Time labelling of independently acquired lateralized engrams in rats.
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Animals↗
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Results for “Transfer learning”
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Hippocampal lesions in the rat: effects on spatial and visual habits.
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Animals↗
The effects of pimozide during pairing on the transfer of classical conditioning to an operant discrimination.
Transfer of classical conditioning to operant learning was demonstrated by showing enhanced acquisition of an operant discrimination in a group of rats (n = 6) previously exposed to pairings of the discriminative stimulus with food as compared to control animals (n = 6). A group (n = 6) that received the classical conditioning sessions while under the influence of the neuroleptic, pimozide (1.0 mg/kg, IP) also showed enhanced acquisition of the discrimination when tested while undrugged but their performance was intermediate between that of the other groups for the first seven sessions. For the remaining sessions, the two groups that had received classical conditioning did not differ from each other and both groups discriminated better than the controls. These data may indicate a role for dopaminergic neurons in the mechanism by which the effects of classical conditioning influence operant responding.
Animals↗
A new approach to the role of noradrenaline in learning: problem-solving in the marmoset after alpha-noradrenergic receptor blockade.
Nine marmosets (Callithrix jacchus) were tested on a variety of visual discrimination learning tasks in a Wisconsin General Test Apparatus with or without alpha-noradrenergic receptor blockade achieved by the administration of aceperone. After aceperone, animals were found to be severely and consistently impaired at learning the first task of each test session and to be impaired on new and repeated reversal learning. They were, however, unimpaired on learning another similar task in each test session and on performance of a well-learnt task. Results were interpreted as evidence for defective association formation which can be compensated for by suitable priming or practice.
Adrenergic alpha-Antagonists↗
Visual discrimination learning under conditions of interocular conflict in hooded and albino rats.
Hooded and albino rats were trained on a paradigm of interocular conflict, in which the animals were trained on a discrimination of vertically inverted triangles with one eye, and on the reversed discrimination with the other eye on alternate days. Albino rats acquired the conflicting tasks as quickly as a single monocularly trained task. Hooded rats required considerably longer training on the conflicting discriminations. The role of some non-visual behavioral strategies in the performance of the conflicting tasks was explored, and possible mechanisms are discussed with reference to the different size of the ipsilateral optic projection in hooded and albino rats.
Animals↗
Alcohol and proactive interference: a test of response eccentricity theory of alcohol's psychological effects.
A theory is offered which proposes that alcohol induces eccentricity in the neurophysiological mechanism by which responses are selected for emission by the nervous system. Hence, in a specific stimulus situation, normally high probability responses decrease in frequency, while lower probability responses increase in frequency. From this postulate, the prediction is derived that in a verbal paired-associate learning task administered over two days, alcohol will decrease proactive interference from first-day learning (high probability associate) and result in enhanced acquisition of second day items. This paper reports two experimental tests of the prediction, each of which employs four subject groups tested over two days. Experiment 1 (n = 24) provides tentative support while ruling out some potential confounds. With these confounds eliminated, Experiment 2 (n = 40) confirms the prediction in a more direct test. A variety of possible alternative explanations for the counter-intuitive finding of improved cognitive performance under alcohol are evaluated against the theory proposed, as are other recent theories which address the variable behavioral effects of alcohol. Finally, the new data gathered on the effects of imagery instructions on proactive interference are considered.
Adult↗
"Spontaneous" transfer of stimulus control from tact to mand contingencies.
An important issue in teaching verbal behavior to persons with severe handicaps is the transfer of stimulus control from tact (e.g., naming) to mand (e.g., requesting) relationships. Previous research has shown that topographies taught as tacts frequently fail to appear as mands unless transfer between these two response classes is explicitly programmed. Procedures promoting this transfer would provide a necessary instructional tool. Transfer from tact to mand contingencies was investigated in two adults with severe mental retardation. Correct pointing responses to line drawing symbols depicting the utensils required to access previously requested food (beverage) items were assessed prior to and following tact intervention. Mands for two of three utensils emerged following tact intervention. The results suggest transfer from tact variables to the conditioned establishing operation may be facilitated by the prior development of a minimal mand repertoire.
Adult↗
Effect of neurofeedback on hemispheric word recognition.
We applied SMR/theta neurofeedback (NF) training at central sites of 20 Israeli children aged 10-12 years, half boys and half girls. Half of the subjects received C3 training and the other half C4 training, consisting of 20 half-hour sessions. We assessed the effects of training on lateralized lexical decision in Hebrew. The lateralized lexical decision test reveals an independent contribution of each hemisphere to word recognition (Barnea, Mooshagian, & Zaidel, 2003). Training increased accuracy and sensitivity. It increased left hemisphere (LH) specialization under some conditions but it did not affect interhemispheric transfer. Training did affect psycholinguistic processing in the two hemispheres, differentially at C3 and C4. Training also increased hemispheric independence. There were surprising sex differences in the effects of training. In boys, C4 training improved LH accuracy, whereas in girls C3 training improved LH accuracy. The results suggest that the lateralized NF protocol activates asymmetric hemispheric control circuits which modify distant hemispheric networks and are organized differently in boys and girls.
Analysis of Variance↗
Promoting the implementation of practices that are supported by research: the National Implementing Evidence-Based Practice Project.
The National Implementing Evidence-Based Practice Project is an ongoing effort to promote the implementation of effective practices for adults who have severe mental illnesses. The project members designed and developed integrated packages of materials and services to help practice sites implement evidence-based practices and is field-testing the approach in eight states. These implementations are being evaluated carefully to learn how to make the technology transfer process more efficient in the future. This article describes the project and provides some early reflections on the implementation experience.
Adolescent↗
Studies of learning and problem solving in two species of Australian marsupials.
This article reviews the authors' recent work with two species of Australian marsupials on several learning and conditioning experiments. The quokka (Setonix brachyurus) is a cat-sized herbivorous wallaby that inhabits offshore islands around south-western Australia. The fat-tailed dunnart (Sminthopsis crassicaudata) is a mouse-sized carnivorous marsupial that inhabits much of inland Australia. Both species were successful in learning simple discriminations, learning sets and reversal sets. Quokkas and dunnarts were also tested on two configural discrimination tasks: transverse patterning and negative patterning; only the dunnarts successfully solved these tasks. Dunnarts were also the only species to show one-trial learning in reversal set training. Dunnarts may be particularly useful subjects in future studies of brain-behavior relationships, since these animals have some interesting neuroanatomical features, demonstrate a wide range of fast learning abilities, and as pouch young, can be accessed during early developmental stages.
Animals↗
A transfer appropriate processing approach to investigating implicit memory for emotional words in the cerebral hemispheres.
Forty undergraduate students participated in two experiments designed to investigate the impact of perceptual and conceptual encoding manipulations on implicit memory for emotional words in each cerebral hemisphere. Adopting a transfer appropriate processing approach, the encoding manipulations were designed to promote processing of the surface features of stimuli in Experiment 1, and their semantic meaning in Experiment 2. In both experiments, participants completed the designated encoding task, followed by a lexical decision task where primed and unprimed words were presented to the left (LVF) and right visual fields (RVF). In Experiment 1, implicit memory was observed for RVF presentations of words primed according to their perceptual features. Word valence did not impact on visual field of presentation for primed or unprimed words. In Experiment 2, participation in the conceptual encoding task differentially impacted on processing and implicit memory for emotional words presented in the LVF, where priming the conceptual meaning of words facilitated the processing of positive, relative to negative and non-emotional words. In addition, implicit memory for conceptually primed negative words was reflected in inhibition of primed relative to unprimed negatively valenced words presented in the LVF. In contrast, for RVF presentations, there was evidence of implicit memory for conceptually primed non-emotional words, but not for emotional words. The results are generally consistent with the right hemisphere model of emotion, which posits greater right hemisphere involvement in both the processing and implicit memory of emotional stimuli. The results also support Nagae and Moscovitch's suggestion [Nagae, S., & Moscovitch, M. (2002). Cerebral hemispheric differences in memory of emotional and non-emotional words in normal individuals. Neuropsychologia, 40, 1601-1607] that level of processing be incorporated into studies examining the veracity of the right hemisphere and valence models of emotional processing. The study demonstrated the usefulness of adopting a transfer appropriate processing approach to investigating memory for word valence in each hemisphere.
Cerebral Cortex↗
Fixation stability and saccadic latency in élite shooters.
This study tested the hypothesis that elementary visuo-motor functions involved in visual scanning, as measured by fixation and saccadic tasks, are better in a group of high-level clay target shooters (N=7) than in a control group (N=8). In the fixation task, subject were told to keep fixation as still as possible on a target for 1 min, both in the presence and absence of distracters. For shooters, time did not have an effect on fixation stability, and they had more stable fixation than controls in the distracters condition. Results indicate a difference between groups on both the temporal span of attention and selective attention. In the saccadic task, subjects were asked to saccade, as fast as possible, towards a peripherally displayed target. Two conditions were used: simple reaction to target onset and discrimination between targets and distracters. Shooters had faster saccadic latency to targets than controls in both conditions. Finally, to evaluate the effect of exercise on saccadic latency, we trained one control subject to saccade to a target displayed at a constant spatial position. At the end of the training, saccadic latency reached a value comparable to that recorded in shooters. Learning was largely retinotopic, not showing transfer to untrained spatial positions.
Adult↗
Memory and cortical spreading depression: a comment on Petrinovich's critique.
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Animals↗
Embryonic transplantation and ischemic memory deficit.
Transient forebrain ischemia is associated with selective neuronal vulnerability and persistent memory deficit. This study compares functional outcome and morphological changes in rats subjected to post-ischemic CA1 or hilus/dentate gyrus region hippocampal fetal transplantation. Ischemia was produced by bilateral common carotid artery occlusion with hypotension. Fetal hippocampal neurons were transplanted into both sides of the CA1 or hilus/dentate gyrus region of the dorsal hippocampus, 1 week post-ischemia. Four weeks post transplantation, the rats underwent behavioral testing for 5 consecutive days using the water maze trial. All animals were perfusion fixed for morphological studies. Transplants in the CA1 region of the dorsal hippocampus were associated with memory and morphological recovery, while grafts placed into the hilus/dentate gyrus region of the dorsal hippocampus were not. Similarly, neurons transplanted in the CA1 region of the dorsal hippocampus were morphologically similar to CA1 pyramidal cell neurons and stained positive with calbindin D(28k). In contrast the grafts transplanted into the hilus/dentate gyrus region of the dorsal hippocampus were morphologically heterogeneous and staining with calbindin D(28k) was not as robust. Post-ischemic transplantation in the CA1 region of the dorsal hippocampus is effective in improving memory and morphological function.
Animals↗
[Structural descriptions. Discrimination and learning of these descriptions].
In order for the computer to learn about objects, the user must first provide a good description language for these objects. In this paper we present a new description language which is structural. Structural descriptions portray objects as composite structures consisting of various components. Structural descriptions can be contrasted with attribute descriptions, which specify only global properties of an object. Attribute descriptions can be expressed using propositional logic. Structural descriptions, however, must be expressed in first-order logic. We present how this language works, why it is suitable for biochemical objects and how one can discriminate on structural descriptions. Finally, we present an application on learning about tRNA which has yielded very good results brings evident of feasibility.
Base Sequence↗
Argument structure frames: a lexical complexity metric?
The number of semantic argument structure frames associated with a verb has been reported to influence ease of processing during language comprehension. The present experiments tested the generality of the argument structure complexity effect with three dependent measures: eye-fixation times, naming latencies, and lexical decision latencies. Two eye-movement experiments and two experiments using cross-modal tasks failed to provide evidence supporting the argument structure complexity effect. The present experiments indicated that results reflecting verbs' argument structure complexity are not generalizable.
Attention↗
Transfer of processing in repetition priming: some inappropriate findings.
Transfer effects in repetition priming were found with both picture and word naming, but varied with the type of prime list. Unmixed lists of word or picture primes produced equivalent intra-modal and cross-modal repetition priming in both picture-naming (Experiment 1) and word-naming (Experiment 5) tasks. However, mixing word and picture primes resulted in greater intra-modal than cross-modal priming for both picture-naming (Experiment 2) and word-naming (Experiment 6) tasks. This mixed-list difference between intra-modal and cross-modal priming was reduced by blocking prime types at input (Experiment 3). These findings suggest that differences in priming as a function of prime stimulus format should be cautiously interpreted when mixed prime lists are used.
Adult↗
The role of comparison in the extension of novel adjectives.
Previous reseach has documented that basic-level object categories provide an initial foundation for mapping adjectives to object properties. Children ranging from 21 months to 3 years can successfully extend a novel adjective (e.g., transparent) to other objects sharing a salient property if the objects are all members of the same basic-level category; if the objects are members of different basic-level categories, they fail to extend adjectives systematically (R. S. Klibanoff & S. R. Waxman, 2000a; S. R. Waxman & D. B. Markow, 1998). The present study proposed that the process of comparison is instrumental in children's ability to move beyond this foundation. To promote comparison, 2 target objects were introduced to 3-year-olds. In Experiment 1, the targets had contrastive properties (e.g., 1 transparent and 1 opaque object); in Experiment 2, the targets had consistent properties (e.g., 2 transparent objects). The results of both experiments illustrate that comparison--a general psychological process--operates in conjunction with naming to support the extension of novel adjectives to properties of objects from diverse basic-level categories.
Child, Preschool↗