ABSTRACT
After a half century of use by the Brown University Psychology Department, the Walter S. Hunter Laboratory of Psychology has been scheduled for renovation for another use, and a new building for the department is on the drawing board. Hunter Lab was specifically designed to house an experimental psychology department. Here we comment on the changes and adaptations necessary over the years as teaching and laboratory technology changed and as the department and the university grew larger, and we suggest considerations to others who are planning new or renovated buildings with similar purposes.
Subject(s)
Laboratories/history , Psychology, Experimental/history , Universities/history , History, 20th Century , Humans , Rhode IslandABSTRACT
The effects of transcranial magnetic pulse stimuli on the brain tissue of rats were examined. In Experiment I, 52 male albino rats received pulsed magnetic stimulation of the head. Stimulus intensity, number of stimulations, stimulated sites, and interval between last stimulation and sacrifice for neuropathological examination were varied. High stimulus intensity (2.8 T) and 100 or more stimulations produced clearly defined microvacuolar changes in the neuropil portion of cortical layers 2-6 (especially layers 3 and 4) in 12 of 24 animals. Fewer stimulations and lower intensities produced no such effects in 28 rats given that stimulation. Midline stimulation and stimulation over the left hemisphere produced similar results. No other brain, ocular, or spinal structures manifested such changes. Lesions were present in animals that had intervals up to 30 days between the last stimulation and perfusion. In Experiment II with 18 animals, compound motor action potentials (CMAPs) evoked by magnetic stimulation of the cortical motor area and recorded from the right lower extremity were examined. The electromyographic threshold was 0.83 T. Further increases in stimulus intensity produced increases in CMAP amplitude, up to approximately 1.9 T. It was noted that the lesion-producing intensity (2.8 T) was 0.9 T greater than the intensity needed for near-asymptotic reactions and was 3.4 times the CMAP threshold value.
Subject(s)
Cerebral Cortex/physiopathology , Electroencephalography , Electromagnetic Fields , Muscles/innervation , Animals , Brain Mapping , Cerebral Cortex/pathology , Dominance, Cerebral/physiology , Evoked Potentials/physiology , Male , Rats , Synaptic Transmission/physiology , Vacuoles/ultrastructureABSTRACT
Rats were allowed to drink distinctively flavored water and later received an IP injection of LiCl. In Phase I, between drinking and the onset of the mild malaise, Experimental Group rats received stimulations of the head and Controls received equivalent stimulations of the back. Later, when the flavor was again presented. Experimentals drank 10-15% more, indicating that they had forgotten to some extent that the flavor was associated with illness. In Phase II, the procedure was repeated with a different distinctive flavor. Again, the Experimentals drank more on the test day. In Phase III, all rats received stimulations of the back between tasting and illness. Experimentals and Controls were not different on the test day, indicating that 100 prior head stimulations did not interfere with the establishment of a new taste aversion. Histological examinations revealed no gross morphopathology. We conclude that 50 brief pulse transcranial magnetic stimulations may cause a retrograde memory disruption, but we find no evidence for an anterograde memory effect or for structural changes.
Subject(s)
Avoidance Learning/physiology , Brain/physiology , Conditioning, Classical/physiology , Electromagnetic Fields , Mental Recall/physiology , Taste/physiology , Animals , Chlorides/toxicity , Drinking/physiology , Lithium/toxicity , Lithium Chloride , Male , RatsABSTRACT
Eight autumn-caught female chaffinches were injected with testosterone in their first spring. They were allowed to perch on a particular perch to produce a playback of a normal, male song. Both the course of their song development and the reinforcing effect of the playback song were comparable to that shown by a group of similarly-treated males.
Subject(s)
Birds , Reinforcement, Psychology , Vocalization, Animal , Animals , Female , Male , Testosterone/pharmacologySubject(s)
Cerebral Ventricles/physiology , Conditioning, Operant , Hypothalamus/physiology , Reaction Time , Reinforcement Schedule , Self Stimulation , Animals , Behavior, Animal , Electric Stimulation , Electrodes, Implanted , Male , Motor Activity , Periodicity , Probability , Rats , Time FactorsABSTRACT
Rats were trained to respond to the brighter of two keys. Four animals were trained with food pellets and four with electrical brain stimulation. Each discrimination sequence was initiated when the animal broke a light beam at the rear of the chamber, turning on the key lights and starting a 30-sec reinforcement period. An initial response on the brighter key was immediately reinforced, and further responses on the brighter key were then intermittently reinforced. Any time the dimmer key was pressed, a 30-sec timeout was introduced. During timeout, no response had any programmed consequence. When the reinforcement period or the timeout ended, a new discrimination sequence could be initiated. Daily 1-hr training sessions were conducted, and after seven or eight sessions, all animals were at or near errorless performance levels. The luminance of the brighter key was then systematically reduced, in seven steps, with two 30-min test sessions at each step. Orderly psychometric functions were generated for individual animals. Initial acquisition, once position preferences were broken, was equally rapid for food and for brain-stimulation animals, and the two reinforcement procedures yielded comparable levels of brightness discriminability.
