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F H Baker

Publications and source records attributed to F H Baker.

8 recordsLinked to original sources
PubMed1990

Educational methodology in dealing with animal rights and welfare in public service.

Animal rights and animal welfare have biological, economic, social, philosophical, emotional, political, legal and policy dimensions. Hundred of organizations are active in some aspect of these issues. Viewpoints range in a continuum from animal rights advocates to livestock producers. One long-range goal is to increase understandings of both the benefits and the costs of animal rights and animal welfare for individuals and society. In the short-range, solutions and (or) alternatives for crisis situations are needed. Key aspects for using education as a means to solve these problems are 1) characterization of the issue(s), 2) identification of the audience(s), 3) selection of communications media and channels, and 4) development of appropriate educational materials. Task forces of educators and clientele for audience involvement are essential in planning and testing educational methods. When situations involve political, legal, and policy aspects, two task forces are needed: 1) a multidisciplinary educational group of scientists and educators to prepare objective usable information, and 2) an action group of clientele to communicate potential impacts of political, legal or policy action. Liaison between two groups is very important. Contemporary examples are presented.

Agriculture↗
PubMed1987

The primate globus pallidus: neuronal activity related to direction of movement.

Neurons in the arm areas of the external and internal segments of the globus pallidus (GPe and GPi) and the ventral pallidum (VP) have been examined in a visuomotor step-tracking task. This task, which was similar to that used previously to examine neurons in the arm area of the putamen, dissociated the direction of movement from the pattern of muscle activity associated with the movement. The major finding of the present study is that, as in the putamen, the activity of almost half of the neurons in GPe and GPi was related to the direction of movement. Cells with overall patterns of activity similar to muscle were rare, although many neurons had static and/or dynamic load effects which resembled those seen in muscle. Responses of neurons to load application have also been examined in this paradigm in order to determine the nature of possible somatosensory input. Short-latency "sensory" responses to load application were found in pallidum as previously in putamen, but, by contrast, they occurred somewhat later and included bidirectional responses. Similar proportions of cells in GP and putamen were related to static loads. Some VP neurons appeared to encode information about specific features of the trials, but the majority of responses were nonspecific suggesting relations to more general features of the task.

Animals↗
PubMed1987

The primate nucleus basalis of Meynert: neuronal activity related to a visuomotor tracking task.

The activity of neurons in the nucleus basalis of Meynert (nbM), both the compact (nbMc) and interstitial (nbMi) components, has been examined in monkeys trained to perform a visuomotor step-tracking task. This study was carried out in the same animals and with the same task used to examine neuronal activity in the external and internal segments of globus pallidus (GPe and GPi) and ventral pallidum (VP). The presumed interstitial cells that are located within the laminae surrounding GPe and GPi and identified physiologically by their similarity with nbMc neurons, are referred to as border cells. A major finding of this study is that a large proportion of nbMc and border cells were active in relation to either the step-tracking movements or to load application. Moreover, a high proportion of the responses of border neurons were differential for opposite directions of load and movement. The percentages of directionally specific border and nbMc neurons were considerably less than for GP, with border neurons having more directionally specific responses than nbMc neurons. The similarity between border and GP neuronal properties in this task suggests that both may receive similar sensorimotor afferent input. In the compact portion of nbM, nonspecific neuronal responses following each behavioral event in the paradigm were common. These responses appeared to have been modified by and may have been contingent upon association with reinforcement.

Animals↗
PubMed1975

Spatial and chromatic properties of neurons subserving foveal and parafoveal vision in rhesus monkey.

The response properties of neurons in the region of striate cortex subserving central retina (0 degrees-2 degrees) and in a region of representation of parafoveal retina (4 degrees-7 degrees) were studied in unanesthetized paralyzed macaque monkeys. Neurons sensitive to the orientation of the stimulus in the visual field (simple, complex, and hypercomplex), and neurons lacking orientation selectivity (concentric, and a new class termed uniform) were found. In foveal cortex non-oriented cells were more numerous, and orientation sensitive cells had less strict spatial stimulus requirements than in parafoveal cortex. Most neurons received a monocular input, either exclusively or very predominantly. Three types of neurons were recognized on the basis of their responses to chromatic stimuli. (1) Luminosity neurons (about half the population) gave the same qualitative response to all effective wayelengths and had a spectral sensitivity similar to that of the macaque, determined behaviorally. Cells with all spatial types of receptive fields, except simple, occurred in this group. (2) Spectrally-treated neurons also responded in the same manner to different wavelengths, but over a narrower range than luminosity neurons, and their maximal sensitivity was shifted toward one or the other end of the visible spectrum. All tuned neurons had uniform or complex receptive field. (3) Spectrally-opponent neurons were either excited or inhibited by long wavelengths and responded in the opposite manner to short wavelengths. For cells with uniform or complex receptive fields the two opponent systems were coextensive. Simple or concentric neurons often had dual-opponent organization. The distribution of functional types among different cortical layers was similar in parafoveal and foveal cortex. The functional attributes of ocular dominance and orientation sensitivity were found to be statistically independent dimensions of cortical organization. On the other hand, the correlation between spatial and chromatic properties did not vary between different cytoarchitectonic layers, a finding suggesting that these neuronal properties depend on conjoined projectional and intracortical connecting mechanisms.

Animals↗
PubMed1975

The representation of the visual field in the lateral geniculate nucleus of Macaca mulatta.

Microelectrode recording techniques were used to investigate the projection of the visual field into the lateral geniculate nucleus (LGN) of Macaca mulatta. The data were used to construct charts plotting visual direction, designated in terms of azimuth and elevation, onto sections of the nucleus cut in coronal, sagittal and horizontal Horsley-Clarke planes. The projection of the horizontal meridian divides the LGN along its plane of symmetry into a medial-superior half having negative elevations and a lateral-inferior half having positive elevations. Elevations become more positive or negative with distance from this plane. Azimuths closest to the vertical meridian are located posteriorly, while the most peripheral azimuths are found at the anterior pole. Two families of surfaces representing visual directions of constant azimuth and elevation are described. Visual field zones of increasing eccentricity are represented serially along the posterior-anterior axis of the LGN, with the foveal area restricted to the posterior pole and the monocular crescent projecting to the anterior pole. The mapping is completely continuous across the horizontal meridian. The edges of the stacked cell laminae exposed around the periphery of the LGN form an oval band which receives the projection of the perimeter of the contralateral hemifield. The vertical meridian is represented by the posterior two-thirds of this band, while the periphery of the hemifield projects to the anterior third. The central visual field out to the optic disc is represented by six cell layers, while the rest of the binocular field projects to four layers only (2 parvocellular and 2 magnocellular). The monocular crescent is represented by one parvocellular and one magnocellular layer. Features associated with the projection column of the optic disc are integrated into the transition from six to four layers. Details of the receptive field topography in the vicinity of the optic disc discontinuities indicate that these gaps are produced by intralaminar mechanisms. The magnification factor (mm-3/steradian) increased monotonically from peripheral visual fields to the foveal center, varying over a range of three decades. This range is intermediate between those derived from data reported in the literature for the retina and the striate cortex. The ratio of LGN magnifications at any two angular eccentricities is a power function, with an exponent of 1.34, of the corresponding ratio of retinal ganglion cell densities. Similarly, the ratio of cortical magnifications (mm-2/steradian) at any two eccentricites is a power function, with an exponent of 1.35, of the corresponding ratio of LGN magnifications.

Animals↗