1,721,151 research outputs found
Short-term and long-term plasticity in the visual-attention system: evidence from habituation of attentional capture
No full textAttention is known to be crucial for learning and to regulate activity-dependent brain plasticity. Here we report the opposite scenario, with plasticity affecting the onset-driven automatic deployment of spatial attention. Specifically, we showed that attentional capture is subject to habituation, a fundamental form of plasticity consisting in a response decrement to repeated stimulations. Participants performed a visual discrimination task with focused attention, while being occasionally exposed to a distractor consisting of a high-luminance peripheral onset. With practice, short-term and long-term habituation of attentional capture emerged, making the visual-attention system fully immune to distraction. Furthermore, spontaneous recovery of attentional capture was found when the distractor was temporarily removed. Capture, however, once habituated was surprisingly resistant to spontaneous recovery, taking from several minutes to days to recover. The results suggest that the mechanisms subserving exogenous attentional orienting are subject to profound and enduring plastic changes based on previous experience, and that habituation can impact high-order cognitive functions
Ignoring distractors takes its (memory) toll
Full text linkEffective attentional selection requires filtering task-irrelevant stimuli. We examined the cognitive cost of such filtering using an object-based attention paradigm across four experiments (N = 320). Participants discriminated the orientation of a Gabor patch presented either alone or overlapped with an irrelevant object or scrambled stimulus. The filtering cost was measured as an increase in response times on distractor-absent trials embedded in 'mixed' blocks (with interleaved distractor-present trials) compared to 'pure' distractor-absent blocks. The filtering cost was robust and scaled with distractor probability and with the presence of one, two or four possible distractors occurring within the session. The cost disappeared when eight distractors were interleaved randomly, but re-emerged when the same eight distractors were presented orderly, one in each sequential mini-block, indicating a strategy shift once working-memory capacity is exceeded. The cost correlated negatively with interference on distractor-present trials and was unaffected by distractor semantic content, consistent with the active maintenance in working memory of distractor templates
Habituation to abrupt-onset distractors with different spatial occurrence probability
Full text linkPrevious studies have shown that abrupt onsets randomly appearing at different locations can be ignored with practice, a result that was interpreted as an instance of habituation. Here we addressed whether habituation of capture can be spatially selective and determined by the rate of onset occurrence at different locations, and whether habituation is achieved via spatial suppression applied at the distractor location. In agreement with the habituation hypothesis, we found that capture attenuation was larger where the onset distractor occurred more frequently, similarly to what has been documented for feature-singleton distractors (the "distractor-location effect"), and that onset interference decreased across trials at both the high- and low-probability distractor locations. By contrast, evidence was inconclusive as to whether distractor filtering was also accompanied by a larger impairment in target processing when it appeared at the more likely distractor location (the "target-location effect"), as instead previously reported for feature-singleton distractors. Finally, here we discuss how and to what extent distractor rejection based on statistical learning and habituation of capture are different, and conclude that the two notions are intimately related, as the Sokolov model of habituation operates by comparing the upcoming sensory input with expectation based on the statistics of previous stimulation
Learning to ignore visual onset distractors hinges on a configuration-dependent coordinates system
No full textDecrement of attentional capture elicited by visual onset distractors, consistent with habituation, has been extensively characterized over the past several years. However, the type of spatial frame of reference according to which such decrement occurs in the brain remains unknown. Here, four related experiments are reported to shed light on this issue. Observers were asked to discriminate the orientation of a titled line while ignoring a salient but task-irrelevant visual onset that occurred on some trials. The experiments all involved an initial habituation phase, during which capture elicited by the onset distractor progressively decreased, as in prior studies. Importantly, in all experiments, the location of the target and the distractor remained fixed during this phase. After habituation was established, in a final test phase of the various experiments, the spatial arrangement of the target and the distractor was changed to test for the relative contribution to habituation of retinotopic, spatiotopic, and configuration-dependent visual representations. Experiment 1 indicated that spatiotopic representations contribute little, if at all, to the observed decrement in attentional capture. The results from Experiment 2 were compatible with the notion that such capture reduction occurs in either retinotopic- or configuration-specific representations. However, Experiment 3 ruled out the contribution of retinotopic representations, leaving configuration-specific representation as the sole viable interpretation. This conclusion was confirmed by the results of Experiments 4 and 5. In conclusion, visual onset distractors appear to be rejected at a level of the visual hierarchy where visual events are encoded in a configuration-specific or context-dependent manner. (PsycInfo Database Record (c) 2024 APA, all rights reserved)
Context learning before birth: evidence from the chick embryo
No full textLearning contextual information to form associative memories with stimuli of interest is an important brain function in both human and non-human animals. Intuitively, one would expect that such a sophisticated cognitive skill develops postnatally, as the organism starts exploring the surrounding environment to search for significant contingencies among stimuli. Here we show, instead, that even before hatching, domestic chicks are capable of forming associative memories between discrete alerting sounds and the surrounding context, as attested by the fact that habituation of the freezing response to the sounds is affected by the context of stimulation. This finding indicates that, while in the egg, chicks recognize and learn the context in which they are stimulated. Hence, context learning in chicks is an innate brain function already active before birth, which can provide an immediate survival advantage to the newborns of this precocial avian species
Habituation to onset capture via associative links with contextual information
No full textHabituation shows organisms’ ability to ignore irrelevant repetitive stimuli, allowing attentional resources to be allocated to the relevant information. Here we investigated the role of contextual information in generating expectations that control habituation to visual onset distractors, expectations that arise from associative learning. Experiment 1 showed that the habituated capture response is restored if the onset distractor is momentarily omitted in the same context of habituation, but not if such omission is experienced in another context. Experiment 2 showed that the pre-exposure to a context in which a distractor is later encountered reduced participants’ capacity to ignore it, thus attesting a latent learning phenomenon affecting habituation of capture. Finally, Experiment 3 showed that ignoring a new distractor is easier in a context in which habituation has already taken place for a different distractor. Taken together, these results attest the context-specific nature of habituation and suggest that learning to ignore salient visual stimuli is based on expectations encoded through associative learning
Goal-directed behavior in Tenebrio molitor larvae
Full text linkCan signs of intentional behavior be traced in an insect larva, traditionally thought to be driven only by mere reflexes? We trained Tenebrio molitor coleoptera larvae in a uniform Y-maze to prefer one target branch to get access to food, observing their ability to learn and retain access to the reward-associated side for up to 24 h. During reward devaluation, the reward food (experimental group) and a different food (control group) were paired with an aversive stimulus in a new environment. When tested again in the Y-maze, mealworms of the experimental group significantly reduced their visits to the target branch, whereas mealworms of the control group did not. Importantly, we found that the larvae did not have to experience the unpleasant consequences directly in the target branch to halt their behavior, as the exposure to the aversive taste occurred in a separate unfamiliar context. This is evidence that the mealworms formed a mental representation of action-consequence relationships, demonstrating flexible control of their actions to achieve desired outcomes at an early stage of their development
Context-Specific Habituation of the Freezing Response in Newborn Chicks
No full textPrevious studies have found that in mature animals habituation is context-specific in some species but not in others. Given the mixed evidence present in the literature, we decided to explore whether habituation is context-specific in newborn chicks. The results showed that 3 days after hatching, chicks were capable of using global contextual information to rapidly habituate their freezing response to a series of sudden acoustic stimuli. Our study is the 1st to show context-specific habituation in this avian species, a result in agreement with those of previous findings in adult male zebra finches (Taeniopygia guttata). Furthermore, although our study does not intend to provide a systematic investigation of the ontogeny of habituation in this species, our findings show that a few days after hatching, juvenile chicks are capable of a sophisticated associative learning process that takes into account complex environmental information
Location transfer of perceptual learning: Passive stimulation and double training
No full textSpecificity has always been considered one of the hallmarks of perceptual learning, suggesting that per- formance improvement would reflect changes at early stages of visual analyses (e.g., V1). More recently, however, this view has been challenged by studies documenting complete transfer of learning among dif- ferent spatial locations or stimulus orientations when a double-training procedure is adopted. Here, we further investigate the conditions under which transfer of visual perceptual learning takes place, confirm- ing that the passive stimulation at the transfer location seems to be insufficient to overcome learning specificity. By contrast, learning transfer is complete when performing a secondary task at the transfer location. Interestingly, (i) transfer emerges when the primary and secondary tasks are intermingled on a trial-by-trial basis, and (ii) the effects of learning generalization appear to be reciprocal, namely the pri- mary task also serves to enable transfer of the secondary task. However, if the secondary task is not per- formed for a sufficient number of trials, then transfer is not enabled. Overall, the results lend support to the recent view that task-relevant perceptual learning may involve high-level stages of visual analyses
Desensitizing the attention system to distraction while idling: A new latent learning phenomenon in the visual attention domain
No full textFor the good and the bad, the world around us is full of distraction. In particular, onset stimuli that appear abruptly in the scene grab attention, thus disrupting the ongoing task. Different cognitive mechanisms for distractor filtering have been proposed, but prevalent accounts share the idea that filtering is accomplished to shield target processing from interference. Here we provide novel evidence that challenges this view, as passive exposure to a repeating visual onset is sufficient to trigger learning-dependent mechanisms to filter the unwanted stimulation. In other words, our study shows that during passive exposure the cognitive system is capable of learning about the characteristics of the salient yet irrelevant stimulation, and to reduce the responsiveness of the attention system to it, thus significantly decreasing the impact of the distractor upon start of an active task. However, despite passive viewing efficiently attenuates the spatial capture of attention, a short-lived performance cost is found when the distractor is initially encountered within the context of the active task. This cost, which dissipates in a few trials, likely reflects the need to familiarize with the distractor, already seen during passive viewing, in the new context of the active task. Although top-down inhibitory signals can be applied to distractors for the successful completion of goal-directed behavior, our results emphasize the role of more automatic habituation mechanisms for distraction exclusion based on a neural model of the history of the irrelevant stimulation. (PsycINFO Database Record (c) 2018 APA, all rights reserved)
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