Search results for "Discrimination Learning"
showing 10 items of 53 documents
Conceptual implicit memory: a developmental study.
1995
The widely accepted standpoint that implicit memory emerges earlier in development than explicit memory, and is more stable from childhood to adult age, is based on experimental data essentially collected in perceptual tasks. The present study was aimed at investigating whether these findings still hold when a more conceptual task is used. We compared the performance of children at two age levels (2nd and 4th grades) on a category-exemplar generation task. Results showed that performances of the two groups were comparable when the target items were typical of their categories, as in Experiment 2, and for a subset of the items in Experiment 1. However, the older children outperformed the you…
Single, intense prenatal stress decreases emotionality and enhances learning performance in the adolescent rat offspring: Interaction with a brief, d…
2006
Perinatal manipulations can lead to neurobehavioural changes in the progeny. In this study we investigated, in adolescent male rat offspring, the consequences of a single, intense prenatal stress induced by a 120 min-maternal immobilization at gestational day 16, and of a daily, brief maternal separation from postnatal day 2 until 21, on: unconditioned fear/anxiety-like behaviour in open field and in elevated plus-maze; learning performance in the "Can test", a non-aversive spatial and tactile/visual task; corticosterone plasma levels under basal and stress-induced conditions. Our results indicate that both prenatal stress and maternal separation procedures decrease emotionality and enhance…
Detection performance of normal cats and those lacking areas 17 and 18: a behavioral approach to analyse pattern recognition deficits.
1986
The ability of cats to discriminate between two geometrical outline patterns in the presence of superimposed Gaussian visual noise was tested before and after bilateral removal of cortical area 17 and parts of area 18. The detection probability PD was measured as a function of the signal-to-noise ratio for the parameters: noise bandwidth, spatial frequency content and rate of movement of patterns. In both normal and lesioned cats a broadband noise was found to be most effective in masking the large patterns while two other types of noise, a medium frequency noise and a high frequency noise had little or no masking effect. For recognition of the smaller patterns in normal cats the medium fre…
Influence of the suspension of continued treatment with flurazepam and amobarbital on two discrimination learning schedules.
1977
The authors have studied the effect of the suspension of chronic treatment with flurazepam and amobarbital on the operant behavior of rats that for the first time were in the presence of two fixed-interval discrimination schedules. With the sound discrimination schedule, the responses emitted by the treated animals had characteristics similar to those of control animals. With the temporal discrimination schedule, though it is not possible to distinguish between learning rates, modifications in the intensity of the effect (increases in lever pressing) indicate that, considering the doses, the action of flurazepam is slight and that of amobarbital clear and statistically significant.
Decomposing encoding and decisional components in visual-word recognition: a diffusion model analysis.
2014
In a diffusion model, performance as measured by latency and accuracy in two-choice tasks is decomposed into different parameters that can be linked to underlying cognitive processes. Although the diffusion model has been utilized to account for lexical decision data, the effects of stimulus manipulations in previous experiments originated from just one parameter: the quality of the evidence. Here we examined whether the diffusion model can be used to effectively decompose the underlying processes during visual-word recognition. We explore this issue in an experiment that features a lexical manipulation (word frequency) that we expected to affect mostly the quality of the evidence (the dri…
Do Transposed-Letter Similarity Effects Occur at a Syllable Level?
2006
One key issue for any computational model of visual word recognition is the choice of an input coding scheme for assigning letter position. Recent research has shown that transposed-letter similarity effects occur even when the transposed letters are not adjacent (caniso- casino; Perea & Lupker, 2004 , JML). In the present study we conducted two single-presentation lexical decision experiments to examine whether transposed-letter effects occur at a syllable level. We tested two types of nonwords: (1) nonwords created by transposing two internal CV syllables (PRIVEMARA; the base word is primavera, the Spanish for spring) and (2) nonwords created by transposing two adjacent bigrams that …
Honeybees can recognise images of complex natural scenes for use as potential landmarks
2008
SUMMARY The ability to navigate long distances to find rewarding flowers and return home is a key factor in the survival of honeybees (Apis mellifera). To reliably perform this task, bees combine both odometric and landmark cues,which potentially creates a dilemma since environments rich in odometric cues might be poor in salient landmark cues, and vice versa. In the present study, honeybees were provided with differential conditioning to images of complex natural scenes, in order to determine if they could reliably learn to discriminate between very similar scenes, and to recognise a learnt scene from a novel distractor scene. Choices made by individual bees were modelled with signal detec…
Discrimination of serial auditory patterns in rats : roles of configural and elemental associations
2011
In order to test whether rats could discriminate between tone sequences, food deprived rats were given appetitive discrimination conditioning with repeated ascending or descending series of musical notes serving as conditioned stimuli (CSs). The other type of tone sequence was reinforced as the other was followed by nothing. In Experiment 1, each series of 8 tones formed a 2 s cycle. The cycle was repeated six times so that the duration of the whole sequence was 12 s. In Experiment 2, the CSs were similar to those in Experiment 1 except that they started with a random note. As a result, rats could discriminate between the stimuli when the CS started systematically with the same note. When t…
Transkraniaalisen tasavirtastimulaation vaikutukset erottelu- ja käänteisoppimiseen sekä reagointiherkkyyden muutoksiin
2017
Transkraniaalisella tasavirtastimulaatiolla (tDCS) tarkoitetaan menetelmää, jossa johdetaan heikkoa sähkövirtaa aivokudosten läpi elektrodilta toiselle. Tutkimusten mukaan tDCS:lla näyttäisi olevan monenlaisia kliinisiä ja kognitiivisia vaikutuksia aina masennuksen hoidosta työmuistin parantamiseen. Tulokset ovat kuitenkin monin paikoin varsin ristiriitaisia, eikä stimulaation tarkoista vaikutusmekanismeistakaan olla päästy varmuuteen. Tässä tutkimuksessa halusimme tutkia kokeellisesti tDCS:n vaikutuksia erottelu- ja käänteisoppimiseen sekä reagointiherkkyyden muutoksiin silmäniskuehdollistumisen avulla. Kokeeseen osallistui 39 iältään 18-29-vuotiasta koehenkilöä. Tutkittavat jaettiin kahte…
Intermittent ethanol exposure induces inflammatory brain damage and causes long-term behavioural alterations in adolescent rats
2007
Adolescent brain development seems to be important for the maturation of brain structures and behaviour. Intermittent binge ethanol drinking is common among adolescents, and this type of drinking can induce brain damage. Because we have demonstrated that chronic ethanol treatment induces inflammatory processes in the brain, we investigate whether intermittent ethanol intoxication enhances cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in adolescent rats, and whether these mediators induce brain damage and cause permanent cognitive dysfunctions. Adolescent rats were exposed to ethanol (3.0 g/kg) for two consecutive days at 48-h intervals over 14 days. Levels of COX-2, iN…