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Results for “Discrimination Learning”

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At least 1,081 records · Page 60Linked to original sources
PubMed1979

Learning and interhemispheric transfer of visual pattern discriminations following unilateral suprasylvian lesions in split-chiasm cats.

A suprasylvian lesion removing cortical areas 7 and 21 and portions of area 19 and of the lateral suprasylvian area was placed in one hemisphere of split-chiasm cats. By comparison with the normal side and with cortically intact split-chiasm and split-brain cats, form discrimination learning with the eye on the injured side was severely retarded. This deficit could not be attributed to an unintentional undercutting of areas 17 and 18, since in three cases the laminae of the lateral geniculate nucleus showed little retrograde atrophy; marked degeneration was found in the medial interlaminar nucleus and the pulvinar complex. In addition, interocular transfer of form discriminations to the eye on the injured side was absent or poor, while transfer in the opposite direction was normal. A cat with a suprasylvian lesion undercutting areas 17 and 18 was unable to learn pattern discriminations with the eye on the injured side, in spite of prolonged training with that eye and normal learning with the other eye. Another cat with a suprasylvian lesion selectively removing the anteromedial and posteromedial portions of the lateral suprasylvian area showed no learning deficit on the injured side, but poor transfer to that side. A learning deficit on the side of the lesion emerged in this cat after forebrain commissurotomy. The results support the hypothesis of a major involvement of cortical areas outside of 17 and 18 in the processes of abstraction and generalization of visual information necessary for learning and interhemispheric transfer of form discrimination in the cat.

Animals↗
PubMed1987

Cognitive strengths and weaknesses in language-impaired children: one more look.

The hypothesis-testing abilities of 15 language-impaired and 15 normally developing children matched for mental age were investigated using discrimination-learning tasks. The subjects in both groups were presented with two sets of discrimination-learning problems. One set of problems featured explicit input concerning the correct response choice. The other set of problems featured nonexplicit input. The results revealed both differences in the performance of the MA-matched and language-impaired children and differences in performance on the two types of problems. The children in both groups solved more of the explicit input problems than the nonexplicit input problems. In addition, the MA-matched children performed significantly better than the language-impaired children, particularly on the nonexplicit problems. The findings suggested that the language-impaired children exhibited deficits in solving discrimination-learning problems. The deficits exhibited by the language-impaired children seemed related to deficits in their ability to encode information.

Child↗
PubMed1989

Learning and discrimination of coloured papers in the walking blowfly, Lucilia cuprina.

A new training and testing paradigm for walking sheep blowflies, Lucilia cuprina, is described. A fly is trained by presenting it with a droplet of sugar solution on a patch of coloured paper. After having consumed the sugar droplet, the fly starts a systematic search. While searching, it is confronted with an array of colour marks consisting of four colours displayed on the test cardboard (Fig. 1). Colours used for training and test include blue, green, yellow, orange, red, white and black. Before training, naive flies are tested for their spontaneous colour preferences on the test array. Yellow is visited most frequently, green least frequently (Table 2). Spontaneous colour preferences do not simply depend on subjective brightness (Table 1). The flies trained to one of the colours prefer this colour significantly (Figs. 5 and 9-11). This behaviour reflects true learning rather than sensitisation (Figs. 6-7). The blue and yellow marks are learned easily and discriminated well (Figs. 5, 9, 11). White is also discriminated well, although the response frequencies are lower than to blue and yellow (Fig. 11). Green is discriminated from blue but weakly from yellow and orange (Figs. 5, 9, 10). Red is a stimulus as weak as black (Figs. 8, 9). These features of colour discrimination reflect the spectral loci of colours in the colour triangle (Fig. 14). The coloured papers seem to be discriminated mainly by the hue of colours, but brightness may also be used to discriminate colour stimuli (Fig.13).

Animals↗
PubMedDate not supplied

Developmental neurotoxicity following neonatal exposure to 3,3'-iminodipropionitrile in the rat.

Adult exposure to the neurotoxicant 3,3'-iminodipropionitrile (IDPN), induces a hyperkinetic syndrome consisting of spontaneous head movements, abnormal circling, backward locomotion, and sensory disruption. We report here the behavioral effects of developmental exposure to IDPN in the rat. Animals were exposed (IP) to either saline, 75, 150, or 300 mg/kg/day on postnatal days (PND) 5-7. Animals were tested for: Figure-8 maze activity (PND 13-60); olfactory discrimination learning (PND 18 & 24); T-maze alternation and position discrimination learning (PND 25 & 26); acoustic startle response (PND 23, 61, & 62); passive avoidance (PND 70). To better define the dose response, a separate group of animals was exposed to either saline or 225 mg/kg/day (PND 5-7) and tested in the activity, T-maze, and startle paradigms. Animals exposed to 225 mg/kg/day and 300 mg/kg/day had decreased weight gain and lethality was 25% in the latter group. Signs of the IDPN syndrome, evident in the 225 and 300 mg/kg/day groups, persisted throughout the course of the study. IDPN exposed animals (300 mg/kg/day) were hyperactive on PND 17-60, failing to develop habituation in the Figure-eight maze until PND 60. The acoustic startle response was depressed for the 225 and 300 mg/kg/day groups on PND 23 only. Auditory thresholds were elevated for a high-frequency (40 kHz) but not a low-frequency tone (5 kHz) for the 225 and 300 mg/kg/day groups, indicating a hearing loss. IDPN treatment also disrupted performance of olfactory discrimination learning and produced cognitive deficits in T-maze learning in infants (300 mg/kg/day). That cognitive deficits also appeared in adulthood (PND 70) was demonstrated by learning deficits in a passive avoidance task at 150 and 300 mg/kg/day. IDPN (300 mg/kg/day) also caused a decrease in the wet weight of the whole brain (8%) and the cerebellum (12%) but not the hippocampus. These data demonstrate that short-term, neonatal exposure to IDPN in the rat produced persistent alterations in sensory, motor, and cognitive aspects of nervous system function.

Animals↗
PubMed2000

Learning and discrimination of colored papers in jumping spiders (Araneae, Salticidae).

Color discrimination in jumping spiders Hasarius adansoni was examined by heat-avoidance learning in association with colored papers. The arena for the experiment was divided into two halves by a pair of colored papers. The colored papers used in this study were blue, green, yellow, red, white, gray and black. In training sessions, one half of the arena was heated from the bottom by a hot plate, and freely walking spiders were individually trained to avoid the heated half. In subsequent memory tests without heat, they consistently avoided the heat-associated colored papers. We found that jumping spiders could learn blue-green, blue-yellow, blue-red, blue-gray, green-yellow, green-red, green-gray, yellow-red, yellow-gray and red-gray patterns. Moreover, spiders trained with a blue-white pattern, a green-white pattern, a yellow-white pattern or a red-white pattern could discriminate the blue, green, yellow or red from black. It seems that jumping spiders can discriminate the blue, green, yellow and red papers by their hue, although brightness may also be used together with the color cue to discriminate colored papers.

Animals↗
PubMed1992

Frustration theory--many years later.

The role of frustration in learning theory, in the invigoration of behavior and in the development of learned persistence and discrimination learning, is conceptualized. This and other phenomena are facets of the larger explanatory domain of what has come to be known as frustration theory, a theory that has guided the author's own research--from behavioral to developmental to psychobiological --until the present time and has had some influence on the research of other investigators. This is a commentary on the 1st of several published theoretical papers on frustration theory.

Animals↗
PubMed2003

The use of prosodic cues in language discrimination tasks by rats.

Recent research with cotton-top tamarin monkeys has revealed language discrimination abilities similar to those found in human infants, demonstrating that these perceptual abilities are not unique to humans but are also present in non-human primates. Specifically, tamarins could discriminate forward but not backward sentences of Dutch from Japanese, using both natural and synthesized utterances. The present study was designed as a conceptual replication of the work on tamarins. Results show that rats trained in a discrimination learning task readily discriminate forward, but not backward sentences of Dutch from Japanese; the results are particularly robust for synthetic utterances, a pattern that shows greater parallels with newborns than with tamarins. Our results extend the claims made in the research with tamarins that the capacity to discriminate languages from different rhythmic classes depends on general perceptual abilities that evolved at least as far back as the rodents.

Animal Communication↗
PubMed1986

Somatostatin and (D-Trp8, D-Cys14)-somatostatin delay extinction and reverse electroconvulsive shock induced amnesia in rats.

In the present study the effects of somatostatin and its analogs on active avoidance behavior, electroconvulsive shock (ECS)-induced retrograde amnesia, and spatial-discrimination learning were compared in rats. (D-Trp8, D-Cys14)-somatostatin (as did the somatostatin molecule itself) delayed the extinction of active avoidance behavior, antagonized ECS-induced amnesia, and did not modify spatial-discrimination learning. Des-Asn5-(D-Trp8, D-Ser13) somatostatin and des-AA1,2,4,5,12,13,-(D-Trp8) somatostatin did not influence these behaviors. The data suggest that certain parts of the somatostatin molecule are important for its behavioral actions.

Amnesia↗
PubMed1979

Middle temporal cortical visual area and visuospatial function in Galago senegalensis.

Bushbabies with lesions restricted to the middle temporal (MT) area and animals with larger extrastriate lesions including area MT were compared with normal control animals on test of visuospatial localization and discrimination learning. Ablation of area MT was sufficient to produce impairments in directing behavior appropriately on the basis of visuospatial cues. Extension of the lesion into areas 18 and 19 produced more profound deficits. Retardation in learning a stripe discrimination problem was correlated with the extent of damage to the geniculostriate system. It is hypothesized that area MT is important in achieving and maintaining fixation on a target whereas cortical areas 18 and 19 are necessary for establishing the location of stimulation in visual space.

Animals↗
PubMed2006

Associative encoding in posterior piriform cortex during odor discrimination and reversal learning.

Recent proposals have conceptualized piriform cortex as an association cortex, capable of integrating incoming olfactory information with descending input from higher order associative regions such as orbitofrontal cortex and basolateral amygdala (ABL). If true, encoding in piriform cortex should reflect associative features prominent in these areas during associative learning involving olfactory cues. We recently reported that neurons in anterior piriform cortex (APC) in rats exhibited significant plasticity in their responses to odor cues during associative learning. Here, we have repeated this study, recording from neurons in posterior piriform cortex (PPC), a region of piriform cortex that receives much stronger input from ABL. If associative encoding in piriform cortex is driven by inputs from ABL, then we should see more plasticity in PPC neurons than we observed in APC. Consistent with this hypothesis, we found that PPC neurons were highly associative and appeared to be somewhat more likely than neurons recorded in APC to alter their responses to the odor cues after reversal of the odor-outcome associations in the task. Further, odor-selective PPC populations exhibited markedly different firing patterns based on the valence of the odor cue. These results suggest associative encoding in piriform cortex is represented in a topographical fashion, reflecting the stronger and more specific input from olfactory bulb concerning the sensory features of odors in anterior regions and stronger input from ABL concerning the meaning of odors in posterior regions.

Amygdala↗
PubMed1979

Control by stimulus features during fading.

Sixteen children were given four successive circle-size discrimination problems with luminance as the fading stimulus. Children who were first presented with a difficult size discrimination failed to acquire this discrimination. Those who first received an easy discrimination learned the difficult discrimination. At the end of each 10-trial block, two probe stimuli were presented to monitor any shift in control from luminance to size. One probe was the same size as the positive stimulus but of different luminance; the other was the same luminance but of different size. If, in the course of fading, size and luminance both controlled responding, fading was successful. If luminance alone controlled responding until the end of fading, the size discrimination was not established. Dual control, and thus successful fading, resulted when the target stimuli were very discriminable, or when the target stimuli were subtly different provided that previous fading series had first established less subtle discriminations.

Child↗
PubMed2006

Early discrimination reversal learning impairment and preserved spatial learning in a longitudinal study of Tg2576 APPsw mice.

To understand the relationship between amyloid-beta and cognitive decline in Alzheimer's disease, we evaluated cortical and hippocampal function in a transgenic mouse model of amyloid over-expression in Alzheimer's disease, the Tg2576 mouse. Tg2576 mice and their non-transgenic littermates were assessed at both 6 and 14 months of age in a battery of cognitive tests: attentional set-shifting, water maze spatial reference memory and T-maze working memory. Spatial reference memory was not affected by Tg status at either age. Working memory was only affected by age, with 6-month-old mice performing better than 14-month-old ones. Older mice were also significantly impaired on reversal learning and on the intra- and extra-dimensional shift in attentional set-shifting. A significant transgene effect was apparent in reversal learning, with Tg2576 mice requiring more trials to reach criterion at 6 months old. These data indicate that the effects of normal aging in C57B6xSJL F1 mice are most pronounced on putative frontal cortex-dependent tasks and that increasing Abeta load only affects discrimination reversal learning in our study.

Age Factors↗