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251.
Uneconomical choices by humans or animals that evaluate reward options challenge the expectation that decision-makers always
maximize the return currency. One possible explanation for such deviations from optimality is that the ability to sense differences
in physical value between available alternatives is constrained by the sensory and cognitive processes for encoding profitability.
In this study, we investigated the capacity of a nectarivorous bat species (Glossophaga commissarisi) to discriminate between sugar solutions with different concentrations. We conducted a two-alternative free-choice experiment
on a population of wild electronically tagged bats foraging at an array of computer-automated artificial flowers that recorded
individual choices. We used a Bayesian approach to fit individual psychometric functions, relating the strength of preferring
the higher concentration option to the intensity of the presented stimulus. Psychometric analysis revealed that discrimination
ability increases non-linearly with respect to intensity. We combined this result with a previous psychometric analysis of
volume perception. Our theoretical analysis of choice for rewards that vary in two quality dimensions revealed regions of
parameter combinations where uneconomic choice is expected. Discrimination ability may be constrained by non-linear perceptual
and cognitive encoding processes that result in uneconomical choice. 相似文献
252.
Different event-related potentials (ERPs) have been shown to correlate with learning from feedback in decision-making tasks
and with learning in explicit memory tasks. In the present study, we investigated which ERPs predict learning from corrective
feedback in a multiple-choice test, which combines elements from both paradigms. Participants worked through sets of multiple-choice
items of a Swahili–German vocabulary task. Whereas the initial presentation of an item required the participants to guess
the answer, corrective feedback could be used to learn the correct response. Initial analyses revealed that corrective feedback
elicited components related to reinforcement learning (FRN), as well as to explicit memory processing (P300) and attention
(early frontal positivity). However, only the P300 and early frontal positivity were positively correlated with successful
learning from corrective feedback, whereas the FRN was even larger when learning failed. These results suggest that learning
from corrective feedback crucially relies on explicit memory processing and attentional orienting to corrective feedback,
rather than on reinforcement learning. 相似文献
253.
Cooper NR Puzzo I Pawley AD Bowes-Mulligan RA Kirkpatrick EV Antoniou PA Kennett S 《Cognitive, affective & behavioral neuroscience》2012,12(2):393-405
Ongoing debate in the literature concerns whether there is a link between contagious yawning and the human mirror neuron system
(hMNS). One way of examining this issue is with the use of the electroencephalogram (EEG) to measure changes in mu activation
during the observation of yawns. Mu oscillations are seen in the alpha bandwidth of the EEG (8–12 Hz) over sensorimotor areas.
Previous work has shown that mu suppression is a useful index of hMNS activation and is sensitive to individual differences
in empathy. In two experiments, we presented participants with videos of either people yawning or control stimuli. We found
greater mu suppression for yawns than for controls over right motor and premotor areas, particularly for those scoring higher
on traits of empathy. In a third experiment, auditory recordings of yawns were compared against electronically scrambled versions
of the same yawns. We observed greater mu suppression for yawns than for the controls over right lateral premotor areas. Again,
these findings were driven by those scoring highly on empathy. The results from these experiments support the notion that
the hMNS is involved in contagious yawning, emphasise the link between contagious yawning and empathy, and stress the importance
of good control stimuli. 相似文献
254.
Ravizza SM Goudreau J Delgado MR Ruiz S 《Cognitive, affective & behavioral neuroscience》2012,12(1):193-206
Disruption of the dorsal frontostriatal pathways in Parkinson’s disease (PD) is associated with impairments in motivation,
as well as in executive function. The goal of this study was to investigate whether these impairments are related and, if
so, whether the disruption of frontostriatal pathways compromises the ability to process the motivational aspects of feedback
in such tasks. In Experiment 1, informative feedback improved the performance of young, healthy participants in a task-switching paradigm. This task-switching
paradigm was then used in Experiment 2 to test whether feedback would improve the performance of 17 PD patients and age-matched controls. The PD group benefitted
from feedback to the same degree as control participants; however, depression scores on the Beck Depression Inventory were
significantly related to feedback usage, especially when response selection demands were high. Regardless of feedback, PD
patients were more impaired when response demands were high than in an equally difficult condition with low action demands.
These results suggest that response selection is a core impairment of insufficient dopamine to the dorsal frontal striatal
pathways. 相似文献
255.
Although the amount or scale of biographical knowledge held in store about a person may differ widely, little is known about
whether and how these differences may affect the retrieval processes triggered by the person’s face. In a learning paradigm,
we manipulated the scale of biographical knowledge while controlling for a common set of minimal knowledge and perceptual
experience with the faces. A few days after learning, and again after 6 months, knowledge effects were assessed in three tasks,
none of which concerned the additional knowledge. Whereas the performance effects of additional knowledge were small, event-related
brain potentials recorded during testing showed amplitude modulations in the time range of the N400 component—indicative of
knowledge access—but also at a much earlier latency in the P100 component—reflecting early stages of visual analysis. However,
no effects were found in the N170 component, which is taken to reflect structural analyses of faces. The present findings
replicate knowledge scale effects in object recognition and suggest that enhanced knowledge affects both early visual processes
and the later processes associated with semantic processing, even when this knowledge is not task-relevant. 相似文献
256.
Recalling positive autobiographical memories is a powerful emotion regulation strategy that can be used to repair low mood and alleviate negative affect. Unlike healthy individuals, those with current or past depression do not experience an improvement in mood as a consequence of recalling positive memories. We tested whether differences in processing mode might account for this impairment. Following mood induction procedures designed to ensure equivalence of mood state, depressed (n = 35) and recovered depressed (n = 33) participants were instructed to recall a positive memory and focus on it while adopting either an abstract or a concrete mode of processing. Participants in the abstract processing condition experienced no change in mood, while those in the concrete processing condition showed improved mood after memory recall. This research illustrates that the process by which positive autobiographical memories are recalled is important in determining their emotional impact and suggests that psychological interventions for depression may be improved by explicitly targeting processing mode. 相似文献
257.
The present study addressed the hypothesis that emotional stimuli relevant to survival or reproduction (biologically emotional
stimuli) automatically affect cognitive processing (e.g., attention, memory), while those relevant to social life (socially
emotional stimuli) require elaborative processing to modulate attention and memory. Results of our behavioral studies showed
that (1) biologically emotional images hold attention more strongly than do socially emotional images, (2) memory for biologically
emotional images was enhanced even with limited cognitive resources, but (3) memory for socially emotional images was enhanced
only when people had sufficient cognitive resources at encoding. Neither images’ subjective arousal nor their valence modulated
these patterns. A subsequent functional magnetic resonance imaging study revealed that biologically emotional images induced
stronger activity in the visual cortex and greater functional connectivity between the amygdala and visual cortex than did
socially emotional images. These results suggest that the interconnection between the amygdala and visual cortex supports
enhanced attention allocation to biological stimuli. In contrast, socially emotional images evoked greater activity in the
medial prefrontal cortex (MPFC) and yielded stronger functional connectivity between the amygdala and MPFC than did biological
images. Thus, it appears that emotional processing of social stimuli involves elaborative processing requiring frontal lobe
activity. 相似文献
258.
Elevated internalized stigma is common and is linked to subjective and objective outcomes for severe mental illness. The authors developed a manualized group-based intervention (Narrative Enhancement/Cognitive Therapy; NECT) to address internalized stigma in severe mental illness. The purpose of the present study was to evaluate the feasibility and effectiveness of NECT. In total, 144 individuals were screened at two sites to evaluate if they met criteria for "elevated" internalized stigma; 39 and were eligible were randomized to NECT or to treatment as usual (TAU) and were assessed at baseline, posttreatment, and 3-month follow-up. Fifteen of the 21 individuals assigned to NECT were classified as "exposed" to treatment. Intent-to-treat analyses found no significant difference between the NECT and TAU groups. A comparison of exposed versus unexposed participants noted trends for exposed participants to have improved more in two aspects of self-stigma as well as insight. We conclude that NECT is feasible and tolerable, but findings did not support the hypothesis that NECT was more effective than TAU, although small sample size and significant dropout may have restricted the ability to detect an effect. 相似文献
259.
Baguley T 《Behavior research methods》2012,44(1):158-175
The psychological and statistical literature contains several proposals for calculating and plotting confidence intervals
(CIs) for within-subjects (repeated measures) ANOVA designs. A key distinction is between intervals supporting inference about
patterns of means (and differences between pairs of means, in particular) and those supporting inferences about individual
means. In this report, it is argued that CIs for the former are best accomplished by adapting intervals proposed by Cousineau
(Tutorials in Quantitative Methods for Psychology, 1, 42–45, 2005) and Morey (Tutorials in Quantitative Methods for Psychology, 4, 61–64, 2008) so that nonoverlapping CIs for individual means correspond to a confidence for their difference that does not include zero.
CIs for the latter can be accomplished by fitting a multilevel model. In situations in which both types of inference are of
interest, the use of a two-tiered CI is recommended. Free, open-source, cross-platform software for such interval estimates
and plots (and for some common alternatives) is provided in the form of R functions for one-way within-subjects and two-way
mixed ANOVA designs. These functions provide an easy-to-use solution to the difficult problem of calculating and displaying
within-subjects CIs. 相似文献
260.
Welch’s (Biometrika 29: 350–362, 1938) procedure has emerged as a robust alternative to the Student’s t test for comparing the means of two normal populations with unknown and possibly unequal variances. To facilitate the advocated
statistical practice of confidence intervals and further improve the potential applicability of Welch’s procedure, in the
present article, we consider exact approaches to optimize sample size determinations for precise interval estimation of the
difference between two means under various allocation and cost considerations. The desired precision of a confidence interval
is assessed with respect to the control of expected half-width, and to the assurance probability of interval half-width within
a designated value. Furthermore, the design schemes in terms of participant allocation and cost constraints include (a) giving
the ratio of group sizes, (b) specifying one sample size, (c) attaining maximum precision performance for a fixed cost, and
(d) meeting a specified precision level for the least cost. The proposed methods provide useful alternatives to the conventional
sample size procedures. Also, the developed programs expand the degree of generality for the existing statistical software
packages and can be accessed at brm.psychonomic-journals.org/content/ supplemental. 相似文献