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J K Kovach

Publications and source records attributed to J K Kovach.

At least 19 recordsLinked to original sources
PubMed1997

Unconditional discrimination as a paradigm for investigating visual processing in the avian brainstem.

Visual discrimination between colors and patterns was studied in telencephalectomized chicks of Japanese quail lines that were artificially selected for early approach preferences for particular colors and patterns. Since these preferences are not conditional on prior learning, they provide an effective experimental paradigm to study visual discrimination without reliance on acquired stimulus discrimination. The data indicate that the quail's brainstem-thalamus complex is sufficient for relatively fine discriminations between various colors and achromatic patterns.

Animals↗
PubMed1995

Effects of diencephalic lesions on approach responses and color preferences in quail.

The effects of stereotaxic radio-frequency lesions on artificially selected approach responses and artificially selected or imprinted red or blue preferences were studied in Japanese quail chicks. No effects were found from lesions in anterior preoptic or pretectal areas and only slight attenuation of red preferences by lesions in nucleus rotundus, opticus principalis thalami and geniculatus lateralis pars ventralis. Extensive lesions in medial diencephalic and bordering areas of telencephalon, ansa lenticularis, lateral and medial forebrain bundle diminished approach tendencies and greatly attenuated the genetically influenced red preferences. Medial diencephalic lesions confined to the dorsomedial thalamic complex and lateral hypothalamus left approach tendencies intact but similarly attenuated only red preferences. Imprinted red or blue preferences of a highly imprintable quail line were also attenuated; red preference strongly, blue preference moderately. The data indicate differential diencephalic mediation of the quail's genetically distinct color preferences and suggest diverse subtelencephalic channels for mediation of approach responses and stimulus preferences. The results also suggest common neural mediation of genetically determined and acquired stimulus preferences.

Animals↗
PubMed1993

Effects of bilateral hemispherectomy on genetically variable stimulus preferences and imprinting in quail chicks.

Bilateral ablation of the telencephalon on the 1st posthatch day prevented learning from imprinting to colored stimuli in Japanese quail chicks C. coturnix japonica, but it spared their artificially selected approach preferences for particular colors and patterns. Post-imprinting decerebration on the 3rd posthatch day erased the imprinted memory, but did not revert the chicks' approach choices to the colors of their genetically distinct initial preferences. The genetically determined and the acquired preferences were both lost in the latter birds, regardless whether they were imprinted to the initially preferred or the initially nonpreferred stimuli before decerebration. Discussion focuses on implications of the data for modeling specific interactions between and the interrelated neural representation of genetic and environmental influences in early behavioral development.

Animals↗
PubMed1993

Sources of behavioral deviation modeled by early color preferences in quail. III. Developmental stability and normative canalization.

Successful artificial selection of quail (C. coturnix japonica) for divergent early approach preferences for, and imprintabilities to, the wavelength characteristics of otherwise identical visual stimuli decreased the trait's developmental stability. The developmental error that resulted from selecting for extreme initial preferences was associated with enhanced imprintabilities. Conversely, the developmental error that resulted from selecting for extreme imprintabilities was associated with enhanced expression of directional gene effects in extreme initial preferences. The data are attributed to selectively relaxed normative canalization of trait development, and to related enhanced expression of genetic, environmental, and stochastic influences in trait deviations.

Animals↗
PubMed1993

Persistence of approach response after decerebration in newly hatched quail chicks.

The role of telencephalon in controlling the unconditional approach response was studied in newly hatched Japanese quail chicks by lesions. Approach to flickering light and a moving object were not diminished by ablation of various telencephalic areas, ranging from caudal forebrain lesions to complete bilateral hemispherectomy. Open field activity and tonic immobility were likewise unaffected. Results indicated that the neural mediation of unconditional sensory-motor components of imprinting is anatomically separated from the telencephalon, where recognition memory is thought to be formed.

Animals↗
PubMed1993

Subtelencephalic visual discrimination in selected lines of Japanese quail.

We studied visual discrimination capabilities of the avian brain stem in genetic lines of Japanese quail artificially selected for unconditional approach preference for blue, red or an achromatic pattern stimulus. Complete telencephalectomy did not abolish approach behavior and visual discrimination. Our data indicate that visual feature extraction and motor coordination related to early approach preferences in birds may be mediated by brain stem and thalamic circuitries which do not require input from higher level visual and motor regions.

Animals↗
PubMed1992

Sources of behavioral deviation modeled by early color preferences in quail. I. Behavioral synergism and systemic instability.

Differences between population-typical norms of individual variability were studied in five genetic lines of Japanese quail (Coturnix coturnix japonica); two (BL and RL) were bidirectionally selected for early approach preference between blue and red stimuli, two (Hi and Lo) for high and low imprintabilities to the same stimuli, and the fifth (CL) was an unselected genetic control line. Selection resulted in reliably divergent extreme choice performances and imprintabilities and in progressively increasing choice variances in the BL x RL hybrids and the Hi imprintability line. Experimentation tested and rejected the hypotheses that correlated selection of synergistically acting but otherwise extraneous stimulus influences, social interaction effects, or phototactic and short-term learning effects may have been responsible for the observed large variance increases. An alternative interpretation is discussed, according to which directional selection relaxes the genetic buffering and the variance increases reflect the resulting developmental instability of the trait.

Animals↗
PubMed1992

Sources of behavioral deviation modeled by early color preferences in quail. II. Diathetic genes and the leftover variance "V(e)".

The sources of deviation from population-typical norms of variability were studied in relation to early approach preferences between colors in newly hatched Japanese quail chicks (Coturnix coturnix japonica). Subjects were drawn from an unselected genetic control line, two genetic lines that were artificially selected for extreme blue and red preferences, their hybrids, and a large set of backcross and assortatively derived generations. Large progressive increases were observed with selection in the leftover (V(e)) component of F1 variance and consistent additional variance increases in F2 hybrids. Backcross generations exhibited greater than expected expression of the blue and red preference genes. Discussion differentiates between diathetic and normative influences in preference deviations and relates the increased Ve to relaxed normative canalization of preference development by directional selection.

Animals↗
PubMed1985

Constitutional biases in early perceptual learning: III. Similarities and differences between artificially selected and imprinted color preferences in quail chicks (Coturnix coturnix japonica).

Color preferences and preference generalization were tested in naive and imprinted Japanese quail chicks drawn from the 20th generation of a genetic control line and two genetic lines that were bidirectionally selected for preferences between blue and red. Twelve hours of imprinting to blue or red on the first posthatch day resulted in large preference changes in the genetic controls, and these subjects exhibited no or only small additional changes from 3 more days of imprinting (for the total of 66 hr of exposure time). By contrast, 12 hr of imprinting of artificially selected subjects did not change or only marginally changed their genetically manipulated preferences, but 66 hr of imprinting changed them by magnitudes as large as or larger than those in genetic controls. Reciprocal imprinting partially mimicked the phenotypic effects of bidirectional selection. Differences between transfer and generalization of phenotypically similar but genetically and experimentally different preferences indicated dissimilar mediation of the implicit gene effects and learning effects.

Animals↗
PubMed1983

Perceptual imprinting: genetic influences and genotype-environment interactions.

One-day-old visually naive and experienced quail chicks (C. coturnix japonica) were mass-screened for approach preferences by pairs of stimuli that were identical in size and luminance but different in color, or pattern, or both color and pattern. Subjects were drawn from the 18th generation of quail lines that were bidirectionally selected for color preferences, and from an unselected genetic control line. Experience consisted of 12 hr of unreinforced perceptual exposure to colored or white stimuli, with and without associated pattern. Data indicated strong genetic influences in the preferences of exposure to color and pattern resulted in selective learning of color but not pattern. Systematic variations in postexposure choices between composite stimuli of colors and pattern. Systematic variations in postexposure choices between composite stimuli of colors and patterns were traced to variations of genotype, experience, and genotype-experience interactions.

Animals↗
PubMed1983

Constitutional biases in early perceptual learning: I. Preferences between colors, patterns, and composite stimuli of colors and patterns in genetically manipulated and imprinted quail chicks (C. coturnix japonica).

Bidirectional genetic selection of quail for early color preferences, for eighteen generations, resulted in nearly perfect choices of blue over red in one and red over blue in the other selected line. It also enhanced the preference of a grated over a dotted black-and-white pattern. Color and pattern preferences in hybrids of selected and control lines fell back to about halfway between parental values. Choices between composite stimuli of colors and patterns indicated summation of the respective, genetically influenced preference values, with partial dominance of color over pattern effects. Exposure to colors modified color choices. Exposure to colored patterns likewise modified color choices, but it did not change, or only marginally changed, choices between patterns. The phenotypic expression of this selective learning, however, was influenced by the genetically manipulated preference values and preference combinations of colors and patterns in the stimuli with which postexposure performances were tested. Overall, the data highlighted the need for concepts that would discriminate between the developmental and the episodic expression of genetic influences and genotype--environment interactions in behavior.

Animals↗
PubMed1983

Constitutional biases in early perceptual learning II. Visual preferences in artificially selected, visually naive and imprinted quail chicks (C. coturnix japonica).

Approach choices were tested in genetically and environmentally manipulated quail chicks with pairs of stimuli identical in size and luminance but different in color, flicker, or both color and flicker. Data indicated comparable flicker and vastly different color preferences in subjects that were bidirectionally selected for color choices. In the choices between composite stimuli, flicker effects dominated over color effects in genetic controls, and color effects over flicker effects in selected subjects. Imprinting to colors modified color preferences, but imprinting to white or colored flicker did not change, or only marginally changed, flicker preferences. Flicker in testing stimuli, however, influenced the phenotypic expression of acquired color preferences. The data are examined for implications about the nature of constitutional biases and constitution--environment interactions in early perception and perceptual learning.

Animals↗
PubMed1981

Normal EEG of the restrained twenty-four-hour-old Japanese quail (Coturnix coturnix japonica).

A new method for obtaining bipolar electroencephalographic (EEG) recordings from day-old Japanese quail (Coturnix coturnix japonica) is described. The electrodes are chronically placed stainless steel suture wires sewn into the skull and secured with dental acrylic. Using this arrangement, recordings were made over the hyperstriatum accessorum and dorsoarchistriatum regions of the brain. These records showed a preponderance of high amplitude slow waves. Transitions to low amplitude fast waves were also evident, and rare instances of paradoxical sleep were noted. computerized frequency analyses of the recordings divided wave numbers into distinct groups over the 1 to 17 Hz range: 1 to 4 Hz, 4 to 8 Hz, 8 to 13 Hz, and 13 to 17 Hz. Frequencies of waves detectable across the hyperstriatum accessorum were primarily confined to the 1 to 7 Hz range, whereas waves generated around the dorsoarchistriatus showed more abundant high frequency patterns. Mean amplitude of the waves (10 to 50 muV) showed an inverse exponential relationship with frequency. The method described produced an EEG of good quality on unanesthetized birds with the electrode placement procedures requiring less than 30 min.

Animals↗
PubMed1980

Mendelian units of inheritance control color preferences in quail chicks (Coturnix coturnix japonica).

Genetic analysis of approach preferences for blue and red colors in 1-day-old, experientially naïve quail, at 12th through 14th generations of bidirectional genetic selection, implicate four to eight segregating units of inheritance. Because the quails' initial approach choices are also readily modifiable by experience, these results point the way to studying the mediation of gene effects, environment effects, and gene-environment interactions in visually guided behaviors.

Animals↗
PubMed1980

Visual information and approach behavior in genetically manipulated quail chicks: preference hierarchies and interactions of flash rate, flash amplitude, luminance, and color.

Visual preferences were studied in 18,225 quail chicks (Coturnix coturnix japonica) of three genetic populations, in relation to 185 pairs of systematically varied and combined flash rates, flash amplitudes, luminances, and colors. Results indicate additive and nonadditive interactions between preference values of stimulus elements embedded in complex stimulus information. Flicker preferences changed with changes in overall stimulus liminances, flash amplitudes, and colors. Likewise, color preferences changed with the presence or absence and rate of flicker. Interactions between preference values of stimuli were related to threshold effects and genetic influences. Dominance of flicker over color preference was found in genetic controls, but subjects drawn from the 14th generation of bidirectional genetic selection for color choices preferred the genetically favored colors regardless of flicker. Discussion examines the data from the perspectives of coding and processing stimulus information.

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