PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Association Learning”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed2006

Odour-place paired-associate learning and limbic thalamus: comparison of anterior, lateral and medial thalamic lesions.

Several subregions in the limbic thalamus have been suggested as the key locus for diencephalic amnesia, including the anterior thalamic nuclei, intralaminar nuclei and mediodorsal nuclei. There is, however, no consensus as to a single critical site and recent research has suggested instead that different thalamic areas may contribute to diencephalic amnesia in subtly different ways. This study compared the effects of lesions to anterior (AT), lateral (LT) and posteromedial (MT) aggregates of thalamic nuclei on Gilbert and Kesner's [Gilbert, PE, Kesner, RP. Role of the rodent hippocampus in paired-associate learning involving associations between a stimulus and a spatial location. Behav Neurosci 2002;116(1):63-71; Gilbert, PE, Kesner, RP. Localization of function within the dorsal hippocampus: the role of the CA3 subregion in paired-associate learning. Behav Neurosci 2003;117(6):1385-94] paired-associate task, in which rats were postoperatively trained to form an arbitrary association between odours and spatial locations in a circular open field. Both AT and LT lesions, but not MT lesions, severely impaired odour-place paired-associate learning. Probe trials revealed that the rats were not using specific location information after acquisition training. All groups were able to learn non-associative odour and place discrimination tasks quickly, with only the AT group showing delayed acquisition. This study provides the first direct comparison of different thalamic lesions on paired-associate learning and new evidence on the importance of the LT region in learning and memory. The results support the notion that injury to both the AT and LT subregions of the thalamus may each be major contributors to diencephalic amnesia. There is need for traditional models of memory function to take greater account of the contributions of thalamic nuclei.

Animals↗
PubMed2005

Functionally segregated neural substrates for arbitrary audiovisual paired-association learning.

To clarify the neural substrates and their dynamics during crossmodal association learning, we conducted functional magnetic resonance imaging (MRI) during audiovisual paired-association learning of delayed matching-to-sample tasks. Thirty subjects were involved in the study; 15 performed an audiovisual paired-association learning task, and the remainder completed a control visuo-visual task. Each trial consisted of the successive presentation of a pair of stimuli. Subjects were asked to identify predefined audiovisual or visuo-visual pairs by trial and error. Feedback for each trial was given regardless of whether the response was correct or incorrect. During the delay period, several areas showed an increase in the MRI signal as learning proceeded: crossmodal activity increased in unimodal areas corresponding to visual or auditory areas, and polymodal responses increased in the occipitotemporal junction and parahippocampal gyrus. This pattern was not observed in the visuo-visual intramodal paired-association learning task, suggesting that crossmodal associations might be formed by binding unimodal sensory areas via polymodal regions. In both the audiovisual and visuo-visual tasks, the MRI signal in the superior temporal sulcus (STS) in response to the second stimulus and feedback peaked during the early phase of learning and then decreased, indicating that the STS might be key to the creation of paired associations, regardless of stimulus type. In contrast to the activity changes in the regions discussed above, there was constant activity in the frontoparietal circuit during the delay period in both tasks, implying that the neural substrates for the formation and storage of paired associates are distinct from working memory circuits.

Acoustic Stimulation↗
PubMed2004

Use of sequence information in associative learning in control subjects and cerebellar patients.

Previous studies of our group have shown that cerebellar patients are impaired in their ability to associate a color and a numeral or two colors with a button push. The aim of the present study was to examine whether control subjects make use of sequence information in visuomotor associative learning tasks and if this ability is impaired in cerebellar patients. A group of eight patients with degenerative cerebellar disease and eight age, sex and IQ matched controls were tested. Subjects had to learn the association between pairs of colored squares and a button push. Two colored squares were shown one after the other in a fixed or random order on a computer screen. Control subjects but not cerebellar patients took advantage of the fixed order information of colored squares in order to improve associative learning. Differences between groups could not be explained by differences in verbal and visuospatial short-term memory, color discrimination, affective state or motor disturbances. Results suggest that impaired sequencing of sensory stimuli may contribute to disorders in visuomotor associative learning in cerebellar patients.

Adult↗
PubMed2003

Role of the hippocampal system in associative learning beyond the spatial domain.

Expert opinion remains divided on the issue of whether the hippocampal system functions exclusively in spatial information processing, e.g. in navigation or in understanding spatial relations, or whether it plays a more general role in higher brain function. Previous work on monkeys and rats has tended to support the former view, whereas observations in the clinic point to the latter, including functions as diverse as declarative knowledge, episodic memory, word learning, and understanding relations among objects. One influential theory posits a general role for the hippocampal system in associative learning, with emphasis on associations learned rapidly and recently. The results presented here are consistent with this theory, along with previous clinical and theoretical studies indicating that the hippocampal system is necessary for associative learning even if no component of the association relies on spatial information. In the study reported here, rhesus monkeys learned a series of conditional stimulus-response associations involving complex visual stimuli presented on a video monitor. Each stimulus instructed one of three responses: tapping the stimulus with the hand, steady hand contact with the stimulus for a brief period of time, or steady contact for a longer time. Fornix transection impaired the learning of these associations, even though both the stimuli and the responses were nonspatially differentiated, and this deficit persisted for at least 2 years. This finding indicates that the hippocampal system plays an important role in associative learning regardless of the relevance of spatial information to any aspect of the association. Fornix-transected monkeys were impaired in learning new stimulus-response associations even when the stimuli were highly familiar. Thus, the deficit was one of associating each stimulus with a response, as opposed to problems in distinguishing the stimuli from each other. In contrast to these effects, fornix transection did not impair performance when familiar stimuli instructed a response according to an already-learned association, which shows that the deficit was one of learning new associations rather than one of retention or retrieval of previously learned ones. Taken together, these results show that fornix transection causes a long-lasting impairment in associative learning outside of the spatial domain, in a manner consistent with theories of hippocampal-system function that stress a general role in the rapid acquisition of associative knowledge.

Animals↗
PubMed1998

The relevance of associative learning pathways in the development of obsessive-compulsive washing.

The relevance of associative learning in the development of Obsessive-Compulsive Disorder (OCD) was investigated in a group of 23 OCD patients whose main concern was washing and 23 age and sex matched control subjects who did not have OCD. OC washers completed an origins instrument based on Menzies and Clarke's (1993, Behaviour Research and Therapy, 31, 355-365) Origins Questionnaire (OQ) for the phobic disorders. Control subjects completed a modified version of this measure designed to give a comprehensive picture of their experiences with relevant contamination-related stimuli. In general, the results question the relevance of associative-learning per se in the development of OC washing. Direct and indirect conditioning events were very rare in the OCD group, accounting for less than 13% of cases. No significant differences between groups were found in the proportion of subjects who knew other OC washers, or had experienced direct associative-learning events prior to onset. Contrary to expectation, significantly more non-OCD subjects had experienced vicarious learning events related to dirt and washing than OCD subjects. However, of note, associative-learning events that took place during episodes of depression were significantly more frequently reported in the OCD group than in the control group. Depression appeared to play a facilitating role in the associative-learning of OC washing. The implications of these findings for theoretical accounts of OCD are discussed.

Adolescent↗
PubMed2001

Identification and expression of a novel gene in odour-taste associative learning in the terrestrial slug.

Odour-taste associative learning in the terrestrial slug offers a useful model for long-term memory formation and retention. The genes which are expressed over 2 h after a learning event are thought to include those related to memory formation and/or consolidation. It is very important to examine what kinds of genes are expressed following associative learning. We identified a novel slug gene, the expression of which was regulated by associative learning and mostly restricted to the procerebrum (PC), a place that olfactory information is believed to be processed in slug. This gene encodes a 121 amino acid, 18 kDa secretory protein which we term LAPS18. Expression of the LAPS18 gene was induced in somata and the protein spread to neurites in the PC of slugs subjected to paired conditioning. Recombinant LAPS18 promoted the aggregation and movement of PC neurones in culture and they were blocked by the anti-LAPS18 antibody. Beads coupled with LAPS18 protein attached to PC neurones and the beads aggregated through PC cells but not by themselves, suggesting that LAPS18 may require a counterpart molecule for PC neurone aggregation. An increased expression and translocation of LAPS18 protein after paired conditioning may be needed for long-term memory formation and retention in the slug. Since genes homologous to LAPS18 genes in the land slug Limax are found from vertebrates including human, analysing the expression and function of LAPS18 may be important in understanding the molecular mechanism of memory formation and retention.

Amino Acid Sequence↗
PubMed1999

Olfactory associative learning in Caenorhabditis elegans is impaired in lrn-1 and lrn-2 mutants.

The C. elegans mutants, lrn-1 and lrn-2, are impaired in associative learning using conditioned taste cues. Both mutants are defective in associative learning about appetitive and aversive events, indicating that lrn-1 and lrn-2 exert effects across motivational boundaries. In a new olfactory associative learning paradigm, in which wild type worms learn to avoid a previously attractive diacetyl odor after it has been paired with an aversive acetic acid solution, lrn-1 and lrn-2 are impaired. Although defective in associative learning using a conditioned olfactory cue, nonassociative learning (habituation and dishabituation) using this same olfactory cue is unaffected. The discovery that lrn-1 and lrn-2 are defective in associative learning with both taste and olfactory cues may suggest that associative learning in different sensory modalities converges on a common genetic pathway in C. elegans that is subserved by lrn-1 and lrn-2.

Animals↗
PubMed1990

[Associative learning in a neuromimetic network with local competitions].

Presented here is a neuromimetic model for the learning of associations between activity patterns originating from recoding layers. These layers are described as networks of cellular clusters made up of competitive formal neurons. A rule of synaptic plasticity with improved neurobiological realism is proposed; it allows for fast learning of large sets of associations.

Association Learning↗
PubMed2002

Differences in trace and delay visuomotor associative learning in cerebellar patients.

Recent studies revealed an impairment of patients with cerebellar lesions in cognitive associative learning paradigms, which could not be explained by motor deficits or increased attentional demands during performance of the motor part of the particular task. To further test the role of the cerebellum in cognitive associative learning a visuomotor associative learning paradigm was conducted, which showed some similarities to reflex conditioning. Subjects had to learn the association between a visual stimulus (i.e., a colored square) and a correct motor response (i.e., pressing a left or right target button on a specialized keyboard) in a stimulus-response paradigm. The correct side of the response was always indicated by a growing circle. The stimuli were presented in two forms: (1) the colored square ("conditioned stimulus", "CS") preceded the growing circle ("unconditioned stimulus", "US") and coterminated with the "US" (delay-condition) or (2) the offset of the colored square was separated from the onset of the circle by a short time interval (trace-condition). Eight patients with degenerative cerebellar disorders and eight age-, sex-, IQ-, and education level-matched controls participated. Both control subjects and cerebellar patients showed significant effects of learning based on reduction of decision times during performance of the task. The explicit knowledge of the correct motor response associated with each of the presented colors, however, was significantly better in control subjects. Furthermore, within-group comparisons revealed that control subjects performed significantly better in the trace-condition compared to the delay-condition, whereas no significant difference was obtained in the cerebellar group. Part of the findings in controls was explained by an age-related decline in the delay-condition. In addition, elderly control subjects appeared to benefit from cue-effects and timing-effects (i.e., fixed trace interval) in the trace-condition resulting in reduced decision times. Neither cue- nor timing-related effects fully accounted for differences between cerebellar patients and controls. The lack of a better performance in the trace-condition compared to the delay-condition in cerebellar patients suggests deficits in learning the stimulus-response association.

Age Factors↗
PubMed2004

Stimulus generalization in two associative learning processes.

Recent studies involving nonlinear discrimination problems suggest that stimuli in human associative learning are represented configurally with narrow generalization, such that presentation of stimuli that are even slightly dissimilar to stored configurations weakly activate these configurations. The authors note that another well-known set of findings in human associative learning, cue-interaction phenomena, suggest relatively broad generalization. Three experiments show that current models of human associative learning, which try to model both nonlinear discrimination and cue interaction as the result of 1 process, fail because they cannot simultaneously account for narrow and broad generalization. Results suggest that human associative learning involves (a) an exemplar-based process with configural stimulus representation and narrow generalization and (b) an adaptive learning process characterized by broad generalization and cue interaction.

Cues↗
PubMedDate not supplied

The effects of prenatal alcohol exposure on odor associative learning in rats.

Alcohol was administered to pregnant females via a liquid diet that contained either 35% ethanol-derived calories (35% EDC) or 0% EDC on gestation days 6-20. An ad lib lab chow group (LC) was also included. In Experiment 1, odor-aversion learning was examined in 10-day-old offspring. While both the 0% EDC and LC groups displayed odor aversions, the 35% EDC offspring did not. In Experiment 2, learning was assessed in an appetitive paradigm in three-day-old offspring. Once again, the 35% EDC offspring showed no evidence of learning. Experiment 3 examined odor-aversion learning in adults. Both alcohol-exposed offspring and controls learned the odor association equally well. These findings suggest that odor associative learning is a sensitive indicator for alcohol-related learning deficits in rat pups although these deficits may dissipate as the offspring matures. Since odor associations play a critical role in neonatal behaviors, these deficits may help explain other behavioral anomalies noted following prenatal alcohol exposure.

Age Factors↗
PubMed2003

Associative learning and memory in Drosophila: beyond olfactory conditioning.

The associative learning abilities of the fruit fly, Drosophila melanogaster, have been demonstrated in both classical and operant conditioning paradigms. Efforts to identify the neural pathways and cellular mechanisms of learning have focused largely on olfactory classical conditioning. Results derived from various genetic and molecular manipulations provide considerable evidence that this form of associative learning depends critically on neural activity and cAMP signaling in brain neuropil structures called mushroom bodies. Three other behavioral learning paradigms in Drosophila serve as the main subject of this review. These are (1) visual and motor learning of flies tethered in a flight simulator, (2) a form of spatial learning that is independent of visual and olfactory cues, and (3) experience-dependent changes in male courtship behavior. The present evidence suggests that at least some of these modes of learning are independent of mushroom bodies. Applying targeted genetic manipulations to these behavioral paradigms should allow for a more comprehensive understanding of neural mechanisms responsible for diverse forms of associative learning and memory.

Journal Article↗
PubMed1986

Sensation seeking, paired associate learning and brain catecholamines.

Paired associate learning performance and strategies were analyzed in terms of learning situations (training vs. 'contextual' and 'noncontextual' transfer), personality factors [Thrill and adventure seeking (TAS) and disinhibition (Dis)] and catecholamine enzyme activity [dopamine-beta-hydroxylase (DBH) and monoamine-oxydase (MAO)]. Performance was better in transfer situations, in high MAO-high DBH subjects (high catecholamine turnover rate?), and as a negative function of DBH (preponderance of dopaminergic activity?). Error patterns of response selection (high omission and low intrusion error rate) were found to be a positive function of contextual transfer, TAS and DBH (high response-contingent noradrenergic activity?).

Adult↗
PubMed2002

Transverse patterning reveals a dissociation of simple and configural association learning abilities in rats with 192 IgG-saporin lesions of the nucleus basalis magnocellularis.

This experiment tests the hypothesis that the cholinergic nucleus basalis magnocellularis (NBM) is necessary for complex or configural association learning, but not elemental or simple association learning. Male Long-Evans rats with bilateral 192 IgG-saporin lesions of the NBM (n = 12) and sham-operated controls (n = 8) were tested in the transverse patterning problem, which provides a test of both simple and configural association learning. Rats were trained in phases to concurrently solve first one, then two, and finally three different visual discriminations; Problem 1 (A+ vs B- sign) and Problem 2 (B+ vs C-) could be solved using simple associations, whereas solving Problem 3 (C+ vs A-) required the ability to form configural associations. Consistent with our hypothesis, the NBM lesion group solved the simple discriminations in Problems 1 and 2 but showed impaired configural association learning in Problem 3. Additionally, when Problem 2 was introduced, previously high levels of performance on Problem 1 suffered more in the NBM lesion group than in the control group; this finding suggests an impairment in the ability of animals with NBM lesions to divide attention among multiple stimuli or to shift between strategies for solving different problems. Results support our argument that the NBM is critically involved in the acquisition of associative problems requiring a configural solution but not in problems that can be solved using only simple associations. The observed impairments in configural association learning and the apparent loss of cognitive flexibility or capacity are interpreted as reflecting specific attentional impairments resulting from NBM damage.

Acetylcholine↗
PubMed1994

A functional anatomical study of associative learning in humans.

The purpose of the study was to map the functional neuroanatomy of simple associative learning in humans. Eyeblink conditioning was studied in eight normal volunteers using positron emission tomography and H215O. Regional cerebral blood flow was assessed during three sequential phases: (i) explicitly unpaired presentations of the unconditioned stimulus (air puff to the right eye) and conditioned stimulus (binaural tone), (ii) paired presentations of the two stimuli (associative learning), and (iii) presentation of the conditioned stimulus alone. During associative learning, relative to the unpaired phase, blood flow was significantly increased in primary auditory and left posterior cingulate cortices and significantly decreased in areas of the right cerebellar, right prefrontal, right parietal, and insular cortices and right neostriatum. The lateralization of the changes may relate to the functional organization of memory and learning processes in the brain. The activation in primary auditory cortex is an example, using a neuroimaging technique, of a learning-related change in primary sensory cortex in humans. The changes in areas such as the cerebellum, prefrontal cortex, and neostriatum provide support for their roles in associative learning as proposed by animal models. Moreover, these findings show that in humans, even simple classical conditioning involves distributed changes in multiple neural systems.

Adolescent↗
PubMed2002

Associative learning acquisition and retention depends on developmental stage in Lymnaea stagnalis.

Associative learning dependent on visual and vestibular sensory neurons and the underlying cellular mechanisms have been well characterized in Hermissenda but not yet in Lymnaea. Three days of conditioning with paired presentations of a light flash (conditional stimulus: CS) and orbital rotation (unconditional stimulus: UCS) in intact Lymnaea stagnalis results in a whole-body withdrawal response (WBWR) to the CS. In the current study, we examined the optimal stimulus conditions for associative learning, including developmental stage, number of stimuli, interstimulus interval, and intertrial interval. Animals with a shell length longer than 18 mm (sexually mature) acquired and retained the associative memory, while younger ones having a shell length shorter than 15 mm acquired but did not retain the memory to the following day. For mature animals, 10 paired presentations of the CS and UCS presented every 2 min were sufficient for the induction of a WBWR to the CS. Furthermore, animals conditioned with the UCS presented simultaneously with the last 2 s of the CS also exhibited a significant WBWR in response to the CS. Blind animals did not acquire the associative memory, suggesting that ocular photoreceptors, and not dermal photoreceptors, detected the CS. These results show that maturity was key to retention of associative learning.

Animals↗
PubMed1993

Role of the amygdala complex in early olfactory associative learning.

Although olfactory associative conditioning in newborn rats produces marked structural and functional changes in the olfactory bulb, recent evidence suggests that extrabulbar circuits must be involved in storing these early memories. The present experiments examined the role of the amygdala complex on early olfactory learning. Bilateral amygdala lesions or sham lesions were performed on Postnatal Day (PN) 5. On PN6, pups were trained in a standard classical conditioning paradigm associating odor with tactile stimulation. Behavioral testing on PN7 revealed that amygdala lesions blocked odor preferences but had no effect on conditioned behavioral activation. Similar sized neocortical lesions did not impair odor preferences. Importantly, amygdala lesion effects on learned odor preferences could be reversed by extensive overtraining. These results suggest that the amygdala complex plays a critical role in modulating associative learning as early as the first postnatal week in the rat.

Aging↗