaris lamarck

Eighteen octopuses were trained by a method of successive discrimination training to discriminate between a vertical and a horizontal rectangle. They were then overtrained for either 20 or 60 trials, after which they learnt the reverse discrimination. At the beginning of each reversal they were given 20 trials pretraining on the new positive stimulus. The subjects completed from two to nine reversals.

It was found that the amount of overtraining had no effect on the rate of learning the subsequent reversal. The first four reversals all took significantly longer to learn than the original problem, but did not differ significantly from one another. However, examination of the raw data suggests that later reversals do take longer to learn. The performance when learnt (i.e. on the first day of overtraining) was as good after reversal learning as after the learning of the original problem.

The results do not show definite signs that could be interpreted as an exhaustion of a limited supply of neurones available for learning.     

Reversal learning in octopus vulgaris lamarck with and without irrelevant cues

Three groups of eight octopuses each were trained on a brightness discrimination and its reversal. Within each group half the animals were overtrained on the original problem and half were not. For Group I the discrimination was a simple one, for the other two groups irrelevant cues were introduced (for Group II position and for Group III orientation).

It was found that the overtrained animals learnt the reversal significantly faster than the non-overtrained only where irrelevant cues were present (i.e. only in Groups II and III). The results are discussed in relation to various theories of discrimination reversal.     

The role of stimulus preexposure in problem solving by Octopus vulgaris

Octopus vulgaris is able to open transparent glass jars closed with plastic plugs and containing live crabs. The decrease in performance times for removing the plug and seizing the prey with increasing experience of the task has been taken to indicate learning. However, octopuses’ attack behaviors are typically slow and variable in novel environmental situations. In this study the role of preexposure to selected features of the problem-solving context was investigated. Although octopuses failed to benefit from greater familiarity with the training context or with selected elements of the task of solving the jar problem, the methodological strategies used are instructive in potentially clarifying the role of complex problem-solving behaviors in this species including stimulus preexposure and social learning. Received: 27 April 1998 / Accepted after revision: 24 July 1998     

Contrasting speech patterns in apraxia of speech and phonemic paraphasia

This study was designed to determine if perceptual phonological analysis would reveal distinctions between patients with apraxia of speech and patients with phonemic paraphasic speech. Test findings from 10 Broca's aphasics with apraxia of speech were compared to findings from 10 paraphasic speakers (5 conduction and 5 Wernicke's aphasics). Several marked differences were revealed. Predominant locus of errors and relative difficulty of different classes of phonemic segments were significant discriminators. There was a nonsignificant trend for substituted phonemes to be further from target phonetically in the paraphasic patients. In addition, the two groups showed certain consistent differences in the types of errors they produced. Apraxic patients produced many errors of transitionalization, while sequencing errors were more typical of the patients with phonemic paraphasia. The findings are interpreted in relation to a neuropsychological model of speech. It is suggested that phonemic paraphasia represents a breakdown mainly in the retrieval of phonological word patterns, while apraxia of speech is characterized predominantly by a disturbance in encoding phonological patterns into appropriate speech movements.     

Contrasting patterns in the acquisition of spatial/temporal terms

Competing hypotheses about the acquisition of terms that refer to relationships in both time and space are tested. One hypothesis is that the language of time is acquired as a spatial metaphor; consequently, such terms will be acquired in their spatial sense first. The competing hypothesis is that differential experience with the dual senses of each term will result in different patterns of acquisition, depending upon which sense is dominant in actual usage. Comprehension of before-after, first-last, and ahead-behind by 4- to 6-year-olds was assessed in spatial, temporal, and spatial-temporal meaning tasks. Results support the second view: there is no consistent order of acquisition; the sense acquired first is the dominant sense, as determined by both linguistic evidence and empirical survey.     

Appraisal patterns of envy and related emotions

Envy is a frustrating emotion that arises from upward social comparison. Two studies investigated the appraisals that distinguish benign envy (aimed at improving one's own situation) from malicious envy (aimed at pulling down the superior other). Study 1 found that appraisals of deservingness and control potential differentiated both types of envy. We manipulated these appraisals in Study 2 and found that while both did not influence the intensity of envy, they did determine the type of envy that resulted. The more a situation was appraised as undeserved, the more participants experienced malicious envy. Benign envy was experienced more when the situation was not undeserved, and the most when the situation was appraised as both deserved and controllable. The current research also clarifies how the types of envy differ from the related emotions admiration and resentment.     

Localization of targets by strabismic subjects: Contrasting patterns in constant and alternating suppressors

Strabismic subjects in whom vision in one eye is constantly suppressed localized targets at different points in space when using each eye. Whether they were esotropes or exotropes determined the relation between the two locations and the angle of their vergence error correlated with the magnitude of the interocular discrepancy. These relationships suggest that constant suppressors utilize information about posture of the dominant eye in reaching toward targets presented to the normally suppressed eye. Neither orthotropes nor strabismics in whom vision in each eye is alternately suppressed showed this anomaly. These results were attributed to differences in the way in which visual space is represented, an outcome of the pattern of use of the eyes during early development.     

Visual discrimination of shape by octopus circles and squares, and circles and triangles

An investigation of the relative discriminability of circles and squares, and circles and triangles for octopus is described. The main findings were: (1) The three pairs of figures, circle and square with base horizontal, circle and square with base at 45° to the horizontal, circle and equilateral triangle were equally discriminable for the octopus. (2) Complete transfer occurred to larger and smaller figures. (3) No transfer occurred from a square in one orientation to a square rotated through 45°, nor did training with the square in one orientation lead to any saving when the discrimination was relearned with the square in the other orientation. (4) No transfer occurred from a square to a pentagon. (5) The method of training with reward on every positive trial leads to quicker initial learning of a discrimination than training with reward only where the positive figure is attacked, but discriminatory performance with the two methods approached the same asymptote. The results are in agreement with findings with other animals where these are available for comparison.     

Adolescent patterns of communication about sexually related topics

For this investigation, a sample survey of 179 black females, representing 53 family units, provided data for examining familial patterns in the amounts of information received about the menstrual cycle, sex, and contraception among adolescent daughters, mothers, and grandmothers, and the major source of information about these three topic areas. Significant relationships were found within the triads in the amount of information received about the three topic areas, suggesting familial patterns in the amount of information transmitted intergenerationally. This sample was more likely to report mothers as the source of information, suggesting their importance as formal agents of sexual socialization. Although this sample received large amounts of information about the menstrual cycle, sex, and contraception from their mothers, much information that is necessary for sexual health and informed decision making was neglected. The very young mean age (12.3 years) at first intercourse and the low proportion (24.2%) of teenagers using a method of birth control at first intercourse suggested that intergenerational communication about sex and contraception may not be meeting adolescents' needs. Consequently, attention should be focused not only on mothers as agents of sexual socialization of teenagers, but also the quality and impact of that information on the sexual health of teenagers.     

Incidence of depression related to isotretinoin treatment in 100 acne vulgaris patients

The incidence of depression in acne patients using isotretinoin was assessed in 100 patients with moderate and nodulocystic acne. All patients received 0.75-1.00 mg/kg/day of isotretinoin for 20-28 weeks after acne was assessed. All patients' acne lesions were improved at the end of the treatment period. Psychological state was evaluated at baseline, at Month 3, and Month 6 by a psychiatrist using a Turkish version of the Hamilton Depression Rating Scale. Only one patient's score increased to the clinical level of depression at Month 3 of treatment and declined to subclinical levels at Month 6. Although Hamilton scores increased at Month 3 over baseline scores, except for one patient, others' scores remained below the subclinical level for depression. At the end of Month 6, the mean score decreased below that at Month 3. These changes in means might be related to the onset of clinical effect of isotretinoin.     

An overview and analysis of journal operations, journal publication patterns, and journal impact in school psychology and related fields

This article describes the results of three studies designed to understand better the journal operations, publishing practices, and impact of school psychology journals in recent years. The first study presents the results of a survey focusing on journal operations and peer-review practices that was completed by 61 journal editors of school psychology and aligned journals. The second study presents the results of review and classification of all articles appearing in one volume year for nine school psychology journals (i.e., The California School Psychologist, Canadian Journal of School Psychology, Journal of Applied School Psychology, Journal of School Psychology, Psychology in the Schools, School Psychology Forum, School Psychology International, School Psychology Quarterly, and School Psychology Review). The third study employed multilevel modeling to investigate differences in the longitudinal trends of impact factor data for five school psychology journals listed in the Web of Science (i.e., Journal of School Psychology, Psychology in the Schools, School Psychology International, School Psychology Quarterly, and School Psychology Review). The article addresses implications for authors, editors, and journal editorial teams as well as the status and impact of school psychology journals.     

Blocking and overshadowing in two species of fish.

In Experiment 1, a mixed blocking-overshadowing effect of color on an auditory discrimination was demonstrated in goldfish. In Experiment 2 (with lines differing in color and angle), blocking of angle by color and of color by angle was demonstrated in goldfish, In Experiment 3 (again with lines differing in color and angle), overshadowing of angle by color was demonstrated in carp, but the same animals (like goldfish in a previous study) failed to show greater intradimensional than extradimensional transfer. These results are consistent with the hypothesis that blocking and overshadowing are general phenomena of vertebrate learning. They suggest also that the processes responsible for blocking and overshadowing are different from those which produce the dimensional transfer effect.     

Sex differences in spatial ability and activity in two vole species (Microtus ochrogaster and M. pennsylvanicus)

The hypothesis that sex differences in maze learning result from sex differences in activity was tested with wild-caught prairie (Microtus ochrogaster) and meadow (M. pennsylvanicus) voles. For 38 voles error production and activity were simultaneously measured in a series of 7 symmetrical mazes. Repeated-measures analyses of variance (ANOVAS) examined species, sex, maze, and interaction effects for 3 dependent variables: errors, activity, and errors/activity. The pattern of significant effects was very different for the errors and activity ANOVAS, which suggests that differential activity cannot explain differential error rates. In contrast, the pattern of effects was very similar for errors and errors/activity ANOVAS, which suggests that controls for activity do not remove differences in error production. These results fail to support the activity hypothesis.     

Contrasting intellectual patterns predict creativity in the arts and sciences: tracking intellectually precocious youth over 25 years

A sample of 2,409 intellectually talented adolescents (top 1%) who were assessed on the SAT by age 13 was tracked longitudinally for more than 25 years. Their creative accomplishments, with particular emphasis on literary achievement and scientific-technical innovation, were examined as a function of ability level (sum of math and verbal SAT scores) and tilt (math SAT score minus verbal SAT score). Results showed that distinct ability patterns uncovered by age 13 portend contrasting forms of creative expression by middle age. Whereas ability level contributes significantly to creative accomplishments, ability tilt is critical for predicting the specific domain in which they occur (e.g., securing a tenure-track position in the humanities vs. science, technology, engineering, or mathematics; publishing a novel vs. securing a patent).     

Perception of missing fundamental by a species of songbird (Sturnus vulgaris)

Two experiments investigated whether a species of songbird perceives missing fundamentals in sounds containing complex frequencies. In Experiment 1, European starlings were trained to discriminate between two sinusoids. This discrimination persisted when the sinusoids were replaced with waveforms composed solely of four consecutive higher harmonics of the training frequencies. In Experiment 2, starlings trained to discriminate between two complex frequencies consisting of sets of higher harmonics transferred the discrimination to the sinusoidal fundamentals. The results demonstrate that starlings can perceive harmonic or periodic structure, and show that a species of songbird can use harmonic structure to gain information about its auditory environment. The findings, together with those obtained from fish and mammals, suggest that periodicity pitch perception may be a general process in vertebrate hearing.     

Visual discrimination of shape by octopus. squares and triangles

An experiment was performed upon visual discrimination of shape by the octopus in order to test two predictions derived from a theory of visual discrimination of orientation and shape. Two groups of octopuses were trained to discriminate between a square and a triangle and between a diamond and a triangle. It was found that octopuses discriminate more readily between a square with base horizontal and a triangle than between a diamond and a triangle. Transfer tests showed that: (1) For the octopus, an upright and an inverted triangle have more equivalence than a diamond and a square with base horizontal. (2) Octopuses do not discriminate between the figures used by analysing only differences in one part of the figures (e.g. bases or tops). (3) Having learned the initial discrimination, octopuses transfer to both larger and smaller figures. (4) A pentagon has more equivalence to a square or diamond than to a triangle. (5) A circle is not treated as equivalent to a square. The results are taken to be in agreement with the theory that octopuses analyse the vertical and lateral extents of figures, and that shape discrimination is achieved by analysing the changes in the rates of change in the firing of neurons representing the vertical and lateral extents of the shapes. The results are shown to differ from those obtained with birds and rats, but to agree with results found for higher mammals where these are available for comparison.