Sex differences,sex-role orientation,and reward allocations

In study 1, 52 male and 52 female undergraduates allocated rewards to pairs of children for their performances in team and competitive situations. Males allocated rewards more equitably, especially when allocating to boys in competition, while females allocated rewards more equally. Boys, but not girls, who did more work received more rewards than their partner; and children with greater work inputs under competitive conditions received more rewards than children in team conditions. In study 2, the sex-role orientation of 60 college students was found to be related to their reward allocations. Males and females with a masculine sex-role orientation allocated rewards equitably, while individuals with a feminine sex-role orientation allocated rewards equally. Results indicated that sex and situational differences in reward allocations are affected by sex-role orientation and differential socialization practices by adults.Portions of study 1 were presented at the Midwestern Psychological Association Meeting, Chicago, May 1978.     

Visual symmetry recognition by pigeons

Summary Pigeons learned to discriminate a large number of bilateral symmetric and asymmetric visual patterns successively projected on the pecking-key of an operant conditioning chamber. Responses to the positive stimuli were reinforced according to a variable interval schedule. Once acquisition was complete generalization trials, involving sets of new stimuli, were instituted under extinction. The birds classified these novel test stimuli with high accuracy throughout, according to their symmetry or asymmetry. Their performance was not disturbed by sets of test stimuli whose geometrical style differed considerably from the training stimuli. Pigeons were even able to discriminate when only allowed the use of one eye. The generalization series were partly designed to test some classical symmetry recognition theories. None was found to be adequate. Subsidiary experiments suggested that most pigeons have a slight spontaneous preference for asymmetric patterns and that symmetry/asymmetry differences can aid pattern discrimination learning at an early stage. It is concluded that pigeons, much like humans, can discriminate bilaterally symmetric from non-symmetric visual forms in a concept-like, generalizing way. The ontogenetic and phylogenetic development of this competence is considered. A novel symmetry recognition hypothesis based on spatial frequency analysis and neuronal feature-detector considerations is proposed.     

Deletion of the mu opioid receptor results in impaired acquisition of Pavlovian context fear

The mu opioid receptor may constitute a critical component of a negative feedback system that regulates Pavlovian fear conditioning. We investigated context fear conditioning acquisition and expression in mu opioid receptor knockout mice (on an inbred, C57 genetic background). We discovered that the mu receptor knockout results in an unexpected and significant deficit in context fear acquisition. Mice lacking the mu receptor showed normal fear acquisition when subjected to a 1-day fear conditioning protocol but evinced deficient fear learning when acquisition was conducted across 5 days. The knockout mice showed normal reactivity to footshock in both fear conditioning protocols. Finally, we confirmed the effectiveness of the receptor deletion in the C57 strain by subjecting the mice to a test of morphine analgesia in the hot-plate assay. As has been seen with mixed genetic background, the receptor deletion resulted in a complete lack of analgesic response to 10 mg/kg morphine. Surprisingly, mice with a single copy of the mu receptor gene (heterozygous knockouts) showed intact sensitivity to morphine but a significant deficit in Pavlovian fear conditioning. The results indicate that deletion of the mu receptor gene impairs fear conditioning and that the conditioning and analgesia effects of heterozygous deletion are dissociable. The conditioning deficit seen in this line of mice may be related to impairment in hippocampus function.     

Unimodal and crossmodal effects of endogenous attention to visual and auditory motion

Three experiments were conducted examining unimodal and crossmodal effects of attention to motion. Horizontally moving sounds and dot patterns were presented and participants’ task was to discriminate their motion speed or whether they were presented with a brief gap. In Experiments 1 and 2, stimuli of one modality and of one direction were presented with a higher probability ( p = .7) than other stimuli. Sounds and dot patterns moving in the expected direction were discriminated faster than stimuli moving in the unexpected direction. In Experiment 3, participants had to respond only to stimuli moving in one direction within the primary modality, but to all stimuli regardless of their direction within the rarer secondary modality. Stimuli of the secondary modality moving in the attended direction were discriminated faster than were oppositely moving stimuli. Results suggest that attending to the direction of motion affects perception within vision and audition, but also across modalities.     

Diagnosis and rehabilitation attempt of a patient with acquired deep dyslexia

This study presents a patient (JH) suffering from acquired deep dyslexia. According to a cognitive model of reading, JH exhibited a significant impairment in both the phonological and lexical routes to reading. A rehabilitation program was proposed. We decided to focus on the lexical route using a priming paradigm. The written words were associated with a picture and the patient was invited to construct a mental association between the written word and the image. During five sessions, JH was trained to read 50 words. A pre-test, a post-test, and an 8-month follow-up session consisted of reading 140 written words including the 50 trained words. At the post-test, 90% of the trained words were accurately read. At the follow-up session, JH's reading performance for the trained words was still highly accurate at 84%. This strong effect is discussed and ways of increasing the patient's abilities to read are proposed.     

Semantic categorization in the human brain: spatiotemporal dynamics revealed by magnetoencephalography

We examined the cortical representation of semantic categorization using magnetic source imaging in a task that revealed both dissociations among superordinate categories and associations among different base-level concepts within these categories. Around 200 ms after stimulus onset, the spatiotemporal correlation of brain activity elicited by base-level concepts was greater within than across superordinate categories in the right temporal lobe. Unsupervised clustering of data showed similar categorization between 210 and 450 ms mainly in the left hemisphere. This pattern suggests that well-defined semantic categories are represented in spatially distinct, macroscopically separable neural networks, independent of physical stimulus properties. In contrast, a broader, task-required categorization (natural/man-made) was not evident in our data. The perceptual dynamics of the categorization process is initially evident in the extrastriate areas of the right hemisphere; this activation is followed by higher-level activity along the ventral processing stream, implicating primarily the left temporal lobe.     

What are the phenomena of physics?

Depending on different positions in the debate on scientific realism, there are various accounts of the phenomena of physics. For scientific realists like Bogen and Woodward, phenomena are matters of fact in nature, i.e., the effects explained and predicted by physical theories. For empiricists like van Fraassen, the phenomena of physics are the appearances observed or perceived by sensory experience. Constructivists, however, regard the phenomena of physics as artificial structures generated by experimental and mathematical methods. My paper investigates the historical background of these different meanings of “phenomenon” in the traditions of physics and philosophy. In particular, I discuss Newton’s account of the phenomena and Bohr’s view of quantum phenomena, their relation to the philosophical discussion, and to data and evidence in current particle physics and quantum optics.